Calf birth weight, gestation length, calving ease, and neonatal calf mortality in Holstein, Jersey, and crossbred cows in a pasture system

Abstract

Holstein (HH), Jersey (JJ), and crosses of these breeds were mated to HH or JJ bulls to form purebreds, reciprocal crosses, backcrosses, and other crosses in a rotational mating system. The herd was located at the Center for Environmental Farming Systems in Goldsboro, North Carolina. Data for calf birth weight (CBW), calving ease (0 for unassisted, n=1,135, and 1 for assisted, n=96), and neonatal calf mortality (0 for alive, n=1,150, and 1 for abortions recorded after mid-gestation, stillborn, and dead within 48 h, n=81) of calves (n=1,231) were recorded over 9 calving seasons from 2003 through 2011. Gestation length (GL) was calculated as the number of days from last insemination to calving. Linear mixed models for CBW and GL included fixed effects of sex, parity (first vs. later parities), twin status, and 6 genetic groups: HH, JJ, reciprocal F(1) crosses (HJ, JH), crosses >50% Holsteins (HX) and crosses >50% Jerseys (JX), where sire breed is listed first. The CBW model also included GL as a covariate. Logistic regression for calving ease and neonatal calf mortality included fixed effects of sex, parity, and genetic group. Genetic groups were replaced by linear regression using percentage of HH genes as coefficients on the above models and included as covariates to determine various genetic effects. Year and dam were included as random effects in all models. Female calves (27.57±0.54 kg), twins (26.39±1.0 kg), and calves born to first-parity cows (27.67±0.56 kg) had lower CBW than respective male calves (29.53±0.53 kg), single births (30.71±0.19 kg), or calves born to multiparous cows (29.43±0.52 kg). Differences in genetic groups were observed for CBW and GL. Increased HH percentage in the calf increased CBW (+9.3±0.57 kg for HH vs. JJ calves), and increased HH percentage in the dams increased CBW (+1.71±0.53 kg for calves from HH dams vs. JJ dams); JH calves weighed 1.33 kg more than reciprocal HJ calves. Shorter GL was observed for twin births (272.6±1.1 d), female calves (273.9±0.6 d), and for first-parity dams (273.8±0.6 d). Direct genetic effects of HH alleles shortened GL (-3.5±0.7 d), whereas maternal HH alleles increased GL (2.7±0.6 d). Female calves had lower odds ratio (0.32, confidence interval=0.10-0.99) for neonatal calf mortality in second and later parities than did male calves. Maternal heterosis in crossbred primiparous dams was associated with reduced calf mortality.

Prevalence and risk factors for stillbirths in Holstein cows in a hot environment

“…Also, gestation length is typically reduced by 4 to 5 d with hyperthermia during the dry period, which may account for smaller calf size with lower vitality (Tao & Dahl, 2013). Gestation length significantly explained variation (p<0.01) for birth weight, with an increase of 0.37 ± 0.004 kg of birth weight per day of gestation, which closely agrees with observations of Dhakal et al (2013). As birth body weight increased or decreased, the risk of stillbirths increased in a curvilinear manner (Fig.…”

“…These results are consistent with several studies where it has been reported that male calves have higher odds of stillbirths than female calves (Maltecca et al, 2006;Dhakal et al, 2013). In contrast to these results, Meyer et al (2001) observed that female calves had 12% higher odds for stillbirth than male calves if they were from multiparous cows, but 7% lower odds if they were born from primiparous cows.…”

Influence of selected feed supplements on the growth and health of calves depending on the sex, season of birth, and number of the dam’s lactations

“…Males were heavier at birth and at 28 days of life than females. Kertz et al (1997) reported in their study different weight gains in young bulls and heifers; the gains in young bulls were higher by 8.5% compared to heifers; similar results were found out also by Dhakal et al (2013).…”

Characterisation of haematological profiles and whole blood relative gene expression levels in Holstein-Friesian and Jersey bull calves undergoing gradual weaning

“…Two of the predominant dairy breeds used internationally, including in Ireland, are H-F and J (DAFM, 2013;Dhakal et al, 2013). They also vary greatly in many body characteristics including birth weight (Dhakal et al, 2013) and subsequent growth rate .…”

“…They also vary greatly in many body characteristics including birth weight (Dhakal et al, 2013) and subsequent growth rate . Therefore, these breeds were chosen to characterise the immune response to gradual weaning in dairy calves.…”