Characterisation and In Vitro Evaluation of Fenugreek (Trigonella foenum-graecum) Seed Gum as a Potential Prebiotic in Growing Rabbit Nutrition

[EN] A fenugreek seed gum, extracted fromTrigonella foenum-graecumseeds and rich in galactomannan, was chemically and physically characterised and its prebiotic potential for young rabbits was evaluated in vitro, both as pure fenugreek seed gum and when included up to 20 g/kg in rabbit diets rich in soluble and insoluble fibre. Fenugreek seed gum was resistant to pepsin and pancreatin digestion but was totally fermented by rabbit caecal bacteria. Fenugreek seed gum linear inclusion up to 20 g/kg in diets rich in soluble fibre has led to a reduction in the solubility of some nutrients during in vitro enzymatic phase and an increase in the fermented fraction. Fenugreek seed gum satisfies two essential conditions of a prebiotic: resistance to enzymatic digestion and being totally fermented by caecal bacteria. Some components of soluble fibre appear to have prebiotic effects that can contribute to improving digestive health in post-weaning rabbits. In this work, a fenugreek seed gum (FGS), extracted fromTrigonella foenum-graecumseeds and rich in galactomannan, was characterised. Both the pure FSG and ten substrates obtained by the inclusion of 0, 5, 10, 15 and 20 g/kg of FSG in diets rich in soluble (SF) and insoluble (IF) fibre were evaluated in vitro to determine FSG prebiotic potential for rabbit diets. FSG was rich in total sugars (630 g/kg dry matter), consisting entirely of galactose and mannose in a 1:1 ratio, and a moderate protein content (223 g/kg dry matter). Pure FSG was affected very little by in vitro digestion, as only 145 g/kg of the FSG was dissolved during the enzymatic phase. However, the linear inclusion of FSG up to 20 g/kg in growing rabbit feeds has led to a reduction in the solubility of some nutrients during in vitro enzymatic phase, especially in SF diets. Pure FSG not digested during the enzymatic phase almost completely disappeared during the in vitro fermentation phase, 984 g/kg of this indigestible fraction. However, although linear inclusion of FSG up to 20 g/kg in SF diets increased the fermented fraction, no relevant changes in the fermentation profile were observed. In conclusion, FSG satisfies two essential conditions of the prebiotic effect, showing resistance to in vitro enzymatic digestion and being totally fermented in vitro by caecal bacteria, although in vivo studies will be necessary to determine its prebiotic potential.This study is supported by the Ministerio de Economia, Industria y Competitividad of the Spanish Government (AGL2017-85162-C2-1R), the Universitat Politecnica de Valencia (Project 20180290; Spain), and the Higher School of Agriculture of Mateur of the Carthage University (Tunisia Republic). The grant for Jihed Zemzmi from the Carthage University is also gratefully acknowledged.Zemzmi, J.; Ródenas Martínez, L.; Blas Ferrer, E.; Najar, T.; Pascual Amorós, JJ. (2020). Characterisation and In Vitro Evaluation of Fenugreek (Trigonella foenum-graecum) Seed Gum as a Potential Prebiotic in Growing Rabbit Nutrition. Animals. 10(6):1-15. https://doi.org/10.3390/ani10061041S115106Rosell J.M., de la Fuente L.F., Badiola J.I., Fernández de Luco D., Casal J., & Saco M. (2010). Study of urgent visits to commercial rabbit farms in Spain and Portugal during 1997-2007. World Rabbit Science, 17(3). doi:10.4995/wrs.2009.652Gidenne, T., Arveux, P., & Madec, O. (2001). The effect of the quality of dietary lignocellulose on digestion, zootechnical performance and health of the growing rabbit. Animal Science, 73(1), 97-104. doi:10.1017/s1357729800058094Carabaño R., Villamide M.J., García J., Nicodemus N., Llorente A., Chamorro S., & Menoyo D. (2010). New concepts and objectives for protein-amino acid nutrition in rabbits: a review. World Rabbit Science, 17(1). doi:10.4995/wrs.2009.664Trocino, A., García Alonso, J., Carabaño, R., & Xiccato, G. (2013). A meta-analysis on the role of soluble fibre in diets for growing rabbits. World Rabbit Science, 21(1). doi:10.4995/wrs.2013.1285Gidenne, T. (1995). Effect of fibre level reduction and gluco-oligosaccharide addition on the growth performance and caecal fermentation in the growing rabbit. Animal Feed Science and Technology, 56(3-4), 253-263. doi:10.1016/0377-8401(95)00834-9Morisse, J., Maurice, R., Boilletot, E., & Cotte, J. (1993). Assessment of the activity of a fructo-oligo-saccharide on different caecal parameters in rabbits experimentally infected with E coli 0.103. Annales de Zootechnie, 42(1), 81-87. doi:10.1051/animres:19930109Mourão, J. L., Pinheiro, V., Alves, A., Guedes, C. M., Pinto, L., Saavedra, M. J., … Kocher, A. (2006). Effect of mannan oligosaccharides on the performance, intestinal morphology and cecal fermentation of fattening rabbits. Animal Feed Science and Technology, 126(1-2), 107-120. doi:10.1016/j.anifeedsci.2005.06.009Jiang, J. X., Zhu, L. W., Zhang, W. M., & Sun, R. C. (2007). Characterization of Galactomannan Gum from Fenugreek (Trigonella foenum-graecum) Seeds and Its Rheological Properties. International Journal of Polymeric Materials, 56(12), 1145-1154. doi:10.1080/00914030701323745Van Nevel, C. J., Decuypere, J. A., Dierick, N. A., & Molly, K. (2005). Incorporation of galactomannans in the diet of newly weaned piglets: Effect on bacteriological and some morphological characteristics of the small intestine. Archives of Animal Nutrition, 59(2), 123-138. doi:10.1080/17450390512331387936Dakia, P. A., Blecker, C., Robert, C., Wathelet, B., & Paquot, M. (2008). Composition and physicochemical properties of locust bean gum extracted from whole seeds by acid or water dehulling pre-treatment. Food Hydrocolloids, 22(5), 807-818. doi:10.1016/j.foodhyd.2007.03.007Majeed, M., Majeed, S., Nagabhushanam, K., Arumugam, S., Natarajan, S., Beede, K., & Ali, F. (2018). Galactomannan fromTrigonella foenum-graecumL. seed: Prebiotic application and its fermentation by the probioticBacillus coagulansstrain MTCC 5856. Food Science & Nutrition, 6(3), 666-673. doi:10.1002/fsn3.606Fernández-Carmona J., Blas E., Pascual J.J., Maertens L., Gidenne T., Xiccato G., & García. (2010). Recommendations and guidelines for applied nutrition experiments in rabbits. World Rabbit Science, 13(4). doi:10.4995/wrs.2005.516NARAYANA, K., & NARASINGA RAO, M. S. (1982). Functional Properties of Raw and Heat Processed Winged Bean (Psophocarpus tetragonolobus) Flour. Journal of Food Science, 47(5), 1534-1538. doi:10.1111/j.1365-2621.1982.tb04976.xSchofield, P., Pitt, R. E., & Pell, A. N. (1994). Kinetics of fiber digestion from in vitro gas production. Journal of Animal Science, 72(11), 2980-2991. doi:10.2527/1994.72112980xEdeoga, H. O., Okwu, D. E., & Mbaebie, B. O. (2005). Phytochemical constituents of some Nigerian medicinal plants. African Journal of Biotechnology, 4(7), 685-688. doi:10.5897/ajb2005.000-3127Kumar, A., Ilavarasan, R., Jayachandr, T., Decaraman, M., Aravindhan, P., Padmanabha, N., & Krishnan, M. R. V. (2008). Phytochemicals Investigation on a Tropical Plant, Syzygium cumini from Kattuppalayam, Erode District, Tamil Nadu, South India. Pakistan Journal of Nutrition, 8(1), 83-85. doi:10.3923/pjn.2009.83.85Batey, I. L. (1982). Starch Analysis Using Thermostable alpha-Amylases. Starch - Stärke, 34(4), 125-128. doi:10.1002/star.19820340407Van Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition. Journal of Dairy Science, 74(10), 3583-3597. doi:10.3168/jds.s0022-0302(91)78551-2Bosch, L., Alegría, A., & Farré, R. (2006). Application of the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) reagent to the RP-HPLC determination of amino acids in infant foods. Journal of Chromatography B, 831(1-2), 176-183. doi:10.1016/j.jchromb.2005.12.002McCleary, B. V. (1988). Carob and guar galactomannans. Biomass Part A: Cellulose and Hemicellulose, 523-527. doi:10.1016/0076-6879(88)60163-7Chaires-Martínez, L., Salazar-Montoya, J. A., & Ramos-Ramírez, E. G. (2008). Physicochemical and functional characterization of the galactomannan obtained from mesquite seeds (Prosopis pallida). European Food Research and Technology, 227(6), 1669-1676. doi:10.1007/s00217-008-0892-0Nour, A. A. M., & Magboul, B. I. (1986). Chemical and amino acid composition of fenugreek seeds grown in Sudan. Food Chemistry, 22(1), 1-5. doi:10.1016/0308-8146(86)90002-6Piquer, O., Casado, C., Biglia, S., Fernández, C., Blas, E., & Pascual, J. (2009). In vitro gas production kinetics of whole citrus fruits. Journal of Animal and Feed Sciences, 18(4), 743-757. doi:10.22358/jafs/66449/2009Abad-Guzmán, R., Larrea-Dávalos, J. A., Carabaño, R., García, J., & Carro, M. D. (2018). Influence of inoculum type (ileal, caecal and faecal) on the in vitro fermentation of different sources of carbohydrates in rabbits. World Rabbit Science, 26(3), 227. doi:10.4995/wrs.2018.9726Ocasio-Vega, C., Abad-Guamán, R., Delgado, R., Carabaño, R., Carro, M. D., & García, J. (2018). Effect of cellobiose supplementation and dietary soluble fibre content on in vitro caecal fermentation of carbohydrate-rich substrates in rabbits. Archives of Animal Nutrition, 72(3), 221-238. doi:10.1080/1745039x.2018.1458459Gómez-Conde, M. S., de Rozas, A. P., Badiola, I., Pérez-Alba, L., de Blas, C., Carabaño, R., & García, J. (2009). Effect of neutral detergent soluble fibre on digestion, intestinal microbiota and performance in twenty five day old weaned rabbits. Livestock Science, 125(2-3), 192-198. doi:10.1016/j.livsci.2009.04.010Trocino, A., Fragkiadakis, M., Majolini, D., Tazzoli, M., Radaelli, G., & Xiccato, G. (2013). Soluble fibre, starch and protein level in diets for growing rabbits: Effects on digestive efficiency and productive traits. Animal Feed Science and Technology, 180(1-4), 73-82. doi:10.1016/j.anifeedsci.2013.01.007Gibson, G. R., & Roberfroid, M. B. (1995). Dietary Modulation of the Human Colonic Microbiota: Introducing the Concept of Prebiotics. The Journal of Nutrition, 125(6), 1401-1412. doi:10.1093/jn/125.6.1401Roberfroid, M. (2007). Prebiotics: The Concept Revisited. The Journal of Nutrition, 137(3), 830S-837S. doi:10.1093/jn/137.3.830sGidenne, T. (2015). Dietary fibres in the nutrition of the growing rabbit and recommendations to preserve digestive health: a review. Animal, 9(2), 227-242. doi:10.1017/s1751731114002729Marounek, M., Vovk, S. J., & Benda, V. (1997). Fermentation Patterns in Rabbit Caecal Cultures Supplied with Plant Polysaccharides and Lactate. Acta Veterinaria Brno, 66(1), 9-13. doi:10.2754/avb199766010009García, J., Gidenne, T., Luisa Falcao-e-Cunha, & de Blas, C. (2002). Identification of the main factors that influence caecal fermentation traits in growing rabbits. Animal Research, 51(2), 165-173. doi:10.1051/animres:2002011Volek, Z., & Marounek, M. (2011). Dried chicory root (Cichorium intybus L.) as a natural fructan source in rabbit diet: effects on growth performance, digestion and caecal and carcass traits. World Rabbit Science, 19(3). doi:10.4995/wrs.2011.850Owusu-Asiedu, A., Patience, J. F., Laarveld, B., Van Kessel, A. G., Simmins, P. H., & Zijlstra, R. T. (2006). Effects of guar gum and cellulose on digesta passage rate, ileal microbial populations, energy and protein digestibility, and performance of grower pigs1,2. Journal of Animal Science, 84(4), 843-852. doi:10.2527/2006.844843xDartois, A., Singh, J., Kaur, L., & Singh, H. (2010). Influence of Guar Gum on the In Vitro Starch Digestibility—Rheological and Microstructural Characteristics. Food Biophysics, 5(3), 149-160. doi:10.1007/s11483-010-9155-

