Effect of hair shearing on live performance and carcass traits of growing rabbits under hot ambient temperature

[EN] The aim of the study was to examine the effect of hair shearing in growing rabbits reared at high ambient temperature. The live performance and carcass traits of growing rabbits reared at 20°C (not sheared, C, n=50) or at 28°C (not sheared, H, n=50, or sheared at 5, 7 and 9 wk, HS, n=50) were compared. The ambient temperature and relative humidity were 20.5±1.1°C and 54±11% in the 20°C room and 28.8±0.2°C and 35±8% in 28°C room, respectively. Feed intake of H and HS groups decreased by 29.0 and 20.4%, respectively, compared to C rabbits (P<0.001). The same data for weight gain were 24.6 and 16.9% (P<0.001), and for body weight at 12 wk were 16.8 and 11.5% (P<0.001). At the same time, the feed conversion ratio improved (C: 3.53, HS: 3.34, H: 3.31; P<0.001). Nevertheless, the mortality rate of rabbits was not affected by the studied treatment and was overall low (0-4%). No differences were observed in dressing out percentages either (ratio of chilled carcass (CC) to the slaughter weight: 61.6-61.9%). The ratio of liver to CC differed among the experimental groups, with the highest value recorded in C group and the lowest in H group; HS rabbits showed intermediate results (C: 4.86%, HS: 4.27%, H: 3.91%; P<0.001). Lower ratios of fat deposits to reference carcass were also observed in rabbits kept at high ambient temperature (perirenal fat: C: 2.59%, HS: 1.82%, H: 1.60%; P<0.001; scapular fat: C: 0.89%, HS: 0.66%, H: 0.51%; P<0.001). It can be concluded that the negative effect of higher ambient temperature (28 vs. 20°C) on production in growing rabbits can be reduced significantly by hair shearing.En este agradecimieento: "The work was supported by the GINOP-2.3.4-15-2016-00005 project. Publication was supported by the EFOP-3.6.3-VEKOP-16–2017–00008 project. The project is co-funded by the European Union and the European Social Fund"Matics, Z.; Kasza, R.; Gerencsér, Z.; Radnai, I.; Dalle Zotte, A.; Cullere, M.; Szendrő, Z. (2020). Effect of hair shearing on live performance and carcass traits of growing rabbits under hot ambient temperature. World Rabbit Science. 28(3):161-167. https://doi.org/10.4995/wrs.2020.13164OJS161167283Balnave D. 1972. The effect of temperature and length of exposure on liver composition and hepatic lipogenic enzyme activity in the immature male chick (Gallus domesticus). Comp. Biochem. Physiol., 438: 999-1007. https://doi.org/10.1016/0305-0491(72)90244-1Blasco A., Ouhayoun J. 1996. Harmonization of criteria and terminology in rabbit meat research. Revised proposal. World Rabbit Sci., 4: 93-99. https://doi.org/10.4995/wrs.1996.278Chiericato G.M., Rizzi C., Rostellato V. 1993. Effect of genotype and environmental temperature on performance of the young meat rabbit. World Rabbit Sci., 1: 119-125. https://doi.org/10.4995/wrs.1993.204Chiericato G.M., Ravarotto L., Rizzi R. 1994. Study of the metabolic profile of rabbits in relation to two different environmental temperatures. World Rabbit Sci., 2: 153-160. https://doi.org/10.4995/wrs.1994.232Chiericato G.M., Rizzi C., Rostellato V. 1996. Growth and slaughtering performance of three rabbit genotypes under different environmental conditions. Ann. Zootech., 45: 311-318. https://doi.org/10.1051/animres:19960403Deltoro J., López A.M. 1986. Development of commercial characteristics of rabbit carcasses during growth. Livest. Prod. Sci., 15: 271-283. https://doi.org/10.1016/0301-6226(86)90034-5EC 2010. Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. Official Journal of the European Union L276: 33-79.Fernández-Carmona J., Cervera C., Sabater C., Blas E. 1995. Effect of diet composition on the production of rabbit breeding does housed in a traditional building and at 30°C. Anim. Feed Sci. Technol., 52: 289-297. https://doi.org/10.1016/0377-8401(94)00715-LFinzi A., Morera P., Kuzminsky G. 1992. Effect of shearing on rabbit bucks performances in hot ambient conditions. J. Appl. Rabbit Res., 15: 489-494.Fuquay J.W. 1981. Heat stress as it affects animal production. J. Anim. Sci., 52: 164-174. https://doi.org/10.2527/jas1981.521164xHermes I.H., Ahmed B.M., Khalil M.H., Salah M.S., Al-Homidan A.A. 1999. Growth performance, nutrients utilization and carcass traits of growing Californian rabbits raised under different ambient temperatures. Egypt. J. Rabbit Sci., 9: 117-138.Jackson R., Rogers A.D, Lukefahr S.D. 2006. Effects of the naked gene on postweaning performance and thermotolerance characters in fryer rabbits: Final results. World Rabbit Sci., 14: 147-155. https://doi.org/10.4995/wrs.2006.559Kovitvadhi A., Chundang P., Thongprajukaew K., Tirawattanawanich C. 2019. Effects of different ambient temperatures on growth performances, digestibility, carcass traits and meat chemical components in fattening rabbits. J. Agriculture, 35: 495-502.Lebas F., Ouhayoun J. 1987. Incidence du niveau protéique de l'aliment, de milieu d'élevage et de la saison sur la croissance et les qualités bouchéres du lapin. Ann. Zootech., 36: 421-432. https://doi.org/10.1051/animres:19870406Lebas F., Coudert P., de Rochambeau H., Thébault R.G. 1997. The rabbit: husbandry, health and production. FAO Anim. Prod. and Health Series No. 21Lukefahr S.D., Ruiz-Feria C.A. 2003. Rabbit growth performance in a subtropical and semi-arid environment: Effects of fur clipping, ear length, and body temperature. Livest. Res. Rural Devel. 15: 2. Available at http://www.cipav.org.co/lrrd/lrrd15/2/luke152.htm Accessed October 2019.Marai I.F.M., Habeeb A.A.M., Gad A.E. 2002. Rabbits' productive, reproductive and physiological performance traits as affected by heat stress: a review. Livest. Prod. Sci., 78: 71-90. https://doi.org/10.1016/S0301-6226(02)00091-XMaya-Soriano M.J., Taberner E., Sabes-Alsina M., Ramon J., Rafel O., Tusell L., Piles M., López-Béjar M. 2015. Daily exposure to summer temperatures affects the motile subpopulation structure of epididymal sperm cells but not male fertility in an in vivo rabbit model. Theriogenology, 84: 384-389. https://doi.org/10.1016/j.theriogenology.2015.03.033Metzger Sz. 2006. Examination on carcass traits and meat quality of rabbit. (in Hung.) Doctoral (Ph.D.) dissertation. pp. 135.NASA https://climate.nasa.gov/Perez J.M., Lebas F., Gidenne T., Maertens L., Xiccato G., Parigi-Bini R., Dalle Zotte A., Cossu M.E., Carazzolo A., Villamide M.J., Carabaño R., Fraga M.J., Ramos M.A., Cervera C., Blas E., Fernández J., Falcão-e-Cunha L., Bengala Freire J. 1995. European reference method for in vivo determination of diet digestibility in rabbits. World Rabbit Sci. 3: 41-43. https://doi.org/10.4995/wrs.1995.239Renaudeau D., Collin A., Yahav S., de Basilio V., Gourdine J.L., Collier R.J. 2012. Adaptation to hot climate and strategies to alleviate heat stress in livestock production. Animal, 6: 707-728. https://doi.org/10.1017/S1751731111002448SAS Version 9.4. 2014. SAS Institute Inc; Cary, NC. Schlolaut W. 1995. Das grosse Buch vom Kaninchen. DLG-Verlag, Frankfurt am Main.Stephan E. 1980. The influence of environmental temperatures on meat rabbits of different breeds. Commercial Rabbit, 8: 12-15.Szendrő Zs., Rashwan R.R., Biró-Németh E., Radnai I., Orova Z. 2007. Effect of shearing of hair in summer on production of rabbit does. Acta Agr. Kapos., 11: 37-42.Szendrő Zs., Papp Z., Kustos K. 2018. Effect of ambient temperature and restricted feeding on the production of rabbit does and their kits. Acta Agr. Kapos., 22: 1-17. https://doi.org/10.31914/aak.2272Verga M., Luzi F., Carenzi C., 2007. Effects of husbandry and management systems on physiology and behaviour of farmed and laboratory rabbits. Horm. Behav., 52, 122-129. https://doi.org/10.1016/j.yhbeh.2007.03.024Zeferino P.C., Moura T.M.A.S.A., Fernandes S., Kanayama S.J., Scapinello C., Sartori R.J. 2011. Genetic group × ambient temperature interaction effects on physiological responses and growth performance of rabbits. Livest. Sci., 140: 177-183. https://doi.org/10.1016/j.livsci.2011.03.02

