Quantitative analysis of calf mortality in Great Britain

Abstract

National bodies in Great Britain (GB) have expressed concern over young stock health and welfare and identified calf survival as a priority; however, no national data have been available to quantify mortality rates. The aim of this study was to quantify the temporal incidence rate, distributional features, and factors affecting variation in mortality rates in calves in GB since 2011. The purpose was to provide information to national stakeholder groups to inform resource allocation both for knowledge exchange and future research. Cattle birth and death registrations from the national British Cattle Movement Service were analyzed to determine rates of both slaughter and on-farm mortality. The number of births and deaths registered between 2011 and 2018 within GB were 21.2 and 21.6 million, respectively. Of the 3.3 million on-farm deaths, 1.8 million occurred before 24 mo of age (54%) and 818,845 (25%) happened within the first 3 mo of age. The on-farm mortality rate was 3.87% by 3 mo of age, remained relatively stable over time, and was higher for male calves (4.32%) than female calves (3.45%). Dairy calves experience higher on farm mortality rates than nondairy (beef) calves in the first 3 mo of life, with 6.00 and 2.86% mortality rates, respectively. The 0-to 3-mo death rate at slaughterhouse for male dairy calves has increased from 17.40% in 2011 to 26.16% in 2018, and has remained low (<0.5%) for female dairy calves and beef calves of both sexes. Multivariate adaptive regression spline models were able to explain a large degree of the variation in mortality rates (coefficient of determination = 96%). Mean monthly environmental temperature and month of birth appeared to play an important role in neonatal on-farm mortality rates, with increased temperatures significantly reducing mortality rates. Taking the optimal month of birth and environmental temperature as indicators of the best possible environmental conditions, maintaining these conditions throughout the year would be expected to result in a reduction in annual 0-to 3-mo mortality of 37,571 deaths per year, with an estimated economic saving of around £11.6 million (USD $15.3 million) per annum. National cattle registers have great potential for monitoring trends in calf mortality and can provide valuable insights to the cattle industry. Environmental conditions play a significant role in calf mortality rates and further research is needed to explore how to optimize conditions to reduce calf mortality rates in GB.

Pre-Weaned Calf Rearing on Northern Irish Dairy Farms: Part 1. A Description of Calf Management and Housing Design

“…The herd sizes observed in this study were typically smaller than those reported in the US and other parts of the UK [11,15] but larger than those surveyed in Europe [17,28]. Several studies have associated larger herd sizes with increased calf mortality [28,29]; however, Murray et al [30] found conflicting evidence.…”

“…As the dairy heifer accumulates cost throughout the rearing period until first calving, this represents a significant economic loss to farmers. More recently, Hyde et al [11] found mortality in dairy calves in the UK to be 6% in the first 3 months of life and that changes in mortality were minimal when compared with the 1990s [12]. Improvements to calf health and performance with developments in nutrition and healthcare may be limited by a poor environment, and similarly poor nutrition and healthcare may negate the effects of a good environment.…”

“…Although environmental factors such as ambient temperature have been shown to play a fundamental role in calf mortality [11], many studies only provide limited environmental descriptors when reviewing calf rearing systems. Additionally, systems vary across different regions.…”

Refining livestock mortality indicators: a systematic review

“…Again, these observations are supported by many of the other studies that either did not report exact numbers over time or that presented data over a shorter period of time. Findings reported by authors included those where the largest proportion of deaths in cattle occurred intrapartum ( Mock et al ., 2020 ), in the first 48 hours ( Busato et al ., 1997 ; Raboisson et al ., 2013 ), the first week ( Gardner et al ., 1990 ), first one- ( Menzies et al ., 1996 ), two- ( Santman-Berends et al ., 2019 ), or three- ( Hyde et al ., 2020 ) months of life.…”

An observational study of growth rate and body weight variance partition for United Kingdom dairy calves from birth to 20 weeks of age

“…This could give an overly optimistic representation of calf production on the selected farms by being based on the best calves. Reasons for decreasing numbers of calves weighed with increasing age are unknown; however, calf mortality as a contributory factor (Brickell and Wathes, 2011;Hyde et al, 2020) should be considered before developing calf management strategies based on weight measurements alone.…”