The effect of genotype and sex on growth and carcass traits of lambs

Abstract

Submitted 2020-07-24 | Accepted 2020-08-31 | Available 2020-12-01 https://doi.org/10.15414/afz.2020.23.mi-fpap.276-281 The objective of the present study was to investigate the effect of genotype and sex on growth and carcass traits of grazing lambs. A total of 32 lambs (16 Improved Jezersko-Solcava - JSR and 16 crossbreds with Texel - JSRT, 8 males and 8 females within each genotype) were included in the study. The lambs were grazed together with their dams from the beginning of the grazing period and had free access to commercial concentrate from the age of 10 days. Lambs were weaned at the average body weight of 22.9 kg. Feeding with a concentrate was finished when lambs achieved 35 kg of body weight and were slaughtered. Daily gains from birth to slaughter and from weaning to slaughter were calculated. Several carcass traits were determined. JSRT lambs had significantly higher daily gain from birth to slaughter, hot and cold carcass weights, and dressing percentages compared to JSR lambs. Carcass conformation was higher in JSRT than JSR carcasses. Also, carcasses of JSRT were shorter and wider than JSR carcasses. Rib eye muscle areas of JSRT lambs were significantly larger, and the colour was significantly lighter. Males had significantly higher average daily gain from birth to slaughter and from weaning to slaughter than females. Females had higher dressing percentages and subcutaneous and internal fatness scores than males. Females had significantly higher amount of kidney fat. The colour of males’ meat was significantly lighter than that of females. Crossbreeding with Texel rams improved growth and carcass traits of lambs, and males had better growth performance and several carcass traits than females. Keywords: lambs, commercial crossbreeding, sex, growth, carcass trait References Blasco, M. et al. (2019). Effect of Texel crossbreeding on productive traits, carcass and meat quality of Segurena lambs. Journal of the Science of Food and Agriculture, 99, 3335-3342. https://doi.org/10.1002/jsfa.9549 Cardoso, M. T. M. et al. (2013). Performance and carcass quality in three genetic groups of sheep in Brazil. Revista Brasileira de Zootecnia, 42(10), 734-742. https://doi.org/10.1590/S1516-35982013001000007 Claffey, N. A. et al. (2018). Effect of breed and castration on production and carcass traits of male lambs following an intensive finishing period. Translational Animal Science, 2, 407-418. https://doi.org/10.1093/tas/txy070 Do Prado Paim, T. et al. (2013). Performance, survivability and carcass traits of crossbred lambs from five paternal breeds with local hair breed Santa Ines ewes. Small Ruminant Research, 112, 28-34. https://doi.org/10.1016/j.smallrumres.2012.12.024 Facciolongo, A. M. et al. (2018). Effect of diet lipid source (linseed vs. soybean) and gender on performance, meat quality and intramuscular fatty acid composition in fattening lambs. Small Ruminant Research, 159, 11-17. https://doi.org/10.1016/j.smallrumres.2017.11.015 Freitas-de-Melo, A. et al. (2019). Behavioral pattern in Texel x Corriedale terminal crossbreeding: Maternal behavior score at birth, lambs’ feeding behaviors, and behavioral responses of lambs to abrupt weaning. Journal of Veterinary Behavior, 30, 9-15. https://doi.org/10.1016/j.jveb.2018.10.007 Nunes, I. A. et al. (2019). Performance, carcass characteristics, and centesimal composition of meat from Santa Ines lambs and Texel crossbred lambs (Santa Ines × Texel). Canadian Journal of Animal Science, 99(2), 228-236. https://doi.org/10.1139/cjas-2016-0231 Perez, P. et al. (2007). Gender and slaughter weight effects on carcass quality traits of suckling lambs from four different genotypes. Small Ruminant Research, 70, 124-130. https://doi.org/10.1016/j.smallrumres.2006.01.013 SAS. (2014). SAS/STAT® 13.2 User’s Guide. SAS Institute Inc., Cary, NC, USA. Scales, G. H. et al. (2000). Effect of sire breed on growth, carcass, and wool characteristics of lambs born to Merino ewes in New Zealand. New Zealand Journal of Agricultural Research, 43(1), 93-100. https://doi.org/10.1080/00288233.2000.9513412