Fertility Responses of Mexican Holstein Cows to US Sire Selection

Abstract

Genetic relationships between 2 fertility traits and milk production were investigated using mature-equivalent lactation records of 55,162 daughters of 1,339 Holstein sires in Mexico and 499,401 daughters of 663 Holstein sires in the northeastern United States. Data sets contained yields in first and second lactation, age at first calving (AFC), and calving interval (CI). There were 474 US sires in common between countries. A herd-year standard deviation criterion defined nonoverlapping low- (< or = 1,300 kg) and high- (> or = 1,600 kg) opportunity Mexican herd environments and a low-opportunity (< or = 1,024 kg) US environment. Genetic variances for the average Mexican herd (all data) for AFC and CI were 65 and 85% as large as those obtained from half-sisters in the average US herd. Genetic correlations for first-lactation milk in the average US herd and AFC and CI in the average Mexican environment were unfavorable (0.18 and 0.10). Regression coefficients of AFC in Mexican environments on US genetic gain in milk ranged from 2 to 7 d/1,000 kg. However, the favorable predicted response in AFC from genetic gain in milk in Mexican environments, like those in average US herds, ranged from -4 to -7 d/1,000 kg (r(g) = - 0.20). This unequal AFC response may indicate genotype by environment interaction in fitness performance or differential breeding management of high and low yielding Mexican cows. The potential effects of age at first service of breeding females need to be disentangled to accurately assess genetic improvement needs for Mexican Holstein herds.

Estimation of genetic and phenotypic relationships between age at first calving and productive performance in Iranian Holsteins

“…Also, consistent with the current results, Ruiz-Sánchez et al (2007) reported that the genetic correlations between AFC and MY were negative regardless of herd level. The genetic correlation between AFC and MY in this study was slightly larger than those in previous reports for Holstein cows that ranged from −0.20 to −0.33 (Pirlo et al 2000;Mäntysaari et al 2002;Cienfuegos-Rivas et al 2006), although positive genetic and phenotypic correlations between AFC and MY have also been reported in Sahiwal cattle in semi-arid Kenya (Ilatsia et al 2007). Also, generally consistent with the results of this study, Ghavi Hossein-Zadeh and Ardalan (2011) reported that genetic correlations among milk traits were consistently high in Holstein dairy cows.…”

Genetic parameters for milk yield and reproduction traits in the Chilean Dairy Overo Colorado cattle breed

“…The sire-herd effect on AF, measured as a proportion of phenotypic variance, was larger in this study (0.10) than the additive genetic effects. This magnitude of the sire-herd variance may imply that daughters of specific sires may receive shared management practices, creating a confounding between sire genetic and environmental effects (Pirlo et al, 2000;Cienfuegos-Rivas et al, 2006), which may also explain why estimates of heritability for this trait span such a wide range across studies. The sire-herd proportion of phenotypic variance was generally small for other traits (Tables 2 and 3).…”

Genotype by environment interaction estimated by using reaction norms in cattle

“…recommended grouping animals by sire PTA milk, rainfall, fat to protein ratio, and standard deviation of milk yield instead of by country borders. This has the potential to increase genetic progress by increasing the accuracy for such international genetic selection programs.The use of sires across multiple countries within the dairy industry has an effect on milk yield, age at first calving, and milk fat(Ceron-Munoz et al, 2004a;Ceron- Munoz et al, 2004b;Cienfuegos-Rivas et al, 2006;Costa et al, 2000). The genetic correlations for milk yield and age at first calving were inconsistent between Mexico and the United States in the study conducted byCienfuegos-Rivas et al (2006).…”

“…This has the potential to increase genetic progress by increasing the accuracy for such international genetic selection programs.The use of sires across multiple countries within the dairy industry has an effect on milk yield, age at first calving, and milk fat(Ceron-Munoz et al, 2004a;Ceron- Munoz et al, 2004b;Cienfuegos-Rivas et al, 2006;Costa et al, 2000). The genetic correlations for milk yield and age at first calving were inconsistent between Mexico and the United States in the study conducted byCienfuegos-Rivas et al (2006). A negative correlation existed between milk yield and age at first calving when analyzed within countries, but the correlation was positive when analyzed between countries(Cienfuegos- Rivas et al, 2006) Ceron-Munoz et al (2004a.).…”

“…The genetic correlations for milk yield and age at first calving were inconsistent between Mexico and the United States in the study conducted byCienfuegos-Rivas et al (2006). A negative correlation existed between milk yield and age at first calving when analyzed within countries, but the correlation was positive when analyzed between countries(Cienfuegos- Rivas et al, 2006) Ceron-Munoz et al (2004a.). completed a study to determine if GxE had an effect on age of first calving between the countries of Brazil and Colombia.…”