Genetic parameters for production, health, fertility and longevity traits in dairy cows

Abstract

Milk production, fertility, longevity and health records, were extracted from databases of two milk recording organisations in the United Kingdom for the first three lactations of the Holstein-Friesian breed. These included data related to health events (mastitis and lameness), voluntarily recorded on a proportion of farms. The data were analysed to calculate disease incidence levels and to estimate genetic parameters for health traits and their relationships with production and other functional traits. The resulting dataset consisted of 124 793 lactations from 75 137 animals of 1586 sires, recorded in 2434 herds. Incidence of health events increased with parity. The overall incidence of mastitis (MAS) and lameness (LAM), defined as binary traits, were 17% and 16%, respectively. Heritability estimates for MAS and LAM were 0.04 and 0.02, respectively, obtained from repeatability linear sire models. Heritability estimates of mastitis and lameness as count traits were slightly higher, 0.05 and 0.03, respectively. Genetic correlations were obtained by bivariate analyses of all pair-wise combinations between milk 305-day yield (MY), protein 305-day yield (PY), fat 305-day yield (FY), lactation average log e transformed lactation average somatic cell count (SCS), calving interval (CI), days to first service (DFS), non-return at 56 days (NR56), number of inseminations (NINS), mastitis (MAS), number of mastitis episodes (NMAS), lameness (LAM), number of lameness episodes (NLAM) and lifespan score (LS). As expected, MAS was correlated most strongly with SCS (0.69), which supports the use of SCS as an indicator trait for mastitis. Genetic correlations between MAS and yield and fertility traits were of similar magnitude ranging from 0.27 to 0.33. Genetic correlations between MAS with LAM and LS were 0.38 and 20.59, respectively. Not all genetic correlations between LAM and other traits were significant because of fewer numbers of lameness records. LAM had significant genetic correlations with MY (0.38), PY (0.28), CI (0.35), NINS (0.38) and LS (20.53). The heritability estimates of mastitis and lameness were low; therefore, genetic gain through direct selection alone would be slow, yet still positive and cumulative. Direct selection against mastitis and lameness as additional traits should reduce incidence of both diseases, and simultaneously improve fertility and longevity. However, both health traits had antagonistic relationships with production traits, thus genetic gain in production would be slower.

Genetic correlations between production and disease traits during first lactation in Holstein cows

“…The overall frequency of mastitis in this study (6.1%) was lower than that in first-parity Holstein cows in the United States (9.5%; Appuhamy et al, 2009) and in the United Kingdom (14%; Pritchard et al, 2013). The overall frequency of CLD (2.0%) was much lower than that in Danish Holstein cows (6.3%; Laursen et al, 2009).…”

“…Van Dorp et al, 1998;Carlén et al, 2004;Pritchard et al, 2013). Such correlations have the potential to cause serious problems in countries such as Japan, where breeders have been selecting Holstein cows mainly on the basis of milk yield.…”

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

“…On the other hand, Fuerst-Waltl et al (2013) reported unfavourable correlations between milk yield and LPL in both extensive (−0.159) and intensive (−0.192) management systems in Austrian Fleckvieh (dual-purpose Simmental). Pritchard et al (2013) stated that lifespan score is negatively correlated with milk yield (−0.34) and fat yield (−0.18) in the Holstein-Friesian breed. Differences among estimates can be due to different study breed (dairy and dual-purpose), data size and fitted model.…”

Associations between strain, herd size, age at first calving, culling reason and lifetime performance characteristics in Holstein-Friesian cows

“…since 2014, the weight of these traits in the Polish selection IndexProduction and Functionality, is 60%) and the latter in improving the environmental conditions for dairy cattle (Oltenacu and Broom, 2010;Zavadilová and Zink, 2013;Polish Federation of Cattle Breeders and Dairy Farmers in Warsaw (PFCBDF), 2015). The increasingly common selection for the so-called functional longevity, understood as the true longevity corrected for milk yield, should result in more robust cows well adapted to diverse living conditions (Pritchard et al, 2013;Zavadilová and Zink, 2013). However, a direct way to extend the lifetime of high-yielding cows is to ensure them proper welfare.…”