Genetic Analysis of Calving Difficulty and Stillbirth in Norwegian Red Cows

Abstract

The objectives of this study were to infer genetic parameters for stillbirth (SB) and calving difficulty (CD) and to evaluate phenotypic and genetic change for these traits in the Norwegian Red breed. Stillbirth is recorded as a binary trait and calving difficulty has 3 categories: 1) easy calving, 2) slight problems, and 3) difficult calving. The overall mean frequency of SB in Norwegian Red was 3% at first calving and 1.5% for second and later calvings; mean frequency of the category "difficult calving" was 2 to 3% for heifers and 1% for cows at second and later calvings. Mean stillbirth rate has remained unchanged from 1978 to 2004. The proportion of the category "difficult calving" has not changed over the years, but the "slight problems" category increased from 4 to 7% for heifers and from 2 to 3% for cows. A total of 528,475 first-calving records were analyzed with a Bayesian bivariate sire-maternal grandsire threshold liability model. Posterior means of direct and maternal heritabilities were 0.13 and 0.09 for CD, and 0.07 and 0.08 for SB, respectively. Strong genetic correlations were found between direct SB and direct CD (0.79), and between maternal SB and maternal CD (0.62), whereas all genetic correlations between direct and maternal effects within or between traits were close to zero. These positive correlations are favorable in the sense that selection for one of the traits would result in a favorable selection response for the second trait. No genetic correlations between direct and maternal effects imply that bulls should be evaluated both as sire of the calf (direct) and sire of the cow (maternal). No genetic change for SB was found, and a slight genetic improvement for CD was detected.

Genetic parameters for calving ease, gestation length and stillbirth in three endangered Austrian blond cattle breeds

“…The results of direct and maternal heritabilities for stillbirth and calving ease in this study were lower than the results from other studies ranging from 0.07 to 0.10 for direct stillbirth, 0.05 to 0.13 for direct calving ease, 0.06 to 0.13 for maternal stillbirth and 0.05 to 0.06 for maternal calving ease (LUO et al 1999, AMIN et al 2000, HANSEN et al 2004, HERINGSTAD et al 2007. Lower heritabilities for calving ease in cows (0.017 direct, 0.014 maternal) were however found by CUE et al (1990).…”

“…However, in this study we followed the linear model applied in the Austrian-German routine breeding value estimation. The genetic correlation between direct and maternal effects of stillbirth and calving ease were found to be negative like in other studies (LUO et al 1999, FÜRST and FÜRST-WALTL 2006, HERINGSTAD et al 2007, LÓPEZ DE MATURANA et al 2007. Genetic correlations between direct and maternal effect of gestation length (0.002-0.063) were lower than results found in earlier studies (PHILIPSSON 1976, NADARAJAH et al 1989, HANSEN et al 2004.…”

“…Another reason might be that a linear model was applied while other studies used threshold models. In general, linear model estimates of heritability are lower than those obtained from threshold models (HERINGSTAD et al 2007). However, in this study we followed the linear model applied in the Austrian-German routine breeding value estimation.…”

Genotype by environment interaction for livability of dairy calves from first parity cows

“…This justifies the use of sire maternal grandsire models (with bulls as genotype) for our study instead of animal models that are used for routine genetic evaluations for livability in several countries (van Pelt and de Jong, 2011). Moreover, variance components for livability in many cases are estimated using sire-maternal grandsire models (Hansen et al, 2004;Cole et al, 2007;Heringstad et al, 2007).…”

“…In general, stillbirth rates are considerably higher for calves of heifers than for calves of older cows (Harbers et al, 2000;Steinbock et al, 2003;Eriksson et al, 2004). Relatively high stillbirth rates have been reported for calves of Holstein heifers in the Netherlands and several other countries (Harbers et al, 2000;Meyer et al, 2000;Steinbock et al, 2003;Hansen et al, 2004) compared with Norwegian red heifers (Heringstad et al, 2007), American Jersey and Brown Swiss (Yao et al, 2014) and several Holstein crosses (Heins et al, 2006). According to Mee (2013), continuing high and sometimes even increasing stillbirth rates have resulted in a kind of normalisation and farm blindness to the issue.…”