Agrumes entiers dans les rations totales mélangeés pour brebis laitières méditerranéennes. Production et composition du lait

[Otros] Dans cette étude, 48 brebis en lactation, appartenant à 2 races méditerranéennes, la race Guirra (race autochtone rustique) ou la race Manchega (race mixte) ont été utilisées pour évaluer l¿effet de l¿inclu- sion de fruits d¿agrumes entiers (WCF) dans leurs rations. Quatre rations complètes ont été formulées pour être iso-énergétiques et iso-azotées. Elles se différenciaient par le taux d¿incorporation de WCF (0, 10, 20 et 30%) qui était substitué, sur une base matière sèche, à de l¿orge concassée ou à de la pulpe de betterave en pellets. La production et la composition du lait ont été mesurées une fois par semaine sur deux traites successives (matin et soir). La production de lait obtenue avec le group recevant 30% WCF a été supérieure de 12% à celle des autres groupes. De plus, on a observé une réduction du taux butyrique avec l¿inclusion de WCF. Elle était de 8,2; 7,95; 7,69 and 7,1 pour les groups recevant respectivement 0, 10, 20 et 30% de WCF (P<0,05). La teneur en protéines du lait a été maximale avec le group recevant 10% WCF (6,4%) et minimale avec celui ayant 30%WCF (6,0% ; P<0,05), car la teneur en caséine du lait a été la plus faible avec le groupe recevant 30%WCF (-0,3% par rapport aux groupes avec 0 et 10% de WCF; P< 0,05), tandis que la teneur en protéines solubles a été similaire pour tous les groupes (moyenne: 1,17%). Tout au long de la période expérimentale, on a observé une diminution de la production de lait standard (6%FCM) avec toutes les rations (-35% par semaine), mais il a été plus prononcé pour les groupes recevant 20% et 30% WCF que pour les autres. En conclusion, l¿incorporation de WCF pourrait contribuer à diminuer la dépendance vis à vis des céréales pour les brebis à haute production sans affecter les paramètres de production laitière ; mais d¿autres études relatives aux effets de WCF sur la condition corporelle et sur la capacité des animaux en lac- tation à mobiliser leurs réserves doivent être faites.[EN] A total of 48 lactating ewes, belonging to 2 different Mediterranean breeds Guirra (rustic native breed) and Manchega (mixed aptitude breed) were used to evaluate the effect of the inclusion of whole citrus fruits (WCF) in their rations. Four iso-energetic and iso-protein total mixed rations were formulated containing fresh WCF at 0, 10, 20 and 30% replacing dry-rolled barley and pelleted beet pulp on a DM basis. The milk yield and composition were obtained once a week at morning and afternoon milking. Total milk yield values observed for 30% WCF group were 12% higher than for the others. Also, a reduction of the milk fat content with the inclusion of WCF was observed, being 8.2, 7.95, 7.69 and 7.1% for 0, 10, 20 and 30% WCF groups (P<0.05). Milk protein content was maximum for ewes on 10% WFC ration (6.4%) and minimum for 30% WCF group (6.0%; P<0.05), due to the lower milk casein content of 30% WCF group (-0.3% respect to 0 and 10% WCF groups; P<0.05), while soluble protein content was similar for all the groups (mean: 1.17%). Throughout the experimental period, a reduction of 6% fat corrected milk (6%FCM) production was observed with all the rations (-35 ml per week), but it was steeper for 20 and 30% WCF groups than for the other 2 groups. In conclusion, WCF could contribute to diminishing dependence of high-milking ewes on grains without affecting the milk output, however further studies related to WCF effect on body condition and on the capacity of lactating animals to mobilize body reserves should be made.This study was subsidized by the Consejeria de Agricultura, Pesca y Alimentación of the Regional Government of Valencia, and by the project INIA CAL03-089. 6.Piquer Querol, O.; Rodríguez Garcia, M.; Blas Ferrer, E.; Cerisuelo, A.; Fernández Martínez, CJ.; Pascual Amorós, JJ. (2011). Whole citrus fruits in total mixed rations for Mediterranean milking ewes. Milk production and composition. Options Mediterraneennes. Serie A: Seminaires Mediterraneens. 99:251-258. http://hdl.handle.net/10251/147521S2512589

A moderate protein diet does not cover the requirements of growing rabbits with high growth rate

