Herd-level risk factors for cow and calf on-farm mortality in Estonian dairy herds

Abstract

Background: On-farm mortality (unassisted death and euthanasia) is the unwanted loss of animals, and it comes with negative economic consequences. On-farm mortality rates reflect a herd's animal welfare status. The objective of this historical longitudinal single cohort study was to identify the associations between herd characteristics, animal housing conditions and management routines and within-herd calf and cow mortality rates in participating Estonian dairy herds. All farmers enrolled in the voluntary production recording system with a herd size of 20 or greater cow-years in 2015-2017 were contacted by mail or telephone between October 2017 and March 2018. The survey included questions about management routines and housing conditions of calves up to 3 months of age and of cows. In total, 214 completed questionnaires were returned, corresponding to a 63.3% response rate. The withinherd mortality rate of calves (aged 21-90 days) and cows (cattle over 24 months of age) in years 2017-2018 were calculated and used as outcome variables. Negative binomial and linear regression models were applied for risk factor analysis in calf and cow datasets, respectively. Results: The median within-herd mortality rate for calves aged 21 to 90 days was 0.15 per 100 calf-months (quartiles 0.00; 0.36). The median within-herd mortality rate for cattle over 24 months of age was 4.57 per 100 cow-years (quartiles 2.44; 6.86). Factors significantly associated with increased mortality of calves were larger herd size, higher proportion of stillbirths and abortions in a herd, prophylactic administration of vitamins to all calves and housing preweaned calves in single pens only compared with housing in both single and group pens. Also, farmers who attended more frequent trainings had higher calf mortality rates. Calving in a group pen or in a tie-stall compared with calving in multiple systems was associated with higher calf mortality rates. Higher cow mortality rates were present in herds that had a higher proportion of stillbirths and on farms where employees handled cows. Housing cows in free-stall barns, grazing cows and more frequent hoof trimming were protective for cow on-farm mortality. Conclusions: This study identified the importance of housing conditions for on-farm cow and calf mortality rates. Our study results suggest that providing good care might ensure better health and welfare of dairy cows and calves.

Dairy Calf Welfare and Factors Associated with Diarrhea and Respiratory Disease among Chilean Dairy Farms

“…Herds with ≤ 71 calves [OR= 0.85; p wald <0.05; CI 95 = 0.02, 0.33] and herds with >129 to ≤ 215 calves [OR= 0.74; p wald < 0.05; CI 95 = 0.02, 0.43] (compared with > 215 calves) were associated with decreased odds of diarrhea. Herd size has been described in other studies as a risk factor for diarrhea [ 20 ] and mortality in calves [ 21 , 22 ]. Klein-Jöbstl et al [ 20 ] explained that the association between diarrhea and greater herd size could be due to the insufficient caretakers on large-scale farms.…”

Invited review: The welfare of dairy cattle housed in tiestalls compared to less-restrictive housing types: A systematic review

“…Effects of housing type were mixed or neutral in reference to mortality (Alvåsen et al, 2012;Popescu et al, 2014;Reimus et al, 2020), diarrhea (Mattiello et al 2009;Ostojić-Andrić et al 2011;Popescu et al 2014), and respiratory disorders (Mattiello et al, 2009;Ostojić-Andrić et al, 2011;Popescu et al, 2014). One of 4 studies addressing Johne's disease found a beneficial effect of tiestall housing on environmental prevalence of Mycobacterium avium ssp.…”

Management of calves in commercial dairy farms in Mecklenburg-Western Pomerania, Germany and its impact on calf mortality and prevalence of rotavirus and Cryptosporidium parvum infections in pre-weaned calves

“…There are no reports on the specific association between mortality of calves and immunization activity against respiratory diseases in calves. Vaccination for endemic bovine infections is described as a herd-level risk factor for the mortality of dairy cows ( McConnel, Lombard, Wagner, Kopral & Garry, 2015 ; Reimus, Alvåsen, Emanuelson, Viltrop & Mõtus, 2020 ; Reski-Weide, 2013 ). However, recent studies have described associations between management practices that focus on strengthening the immune system.…”