Efecto de la dieta sobre la producción de metano en ganado caprino: resultados preliminares y puesta a punto de la metodología

Se realizaron dos pruebas de digestibilidad mediante la administración de dos dietas que difirieron únicamente en el tipo de cereal (grano de cebada o maíz). La producción de metano y CO2, y el consumo de O2, se determinaron por calorimetría indirecta mediante una máscara de circuito abierto adaptada a pequeños rumiantes.López Luján, MDC. (2009). Efecto de la dieta sobre la producción de metano en ganado caprino: resultados preliminares y puesta a punto de la metodología. http://hdl.handle.net/10251/11273Archivo delegad

Low-cost mobile open-circuit hood system for measuring gas exchange in small ruminants: from manual to automatic recording

Table 2 contained an incorrect footnote. The correct version is supplied at: http://dx.doi.org/10.1017/S0021859615000556[EN] Improvements of a home-made mobile open-circuit respirometry system for the rapid determination of methane (CH4) and carbon dioxide (CO2) production, oxygen (O-2) consumption and, thereafter, heat production (HP) for small ruminants are described and validated. Upgrades consisted of three main features: utilization of a head hood (replacing the previous face mask); use of a computerized control system, data acquisition and recording for gases and air flux (replacing collecting bags for air sampling); and use of a gas cooler to remove the air sample moisture (replacing the chemical drier (silica gel) approach). Calibration factors were established by injecting nitrogen (N-2) and CO2 in the system into the head hood. Repetitive and consistent values for the calibration factor were obtained for O-2 and CO2 which confirmed the absence of leaks and the good performance of the system. In addition, an experimental test with 12 Manchega female dry sheep was conducted to validate the system. Three diets based on cereal grain, fibrous by-products and alfalfa hay (ALH) were used with four sheep per diet. Metabolizable energy intake was close to metabolizable energy for maintenance. Average HP measured by indirect calorimetry (respiratory quotient (RQ) method) was close to the average HP determined from Carbon-Nitrogen balance (CN method) accounting for 443 and 426 kJ/kg(075) body weight (BW) per day, respectively. Fasting HP was determined by the RQ method with two sheep from the ALH diet accounting for 269 kJ/kg(075) BW per day. The head hood and computerized control, data acquisition and recording as well as the gas cooler improved the system by reducing the labour input without loss of functionality for measuring gas exchange and energy metabolism in small ruminantsThis study was supported by INIA Project (ref. no. RTA2011-00107-C02-02).Fernández Martínez, CJ.; López Luján, MDC.; Lachica, M. (2015). Low-cost mobile open-circuit hood system for measuring gas exchange in small ruminants: from manual to automatic recording. Journal of Agricultural Science. 153(7):1302-1309. https://doi.org/10.1017/S0021859615000416S130213091537Tovar-Luna, I., Puchala, R., Sahlu, T., Freetly, H. C., & Goetsch, A. L. (2010). Effects of stage of lactation and dietary concentrate level on energy utilization by Alpine dairy goats. Journal of Dairy Science, 93(10), 4818-4828. doi:10.3168/jds.2010-3315Freetly, H. C., Nienaber, J. A., Leymaster, K. A., & Jenkins, T. G. (1995). Relationships among heat production, body weight, and age in Suffolk and Texel ewes. Journal of Animal Science, 73(4), 1030-1037. doi:10.2527/1995.7341030xJust A. , Fernández J. A. & Jørgensen H. (1982). Nitrogen balance studies and nitrogen retention. In Digestive Physiology in the Pig. 2nd International Seminar Jouy-en-Josas, Versailles, 27–29 October 1982 (Eds J. P. LaPlace , J. Corring & A. Rerat ), pp. 111–122. Paris, France: INRA.Blaxter, K. L. (1967). Techniques in energy metabolism studies and their limitations. Proceedings of the Nutrition Society, 26(1), 86-96. doi:10.1079/pns19670016Fernández, C., López, M. C., & Lachica, M. (2012). Heat production determined by the RQ and CN methods, fasting heat production and effect of the energy intake on substrates oxidation of indigenous Manchega sheep. Animal Feed Science and Technology, 178(1-2), 115-119. doi:10.1016/j.anifeedsci.2012.09.007Lachica, M., & Aguilera, J. F. (2008). Methods to estimate the energy expenditure of goats: From the lab to the field. Small Ruminant Research, 79(2-3), 179-182. doi:10.1016/j.smallrumres.2008.07.016Lachia, M., Aguilera, J. F., & Prieto, L. C. (1997). Energy expenditure related to the act of eating in Granadina goats given diets of different physical form. British Journal of Nutrition, 77(3), 417-426. doi:10.1079/bjn19970042Fernández, C., López, M. C., & Lachica, M. (2012). Description and function of a mobile open-circuit respirometry system to measure gas exchange in small ruminants. Animal Feed Science and Technology, 172(3-4), 242-246. doi:10.1016/j.anifeedsci.2012.01.006Freetly, H. C., Nienaber, J. A., & Brown-Brandl, T. (2002). Relationships among heat production, body weight, and age in Finnsheep and Rambouillet ewes2. Journal of Animal Science, 80(3), 825-832. doi:10.2527/2002.803825xKelly, J. M., Kerrigan, B., Milligan, L. P., & McBride, B. W. (1994). Development of a mobile, open-circuit indirect calorimetry system. Canadian Journal of Animal Science, 74(1), 65-71. doi:10.4141/cjas94-010Christensen, K., Chwalibog, A., Henckel, S., & Thorbek, G. (1988). Heat production in growing pigs calculated according to the RQ and CN methods. Comparative Biochemistry and Physiology Part A: Physiology, 91(3), 463-468. doi:10.1016/0300-9629(88)90619-6YOUNG, B. A., WALKER, V. A., & WHITMORE, W. T. (1988). PROCEDURE FOR MEASURING RESTING AND SUMMIT METABOLISM IN SHEEP AND CALVES. Canadian Journal of Animal Science, 68(1), 173-182. doi:10.4141/cjas88-016Brouwer E. (1965). Report of subcommittee on constraints and factors. In Proceedings of the 3rd Symposium on Energy Metabolism (Ed. K. L. Blaxter ), pp. 441–445. EAAP Publication No. 11. London: Academic Press.Brockway, J. M., Boyne, A. W., & Gordon, J. G. (1971). Simultaneous calibration of gas analyzers and meters. Journal of Applied Physiology, 31(2), 296-297. doi:10.1152/jappl.1971.31.2.296Lachica, M., & Aguilera, J. F. (2005). Energy expenditure of walk in grassland for small ruminants. Small Ruminant Research, 59(2-3), 105-121. doi:10.1016/j.smallrumres.2005.05.002Puchala, R., Tovar-Luna, I., Goetsch, A. L., Sahlu, T., Carstens, G. E., & Freetly, H. C. (2007). The relationship between heart rate and energy expenditure in Alpine, Angora, Boer and Spanish goat wethers consuming different quality diets at level of intake near maintenance or fasting. Small Ruminant Research, 70(2-3), 183-193. doi:10.1016/j.smallrumres.2006.03.002Takahashi, J., Chaudhry, A. ., Beneke, R. ., & Young, B. . (1999). An open-circuit hood system for gaseous exchange measurements in small ruminants. Small Ruminant Research, 32(1), 31-36. doi:10.1016/s0921-4488(98)00163-1Takahashi, J., & Young, B. A. (1992). The modulation of nitrate-enhanced hypothermia by sulphur compounds in cold-exposed sheep. Animal Feed Science and Technology, 39(3-4), 347-355. doi:10.1016/0377-8401(92)90053-9Olthoff, J. C., Dickerson, G. E., & Nienaber, J. A. (1989). Energy Utilization in Mature Ewes from Seven Breeds with Diverse Production Potentials. Journal of Animal Science, 67(10), 2550. doi:10.2527/jas1989.67102550xBrosh, A. (2007). Heart rate measurements as an index of energy expenditure and energy balance in ruminants: A review1. Journal of Animal Science, 85(5), 1213-1227. doi:10.2527/jas.2006-29