[EN] Genetic selection for feed efficiency has increased the growth rate and requirements of growing rabbits, while the protein content of commercial feeds has been adjusted to avoid digestive disorders. The aim of this work was to evaluate how a diet with moderate levels of protein content [146 g crude protein (CP)/kg] could be affecting protein and amino acids acquisition depending on the growth rate of the animals. From 189 weaned rabbits (28 days old), only 41 animals were selected at 42 days, in order to ensure the greatest variability for growth rate during fattening. To achieve this goal, animals came from three genetic lines: H and LP (maternal lines selected by litter size) and R (paternal line selected for growth rate), characterised by normal, moderate and high growth rate during the fattening period, respectively. Apparent faecal digestibility of dry matter (DM), CP and gross energy (GE) of the diet from 49-53 days of age, as well as the ileal apparent digestibility of DM, CP and amino acids at 63 days of age, was determined in all the selected animals. Protein, energy and amino acids retained in the empty body during the fattening period were also determined by slaughtering 15 weaning rabbits at 28 days, and the 41 selected animals at 63 days of age. Animals from the R line showed higher feed intake than those from maternal lines, as well as lower feed conversion ratio, even below that expected from their growth rate. Apparent faecal digestibility of GE and apparent ileal digestibility of DM, CP and cystine of the diet were higher in LP than in H rabbits (P < 0.05), showing intermediate values in R rabbits. However, apparent ileal digestibility of glutamic acid and glycine was significantly higher in R than in H rabbits (P < 0.05), showing intermediate values in LP rabbits. As expected, both daily protein and energy retained in the empty body increased as growth increased. However, R growing rabbits seem to have lower protein retained and higher energy retained in the empty body than that expected from their growth. In fact, protein to energy retained ratio was clearly lower for R growing rabbits. These results seem to show the possible existence of some limiting amino acid when current moderate protein diets are used in growing rabbits with high growth rates, recommending a review of the amino acid requirements for the growing rabbits from paternal lines.This study was supported by the Interministerial Commission for Science and Technology (CICYT) from the Spanish Government (AGL2017-85162-C2-1-R). The grant for Pablo Marin from the Ministry of Education, Culture and Sports (FPU-2014-01203) is also gratefully acknowledged.Marín-García, P.; Ródenas Martínez, L.; Martinez-Paredes, E.; Cambra López, M.; Blas Ferrer, E.; Pascual Amorós, JJ. (2020). A moderate protein diet does not cover the requirements of growing rabbits with high growth rate. Animal Feed Science and Technology. 264:1-11. https://doi.org/10.1016/j.anifeedsci.2020.114495S111264Alagón, G., Arce, O. N., Martínez-Paredes, E., Ródenas, L., Moya, V. J., Blas, E., … Pascual, J. J. (2016). Nutritive value of distillers dried grains with solubles from barley, corn and wheat for growing rabbits. Animal Feed Science and Technology, 222, 217-226. doi:10.1016/j.anifeedsci.2016.10.024Batey, I. L. (1982). Starch Analysis Using Thermostable alpha-Amylases. Starch - Stärke, 34(4), 125-128. doi:10.1002/star.19820340407Birolo, M., Trocino, A., Zuffellato, A., & Xiccato, G. (2016). Effect of feed restriction programs and slaughter age on digestive efficiency, growth performance and body composition of growing rabbits. Animal Feed Science and Technology, 222, 194-203. doi:10.1016/j.anifeedsci.2016.10.014Cartuche, L., Pascual, M., Gómez, E. A., & Blasco, A. (2014). Economic weights in rabbit meat production. World Rabbit Science, 22(3), 165. doi:10.4995/wrs.2014.1747Cifre, J., Baselga, M., García-Ximénez, F., & Vicente, J. S. (1998). Performance of a hyperprolific rabbit line I. Litter size traits. Journal of Animal Breeding and Genetics, 115(1-6), 131-138. doi:10.1111/j.1439-0388.1998.tb00336.xCosta, C., Baselga, M., Lobera, J., Cervera, C., & Pascual, J. J. (2004). Evaluating response to selection and nutritional needs in a three-way cross of rabbits. Journal of Animal Breeding and Genetics, 121(3), 186-196. doi:10.1111/j.1439-0388.2004.00450.xEstany, J., Camacho, J., Baselga, M., & Blasco, A. (1992). Selection response of growth rate in rabbits for meat production. Genetics Selection Evolution, 24(6), 527. doi:10.1186/1297-9686-24-6-527García-Quirós, A., Arnau-Bonachera, A., Penadés, M., Cervera, C., Martínez-Paredes, E., Ródenas, L., … Pascual, J. J. (2014). A robust rabbit line increases leucocyte counts at weaning and reduces mortality by digestive disorder during fattening. Veterinary Immunology and Immunopathology, 161(3-4), 123-131. doi:10.1016/j.vetimm.2014.07.005Gidenne, T., & Perez, J.-M. (2000). Replacement of digestible fibre by starch in the diet of the growing rabbit. I. Effects on digestion, rate of passage and retention of nutrients. Annales de Zootechnie, 49(4), 357-368. doi:10.1051/animres:2000127Lv, J.-M., Chen, M., Qian, L.-C., Ying, H.-Z., & Liu, J.-X. (2009). Requirement of crude protein for maintenance in a new strain of laboratory rabbit. Animal Feed Science and Technology, 151(3-4), 261-267. doi:10.1016/j.anifeedsci.2009.01.001Mínguez, C., Sanchez, J. P., EL Nagar, A. G., Ragab, M., & Baselga, M. (2015). Growth traits of four maternal lines of rabbits founded on different criteria: comparisons at foundation and at last periods after selection. Journal of Animal Breeding and Genetics, 133(4), 303-315. doi:10.1111/jbg.12197Partridge, G. G., Garthwaite, P. H., & Findlay, M. (1989). Protein and energy retention by growing rabbits offered diets with increasing proportions of fibre. The Journal of Agricultural Science, 112(2), 171-178. doi:10.1017/s0021859600085063Pascual, M., & Pla, M. (2007). Changes in carcass composition and meat quality when selecting rabbits for growth rate. Meat Science, 77(4), 474-481. doi:10.1016/j.meatsci.2007.04.009Pascual, M., Pla, M., & Blasco, A. (2008). Effect of selection for growth rate on relative growth in rabbits1,2. Journal of Animal Science, 86(12), 3409-3417. doi:10.2527/jas.2008-0976Quevedo, F., Cervera, C., Blas, E., Baselga, M., & Pascual, J. J. (2006). Long-term effect of selection for litter size and feeding programme on the performance of reproductive rabbit does 2. Lactation and growing period. Animal Science, 82(5), 751-762. doi:10.1079/asc200688Sánchez, J. P., Theilgaard, P., Mínguez, C., & Baselga, M. (2008). Constitution and evaluation of a long-lived productive rabbit line1. Journal of Animal Science, 86(3), 515-525. doi:10.2527/jas.2007-0217Savietto, D., Blas, E., Cervera, C., Baselga, M., Friggens, N. C., Larsen, T., & Pascual, J. J. (2012). Digestive efficiency in rabbit does according to environment and genetic type. World Rabbit Science, 20(3). doi:10.4995/wrs.2012.1152Savietto, D., Cervera, C., Ródenas, L., Martínez-Paredes, E., Baselga, M., García-Diego, F. J., … Pascual, J. J. (2014). Different resource allocation strategies result from selection for litter size at weaning in rabbit does. Animal, 8(4), 618-628. doi:10.1017/s1751731113002437Trocino, A., García Alonso, J., Carabaño, R., & Xiccato, G. (2013). A meta-analysis on the role of soluble fibre in diets for growing rabbits. World Rabbit Science, 21(1). doi:10.4995/wrs.2013.1285Van Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition. Journal of Dairy Science, 74(10), 3583-3597. doi:10.3168/jds.s0022-0302(91)78551-

Plasmatic Urea Nitrogen in Growing Rabbits with Different Combinations of Dietary Levels of Lysine, Sulphur Amino Acids and Threonine