Divergent selection for fat index in Pannon Ka rabbits: genetic parameters, selection response

[EN] The objective of this study was to estimate the response to selection for total body fat content of rabbits measured by computer tomography (CT). A divergent selection experiment was performed using Pannon Ka rabbits, which were previously selected for number of kits born alive. The so-called zero generation consisted of 351 Pannon Ka rabbits, from which the index, total body fat volume (cm3) divided by the body weight (kg), was measured. Rabbits with low and high fat index values were selected to form the parent groups of the lean and fat lines, respectively. The lines consisted of 55-72 females and 35-47 males, depending on the line and generation. After three generations, the rabbits were evaluated by means of a single trait animal model. The fat index showed a moderate heritability estimate (0.28±0.03). The magnitude of the common litter effect was small (0.10±0.02). The breeding values averaged per generation provided slightly asymmetrical responses. Based on the results, the divergent selection was successful in confirming that CT is a very suitable method for performing selection for body composition traits.EFOP-3.6.3-VEKOP-16-2017-00008 project. The project is co-financed by the European Union and the European Social Fund and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00871/19)Kasza, R.; Matics, Z.; Gerencsér, Z.; Donkó, T.; Radnai, I.; Szendrő, Z.; Nagy, I. (2020). Divergent selection for fat index in Pannon Ka rabbits: genetic parameters, selection response. World Rabbit Science. 28(3):129-133. https://doi.org/10.4995/wrs.2020.12733OJS129133283Al-Saef A.M., Khalil M.H., Al-Dobaib S.N., Al-Homidan A.H., García M.L., Baselga M. 2008. Comparing Saudi synthetic lines of rabbits with the founder breeds for carcass, lean composition and meat quality traits. Livest. Res. Rural Dev., 20: 1-12.Donkó T., Czakó B., Kovács Gy., Petneházy Ö., Kasza R., Szendrő Zs., Garamvölgyi R., Matics Zs. 2016. Total body fat content determination by means of computed tomography (CT) in rabbits. In: Proceedings of the 11th World Rabbit Congress, 16-18 June 2016, Qingdao, China, pp. 753-756.Fortun-Lamothe L. 2006. Energy balance and reproductive performance in rabbit does. Anim. Reprod. Sci., 93: 1-15. https://doi.org/10.1016/j.anireprosci.2005.06.009Garreau H., Eady S.J., Hurtaud J., Legarra A. 2008. Genetic parameters of production traits and resistance to digestive disorders in a commercial rabbit population. In: Xiccato G., Trocino A., Lukefahr S. (eds.) In Proc.: 9th World Rabbit Congress. Fondazione Iniziative Zooprofilattiche e Zootechniche, Verona, Italy, pp. 103-108.Falconer D.S., Mackay T.F.C. 1996. Introduction to Quantitative Genetics. 