Heat production partition in sheep fed above maintenece from indirect calorimetry data

[EN] The objective of this study is to compare the partition of heat energy (HE) in two sheep breeds by indirect calorimetry and integral calculus. An experiment was conducted with two Spanish native sheep breeds (dry and non-pregnant) which were fed with pelleted mixed diets above maintenance. Six Guirras and six Manchegas breed sheep were selected (58.8 ± 3.1 and 60.2 ± 3.2 kg body weight, respectively). All sheep were fed with the same concentrate mixed ration (0.300 kg cereal straw as forage and 0.700 kg concentrate) in two meals. Half the daily ration was offered at 800 h and another half at 1600 h. The sheep had free access to water. Sheep were allocated in metabolic cages; energy balance and gas exchange were assessed in each sheep. The statistical analyses included the fixed effect of breed and random effect of sheep. The metabolic energy (ME) for maintenance represented 69% of the total ME intake and the average was 354 kJ per kg of metabolic body weight (kg0.75 BW) on average. The basal metabolism (HeE) was greater (P < 0.05) in Guirra than Manchega breed (270 ± 18 vs. 247 ± 15 kJ/kg0.75 BW and day). As sheep were fed with above maintenance, the retained energy in the body accounted for 22% of the ME intake and 77% of the ME intake was lost as heat. 51% of the MEI was converted to HeE; 5% was lost as physical activity of standing and lying down (HjE), and 13% was associated with the process of feeding and work of digestion and metabolism (HdE). Within HdE, 47% represented the cost of intake and feeding and 54% the cost of digestion and metabolism. No differences in HE partition between breeds were found, although Guirra breed showed less efficiency of energy retention than Manchega breed. Therefore, this study demonstrated a tentative approach of partitioning HE, combining indirect calorimetry and integral calculusThis study was supported by the INIA Project (ref. RTA2011-00107-C02-02).Criscioni, PF.; López Luján, MDC.; Zena, VF.; Fernández Martínez, CJ. (2015). Heat production partition in sheep fed above maintenece from indirect calorimetry data. Open Journal of Animal Sciences. 5:86-98. https://doi.org/10.4236/ojas.2015.52011S8698

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

Do Growing Rabbits with a High Growth Rate Require Diets with High Levels of Essential Amino Acids? A Choice-Feeding Trial