[EN] Formulating diets to maximize nutrient harnessing has positive effects on performance and environment. In the case of growing rabbits, clues exist indicating that animals with high growth rate when consuming current diets show lower protein retention than expected, and it could be related to amino acid supply. The aim of this work is to find the amino acid combination (27 experimental diets: 3 levels of the 3 main limiting amino acids: lysine, sulphur amino acids, and threonine) that would minimize the nitrogen excretion in the bloodstream, a marker of the efficiency in the amino acid use This combination is a good candidate to be tested in order to improve performance and reduce pollution. A total of 27 experimental diets were formulated starting from the same basal mixture, with a moderate content of crude protein and digestible energy (155 g and 9.86 MJ/kg of digestible matter (DM), respectively, both estimated). The contents of lysine, sulphur amino acids and threonine were variable. The first one, close to the current recommendations (Medium, M; 8.1, 5.8 and 6.9 g/kg DM for lysine, sulphur amino acids and threonine, respectively), and two other levels were on average 15% higher (High, H; 9.4, 6.6 and 7.8 g/kg DM for lysine, sulphur amino acids and threonine, respectively) or lower (Low, L; 6.7, 4.9 and 5.7 g/kg DM for lysine, sulphur amino acids and threonine, respectively). Diets were named with three letters, indicating lysine, sulphur amino acids and threonine levels, respectively. In total, 918 weaned rabbits (28 days old) were used (34 per diet). At weaning, animals were fed ad libitum with a commercial diet until day 46, day 47 each collective cage was randomly switched to one experimental diet. At day 48, blood samples were collected at 08:00h then the animals were subjected to 10 h of fasting and a second blood sample was extracted at 21.00h. At 08:00h, Pasmatic urea nitrogen (PUN) was higher with the L level of lysine (p< 0.001), unaffected by the level of sulphur amino acids and increased with the level of threonine (p< 0.001). At 21:00h, minimum PUN was observed with the MHL diet (14.72 +/- 0.661 mg/dL). Taken into account the usual recommendations (established for a diet containing 11.3 MJ DE/kg DM, and then being 0.72, 0.51 and 0.61 g/MJ DE for lysine, sulphur amino acids and threonine, respectively), these results suggest that a diet containing more lysine and sulphur amino acids per energy unit (around 0.82 and 0.67 g/MJ DE) could better fit the growing rabbit requirements, although studies on the effects of such a diet on performance and protein retention are necessary.This study was supported by the Interministerial Commission for Science and Technology (CICYT) from the Spanish Government (AGL2017-85162-C2-1-R). The grant for Pablo Marin from the Ministry of Education, Culture and Sports (FPU-2014-01203) is also gratefully acknowledged.Marín-García, P.; López Luján, MDC.; Ródenas Martínez, L.; Martinez-Paredes, E.; Blas Ferrer, E.; Pascual Amorós, JJ. (2020). Plasmatic Urea Nitrogen in Growing Rabbits with Different Combinations of Dietary Levels of Lysine, Sulphur Amino Acids and Threonine. Animals. 10(6):1-8. https://doi.org/10.3390/ani10060946S18106Quevedo, F., Cervera, C., Blas, E., Baselga, M., & Pascual, J. J. (2006). Long-term effect of selection for litter size and feeding programme on the performance of reproductive rabbit does 2. Lactation and growing period. Animal Science, 82(5), 751-762. doi:10.1079/asc200688Pascual, M., Pla, M., & Blasco, A. (2008). Effect of selection for growth rate on relative growth in rabbits1,2. Journal of Animal Science, 86(12), 3409-3417. doi:10.2527/jas.2008-0976Pascual, M., & Pla, M. (2007). Changes in carcass composition and meat quality when selecting rabbits for growth rate. Meat Science, 77(4), 474-481. doi:10.1016/j.meatsci.2007.04.009Marín-García, P. J., Ródenas, L., Martínez-Paredes, E., Cambra-López, M., Blas, E., & Pascual, J. J. (2020). A moderate protein diet does not cover the requirements of growing rabbits with high growth rate. Animal Feed Science and Technology, 264, 114495. doi:10.1016/j.anifeedsci.2020.114495Carabaño R., Villamide M.J., García J., Nicodemus N., Llorente A., Chamorro S., & Menoyo D. (2010). New concepts and objectives for protein-amino acid nutrition in rabbits: a review. World Rabbit Science, 17(1). doi:10.4995/wrs.2009.664Taboada, E., Mendez, J., & de Blas, J. (1996). The response of highly productive rabbits to dietary sulphur amino acid content for reproduction and growth. Reproduction Nutrition Development, 36(2), 191-203. doi:10.1051/rnd:19960204Taboada, E., Mendez, J., Mateos, G. ., & De Blas, J. . (1994). The response of highly productive rabbits to dietary lysine content. Livestock Production Science, 40(3), 329-337. doi:10.1016/0301-6226(94)90099-xDe Blas, J. C., Taboada, E., Nicodemus, N., Campos, R., Piquer, J., & Méndez, J. (1998). Performance response of lactating and growing rabbits to dietary threonine content. Animal Feed Science and Technology, 70(1-2), 151-160. doi:10.1016/s0377-8401(97)00063-1Roth-Maier, D. A., Ott, H., Roth, F. X., & Paulicks, B. R. (2004). Effects of the level of dietary valine supply on amino acids and urea concentration in milk and blood plasma of lactating sows. Journal of Animal Physiology and Animal Nutrition, 88(1-2), 39-45. doi:10.1046/j.0931-2439.2003.00458.xDonsbough, A. L., Powell, S., Waguespack, A., Bidner, T. D., & Southern, L. L. (2010). Uric acid, urea, and ammonia concentrations in serum and uric acid concentration in excreta as indicators of amino acid utilization in diets for broilers. Poultry Science, 89(2), 287-294. doi:10.3382/ps.2009-00401Marín-García, P. J., López-Luján, M. del C., Ródenas, L., Martínez-Paredes, E. M., Blas, E., & Pascual, J. J. (2020). Plasma urea nitrogen as an indicator of amino acid imbalance in rabbit diets. World Rabbit Science, 28(2), 63. doi:10.4995/wrs.2020.12781Van Milgen, J., & Dourmad, J.-Y. (2015). Concept and application of ideal protein for pigs. Journal of Animal Science and Biotechnology, 6(1). doi:10.1186/s40104-015-0016-1Fernández-Carmona J., Blas E., Pascual J.J., Maertens L., Gidenne T., Xiccato G., & García. (2010). Recommendations and guidelines for applied nutrition experiments in rabbits. World Rabbit Science, 13(4). doi:10.4995/wrs.2005.516Real Decreto 53/2013, Por el Que se Establecen las Normas Básicas Aplicables Para la Protección de los Animales Utilizados en Experimentación y Otros Fines Científicos, Incluyendo la Docencia. BOE 34https://www.boe.es/diario_boe/txt.php?id=BOE-A-2013-1337Cifre, J., Baselga, M., García-Ximénez, F., & Vicente, J. S. (1998). Performance of a hyperprolific rabbit line I. Litter size traits. Journal of Animal Breeding and Genetics, 115(1-6), 131-138. doi:10.1111/j.1439-0388.1998.tb00336.xEstany, J., Camacho, J., Baselga, M., & Blasco, A. (1992). Selection response of growth rate in rabbits for meat production. Genetics Selection Evolution, 24(6), 527. doi:10.1186/1297-9686-24-6-527Bosch, L., Alegría, A., & Farré, R. (2006). Application of the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) reagent to the RP-HPLC determination of amino acids in infant foods. Journal of Chromatography B, 831(1-2), 176-183. doi:10.1016/j.jchromb.2005.12.002Eggum, B. O. (1970). Blood urea measurement as a technique for assessing protein quality. British Journal of Nutrition, 24(4), 983-988. doi:10.1079/bjn19700101Nicodemus, N., Mateos, J., Blas, J. C. de, Carabaño, R., & Fraga, M. J. (1999). Effect of diet on amino acid composition of soft faeces and the contribution of soft faeces to total amino acid intake, through caecotrophy in lactating doe rabbits. Animal Science, 69(1), 167-170. doi:10.1017/s1357729800051201García, A. I., de Bias, J. C., & Carabaño, R. (2004). Effect of type of diet (casein-based or protein-free) and caecotrophy on ileal endogenous nitrogen and amino acid flow in rabbits. Animal Science, 79(2), 231-240. doi:10.1017/s1357729800090093Monteiro-Motta, A. C., Scapinello, C., Oliveira, A. F. G., Figueira, J. L., Catelan, F., Sato, J., & Stanquevis, C. E. (2013). Levels of lysine and methionine+cystine for growing New Zealand White rabbits. Revista Brasileira de Zootecnia, 42(12), 862-868. doi:10.1590/s1516-3598201300120000

Dietary fatty acid profile: effects on caecal fermentation and performance of young and fattening rabbits

[EN] The present work was performed to study the effect of dietary inclusion of different fatty acid combinations (saturated, n-3 and n-6 polyunsaturated fatty acids; PUFA) on caecal fermentation activity, feed intake, growth rate and feed efficiency of young rabbits around weaning (17 to 44 d) and fattening rabbits (28 to 63 d of age). Five diets were formulated using the same raw materials and including 3% of lard (A diet, rich in saturated fat), sunflower oil (S diet, rich in n-6 PUFA), linseed oil (L diet, rich in n-3 PUFA), sunflower oil and lard at 1:1 rate (SA diet), or linseed oil and lard at 1:1 rate (LA diet). In the first trial, the effect of the 5 diets on rabbit performance was evaluated in a fattening period from 28 to 63 d of age, with 490 rabbits allocated in individual cages; mortality rates were measured with 1670 rabbits (750 allocated in individual cages and 920 in collective cages, 8 rabbits/cage). In the second trial, 120 young rabbits were used from 17 to 44 d of age, weaned at 28 d, allocated in collective cages and randomly fed with A, S or L diets, evaluating performance and gut weight and caecum fermentation activity. The use of animal fat or vegetable oil and the richness in n-3 or n-6 PUFA of vegetable oils had no significant effect on the feed intake (130 g dry matter/d) and growth rate of fattening rabbits (45.5 g/d), but the inclusion of sunflower oil in diet improved feed conversion rate (2.79 for S diet vs. 2.87 for the rest of diets; P<0.01). Mortality rate was lower when vegetable oils were included in diet (34 and 37% for S and L diets respectively vs. 45% for A diet; P<0.05). Feed intake and growth rate increased quickly from 17 to 44 d, but only small occasional differences were recorded in growth rate of young rabbits, in favour of rabbits receiving animal fat from 17 to 21 d (P<0.05) or sunflower oil from 28 to 30 d (P<0.05). Caecal traits of rabbits at 30 and 44 d of age were similar for the different dietary groups, although butyric acid concentration in caecum content at 44 d was the lowest (P<0.05) with L diet.This work was supported by a Ministry of Science and Technology grant (AGL2003-06559-C02-02).Casado, C.; Moya, J.; Pascual, JJ.; Blas Ferrer, E.; Cervera Fras, MC. (2013). Dietary fatty acid profile: effects on caecal fermentation and performance of young and fattening rabbits. World Rabbit Science. 21(4):235-242. https://doi.org/10.4995/wrs.2013.1437SWORD23524221