4th Ed. Longman, London, UK. 1-464.Garreau H., Larzul C., Tudela F., Ruesche J., Ducqrocq V., Fortun-Lamothe L. 2017. Energy balance and body reserves in rabbit females selected for longevity. World Rabbit Sci., 25: 205-213. https://doi.org/10.4995/wrs.2017.5216Groeneveld E. 1990. PEST Users' Manual. Institute of Animal Husbandry and Animal Behaviour Federal Research Centre, Neustadt, Germany 1-61.Groeneveld E., Kovac M., Mielenz N. 2008. VCE User's Guide and Reference manual. Version 6.0. Institute of Farm Animal Genetics, Neustadt, Germany, 1-125.Larzul C., de Rochambeau H. 2005. Selection for residual feed consumption in the rabbit. Livest. Prod. Sci., 95: 67-72. https://doi.org/10.1016/j.livprodsci.2004.12.007Larzul C., Gondret F., Combes S., de Rochambeau H. 2005. Divergent selection on 63-day body weight in the rabbit: response on growth, carcass and muscle traits. Genet. Sel. Evol., 37: 105-122. https://doi.org/10.1051/gse:2004038Martínez-Álvaro M., Hernández P., Blasco A. 2016. Divergent selection on intramuscular fat in rabbits: Responses to selection and genetic parameters. J. Anim. Sci., 94: 4993-5003. https://doi.org/10.2527/jas.2016-0590Matics Zs., Nagy I., Gerencsér Zs., Radnai I., Gyovai P., Donkó T., Dalle Zotte A., Curik I., Szendrő Zs. 2014. Pannon breeding program in rabbit at Kaposvár University. World Rabbit Sci., 22: 287-300. https://doi.org/10.4995/wrs.2014.1511Milisits G., Romvári R., Dalle Zotte A., Szendrő Zs. 1999. Non-invasive study of changes in body composition in rabbits during pregnancy using X-ray computerized tomography. Ann. Zootech., 48: 25-34. https://doi.org/10.1051/animres:19990103Nagy I., Ibáñez N., Mekkawy W., Metzger Sz., Horn P., Szendrő Zs. 2006. Genetic parameters of growth and in vivo computerized tomography based carcass traits in Pannon White rabbits. Livest. Sci., 104: 46-52. https://doi.org/10.1016/j.livsci.2006.03.009Romvári R., Milisits G., Szendrő Zs., Sørensen P. 1996. Non invasive method to study the body composition of rabbits by X-ray computerized tomography. World Rabbit Sci., 4: 219-224. https://doi.org/10.4995/wrs.1996.298Rouvier R. 1970. Variabilité génétique du rendement a l'abattage et de la composition anatomique de lapins de trois races. Ann Genet. Sel. Anim., 2: 325-346. https://doi.org/10.1186/1297-9686-2-3-325Shemeis A., Abdallah O.Y. 2000. Possibilities of developing favourable body fat partition via selection indexes - application on rabbits. Arch. Anim. Breed., 43: 193-202. https://doi.org/10.5194/aab-43-193-2000Szendrő Zs., Romvári R., Horn P., Radnai I., Bíró-Németh E., Milisits G. 1996. Two-way selection for carcass traits by computerised tomography. In: Proc. 6th World Rabbit Congress, Toulouse, 2, 371-375.Szendrő Zs., Metzger Sz., Nagy I., Szabó A., Petrási Zs., Donkó T., Horn P. 2012. Effect of divergent selection for the computer tomography measured thigh muscle volume on productive and carcass traits of growing rabbits. Livest. Sci., 149: 167-172. https://doi.org/10.1016/j.livsci.2012.07.011Zomeño C., Hernández P., Blasco A. 2013. Divergent selection for intramuscular fat content in rabbits. 1. Direct response to selection. J. Anim. Sci., 91: 4526-4531. https://doi.org/10.2527/jas.2013-636

Effects of divergent selection for hind leg muscle volume on its lipid peroxide and glutathione redox status, and fatty acid composition in growing rabbits

