Department of Animal Science, State University of Acaraú Valley (UVA), Sobral, CE, 62040-370, Brazil.
Department of Animal Science, "Luiz de Queiroz" College of Agriculture, University of São Paulo (USP), Av. Pádua Dias, 11, Piracicaba, SP, 13.418-900, Brazil.
Trop Anim Health Prod. 2021 Oct 9;53(5):510. doi: 10.1007/s11250-021-02947-1.
Investigations in the Brazilian semi-arid region evaluating the performance and carcass traits of sheep of indigenous breeds and their crossings have been performed; however, these studies use exotic breeds which produce precocious lambs with heavier carcasses, but not adapted to climatic conditions and the extensive production system, jeopardizing the sustainability of the sheep production system. We crossed between three indigenous breeds: Morada Nova (MN - maternal breed); Rabo Largo (RL - paternal breed), and Santa Inês (SI - paternal breed) with the objective of evaluating the effect of genotype and sex on the performance and carcass traits of purebred and crossbred animals. A total of 30 lambs, males and females, reared in a semi-intensive system were evaluated. Birth and weaning weights were 2.26 ± 0.53 and 7.31 ± 1.85, respectively. All lambs were slaughtered at 10 months of age. A completely randomized design in a 3 × 2 factorial scheme (three genotypes and two sexes) was used. Multivariate techniques were also performed to reduce group and discriminate variables. Birth and weaning weight were similar (P > 0.05) among genetic groups and sexes. The weight gain, carcass and morphometric trait characteristics, and the main commercial cuts were higher in crossbred lambs (P < 0.05). All indicators have discriminatory power between genotypes and sexes, but the carcass traits have a higher discriminatory power (P < 0.001). All genotypes, regardless of sex, have particular characteristics, i.e. MN × SI was characterized by greater forelimb and ham perimeters (P < 0.001), and the MN × RL by higher hot carcass weight and finish (P = 0.001). The cluster analysis and the heatmap plot revealed associations between SI and the size of cuts and RL with the cut commercial yield and the reduction in weight loss due to cooling. Our findings confirm the hypothesis that crossing between indigenous breeds represents an adequate alternative in sheep meat production systems in semi-arid regions. Finally, we encourage the use of indigenous breeds for sheep meat production with breed identity in order to favor the conservation of genetic resources and the sustainability of the production system.
在巴西半干旱地区进行了评估绵羊的表现和胴体性状的研究，这些研究使用了早熟、胴体较重的外来品种，但这些品种不适应气候条件和粗放生产系统，这对绵羊生产系统的可持续性构成了威胁。我们对三个本土品种进行了杂交：Morada Nova（MN-母本）、Rabo Largo（RL-父本）和 Santa Inês（SI-父本），目的是评估基因型和性别对纯种和杂交后代动物的性能和胴体性状的影响。共评估了 30 只公母羔羊，在半集约化系统中饲养。出生和断奶体重分别为 2.26±0.53kg 和 7.31±1.85kg。所有羔羊在 10 月龄时屠宰。采用完全随机设计，在 3×2 因子方案（三个基因型和两个性别）下进行。还采用了多元技术来减少组和判别变量。在遗传组和性别之间，出生和断奶体重相似（P>0.05）。杂种羔羊的增重、胴体和形态特征以及主要商业切块较高（P<0.05）。所有指标都有基因型和性别之间的判别能力，但胴体性状的判别能力更高（P<0.001）。所有基因型，无论性别如何，都有其特点，即 MN×SI 具有较大的前肢和火腿周长（P<0.001），而 MN×RL 具有较高的热胴体重和嫩度（P=0.001）。聚类分析和热图揭示了 SI 与切块大小的关系，RL 与切块商业产量和冷却失重减少的关系。我们的研究结果证实了这样一种假设，即本土品种的杂交是半干旱地区绵羊生产系统的一种合适的替代方法。最后，我们鼓励使用具有品种特征的本土品种进行绵羊生产，以有利于遗传资源的保护和生产系统的可持续性。
