Invited review: A systematic literature review and meta-analysis of mortality and culling in dairy cattle

Abstract

Dairy industries and individual farmers are concerned about mortality and culling of dairy animals. This is because the timing and fates of animals that exit dairy farms have important animal welfare and economic consequences that reflect the conditions under which they are farmed and the efficiency of their production systems. Reports from a few countries have indicated increased incidence of mortality, and occasionally culling, of dairy animals in recent decades, and these changes have been associated with intensification of production systems. Dairy industries and farmers need benchmarks for culling and mortality against which they can compare themselves, as well as improved understanding of the extent of any change and of any associated factors. We reasoned that a systematic literature review and meta-analysis of scientific articles published between 1989 and 2014 would allow us to determine whether these reports were universal, to quantify any change over time, and to investigate whether production systems or study factors were associated with culling and mortality. From 3,275 articles retrieved from databases and manual searching of cited articles, 118 articles were appraised independently by 2 assessors, and 51 articles representing 54 studies were determined to be eligible for review and meta-analysis. We estimated that both the annual incidence risk (IR) and incidence density of mortality of cows had increased significantly from 0.02 per cow and 2.32 per 100 cow-years, to 0.04 per cow and 3.75 per 100 cow-years, an increase per decade of 0.02 per cow and 1.42 per 100 cow-years, respectively. We also estimated that the annual IR of culling attributed to low production had declined significantly from 0.07 to 0.05 and that the IR of perinatal, but not neonatal, mortality had increased significantly from 0.04 to 0.06 per decade. We found no evidence of change in overall annual IR of culling of cows over time or any association between study design factors and the IR or incidence density of culling or mortality. These findings provide benchmarks for describing culling and mortality, and should encourage farmers and researchers in countries with modern dairy industries to discover and implement management strategies to reduce the animal welfare and economic costs associated with these changes.

Reduction in morbidity and mortality of dairy calves from an injectable trace mineral supplement

“…A prospective observational study on New Zealand (NZ) pasture-based dairy farms,4 reported a perinatal mortality risk of 5.7 per cent, similar to the 4.3 per cent recorded by Mee and others3 on Irish pasture-based dairy farms and consistent with levels of perinatal mortality reported by Compton and others1 from housed systems.…”

Clarifying dairy calf mortality phenotypes through postmortem analysis

“…An accurate description of dairy mortality is needed to reduce economic and animal welfare costs, as well as the reputational risk posed to the industry by preventable deaths (Compton et al, 2017). Necropsies are warranted when morbidity or mortality exceeds historic or comfortable levels, when there is a perceived treatment failure, for acquiring information necessary for confirmation of a tentative clinical diagnosis, when presenting signs are dramatic or unusual, or to characterize a disease process when no antemortem observation has been made (Mason and Madden, 2007;Thomsen et al, 2012).…”

“…Efforts to document dairy mortality have primarily focused on adult cow death (Thomsen and Houe, 2006;McConnel et al, 2015;Shahid et al, 2015;Compton et al, 2017). Research into heifer health problems tends to distill disease into preweaning or postweaning gas-trointestinal (GI) or respiratory disease (Gorden and Plummer, 2010;Stanton et al, 2012;Klein-Jöbstl et al, 2014;USDA, 2017).…”

“…Standardizing health event nomenclature based on postmortem findings in simple and consistent terms can provide useful information not only for the analysis of deaths but for other health-related questions as well (McConnel and Garry, 2017). Without standardized methods of classification, what little information is available is often wasted (McConnel et al, 2010;Compton et al, 2017).…”

Продуктивное Долголетие Коров Голштинской Породы Европейской Селекции В Условиях Промышленной Технологии

“…Однако коммерциализация молочного скота сопровождается и рядом негативных последствий: ухудшением качества молока, снижением иммунного статуса животных, плодовитости, сокращением периода хозяйственного использования коров в стадах (Goncharenko, 2016;Denholm, et al, 2017;Charfeddine & Pérez-Cabal, 2016). Авторы (Donnik et al, 2010;Weber et al, 2013;Compton et al, 2016;De Vries, 2017) сообщают о том, что короткая длительность хозяйственного использования у высокопродуктивных коров связанна с более высокими обменными процессами в их организме, поскольку в сложных условиях они более склоны к заболеваниям и нарушениям репродуктивной функции, чем животные со средними показателями продуктивности, не исключая при этом влияния генетических факторов (Abdalla et al, 2016;VandeHaar et al, 2016;Tsuruta et al, 2017;Banos et al, 2017). Сокращение сроков продуктивного использования животных в условиях промышленной технологии должно послужить стимулом для глубокого изучения и поиска путей решения этой проблемы.…”