Long-term implications of feed energy source in different genetic types of reproductive rabbit females: I. Resource acquisition and allocation

[EN] To achieve functional but also productive females, we hypothesised that it is possible to modulate acquisition and allocation of animals from different genetic types by varying the main energy source of the diet. To test this hypothesis, we used 203 rabbit females belonging to three genetic types: H (n=66), a maternal line characterised by hyper-prolificacy; LP (n=67), a maternal line characterised by functional hyper-longevity; R (n=79), a paternal line characterised by growth rate. Females were fed with two isoenergetic and isoprotein diets differing in energy source: animal fat (AF) enhancing milk yield; cereal starch (CS) promoting body reserves recovery. Feed intake, weight, perirenal fat thickness (PFT), milk yield and blood traits were controlled during five consecutive reproductive cycles (RCs). Females fed with CS presented higher PFT (+0.2 mm, P0.05), particularly for those fed with AF. Moreover, LP females fed with AF progressively increased PFT across the RC, whereas those fed with CS increased PFT during early lactation (+7.3%; P<0.05), but partially mobilised it during late lactation (-2.8%; P<0.05). Independently of the diet offered, LP females reached weaning with similar PFT. H females fed with either of the two diets followed a similar trajectory throughout the RC. For milk yield, the effect of energy source was almost constant during the whole experiment, except for the first RC of females from the maternal lines (H and LP). These females yielded +34.1% (P<0.05) when fed with CS during this period. Results from this work indicate that the resource acquisition capacity and allocation pattern of rabbit females is different for each genetic type. Moreover, it seems that by varying the main energy source of the diet it is possible to modulate acquisition and allocation of resources of the different genetic types. However, the response of each one depends on its priorities over time.The authors thank Juan Carlos Moreno for his technical support. The grant for Alberto Arnau from the Ministry of Economy and Finance (BES-2012-052345) is also gratefully acknowledged. This study was supported by the Interministerial Commission for Science and Technology (CICYT) of the Spanish Government (AGL2014-53405-C2-1-P).Arnau-Bonachera, A.; Cervera Fras, MC.; Blas Ferrer, E.; Larsen, T.; Martinez-Paredes, E.; Ródenas Martínez, L.; Pascual Amorós, JJ. (2018). Long-term implications of feed energy source in different genetic types of reproductive rabbit females: I. Resource acquisition and allocation. animal. 12(9):1867-1876. https://doi.org/10.1017/S1751731117003287S1867187612

