Heritability estimates derived from threshold analyses for reproduction and stayability traits in a beef cattle herd

Abstract

The object of this study was to estimate heritabilities and sire breeding values for stayability and reproductive traits in a composite multibreed beef cattle herd using a threshold model. A GFCAT set of programmes was used to analyse reproductive data. Heritabilities and product-moment correlations between predicted breeding values for stayability at 36, 48, 60, 72 and 84 months of age, calving success and longevity were estimated. The estimated heritabilities on the underlying scale for these traits were 0.06, 0.10, 0.06, 0.03, 0.11, 0.03 and 0.08 respectively. Product-moment correlations between breeding values for stayability traits were low. The highest correlation of 0.22 was obtained between the ages of 36 and 48 months. Heritability estimates and correlations between traits appear to be of such a low magnitude that selection for these characteristics would result in limited genetic improvement, and also indicate that sires had little influence on the stayability, longevity or calving success of their daughters.

Non-linear model analysis of categorical traits related to female reproduction efficiency in beef cattle

“…A lower sire variance of 0.072 for STAY was estimated with the heritability estimated on the underlying scale as 0.27. This estimate is higher than the heritablities estimated for STAY by Snelling et al (1995) 0.09 and 0.20; Doyle et al (2000) of 0.15; Van der Westhuizen et al (2001) which ranged between 0.03 and 0.08 and Silva et al (2003) with heritabilities ranging 0.11 to 0.17 for Nelore cattle. However, it corresponds to heritability estimates using threshold models by Martinez et al (2002) on Hereford cattle ranging from 0.13 to 0.49.…”

Crossbreeding to increase beef production: Additive and non-additive effects on fitness traits

“…Therefore, the heritability of fitness traits tends to be low, and variation in them among individuals is largely owing to environmental factors (MacNeil et al, 1984;Van der Westhuizen et al, 2001;Weaber, 2009). Still, heterosis effects are expected to improve the productivity of cows (Weaber, 2009), perhaps by reducing the frequency of loci that are homozygous for unfavourable recessive alleles (Charlesworth & Willis, 2009).…”

“…Although low in heritability, further cumulative and permanent changes in fitness traits may arise through selection based on estimated breeding values EBV ( Van der Westhuizen et al, 2001). Optimal crossbreeding systems are predicated on the choice of breeds that contribute to them (Kress & MacNeil, 1999).…”

Genetic Prediction Models and Heritability Estimates for Functional Longevity in Dairy Cattle

“…Veerkamp et al, 2001;Van Pelt & Veerkamp, 2014) or TM models (e.g. Boettcher et al, 1999;Van der Westhuizen et al, 2001;Holtsmark et al, 2009). The survival period could be limited to within lactation (e.g.…”

“…In South Africa, longevity in Holstein cattle has been expressed as the number of lactations initiated among dairy cattle (Setati et al, 2004). Maiwashe et al (2009) and Van der Westhuizen et al (2001) regarded longevity in South African beef cattle as stayability, defined as the probability that a cow would reach a certain age, given the opportunity to reach that age. However, Du Toit (2011) expressed survival in South African Jersey cattle as a binary trait, in which survival to the next lactation was determined based on the presence or absence of a subsequent lactation.…”