[EN] Pannon White bucks were selected divergently using CT method by the volume of the hind leg muscle. Animals showed the highest and lowest muscle volumes were selected as minus and plus-selected variants. The male progenies of the minus and plus-selected parents were slaughtered as fi rst generation which was selected again by CT method and the male progenies of the parents were slaughtered. Results in the fi rst and second generation suggest that selection, as a genetic effect did not affect the rate of lipid peroxidation, as was measured by malondialdehyde content and glutathione redox status, as was measured by the reduced glutathione content and glutathione peroxidase activity of the hind leg muscle. However, there were some differences in the fatty acid composition. Significant (P<0.05) difference was found in palmitoleic acid content which was higher in the minus as compared to the plus variants in the second generation, in eicosadienoic acid which was higher in the fi rst as compared to the second generation of minus variants, and total monounsaturated fatty acids which was higher in the minus as compared to the plus variants in the second generation. It means that selection for higher hind leg volume would not causes marked in changes in the rabbit meat quality as measured by lipid peroxide and glutathione status as well as fatty acid composition.Mézes, M.; Balogh, K.; Fébel, H.; Matics, Z.; Fricska, M.; Szabó, A.; Szendro, Z. (2009). Effects of divergent selection for hind leg muscle volume on its lipid peroxide and glutathione redox status, and fatty acid composition in growing rabbits. World Rabbit Science. 17(1):15-19. doi:10.4995/wrs.2009.665151917

Comparison of productive and carcass traits and economic value of lines selected for different criteria, slaughtered at similar weights

[EN] The aim of the experiment was to compare 3 genetic groups, slaughtered at similar weights, to examine their productive and carcass traits and economic value. Three lines of the Pannon Breeding Programme, selected for different criteria, were examined in the experiment. Pannon Ka (PKa, maternal line) does were inseminated with semen of PKa, Pannon White (PWhite) or Pannon Large (PLarge, terminal line) bucks. The kits (PKa×PKa, PWhite×PKa, PLarge×PKa; n=60 in each genetic group) were weaned at 35 d of age and reared until 88, 83 and 79, respectively, when they reached similar body weights for slaughtering (2.8 kg). The weight gain of PLarge×PKa was the largest (51.0 g/d) and that of PKa×PKa was the smallest (47.2 g/d), while PWhite×PKa (41.8 g/d) was intermediate (P<0.001). Difference was found in feed conversion ratio between weaning and the age of slaughter  PKa×PKa: 3.03 respect to PWhite×PKa: 2.75 and PLarge×PKa: 2.66; , P<0.05). Dressing out percentage and ratio of hind part to reference carcass of PWhite×PKa, PLarge×PKa and PKa×PKa were 62.4 and 37.7, 61.8 and 37.5, 61.3 and 36.8%, respectively (P<0.01). Results show that PLarge×PKa rabbits were able to exceed the average economic indicators compared to other groups. It may be concluded that the production performance of growing rabbits was affected by the adult weight, but the carcass traits were influenced by the computer tomography (CT)-based selection.This paper was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences, and by the GOP-1.1.1-11-2012-0132 project.Szendrő, K.; Szendrő, Z.; Gerencsér, Z.; Radnai, I.; Horn, P.; Matics, Z. (2016). Comparison of productive and carcass traits and economic value of lines selected for different criteria, slaughtered at similar weights. World Rabbit Science. 24(1):15-23. https://doi.org/10.4995/wrs.2016.3684152324

Effect of inulin supplementation and age on growth performance and digestive physiological parameters in weaned rabbits

