Márton Judit, Bene Szabolcs Albin, Szabó Ferenc
Hungarian Hereford, Angus and Galloway Breeders Association, Dénesmajor 2, H-7400 Kaposvár, Hungary.
Georgikon Campus, Hungarian University of Agriculture and Life Sciences, Deák Ferenc U. 16, H-8360 Keszthely, Hungary.
Animals (Basel). 2024 Dec 23;14(24):3715. doi: 10.3390/ani14243715.
This study aimed to examine the age at first calving (AFC) in Hungarian Angus herds. This study was conducted on the basis of data from 2955 registered cows, classified into five groups (based on different Angus types), and 200 breeding bulls, which were the sires of the cows. The data were made available by the Hungarian Hereford, Angus, and Galloway Breeders' Association. The variance and covariance components, heritability, breeding value (BV), and genetic trends of AFC between 1998 and 2021 were evaluated. A general linear model (univariate analysis of variance) was used to examine the various effects, while best linear unbiased prediction was used to estimate the population genetic parameters and BV, and linear regression analysis was used for the trend analysis. The average AFC obtained was 28.1 ± 0.1 months (SD = 5.3 months), showing a relatively large variance (CV = 18.9%). The environmental factors that influenced the development of the phenotype were the cow's birth season (28.99%, < 0.01), cow's birth year (28.7%, < 0.01), the cow's sire (18.32%, < 0.01), and the herd (11.77, < 0.05). The cow's color variant (8.10%, ) was not significant and did not influence the AFC in this study. The direct heritability of AFC (h = 0.51 ± 0.06) was higher than data in the literature (0.38 ± 0.05); however, the maternal heritability was low (h = 0.00 ± 0.03). The correlation between direct and maternal genetic effects was zero (r = -0.97 ± 1.00). The phenotypic trend of AFC increased by +0.03 months per year, which was not statistically significant. The genetic trend calculation showed no significant changes. Based on the h and BV results, it seems that selecting a suitable sire can effectively reduce the AFC of daughters. Since AFC is also an important trait in economic terms, it would be appropriate to include AFC BV in the bull catalog.
本研究旨在考察匈牙利安格斯牛群的初产年龄（AFC）。本研究基于2955头登记奶牛的数据进行，这些奶牛分为五组（基于不同的安格斯类型），还有200头种公牛，它们是这些奶牛的父亲。数据由匈牙利赫里福德、安格斯和加洛韦育种者协会提供。评估了1998年至2021年间AFC的方差和协方差成分、遗传力、育种值（BV）以及遗传趋势。使用一般线性模型（单变量方差分析）来考察各种效应，同时使用最佳线性无偏预测来估计群体遗传参数和BV，并使用线性回归分析进行趋势分析。所获得的平均AFC为28.1±0.1个月（标准差=5.3个月），显示出相对较大的方差（变异系数=18.9%）。影响表型发育的环境因素有奶牛的出生季节（28.99%，<0.01）、奶牛的出生年份（28.7%，<0.01）、奶牛的父亲（18.32%，<0.01）以及牛群（11.77，<0.05）。奶牛的毛色变异（8.10%，）不显著，在本研究中不影响AFC。AFC的直接遗传力（h=0.51±0.06）高于文献中的数据（0.38±0.05）；然而，母系遗传力较低（h=0.00±0.03）。直接遗传效应和母系遗传效应之间的相关性为零（r=-0.97±1.00）。AFC的表型趋势每年增加+0.03个月，这在统计学上不显著。遗传趋势计算显示没有显著变化。基于h和BV的结果，似乎选择合适的种公牛可以有效降低女儿的AFC。由于AFC在经济方面也是一个重要性状，将AFC BV纳入种公牛目录是合适的。
