Effect of dystocia on subsequent reproductive performance and functional longevity in Holstein cows

Abstract

The objective of this study was to evaluate the effect of dystocia on the reproductive performance and functional longevity in Iranian Holsteins. Data consisted of 1 467 064 lactation records of 581 421 Holstein cows from 3083 herds which were collected by the Animal Breeding Center of Iran from April 1987 to February 2014. Reproduction traits in this study included interval from first to second calving, days open and days from first calving to first service. The generalized linear model was used for the statistical analysis of reproductive traits. Survival analysis was performed using the Weibull proportional hazards models to analyse the impact of dystocia on functional longevity. The incidence of dystocia had an adverse effect on the reproductive performance of dairy cows. Therefore, reproductive traits deteriorated along with increase in dystocia score (p < 0.05). The culling risk was increased along with increase in the score of dystocia (p < 0.0001). The greatest culling risk was observed in primiparous cows, small herds and low-yielding cows (p < 0.0001). Also, the lowest culling risk was found for cows calving at the youngest age (<27 months), and cows with age at first calving >33 months had the greatest risk (p < 0.0001). The results of current study indicated that dystocia had important negative effects on the reproductive performance and functional longevity in dairy cows, and it should be avoided as much as possible to provide a good perspective in the scope of economic and animal welfare issues in dairy herds.

Analysis of Longevity Traits in Holstein Cattle: A Review

“…Calving ease significantly reduces the service life and reproductive performance of dairy cows ( Maturana et al, 2007 ). Although the criteria for calving difficulty vary from country to country, the result is that unassisted cows live longer than cows that require assistance during delivery ( Hossein-Zadeh, 2016 ). Dystocia reduces herd profitability, impairs the reproductive performance of cows in the next breeding cycle, and reduces milk production ( Hossein-Zadeh, 2016 ).…”

“…Although the criteria for calving difficulty vary from country to country, the result is that unassisted cows live longer than cows that require assistance during delivery ( Hossein-Zadeh, 2016 ). Dystocia reduces herd profitability, impairs the reproductive performance of cows in the next breeding cycle, and reduces milk production ( Hossein-Zadeh, 2016 ). Rajala-Schultz and Gröhn (1999) found that the risk of culling for dystocic cows was significantly increased during the first 30 days after calving and at the end of the lactation.…”

Risk factor analysis for beef calves requiring assisted vaginal delivery in Great Britain

“…9 One study into the fate of dairy cows after difficult calvings described that 10% of cows that died had "serious difficulties" at calving, 6 whereas another described culling rates in Holstein cows as being increased with an increase in calving assistance score. 56 This study focused on live calves that were delivered per vaginum. It was striking that nearly one in five calves (17.8%) required assistance at calving, which is likely an underestimate of the true rate of dystocia in GB spring born suckler calves, given that Caesarean T A B L E 3 GLMM multivariable mixed logistic model 2 outputs, with fixed effect variables, number of calves (n), number of calves requiring assistance at calving (nAssist), p-values, and odds ratios (including 95% confidence intervals in brackets) sections and calves that died are not included in this study.…”

“…There are also additional welfare considerations relating to pain and discomfort for both the cow and calf. Increased time open after calving (an increase from slight to serious difficulty in calving increased days open from 9.2 to 21.5 days 6 ), decreased pregnancy rates 9,56 and decreased milk production 9,57 are all reported in dairy cows, while poor conception rates and reduced oestrus expression in beef cows post dystocia have also been reported 3 . Dystocia also results in increased loss of bodyweight and condition in affected Holstein‐Friesian cows 9 .…”

“…Dystocia also results in increased loss of bodyweight and condition in affected Holstein‐Friesian cows 9 . One study into the fate of dairy cows after difficult calvings described that 10% of cows that died had “serious difficulties” at calving, 6 whereas another described culling rates in Holstein cows as being increased with an increase in calving assistance score 56 …”