[EN] Two diets were designed to investigate the effect of the growth rate on amino acid requirements in growing rabbits: M diet (with medium levels of amino acids, following current nutritional recommendations for growing rabbits) and H diet (with high levels of lysine, sulphur amino acids and threonine compared with current nutritional recommendations). Performance, nutrient retention and digestibility (faecal and ileal) trials, as well as a choice-feeding test were conducted. We found no differences in animal performance, nutrient retention and digestibility parameters between diets, but the animals showed a preference for the M diet, expressed by a high intra-individual repeatability in preference. Our results provide useful information and nutrition tools to move towards precision protein nutrition in growing rabbits. As a consequence of the genetic selection process in growing rabbits, there are currently fast-growing animals exhibiting an average daily gain that may exceed 45 g/d. The protein requirements of these animals, namely amino acid requirements, may differ from animals with low growth rates. The objective of this work was to evaluate growth performance, the coefficient of total tract apparent digestibility (CTTAD), the apparent ileal digestibility (AID) of amino acids and nutrient retention of fast-growing rabbits when they had access to a diet with high levels of amino acids and/or a diet formulated with current nutritional recommendations in a choice-feeding trial. To this end, two diets were formulated: the M diet following current nutritional recommendations for growing rabbits (including 8.1, 5.8 and 6.9 g/kg dry matter (DM) of total lysine, sulphur amino acids and threonine, respectively) and the H diet with higher levels of total lysine, sulphur amino acids and threonine (9.4, 6.6 and 7.8 g/kg DM, respectively). A total of 220 weaned rabbits, from a paternal line selected for the growth rate, had free access to the M diet, the H diet or both (MH) diets from 28 to 63 days of age. The CTTAD of DM, crude protein and gross energy from 49 to 53 days of age as well as the AID of amino acids of the diets at 63 days of age were determined. Protein, amino acids and energy retained in the empty body from 28 to 63 days of age were also registered. No significant differences in growth performance, CTTAD, AID and nutrient retention between dietary treatments were observed. However, animals fed the H diet showed a higher AID of cysteine (p < 0.05) and higher threonine retention (p < 0.05) compared to the M diet. As regards the choice-feeding trial, MH animals showed a higher feed intake of the M diet compared to the H diet (+8.61%; p < 0.001), and furthermore, more than 50% of the animals preferred the M diet throughout the experimental period (p < 0.05). Our results suggest that animals with high growth rates do not show significantly higher productive traits when fed the H diet compared to the M diet. As regards choice feeding, MH animals were capable of choosing their preferred diet, showing high intra-individual repeatability in preference for the M diet. It would be interesting to continue studying this behaviour of choice based on amino acid levels.This research was funded by the Interministerial Commission for Science and Technology (CICYT; grant no. AGL2017-85162-C2-1-R).Marín-García, PJ.; López Luján, MDC.; Ródenas Martínez, L.; Martinez-Paredes, E.; Cambra López, M.; Blas Ferrer, E.; Pascual Amorós, JJ. (2021). Do Growing Rabbits with a High Growth Rate Require Diets with High Levels of Essential Amino Acids? A Choice-Feeding Trial. Animals. 11(3):1-13. https://doi.org/10.3390/ani11030824S11311

Determinación de producción de metano en caprinos alimentados con dietas con distintos cereales

Three primiparous 1.5 year old Murciano-Granadina female goats in maintenance were used. Their average body weight was 33.08 ± 2.1 kg. The objective was to determine methane production in two diets differing of the type of cereal grain (barley or corn). Two consecutive digestibility trials were conducted using diets differing in the cereal type (barley or maize grains). The adaptation period has a duration of 7 days and the digestibility period 5 days. Methane production (CH4 ) was determined by indirect calorimetry with an open circuit mask adapted to small ruminants. Methane production was determined on day four of digestibility trial, before feeding and three more measurements every 35 minutes during feeding. There were no significant differences neither in dry matter intake (758 g MS/goat and day on average) nor in dry matter digestibility coefficients (CDMS= 69.2% on average). Significant differences (p<0.05) were observed in the methane production during the feeding time with levels of 0.69 and 0.77 l/h for the barley and maize based diets, respectively. No significant differences between diets were observed when CH4 was expressed on gross energy intake basis, and the value obtained for the experimental mixed diets was 4.8.Se utilizaron tres cabras primíparas de raza Murciano-Granadina de un año y medio de edad y en estado de mantenimiento, con un peso medio de 33,08 ± 2,1 kg, con el objeto de determinar la producción de metano al administrarles dos dietas que difirieron únicamente en el tipo de cereal (grano de cebada o maíz). Se realizaron dos pruebas de digestibilidad consecutivas mediante la administración de las dos dietas. Tras un periodo de adaptación de 7 días se analizó la digestibilidad aparente durante 5 días. La producción de metano (CH4) se determinó por calorimetría indirecta mediante una máscara de circuito abierto adaptada a pequeños rumiantes. El CH4 se midió el día 4 de la prueba de digestibilidad, antes de administrar la ración diaria y se realizaron tres medidas más cada 35 minutos mientras comían. No se observaron diferencias significativas en el consumo de materia seca (con 758 g MS/cabra y día de media), ni entre los coeficientes de digestibilidad de materia seca de las dos dietas (CDMS= 69,2% de media). Durante la comida se observaron diferencias (p<0,05) en la producción de metano con valores de 0,69 l/h para la dieta que contenía grano de cebada frente a 0,77 l/h para la dieta con grano de maíz. Cuando se expresó la producción de CH4 sobre la ingestión de energía (Ym) no se observaron diferencias significativas entre dietas, y el valor medio para las dietas mixtas estudiadas fue de 4,8.López Luján, MDC.; Ródenas Martínez, L.; Piquer Querol, O.; Cerisuelo, A.; Cervera Fras, MC.; Fernández Martínez, CJ. (2011). Determinación de producción de metano en caprinos alimentados con dietas con distintos cereales. Archivos de Zootecnia : Revista Trimestral. 60(232):943-951. http://hdl.handle.net/10251/45850S9439516023

