Arikawa Leonardo Machestropa, Mota Lucio Flavio Macedo, Schmidt Patrícia Iana, Salatta Bruna Maria, Nasner Sindy Liliana Caivio, Silva Neto João Barbosa da, Fonseca Larissa Fernanda Simielli, Magalhães Ana Fabrícia Braga, Silva Delvan Alves, Carvalheiro Roberto, Chardulo Luis Artur Loyola, de Albuquerque Lucia Galvão
Department of Animal Science, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, SP, Brazil.
Department of Animal Science, University of Jequitinhonha and Mucuri Valleys, Diamantina, MG, Brazil.
J Anim Breed Genet. 2025 Feb 5. doi: 10.1111/jbg.12927.
For developing beef cattle breeding programmes, it is essential to understand the genetic basis of economically relevant traits, such as carcass, meat quality and female sexual precocity. However, the direct selection of most of these traits is a challenge for producers because of the high cost and measurement difficulty. Genetic correlation estimates between carcass and meat quality traits obtained after slaughter and sexual precocity indicator traits in Nellore are limited in the literature. Thus, this study aimed to estimate genetic parameters for longissimus muscle area (LMA), backfat thickness (BF), hot carcass weight (HCW), shear force tenderness (SF), marbling score (MARB), intramuscular fat content (IMF), age at first calving (AFC), heifer pregnancy (HP) and scrotal circumference (SC) in Nellore cattle, using pedigree and genomic information. For this, data from 6910 young bulls with phenotypic information for carcass and meat traits, 230,682 for sexual precocity indicator traits, and 17,850 animals genotyped with or imputed to the Illumina Bovine HD BeadChip were used. The (co)variance components and genetic parameters were estimated considering BLUP and single-step GBLUP (ssGBLUP) models via Bayesian inference using the GIBBSF90+ software. The multi-trait animal model included additive and residual genetic effects as random; the fixed effects of contemporary group (for all traits) and date of analysis as classes (for BF, SF and MARB); and the linear effects of age at slaughter (all carcass and meat traits) and age at yearling (YW and SC) as covariates. Heritability estimates ranged from 0.13 to 0.34 for carcass and meat quality traits, and for SC, AFC and HP, were 0.33, 0.07 and 0.29, respectively. Favourable genetic correlations were estimated between YW-HCW (0.79 ± 0.03), YW-LMA (0.28 ± 0.05), YW-SC (0.35 ± 0.03), HCW-LMA (0.44 ± 0.05), HCW-SF (-0.22 ± 0.09), HCW-SC (0.19 ± 0.05), MARB-IMF (0.90 ± 0.07), SF-IMF (-0.20 ± 0.11), BF-MARB (0.29 ± 0.08), BF-IMF (0.22 ± 0.09), BF-AFC (-0.21 ± 0.07) and BF-HP (0.24 ± 0.10). In general, the correlations between carcass traits and those of meat quality were low to moderate. Additionally, carcass and meat quality traits did not exhibit strong genetic correlations with female precocity indicators. So, to achieve significant genetic advances in female sexual indicator traits, carcass composition and meat quality, these traits must compose selection indices for Nellore cattle.
对于制定肉牛育种计划而言，了解与经济相关性状的遗传基础至关重要，比如胴体、肉质和雌性早熟性等性状。然而，由于成本高昂且测量困难，对大多数此类性状进行直接选择对生产者来说是一项挑战。在文献中，关于屠宰后获得的胴体和肉质性状与内洛尔牛的早熟性指标性状之间的遗传相关性估计有限。因此，本研究旨在利用系谱和基因组信息，对内洛尔牛的最长肌面积（LMA）、背膘厚度（BF）、热胴体重（HCW）、剪切力嫩度（SF）、大理石花纹评分（MARB）、肌内脂肪含量（IMF）、初产年龄（AFC）、小母牛怀孕率（HP）和阴囊周长（SC）的遗传参数进行估计。为此，使用了6910头具有胴体和肉质表型信息的年轻公牛的数据、230,682头具有早熟性指标性状的数据，以及17,850头用Illumina牛HD基因分型芯片进行基因分型或推算的动物的数据。通过使用GIBBSF90 +软件进行贝叶斯推断，考虑BLUP和单步GBLUP（ssGBLUP）模型估计（协）方差成分和遗传参数。多性状动物模型将加性遗传效应和残差遗传效应视为随机效应；当代组（所有性状）和分析日期（BF、SF和MARB）作为分类的固定效应；屠宰年龄（所有胴体和肉质性状）和周岁年龄（YW和SC）的线性效应作为协变量。胴体和肉质性状的遗传力估计值在0.13至0.34之间，对于SC、AFC和HP，分别为0.33、0.07和0.29。估计了YW - HCW（0.79 ± 0.03）、YW - LMA（0.28 ± 0.05）、YW - SC（0.35 ± 0.03）、HCW - LMA（0.44 ± 0.05）、HCW - SF（ - 0.22 ± 0.09）、HCW - SC（0.19 ± 0.05）、MARB - IMF（0.90 ± 0.07）、SF - IMF（ - 0.20 ± 0.11）、BF - MARB（0.29 ± 0.08）、BF - IMF（0.22 ± 0.09）、BF - AFC（ - 0.21 ± 0.07）和BF - HP（0.24 ± 0.10）之间的有利遗传相关性。总体而言，胴体性状与肉质性状之间的相关性为低到中等。此外，胴体和肉质性状与雌性早熟指标之间未表现出强遗传相关性。因此，为了在内洛尔牛的雌性性指标性状、胴体组成和肉质方面实现显著的遗传进展，这些性状必须纳入内洛尔牛的选择指数。
