Genetic association between milk yield, stayability, and mastitis in Holstein cows under tropical conditions

Abstract

The objective of this study was to estimate genetic parameters for milk yield, stayability, and the occurrence of clinical mastitis in Holstein cows, as well as studying the genetic relationship between them, in order to provide subsidies for the genetic evaluation of these traits. Records from 5,090 Holstein cows with calving varying from 1991 to 2010, were used in the analysis. Two standard multivariate analyses were carried out, one containing the trait of accumulated 305-day milk yields in the first lactation (MY1), stayability (STAY) until the third lactation, and clinical mastitis (CM), as well as the other traits, considering accumulated 305-day milk yields (Y305), STAY, and CM, including the first three lactations as repeated measures for Y305 and CM. The covariance components were obtained by a Bayesian approach. The heritability estimates obtained by multivariate analysis with MY1 were 0.19, 0.28, and 0.13 for MY1, STAY, and CM, respectively, whereas using the multivariate analysis with the Y305, the estimates were 0.19, 0.31, and 0.14, respectively. The genetic correlations between MY1 and STAY, MY1 and CM, and STAY and CM, respectively, were 0.38, 0.12, and -0.49. The genetic correlations between Y305 and STAY, Y305 and CM, and STAY and CM, respectively, were 0.66, -0.25, and -0.52.

Analysis of culling records and estimation of genetic parameters for longevity and some production traits in Holstein dairy cattle

“…Sasaki (2013) reviewed the genetic parameters for longevity traits of dairy cattle and stated that the variations among estimates of most of the estimates of heritability obtained by the linear model are <0.10. Our estimates were lower than those reported by Pfeiffer et al (2015) in Austrian Fleckvieh cattle and Irano et al (2014) in Holstein cows under tropical conditions.…”

<b>Estimation of genetic and environmental relationships between milk yield and different measures of mastitis and hyperkeratosis in Holstein cows

“…Vallimont, Dechow, Sattler and Clay (2009) and Wolf et al (2010) reported genetic correlation between milk yield and NumMast case as 0.25 and 0.34, respectively. However, Irano et al (2014) reported a negative genetic correlation between cumulative 305-day milk yield and Mast in Holstein cows in tropical condition of Brazil. Genetic correlation between Firstmilk and measures of mastitis was relatively similar to those of Milk305 and measures of mastitis.…”

Associação genética entre ocorrência de mastite clínica e produção de leite em vacas Holandesas

“…2 ) foi maior do que a variância genética aditiva (860,53kg A estimativa de herdabilidade para a PR305 foi de 0,16 (Tabela 2), valor que se encontra abaixo dos relatados por outros estudos com a raça Holandesa no Brasil, variando entre 0,19 a 0,30 (ANDRADE et al, 2007;IRANO et al, 2014). A magnitude da estimativa de herdabilidade para a produção de leite obtida neste trabalho indica que, apesar da baixa magnitude, é possível obter ganhos via seleção.…”

“…Na literatura, estimativas de herdabilidade para a MC têm sido menores do que os valores relatados Tabela 1 -Número de animais (n), médias, desvios padrão (DP) e coeficientes de variação (CV%) para a produção de leite acumulada, até 305 dias (PR305), e ocorrência de mastite clínica (MC). IRANO et al (2014), no Brasil, que relataram estimativas entre 0,08 a 0,13. A estimativa de repetibilidade para a PR305 foi de 0,34±0,012 e para a MC foi de 0,21±0,02 (Tabela 2).…”

“…Esse resultado difere da maioria dos trabalhos da literatura, os quais relatam correlação desfavorável entre as características de produção de leite e a mastite clínica, variando de 0,26 a 0,40 (VALLIMONT et al, 2009;GOVIGNON-GION et al, 2012;PÉREZ-CABAL et al, 2013). Entretanto, corroboram os resultados apresentados por IRANO et al (2014), que também relataram correlação negativa entre produção de leite e mastite clínica.…”