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. 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Technol. 182: 100-110. https://doi.org/10.1016/j.anifeedsci.2013.04.00

Energy partitioning and substrate oxidation by Murciano-Granadina goats during mid lactation fed soy hulls and corn gluten feed blend as a replacement for corn grain

The aim of this experiment was to study the effect of substituting corn grain by soy hulls and corn gluten feed blend on energy partitioning, substrate oxidation, and milk performance in dairy goats during mid lactation. Ten multiparous Murciano-Granadina goats in mid lactation were fed 2 isoenergetic and isoproteic diets [19.08 MJ/kg of dry matter (DM) and 18.7% of CP, DM basis] in a crossover design. One group of 5 goats was fed a mixed ration with 373 g of corn grain/kg of DM (CRN diet) and the other diet replaced corn grain with 373 g/kg DM of fibrous by-products [soy hulls and gluten feed (SHGF) diet]: 227 g of soy hulls/kg of DM and 146 g of gluten feed blend/kg DM. Fat was added to the SHGF diet to make it isoenergetic. After 10 d of adaptation, the feed intake, refusal, total fecal and urine output, and milk yield were recorded daily over a 5-d period. Then, gas exchange measurements were recorded by a mobile open-circuit respirometry system using a head box for 10 d. Dry matter intake was similar for both diets (2.07 kg/d, on average). Greater and significant values were found in the SHGF diet for ammonia N, energy in urine, and oxidation of protein. Values were significantly lower for heat production of fermentation, indicating a decrease in rumen fermentation with this diet, probably due to an excess of crude protein in the diet and lack of synchronization of the nonfiber carbohydrates with rumen-degraded protein. The metabolizable energy intake was no different between CRN and SHGF treatments, with an average value of 1,444 kJ/kg of BW0.75. Due to the positive energy balance during mid lactation in this trial, most of the heat production from oxidation of nutrients derived from carbohydrate oxidation (55%, on average), followed by oxidation of fat (29%, on average). No significant differences were observed for milk production, although milk fat was significantly greater for the SHGF diet than the CRN diet (7.0 vs. 5.4%, respectively). Despite the different starch levels and fibrous content used in these mixed diets, no significant differences for the efficiency of use of metabolizable energy for late lactation were observed (0.63, on average). An average nutritive value of 7.52 MJ of net energy of lactation/kg of DM was obtained. This fibrous by-product was utilized by lactating goats without detrimental effect on energy metabolism and resulted in similar performance to grain bases diet. The economic advantages and sustainability of this choice should be evaluated.This study was supported by an Instituto Nacional de Investigacion y Tecnologia Agraria (INIA, Madrid, Spain) project (ref. RTA2011-00107-C02-02).López Luján, MDC.; Fernández Martínez, CJ. (2013). Energy partitioning and substrate oxidation by Murciano-Granadina goats during mid lactation fed soy hulls and corn gluten feed blend as a replacement for corn grain. Journal of Dairy Science. 96(7):4542-4552. https://doi.org/10.3168/jds.2012-6473S4542455296