Plasma urea nitrogen as an indicator of amino acid imbalance in rabbit diets

[EN] In recent decades, recommendations on dietary protein content have been considerably reduced, while fibre content has been increased. Under these conditions, an adequate dietary amino acid balance could be crucial to optimise feed efficiency. Plasma urea nitrogen (PUN) level could be a good indicator of an amino acid imbalance and its potential has already been studied in other species, but not yet in rabbits. The main objective of the present work was to detect the possible interest of PUN in pinpointing amino acid deficiencies in rabbits. Two experimental diets were formulated from the same basal mixture, following all the recommendations for growing rabbits, except lysine, whose content was variable, following current guidelines in diet P8.1 or lower from those in P4.4 (with 8.1 and 4.4 g/kg dry matter of lysine and with 757 and 411 mg of lysine per MJ of digestible energy). Three different trials were designed: one where the animals were fed ad libitum (AL) and two others in which fasting periods of 10 h were included; one where feeding was restored at 08:00 h (Fast8h) and the other at 18:00 h (Fast18h). A total of 72 three-way crossbred growing rabbits (24 animals for each trial in a split-plot trial) up to a total of 12 recordings were used. Blood samples were taken every 4 h in AL trial and every hour after refeeding up to a total of six controls, in trials Fast8h and Fast18h. The differences between balanced and unbalanced diets in lysine were highest (P&lt;0.001) between 04:00 h and 12:00 h in animals fed ad libitum, and at 3 h after refeeding (21:00 h) in Fast18h. These results suggest that PUN could be an adequate indicator to detect deficiencies in amino acids in growing rabbitdiets.This study was supported by the Interministerial Commission for Science and Technology (CICYT) from the Spanish Government (AGL2017-85162-C2-1-R). The grant for Pablo Marín from the Ministry of Education, Culture and Sports (FPU2014-01203) is also gratefully acknowledged.Marín García, PJ.; López Luján, MDC.; Ródenas Martínez, L.; Martínez-Paredes, EM.; Blas Ferrer, E.; Pascual Amorós, JJ. (2020). Plasma urea nitrogen as an indicator of amino acid imbalance in rabbit diets. World Rabbit Science. 28(2):63-72. https://doi.org/10.4995/wrs.2020.12781OJS6372282AOAC. 2000. Official methods of analysis of the Association of Official Analytical Chemists, 18th ed. AOAC, Arlington, USA.Baselga M. 2004. Genetic improvement of meat rabbits. In Proc.: 8th World Rabbit Congress. September, 7-10, 2004, Puebla, México. 1: 1-13.Batey I.L. 1982. Starch analysis using thermostable alphaamylases. Starch, 34: 125-128. https://doi.org/10.1002/star.19820340407Bellier R., Gidenne T., Vernay M., Colin M. 1995. In vivo study of circadian variations of the cecal fermentation pattern in postweaned and adult rabbits. J. Anim. Sci. 73: 128-135. https://doi.org/10.2527/1995.731128xBlasco A. 1989. Genética y nutrición del conejo. In: de Blas C. (ed). Alimentación del conejo. Ediciones Mundi Prensa, Madrid, 1-15.Boletín Oficial del Estado. 2013. Real Decreto 53/2013, por el que se establecen las normas básicas aplicables para la protección de los animales utilizados en experimentación y otros fines científicos, incluyendo la docencia. BOE 34, 11370-11421.Bosch L., Alegría A., Farré R. 2006. Application of the 6-aminoquinolyl-N-hydroxysccinimidyl carbamate (AQC) reagent to the RP-HPLC determination of amino acids in infant foods. J. Chromatogr., 831: 176-183. https://doi.org/10.1016/j.jchromb.2005.12.002Brown J.A., Cline T.R. 1974. Urea excretion in the pig: an indicator of protein quality and amino acid requirements. J. Nutr., 104: 542-545. https://doi.org/10.1093/jn/104.5.542Carabaño R., de Blas J.C., García A.I. 2000. Recent advances in nitrogen nutrition in rabbits. World Rabbit Sci. 8: 14-28.Carabaño R., Piquer J., Menoyo D., Badiola I. 2010. The digestive system of the rabbit. In: de Blas C., Wiseman J. (ed). Nutrition of the Rabbit. CABI Publishing. CAB International, Wallingford, Oxon, UK, 1-18. https://doi.org/10.1079/9781845936693.0001Carabaño R., Villamide M.J., García J., Nicodemus N., Llorente A., Chamorro S., Menoyo D., García-Rebollar P., García-Ruiz A.I., De Blas, J.C. 2009. New concepts and objectives for proteinamino acid nutrition in rabbits. A review. World Rabbit Sci., 17: 1-14. https://doi.org/10.4995/wrs.2009.664Cartuche L., Pascual M., Gómez E.A., Blasco A. 2014. Economic weights in rabbit meat production. World Rabbit Sci., 22: 165-177. https://doi.org/10.4995/wrs.2014.1747Coma J., Carrion D., Zimmerman D.R. 1995. Use of plasma urea nitrogen as a rapid response criterion to determine the lysine requirement of pigs. J. Anim. Sci., 73: 472-481. https://doi.org/10.2527/1995.732472xComa J., Zimmerman D.R., Carrion D. 1996. Lysine requirement of the lactating sow determined by using plasma urea nitrogen as a rapid response criterion. J. Anim. Sci., 74: 1056-1062. https://doi.org/10.2527/1996.7451056xde Blas J.C., Gonzalez-Mateos G. 2010. Feed Formulation. In: de Blas C., Wiseman J. (ed). Nutrition of the Rabbit. second ed. CABI International. Wallingford, 222-232. https://doi.org/10.1079/9781845936693.0222de Blas C., Taboada E., Nicodemus N., Campos R., Piquer J., Méndez J. 1998. Performance response of lactating and growing rabbits to dietary threonine content. Anim. Feed Sci. Technol., 70: 151-160. https://doi.org/10.1016/S0377-8401(97)00063-1Donsbough A.L., Powell S., Waguespack A., Bidner T.D., Southern L. 2010. Uric acid, urea, and ammonia concentrations in serum and uric acid concentration in excreta as indicators of amino acid utilization in diets for broilers. Poult. Sci. 89: 287-294. https://doi.org/10.3382/ps.2009-00401Eggum B.O. 1970. Blood urea measurement as a technique for assessing protein quality. Br. J. Nutr., 24: 983-988. https://doi.org/10.1079/BJN19700101Feki S., Baselga M., Blas E., Cervera C., Gomez E.A. 1996. Comparison of growth and feed efficiency among rabbit lines selected for different objectives. Livest. Prod. Sci., 45: 87-92. https://doi.org/10.1016/0301-6226(95)00081-XForbes J.M. 2007. Voluntary Food Intake and Diet Selection. In: Farm Animals. CAB International, Wallingford, U.K, 226-246. https://doi.org/10.1079/9781845932794.0000Gidenne T., Lebas F., Fortun-Lamothe L. 2010. Feeding behaviour of rabbits. In: de Blas C., Wiseman J. (ed). Nutrition of the Rabbit. CABI International, Wallingford, 233-252. https://doi.org/10.1079/9781845936693.0233Gidenne T., Garreau H., Drouilhet L., Aubert C., Maertens L. 2017. Improving feed efficiency in rabbit production, a review on nutritional, technico-economical, genetic and environmental aspects. Anim. Feed Sci. Technol., 225: 109-122. https://doi.org/10.1016/j.anifeedsci.2017.01.016Hirakawa H. 2001. Coprophagy in leporids and other mammalian herbivores. Mam. Rev., 31: 61-80. https://doi.org/10.1046/j.1365-2907.2001.00079.xMaertens L., Cavani C., Petracci, 2010. Nitrogen and phosphorus excretion on commercial rabbit farms: calculations based on the input-output balance. World Rabbit Sci., 13: 3-16. https://doi.org/10.4995/wrs.2005.533Maertens L. 2009. Possibilities to reduce the feed conversion in rabbit production. In Proc.: Giornate di Coniglicoltura. Associazione Scientifica Italiana di Coniglicoltura. Forli. Italy. 1: 1-10.Marín-García P.J., Ródenas L., Martínez-Paredes E.M., Cambra-López M., Blas E., Pascual J.J. 2019. A moderate protein diet does not cover the requirements of growing rabbits with high growth rate. Anim. Feed Sci. Technol., 264: 114495. https://doi.org/10.1016/j.anifeedsci.2020.114495Marín-García P.J., Blas E., Cervera C., Pascual J.J. 2016. A deficient protein supply could be affecting selection for growth rate in rabbits. In. Proc., 68th Book of Abstracts of Annual Meeting of the European Federation of Animal Science. Belfast, UK, 1: 489.Mertens D.R. 2002. Gravimetric determination of amylase-treated neutral detergent fibre in feeds with refluxing beakers or crucibles: collaborative study. J. AOAC Int., 85: 1217-1240.Nicodemus N., Mateos J., de Blas C., Carabaño R., Fraga M.J. 1999. Effect of diet on amino acid composition of soft faeces and the contribution of soft faeces to total amino acid intake, through caecotrophy in lactating doe rabbits. Anim. Sci., 69: 167-170. https://doi.org/10.1017/S1357729800051201Prud'hon M., Chérubin M., Goussopoulos J., Carles Y. 1975. Évolution, au cours de la croissance, des caractéristiques de la consommation d'aliments solide et liquide du lapin domestique nourri ad libitum. Ann. Zootec., 24: 289-298. https://doi.org/10.1051/animres:19750212Romero C., Nicodemus N., García-Rebollar P., García-Ruiz A.I., Ibáñez M.A., de Blas J.C. 2009. Dietary level of fibre and age at weaning affect the proliferation of Clostridium perfringens in the caecum, the incidence of epizootic rabbit enteropathy and the performance of fattening rabbits. Anim. Feed Sci. Technol., 153: 131-140. https://doi.org/10.1016/j.anifeedsci.2009.05.005Roth-Maier D.A., Ott H., Roth F.X., Paulicks B.R. 2003. Effects of the level of dietary valine supply on amino acids and urea concentration in milk and blood plasma of lactating sows. J. Anim. Physiol. Anim. Nutr., 88: 39-45. https://doi.org/10.1046/j.0931-2439.2003.00458.xSAS. 2009. SAS/STAT ® 9.2 User's guide. SAS Inst. Inc., Cary NC, USA.Schneider J.D., Nelssen J.L., Tokach M.D., Dritz S.S., Goodband R.D., DeRouchey J.M. 2006. Determining the total sulfur amino acid to lysine requirement of the lactating sow. KAESRR, 0: 47-51. https://doi.org/10.4148/2378-5977.6982Taylor A.J., Cole D.J.A., Lewis D. 1982. Amino acid requirements of growing pigs. 3. Threonine. Anim Prod. 34: 1-8. https://doi.org/10.1017/S0003356100000416Taylor S.J., Cole D.A., Lewis D. 1985. Amino acid requirements of growing pigs. 6. Isoleucine. Anim. Prod. 40: 153-160. https://doi.org/10.1017/S0003356100031950Trocino A., García J., Carabaño R., Xiccato G. 2013. A meta-analysis on the role of soluble fibre in diets for growing rabbits. World Rabbit Sci., 21: 1-15. https://doi.org/10.4995/wrs.2013.1285Van Soest P.J., Robertson J.B., Lewis B.A. 1991. Methods for dietary fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74: 3583-3597. https://doi.org/10.3168/jds.S0022-0302(91)78551-2Villamide M.J., García A.I., Llorente A., Carabaño R. 2013. Ileal vs. faecal amino acid digestibility in concentrates and fibrous sources for rabbit feed formulation. Anim. Feed Sci. Technol. 182: 100-110. https://doi.org/10.1016/j.anifeedsci.2013.04.00

Consequences of rearing feeding programme on the performance of rabbit females from 1st to 2nd parturition