[EN] Three diets were formulated, a control diet (C, 40.7% NDF, 15.1% CP), the same diet but medicated (M, 500 mg/kg oxytetracycline and 50 mg/kg thiamulin), and a third diet obtained substituting 4% of barley with inulin (Frutafi t) in C diet (I). Pannon White does and their litters were randomly allocated into three groups (8/group) at 21 d of lactation and diets offered to the does and kids from 21 d of lactation onwards. After weaning (28 d), growing rabbits (30 cages/ treatment, 2 rabbits/cage) were fed the same diet as before weaning. At 28, 35 and 42 d of age, 6 healthy animals from each group (1 animal/cage) were slaughtered. Live body weight, feed intake and feed conversion ratio increased and growth rate decreased with age (P<0.001). Feed intake decreased in rabbits fed I diet compared to those fed M diet (by 11%, P<0.05), with those fed C diet showing an intermediate value. Growth rate from 28 to 35 d of age was not affected by diets, but decreased from 36 to 42 d in rabbits fed I diet compared to those fed C and M diets (P<0.05), with no effect on feed conversion ratio. Inulin did not affect mortality, which was low (¿ 3.3%), but increased morbidity compared to C and M diets (11.7 vs. 2.5%, P<0.05). Diets did not affect caecal weight, pH, cellulase and pectinase activity or microbial counts. Inulin diet decreased caecal xylanase activity (P<0.05) compared to C and M diets, reduced propionic and butyric acid and increased acetic acid concentration compared to M diet, whereas C diet showed intermediate values. Caecal pH and counts of E. coli and total aerobic bacteria increased and pectinase activity decreased (P<0.05) at 35 d of age (compared to 28 and 42 d of age). The number of the strictly anaerobic bacteria decreased and cellulase and xylanase activity increased (P<0.05) at 42 d of age compared to 28 and 35 d. Propionic acid concentration decreased with age from 28 to 42 d (P<0.05) but VFA concentration and acetic and butyric acids proportions did not change. In conclusion, the inclusion of 4% of inulin in the diet of weanling rabbits showed no positive effect.The research was funded by the OTKA (project No. T046999) and the TéT foundation (project No. FR27/2007).The authors are grateful to Dr. L. Maertens (ILVO-Belgium) for his advice on diet formulation.Bónai, A.; Szendró, Z.; Matics, Z.; Fébel, H.; Kametler, L.; Tornyos, G.; Horn, P.... (2010). Effect of inulin supplementation and age on growth performance and digestive physiological parameters in weaned rabbits. World Rabbit Science. 18(3). https://doi.org/10.4995/wrs.2010.588318

Milk production of pseudopregnant multiparous does

The aim of the experiment was to evaluate the milk production of pseudopregnant does. In this experiment, data of multiparous, inseminated, pregnant (IP, n=15) does and two groups of presumably pseudopregnant multiparous does: inseminated, non-pregnant (INP, n=17) and induced to ovulation by GnRH (1.5 microgram per animal) at the day of insemination (11 d after parturition) (non-inseminated, ovulating: NIO, n=15) were analysed. The progesterone level was measured at the 12th d after treatment to determine if females were pseudopregnant. All IP and NIO does were pregnant and pseudopregnant, respectively. Within the INP group, 10 and 7 does were diagnosed as positive (INPO) or negative (INPNO) for pseudopregnancy. Two of the INPNO does perished during lactation. The average milk production of groups IP, INP and NIO was 212, 92 and 72 g/d, respectively (P160 g in the various groups were: IP=0, 0, 0, 0 and 100%, NIO=20, 13, 27, 40 and 0%, INP=15, 15, 15, 55 and 0%, respectively. The daily milk yield of the 5 INPNO does was 2, 6, 27, 84 and 139 g, respectively. These results demonstrated that multiparous empty does, pseudopregnant or non-pseudopregnant, can produce milk, but in lower quantities than multiparous does after kindling.Szendrö, Z.; Matics, Z.; Brecchia, G.; Theau-Clément, M.; Nagy, Z.; Princz, Z.; Biró-Németh, E.... (2010). Milk production of pseudopregnant multiparous does. World Rabbit Science. 18(2). doi:10.4995/WRS.2010.18.1018

Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits

[EN] The aim of the experiment was to examine the effect of group size and stocking density on productive, carcass and meat quality traits. The trial was conducted using 230 Pannon white rabbits weaned at 5 weeks and reared until the age of 11 weeks. Seven groups were formed with different cage/pen sizes (group size) and stocking densities: SC16=small cage (0.12 m2), 16 rabbits/m2 (2 rabbits/cage); LC16=large cage (0.50 m2), 16 rabbits/m2 (8 rabbits/cage); LC12=large cage, 12 rabbits/m2 (6 rabbits/cage); SP16=small pen (0.86 m2), 16 rabbits/m2 (13 rabbits/cage); SP12=small pen, 12 rabbits/m2 (10 rabbits/cage); LP16=large pen (1.72 m2), 16 rabbits/m2 (26 rabbits/cage); LP12=large pen, 12 rabbits/m2 (20 rabbits/cage). Stocking density did not affect production significantly, as stocking densities lower than 16 rabbits/m2 had no effect on the growing rabbits¿ performance. Group size (size of the cage or pen) had an effect on certain growth, carcass and meat quality traits. Increasing group size resulted in lower values for weight gain (SC: 39.2>LC: 39.0> SP: 38.7> LP: 37.8 g/d; P=0.22) and body weight (SC: 2506>LC: 2498> SP: 2487> LP: 2446 g; P=0.35), similarly to other results in the literature, but the differences were not significant. Aggressive behaviour was observed to be more frequent in the larger group sizes. At the age of 11 weeks the proportion of rabbits with ear lesions in the SC, LC, SP and LP groups were 0.0, 7.1, 8.7, and 17.4%, respectively, demonstrating that larger group size increases the risk of ear lesions. The effect of group size on the ratio of the fore part to the reference carcass (SC: 28.5, LC: 28.2, LP: 29.0%; P=0.02) and on the amount of perirenal fat (SC: 21.3, LC: 18.0, LP: 13.7 g; P<0.001) was significant. Meat quality traits (dry matter, protein, fat and ash content, drip loss, pH, L*, a*, b* values) were not affected by group size (cage vs. pen), but successful discriminations were performed using the NIRS method.The authors gratefully acknowledge the financial assistance received from the GAK OMFB-01335/ALAP1- 00121 project.Szendrö, Z.; Princz, Z.; Romvári, R.; Locsmándi, L.; Szabó, A.; Bázár, G.; Radnai, I.... (2009). Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits. World Rabbit Science. 17(3):153-162. https://doi.org/10.4995/wrs.2009.65515316217

EFFECTS OF DIVERGENT SELECTION FOR HIND LEG MUSCLE VOLUME ON ITS LIPID PEROXIDE AND GLUTATHIONE REDOX STATUS, AND FATTY ACID COMPOSITION IN GROWING RABBITS

ABSTRACT: Pannon White bucks were selected divergently using CT method by the volume of the hind leg muscle. Animals showed the highest and lowest muscle volumes were selected as minus and plus-selected variants. The male progenies of the minus and plus-selected parents were slaughtered as fi rst generation which was selected again by CT method and the male progenies of the parents were slaughtered. Results in the fi rst and second generation suggest that selection, as a genetic effect did not affect the rate of lipid peroxidation, as was measured by malondialdehyde content and glutathione redox status, as was measured by the reduced glutathione content and glutathione peroxidase activity of the hind leg muscle. However, there were some differences in the fatty acid composition. Signifi cant (P&lt;0.05) difference was found in palmitoleic acid content which was higher in the minus as compared to the plus variants in the second generation, in eicosadienoic acid which was higher in the fi rst as compared to the second generation of minus variants, and total monounsaturated fatty acids which was higher in the minus as compared to the plus variants in the second generation. It means that selection for higher hind leg volume would not causes marked in changes in the rabbit meat quality as measured by lipid peroxide and glutathione status as well as fatty acid composition

Dietary supplementation of Digestarom® herbal formulation: effect on apparent digestibility, faecal and caecal microbial counts and live performance of growing rabbits

