Yield and Fertility Relationships in Dairy Cattle

Abstract

Measures of yield and fertility were obtained from breeding receipts of artificial insemination and records of test-day yield. Estimates of heritability were by Henderson Method 3, maximum likelihood, and restricted maximum likelihood. Heritabilities for measures of yield varied, but most were within the range of earlier estimates. Measures of fertility had heritabilities from 0 to .03. Alternative upper bounds were placed on days open, number of services, and service period, and always the measure with the lesser bound had higher heritability for first parity. Measures of yield for early stages of lactation had slight positive phenotypic correlations with fertility whereas those for measures of cumulative yield later in lactation increased in relation to effect of gestation. Genetic correlations of first-parity yield and most measures of fertility were positive and less influenced by stage of lactation than phenotypic correlations. Antagonism moderated for second parity. Most genetic correlations were not significantly different from zero for third parity. Considerable genetic antagonism of yield and fertility may be of limited consequence because estimates of genetic variance of fertility were near zero.

Genetic parameters of reproductive traits in Tunisian Holsteins

“…Mean heritability estimates were in the same range as those found in several studies from various populations (Hansen et al, 1983;Campos et al, 1994;Conzàlez-Recio and Alenda, 2005;Liu et al, 2008;Sewalem et al, 2010;Ghiasi et al, 2011). Ghiasi et al (2011) reported 0.074 ± 0.004, 0.076 ± 0.004, 0.044 ± 0.004, 0.058 ± 0.005, and 0.046 ± 0.004 for CI, DO, FIC, DFI, and NI, respectively, using the same model.…”

Estimation of Genetic Parameters for Production and Reproduction in Finnish Ayrshire Cattle

“…Estimates averaged over data sets and different analyses were .10 for DO and .19 for DFI when individual estimates were averaged by weighting by the number of sires in data sets. In other studies where both DFI and DO have been included, heritability of DFI is commonly tbund to be larger than that of DO, with estimates averaging about .04 and .02 for DFI and DO, respectively (2,10,17,18)…”

“…High milk production has long been known to be associated with poor fertility, either because of genetic or environmental reasons (2,6,7,8,10,15,19,23,26). The same studies, however, have shown that heritability of breeding efficiency is generally below .05.…”

Estimates of Genetic and Environmental (Co)Variances for First Lactation Milk Yield, Survival, and Calving Interval

“…Although some studies from field data show an antagonistic relationship between milk yield and fertility in dairy cows (4,5,9,21,25,28) and a complementary relationship among measures of fertility from breeding heifers and measures of their first lactation production (8,17,18), "more knowledge is needed before the genetic relationships are known well enough to determine what, if any, changes are needed in selection practice" (7). Calving interval (CI), influenced by all fertility traits, can be used to estimate the genetic covariance between production and reproduction.…”