[EN] To evaluate how rearing programmes could affect resources allocation and reproductive performance of primiparous rabbit females, a total of 118 rabbit females were used to evaluate the effects of five rearing feeding programmes on their performance from 1st to 2nd parturition: CAL, fed ad libitum C diet (11.0 MJ digestible energy (DE), 114 g digestible protein (DP) and 358 g NDF/kg dry matter (DM) until 1st parturition; CR, fed ad libitum with C diet until 12 weeks of age and then C diet restricted (140 g/day) until 1st parturition; F, fed ad libitum with F diet (8.7 MJ DE, 88 g DP and 476 NDF/kg DM) until 1st parturition; FC, fed with F diet ad libitum until 16 weeks of age, and C diet ad libitum until 1st parturition; FCF, fed with F diet ad libitum until 16 weeks of age, then C diet ad libitum until 20 weeks and then F diet ad libitum until 1st parturition. From 1st parturition, C diet was ad libitum offered to all the experimental groups until 2nd parturition. CAL females presented lower feed intake than females of F, FC and FCF groups in the 1st week of lactation (on av. ¿16.6%; P<0.05). During 1st lactation, the perirenal fat thickness change in CAL females was not different from 0 (+0.02 mm), while in the other four groups it increased (on av. +0.44 mm; P<0.05). Plasma of females fed with F diet during rearing (F, FC and FCF) had lower non-esterified fatty acids content than those exclusively fed with C diet (¿0.088 and ¿0.072 mmol/l compared to CAL and CR, respectively; P<0.05). FCF litters had higher weight than F litters at day 21 of lactation (+247 g; P<0.05), but FCF litter had significantly lower weight than FC litters at weaning (+170 g; P<0.05). CR females had the shortest average interval between the 1st and 2nd parturition (49 days) and FCF females the longest (+ 9 days compared to CR; P<0.05). At 2nd parturition, liveborn litters of F females were larger and heavier than litters of FCF females (+2.22 kits and +138 g; P<0.05), probably due to the lower mortality at birth of F litters (¿16.5 percentage points; P<0.05). In conclusion, rearing females on fibrous diets seems to increase the ability of primiparous rabbit females to obtain resources, especially at the onset of lactation.The authors thank the Spanish Ministry of Education and Science (Project AGL2006-07596) for the economic support to conduct this study.Martinez-Paredes, E.; Savietto, D.; Ródenas Martínez, L.; Cervera Fras, MC.; Blas Ferrer, E.; Brecchia, G.; Boiti, C.... (2019). Consequences of rearing feeding programme on the performance of rabbit females from 1st to 2nd parturition. Animal. 13(10):2173-2182. https://doi.org/10.1017/S175173111900051XS217321821310Verdelhan S , Bourdillon A , David JJ , Huirtaurd JJ , Lédan L , Renouf B , Roulleau X and Salaun JM 2005. Comparaison de deux programmes alimentaires pour la préparation des futures reproductrices. In Proceedings of the 11émes Journées de la Recherche Cunicole, 29–30 November 2005, Paris, France, pp. 119–122.Quevedo, F., Cervera, C., Blas, E., Baselga, M., Costa, C., & Pascual, J. J. (2005). Effect of selection for litter size and feeding programme on the performance of young rabbit females during rearing and first pregnancy. Animal Science, 80(2), 161-168. doi:10.1079/asc40850161Pascual, J. J., Savietto, D., Cervera, C., & Baselga, M. (2013). Resources allocation in reproductive rabbit does: a review of feeding and genetic strategies for suitable performance. World Rabbit Science, 21(3). doi:10.4995/wrs.2013.1236Pascual, J. J., Castella, F., Cervera, C., Blas, E., & Fernández-Carmona, J. (2000). The use of ultrasound measurement of perirenal fat thickness to estimate changes in body condition of young female rabbits. Animal Science, 70(3), 435-442. doi:10.1017/s135772980005178xMartínez-Paredes, E., Ródenas, L., Martínez-Vallespín, B., Cervera, C., Blas, E., Brecchia, G., … Pascual, J. J. (2012). Effects of feeding programme on the performance and energy balance of nulliparous rabbit does. animal, 6(7), 1086-1095. doi:10.1017/s1751731111002643Manal, A. F., Tony, M. A., & Ezzo, O. H. (2010). Feed restriction of pregnant nulliparous rabbit does: consequences on reproductive performance and maternal behaviour. Animal Reproduction Science, 120(1-4), 179-186. doi:10.1016/j.anireprosci.2010.03.010Littell, R. C., Henry, P. R., & Ammerman, C. B. (1998). Statistical analysis of repeated measures data using SAS procedures. Journal of Animal Science, 76(4), 1216. doi:10.2527/1998.7641216xFriggens, N. C., Brun-Lafleur, L., Faverdin, P., Sauvant, D., & Martin, O. (2011). Advances in predicting nutrient partitioning in the dairy cow: recognizing the central role of genotype and its expression through time. animal, 7(s1), 89-101. doi:10.1017/s1751731111001820Blas, C. de, & Mateos, G. G. (s. f.). Feed formulation. Nutrition of the rabbit, 222-232. doi:10.1079/9781845936693.0222Rebollar, P. G., Pereda, N., Schwarz, B. F., Millán, P., Lorenzo, P. L., & Nicodemus, N. (2011). Effect of feed restriction or feeding high-fibre diet during the rearing period on body composition, serum parameters and productive performance of rabbit does. Animal Feed Science and Technology, 163(1), 67-76. doi:10.1016/j.anifeedsci.2010.10.005Statistical Analysis System (SAS) 2002. SAS/SAT user’s guide (release 9.1). SAS Institute Inc., Cary, NC, USA.Bonnano A , Mazza F , Di Grigoli A and Alicata ML 2004. Effects of restricted feeding during rearing, combined with a delayed first insemination, on reproductive activity of rabbit does. In Proceedings of the 8th World Rabbit Congress, 7–10 September 2004, Puebla, México, pp. 224–230.Arnau-Bonachera, A., Cervera, C., Blas, E., Larsen, T., Martínez-Paredes, E., Ródenas, L., & Pascual, J. J. (2017). Long-term implications of feed energy source in different genetic types of reproductive rabbit females: I. Resource acquisition and allocation. animal, 12(9), 1867-1876. doi:10.1017/s1751731117003287Daly, M. E., Vale, C., Walker, M., Alberti, K. G., & Mathers, J. C. (1997). Dietary carbohydrates and insulin sensitivity: a review of the evidence and clinical implications. The American Journal of Clinical Nutrition, 66(5), 1072-1085. doi:10.1093/ajcn/66.5.1072Federation Internationale de Lacterie 1993. Determination de la teneur en azote. FIL Standard: 20B. Secrétariat General Federation Internationale de Lacterie, Brussels, Belgium.Xiccato, G., Bernardini, M., Castellini, C., Dalle Zotte, A., Queaque, P. I., & Trocino, A. (1999). Effect of postweaning feeding on the performance and energy balance of female rabbits at different physiological states. Journal of Animal Science, 77(2), 416. doi:10.2527/1999.772416xViudes-de-Castro, P., Santacreu, M., & Vicente, J. (1991). Effet de la concentration énergétique de l’alimentation sur les pertes embryonnaires et fœtales chez la lapine. Reproduction Nutrition Development, 31(5), 529-534. doi:10.1051/rnd:19910505Pascual, J. J., Cervera, C., Blas, E., & Fernández-Carmona, J. (1999). Effect of high fat diets on the performance, milk yield and milk composition of multiparous rabbit does. Animal Science, 68(1), 151-162. doi:10.1017/s1357729800050177Brecchia, G., Bonanno, A., Galeati, G., Federici, C., Maranesi, M., Gobbetti, A., … Boiti, C. (2006). Hormonal and metabolic adaptation to fasting: Effects on the hypothalamic–pituitary–ovarian axis and reproductive performance of rabbit does. Domestic Animal Endocrinology, 31(2), 105-122. doi:10.1016/j.domaniend.2005.09.006Savietto, D., Cervera, C., Ródenas, L., Martínez-Paredes, E., Baselga, M., García-Diego, F. J., … Pascual, J. J. (2014). Different resource allocation strategies result from selection for litter size at weaning in rabbit does. Animal, 8(4), 618-628. doi:10.1017/s1751731113002437Martínez-Paredes, E., Ródenas, L., Pascual, J. J., & Savietto, D. (2018). Early development and reproductive lifespan of rabbit females: implications of growth rate, rearing diet and body condition at first mating. animal, 12(11), 2347-2355. doi:10.1017/s1751731118000162Rommers, J. M., Meijerhof, R., Noordhuizen, J. P. T. M., & Kemp, B. (2004). Effect of feeding program during rearing and age at first insemination on performances during subsequent reproduction in young rabbit does. Reproduction Nutrition Development, 44(4), 321-332. doi:10.1051/rnd:200403

Effect of increasing lignin in isoenergetic diets at two soluble fibre levels on digestion, performance and carcass quality of growing rabbits