[EN] The experiment aimed to study the effect of Digestarom® dietary inclusion (herbal formulation containing a mixture of essential oils, herbs, spices and extracts) on apparent digestibility and digestive ecosystem of growing rabbits, as well as the effects of its supplementation before and after weaning on growth performance. At kindling, rabbit does and litters were divided into 2 dietary groups (51 does/group) and fed either a control diet (C) or a diet supplemented with 300 mg Digestarom®/kg diet (D) until weaning, which occurred at 35 d (before weaning supplementation). Each group was further divided into 3 dietary groups: CC received the control diet and DD received the D diet from 5 to 12 wk of age, and DC were fed with D (from 5 to 8 wk of age) and C diets (from 8 to 12 wk of age) (after weaning supplementation; 54 kits/group). An in vivo digestibility trial and a faecal microbial count were carried out on growing rabbits that received only the C or D diets during the trial. The C group showed higher DM intake than D group (215 vs. 196 g/d; P<0.05). The faecal digestibility of ether extract (75.9 vs. 59.8%; P<0.001), cellulose (25.9 vs. 20.6%; P<0.05) and gross energy (51.8 vs. 49.1%; P<0.05) was higher for C than for D group, whereas that of starch (98.9 vs. 98.8%; P<0.001) and the digestible protein to digestible energy ratio (13.9 vs. 13.2 g digestible protein/MJ digestible energy; P<0.01) was the highest for rabbits fed D diet. Stomach and caecal pH, caecal and faecal microbial counts were independent of the dietary treatment. The only exception was the stomach pH in 8 wk-old rabbits, which had the lowest value in C rabbits (P<0.05). The D supplementation before weaning improved feed conversion ratio throughout the growing phase (4.3 vs. 4.4 for D and C, respectively; P<0.05), whereas significant differences in daily weight gain, feed conversion ratio and mortality were observed only in the first period after weaning. Based on the results obtained, dietary supplementation with Digestarom® does not seem to confirm the positive results previously reported for growing rabbits.Celia, C.; Cullere, M.; Gerencsér, Z.; Matics, Z.; Giaccone, V.; Kovács, M.; Bónai, A.... (2016). Dietary supplementation of Digestarom® herbal formulation: effect on apparent digestibility, faecal and caecal microbial counts and live performance of growing rabbits. World Rabbit Science. 24(2):129-138. doi:10.4995/wrs.2016.406912913824

Carcass traits and meat quality of growing rabbits in pens with and without different multilevel platforms

[EN] The aim of this trial was to determine the effect of the presence of wire or plastic mesh elevated platforms on carcass traits and meat quality characteristics, with particular attention to the oxidative status of growing rabbits. A total of 174 five-week old rabbits were randomly divided into 3 groups with 2 replications (6 pens; 29 rabbits/pen): pens without platforms (NoP) with a stocking density of 16 rabbits/m2 and pens with wire-mesh platforms (WP) or plastic-mesh platforms (PP) that were placed on 2 levels, with a stocking density of 16 rabbits/m2 on the floor or 9.14 rabbits/m2 when the platform were included. At 84 d rabbits were slaughtered. The slaughter traits and Longissimus lumborum (LL) physical and chemical compositition were not affected by treatments. Rabbits from the PP group showed the highest retinol and γ-tocotrienol content on LL muscle, whereas the NoP ones showed a higher α-tocotrienol and α-tocopherol level. The absence of platforms led to decreased (P<0.001) thiobarbituric acid-reactive substances values and induced an improvement in n-3 polyunsaturated fatty acids. Levels of linoleic, linolenic and docosahexaenoic acids were equal to those of the WP group (23.45, 3.75, 0.64% in NoP and 22.6, 4.14, 0.53% in WP, respectively) but higher than in PP rabbits (20.86, 3.05, 0.45%, respectively). It can be concluded that the pens with elevated platforms provide greater possibilities for movement, which is beneficial from the viewpoint of animal welfare. However, this greater activity influences the oxidative status of the meat, decreasing the antioxidant content and worsening the lipid oxidation of rabbit meat.This research was supported by the GOP-1.3.1-11/B-2011-0045 project and by the János Bolyai Research Scholarship (BO/00373/14/4) of the Hungarian Academy of Sciences.138Martino, M.; Mattioli, S.; Farkas, P.; Szendrő, Z.; Dal Bosco, A.; Ruggeri, S.; Matics, Z.... (2016). Carcass traits and meat quality of growing rabbits in pens with and without different multilevel platforms. World Rabbit Science. 24(2). https://doi.org/10.4995/wrs.2016.392212924