Changes in heat production by sheep of Guirra breed after increase in quantity of barley grain on the diet

The heat production (HP) from CH4 and CO2 production and O-2 consumption was determined by the respirometry quotient (RQ) method and by C-N balance measurements (CN method). Twelve dry and none pregnant Guirras sheep were fed with 3 diets consisting in the same quantity of alfalfa hay (2 kg/d offered) and increasing quantities of barley grain (150,300 and 450 g/d). The experimental design was completely random with 4 replication by treatment. Fasting HP was determinate in one sheep from each group. Ewes were allocated to individual metabolism cages at thermoneutrality. After 10 d of adaptation, feed intake, and total fecal and urine output were recorded daily for each ewe during a 5 d period, as well as BW at the beginning and end of the period. Gas exchange measurements were recorded by open-circuit face mask respirometry system. Average HP measured by RQ method was in agreement with the average HP determined by CN method accounting for 395.6 and 393.4 kJ/kg(0.75) BW/d, respectively. The metabolizable energy requirement for maintenance (MEm) was estimated by linear regression at 352.3 kJ/kg(0.75) BW. (C) 2012 Elsevier B.V. All rights reserved.This study was supported by Agroalimed Foundation and INIA Project (ref. RTA2011-00107-C02-02).López Luján, MDC.; Fernández Martínez, CJ. (2013). Changes in heat production by sheep of Guirra breed after increase in quantity of barley grain on the diet. Small Ruminant Research. 109(2-3):113-118. https://doi.org/10.1016/j.smallrumres.2012.07.008S1131181092-

PRELIMINARY STUDY FOR MAINTENANCE REQUIREMENTS DETERMINATION IN MANCHEGA AND GUIRRA SHEEP

[EN] Twelve sheep of two races were used, six of each race, Manchega and Guirra; two and a half years old, not pregnant, dried and fed under maintenance. Sheep were weighted at the beginning and end of the trial consisting of an adaptation phase to metabolic cages, diet and respirometric mask during 13 days, followed by an experimental phase of another 13 days. The experimental phase consisted of 5 days digestibility, 2 rest, 3 respirometry measures and 3 of fasting for determination of fasting heat production. Intake, digestibility, energy balance were made and the heat production (HP) of sheep were obtained by indirect calorimetry. There were no differences between two breeds in terms of digestibility, energy balance and HP. The net energy requirements for maintenance (ENm), equivalent to basal metabolism, are on average for both breeds of 288.9 KJ ENm/kg PV0.75 .[ES] Los costes de la alimentación en un sistema intensivo de producción ovina española pueden llegar a representar del 50 al 80% de los gastos totales de la explotación. Un abaratamiento de dichos costes implica buscar ingredientes a buen precio en el mercado, pero sin llegar a desequilibrar las necesidades en nutrientes de los animales. Conocer las necesidades nutritivas de nuestras razas es clave para poder elaborar una dieta adecuada y abaratar costes. La mayor parte de las recomendaciones sobre necesidades nutritivas de las razas ovinas españolas (principalmente energía y proteína) que se utilizan a nivel práctico en España corresponden al INRA y al NRC, sistemas productivos que no coinciden con los de nuestro país. La información sobre el metabolismo basal o producción de calor de nuestras razas es desconocida. En ovino, están únicamente los estudios de metabolismo energético del CSIC de Granada (EEZ) en ovejas de razas Segureña. No existe más información sobre necesidades energéticas en razas ovinas españolas. El objetivo de este trabajo es dar una primera información sobre las necesidades de mantenimiento para dos razas autóctonas españolas como son la oveja Manchega y Guirra.Fernández Martínez, CJ.; López Luján, MDC. (2011). Estudio preliminar para determinar las necesidades de mantenimiento en ovejas de raza Manchega y Guirra. En XIV Jornadas sobre Producción Animal. 234-236. http://hdl.handle.net/10251/68094S23423