[EN] To assess the effect of increasing dietary lignin in isoenergetic diets at two soluble fibre (SF) levels on digestion, performance and carcass quality of growing rabbits, four diets were formulated according a 2 x 2 factorial design: low SF-low lignin (LSF/LL), low SF-high lignin (LSF/HL), high SF-low lignin (HSF/LL) and high SF-high lignin (HSF/HL). On average, in HSF diets SF was increased by 49 g/kg DM, mainly replacing starch ( - 53 g/kg DM), and in HL diets lignin was increased by 40 g/kg, mainly reducing starch (-78 g/kg DM), with increasing EE ( + 31 g/kg DM). Two hundred and sixty crossbred weaned rabbits (35 days old) were assigned to the experimental diets, individually housed and fed ad libitum until 63 days of age. Digestibility (from 49 to 53 days old), growth performance (from 35 to 63 days old), carcass quality (at 63 days old) and caecal environment (at 63 days old) were studied in 12, 65, 45 and 16 rabbits per diet, respectively. High SF diets showed higher CTTAD of fibrous fractions ( + 0.206 +/- 0.011, + 0.207 +/- 0.015, + 0.214 +/- 0.011 and + 0.167 +/- 0.015 for aNDFom, ADFom, hemicelluloses and cellulose, respectively, P < 0.001), OM ( + 0.042 +/- 0.004, P < 0.001) and GE ( + 0.055 +/- 0.005, P < 0.001), resulting in high DE content (10.6 vs. 9.30 MJ/kg DM). In contrast, CTTAD of CP was lower ( - 0.023 +/- 0.009, P = 0.013), as well as the DP content (96.9 vs. 103 g/kg DM). This dietary variation reduced the DM content of caecal digesta ( - 28 +/- 3 g/kg, P < 0.001), besides increasing its VFA concentration ( + 18.0 +/- 4.0 mmol/L, P < 0.001) and reducing its pH ( - 0.28 +/- 0.05, P < 0.001). Feed intake and LW gain decreased, with an improvement of feed to gain ratio ( -13.8 %, - 4.7 %, - 9.4 %, respectively; P < 0.001). The proportion of gastrointestinal tract was increased, with a subsequent reduction in dressing out ( + 19 +/- 2 g/kg LW and -15 +/- 2 g chilled carcass weight/kg LW, respectively, P < 0.001). High lignin diets showed lower CTTAD of OM (-0.055 +/- 0.004, P < 0.001) and GE ( - 0.034 +/- 0.005, P < 0.001) without affecting DE and DP contents. This dietary variation increased DM content of caecal digesta ( +21 +/- 3 g/kg, P < 0.001), but did not affect the other caecal digesta traits. Feed intake was higher ( + 4.9 %, P < 0.001), although differences were dependent on the growth phase and the SF level (maximum difference at 35-49 days with low SF diets, + 11.0 %, P < 0.001; minimum difference at 49-63 days with high SF diets, + 1.0 %, P = 0.689), but did not affect LW gain and consequently impaired the feed to gain ratio ( + 5.1 %, P < 0.001). No effect was observed on dressing out, but the dissectible fat proportion increased ( + 6.7 +/- 1.1 g/kg reference carcass weight, P < 0.001).Financial support was provided by the Spanish Ministry of Education and Science (Project AGL2006-07596).Caisin, L.; Martinez-Paredes, E.; Ródenas Martínez, L.; Moya, V.; Pascual Amorós, JJ.; Cervera Fras, MC.; Blas Ferrer, E.... (2020). Effect of increasing lignin in isoenergetic diets at two soluble fibre levels on digestion, performance and carcass quality of growing rabbits. Animal Feed Science and Technology. 262:1-9. https://doi.org/10.1016/j.anifeedsci.2020.114396S19262Batey, I. L. (1982). Starch Analysis Using Thermostable alpha-Amylases. Starch - Stärke, 34(4), 125-128. doi:10.1002/star.19820340407Delgado, R., Nicodemus, N., Abad-Guamán, R., Sastre, J., Menoyo, D., Carabaño, R., & García, J. (2018). Effect of dietary soluble fibre and n-6/n-3 fatty acid ratio on growth performance and nitrogen and energy retention efficiency in growing rabbits. Animal Feed Science and Technology, 239, 44-54. doi:10.1016/j.anifeedsci.2018.03.006Delgado, R., Menoyo, D., Abad-Guamán, R., Nicodemus, N., Carabaño, R., & García, J. (2019). Effect of dietary soluble fibre level and n-6/n-3 fatty acid ratio on digestion and health in growing rabbits. Animal Feed Science and Technology, 255, 114222. doi:10.1016/j.anifeedsci.2019.114222Fernández, C., & Fraga, M. J. (1996). The effect of dietary fat inclusion on growth, carcass characteristics, and chemical composition of rabbits. Journal of Animal Science, 74(9), 2088. doi:10.2527/1996.7492088xGarcía, J., Gidenne, T., Luisa Falcao-e-Cunha, & de Blas, C. (2002). Identification of the main factors that influence caecal fermentation traits in growing rabbits. Animal Research, 51(2), 165-173. doi:10.1051/animres:2002011Gidenne, T. (2015). Dietary fibres in the nutrition of the growing rabbit and recommendations to preserve digestive health: a review. Animal, 9(2), 227-242. doi:10.1017/s1751731114002729Gidenne, T., Perez, J., Lapanouse, A., & Ségura, M. (1994). Apports de lignines et alimentation du lapin en croissance. I. Conséquences sur la digestion et le transit. Annales de Zootechnie, 43(4), 313-322. doi:10.1051/animres:19940401Gidenne, T., Arveux, P., & Madec, O. (2001). The effect of the quality of dietary lignocellulose on digestion, zootechnical performance and health of the growing rabbit. Animal Science, 73(1), 97-104. doi:10.1017/s1357729800058094Grueso, I., De Blas, J. C., Cachaldora, P., Mendez, J., Losada, B., & García-Rebollar, P. (2013). Combined effects of supplementation of diets with hops and of a substitution of starch with soluble fiber on feed efficiency and prevention of digestive disorders in rabbits. Animal Feed Science and Technology, 180(1-4), 92-100. doi:10.1016/j.anifeedsci.2013.01.009Martínez-Vallespín, B., Martínez-Paredes, E., Ródenas, L., Cervera, C., Pascual, J. J., & Blas, E. (2011). Combined feeding of rabbit female and young: Partial replacement of starch with acid detergent fibre or/and neutral detergent soluble fibre at two protein levels. Livestock Science, 141(2-3), 155-165. doi:10.1016/j.livsci.2011.05.014Martínez-Vallespín, B., Martínez-Paredes, E., Ródenas, L., Moya, V. J., Cervera, C., Pascual, J. J., & Blas, E. (2013). Partial replacement of starch with acid detergent fibre and/or neutral detergent soluble fibre at two protein levels: Effects on ileal apparent digestibility and caecal environment of growing rabbits. Livestock Science, 154(1-3), 123-130. doi:10.1016/j.livsci.2013.02.012Nicodemus, N., Carabaño, R., Garcı́a, J., Méndez, J., & de Blas, C. (1999). Performance response of lactating and growing rabbits to dietary lignin content. Animal Feed Science and Technology, 80(1), 43-54. doi:10.1016/s0377-8401(99)00042-5Ocasio-Vega, C., Delgado, R., Abad-Guamán, R., Carabaño, R., Carro, M. D., Menoyo, D., & García, J. (2018). The effect of cellobiose on the health status of growing rabbits depends on the dietary level of soluble fiber. Journal of Animal Science, 96(5), 1806-1817. doi:10.1093/jas/sky106Pascual, M., Soler, M. D., Cervera, C., Pla, M., Pascual, J. J., & Blas, E. (2014). Feeding programmes based on highly-digestible fibre weaning diets: Effects on health, growth performance and carcass and meat quality in rabbits. Livestock Science, 169, 88-95. doi:10.1016/j.livsci.2014.07.007Trocino, A., García Alonso, J., Carabaño, R., & Xiccato, G. (2013). A meta-analysis on the role of soluble fibre in diets for growing rabbits. World Rabbit Science, 21(1). doi:10.4995/wrs.2013.1285Trocino, A., Fragkiadakis, M., Majolini, D., Tazzoli, M., Radaelli, G., & Xiccato, G. (2013). Soluble fibre, starch and protein level in diets for growing rabbits: Effects on digestive efficiency and productive traits. Animal Feed Science and Technology, 180(1-4), 73-82. doi:10.1016/j.anifeedsci.2013.01.007Van Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition. Journal of Dairy Science, 74(10), 3583-3597. doi:10.3168/jds.s0022-0302(91)78551-2Xiccato, G., Trocino, A., Majolini, D., Fragkiadakis, M., & Tazzoli, M. (2011). Effect of decreasing dietary protein level and replacing starch with soluble fibre on digestive physiology and performance of growing rabbits. Animal, 5(8), 1179-1187. doi:10.1017/s175173111100024

Unravelling the Role of Metabolites for Detecting Physiological State of Wild Animals: European Rabbit's (Oryctolagus cuniculus) Case

[EN] The main aim of this work was to know the possible potential of certain metabolites as biomarkers of the European wild rabbit to deepen the biological knowledge of this species and complement specific conservation programs. The main finding of our paper is that, regardless of the weight of the animals and their reproductive state, females show greater feed intake capacity than males, and their metabolism is affected. Furthermore, different reproductive stages are related to different metabolic phenotypes, metabolic behaviors, and metabolic profiles. There are indications of better optimization of resources by females, and evidence of the importance of some metabolites in the reproductive fitness of the species. European wild rabbit (Oryctolagus cuniculus) has been defined as a keystone species in the Mediterranean ecosystem. Rabbits have been classed as "endangered" by the IUCN within their native range. In this sense, animal nutrition may play a fundamental and limiting role in the conservation of wild species. The overarching goal of ecological nutrition is to unravel the extensive web of nutritional links that direct animals in their interactions with their ecological environments. The main aim of this work was to evaluate the effect of different feed intake, geographic location, animal sex, and reproductive stage on glucose, non-esterified fatty acids (NEFA), and plasmatic urea nitrogen (PUN), albumin, glutamate, and total protein metabolites. Additionally, we examined the potential of these metabolites as biomarkers. Full stomach contents and blood samples were collected from European wild rabbits (n = 89) for the analysis of the metabolites described above. Our work shows that the levels of these metabolites are affected by the sex of the animals, as well as by their reproductive stage (glucose, NEFA and albumin). There were signs of better optimisation of resources by females than by other groups of animals. These data may be interesting in the study of nutritional components that could be affecting physiological state of this species.This study was supported by the Regional Ministry of Innovation, Universities, Scienceand Digital Society of the Generalitat Valenciana (GV/2021/115 and CIBEST/2021/157) and Universidad Cardenal Herrera CEU (PUENTE22-03). This study was partially supported by a project granted by the Partnership for Research and Innovation in the Mediterranean Area (PRIMA) and funded by the Spanish Ministry of Science, Innovation and University (REF: PRIMAS2-11-PCI2019-103698). The APC was invited to Pablo Jesus Marin Garcia.Marín-García, PJ.; Llobat, L.; Rouco, C.; Aguayo-Adán, JA.; Larsen, T.; Cambra López, M.; Blas Ferrer, E.... (2022). Unravelling the Role of Metabolites for Detecting Physiological State of Wild Animals: European Rabbit's (Oryctolagus cuniculus) Case. Animals. 12(22):1-9. https://doi.org/10.3390/ani1222322519122