Abstract #M70

Section: Animal Health
Session: Animal Health I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall B
# M70
Risk factors for retained placenta and metritis in grazing dairy herds.
R. R. Daros*1, M. J. Hötzel2, S. J. LeBlanc3, J. A. Bran2, A. J. Thompson1, M. A. G. von Keyserlingk1, 1Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada, 2Laboratório de Etologia Aplicada e Bem-Estar Animal, Departamento de Zootecnia e Desenvolvimento Rural, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil, 3Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.

Retained placenta (RP) and metritis are known to decrease the reproductive performance of dairy cows. There is evidence that the prevalence of RP and metritis is high in pasture-based systems. Thus, the aims of this study were to determine the risk factors for RP and metritis for cows managed on pasture. We visited 53 rotational grazing dairy farms in southern Brazil between February and September 2015. Cows between 3 and 21 d in milk were assessed once for metritis based on vaginal discharge (n = 654; metritic = watery foul discharge 3 to 14 DIM or >50% pus and foul smell 14 to 21 DIM) and for RP (n = 661; > 24h to pass fetal membranes; reported by the farmer). Cow-level measurements included body condition score (BCS), parity, breed, dystocia, and RP. Farm-level variables included use of maternity pen, time before cow-calf separation (>or <12h), and cleanliness of the holding area. Univariable models were used to select variables associated with RP and metritis (P < 0.2). Multivariable multilevel logistic regression models (farm as random effect) were reduced using manual backward elimination. The prevalence of RP and metritis were 13.9% and 11.2%, respectively. The odds of RP were higher if cows had dystocia (OR = 3; 95% CI: 1.6–5.4; P < 0.01) or were in parity ≥3 (OR = 2.3; 95% CI: 1.2–4.6; P = 0.01) and lower if cows were Jerseys (OR = 0.2; 95% CI: 0.1–0.8; P = 0.02), had access to a maternity pen (OR = 0.5; 95% CI: 0.3–1.0; P = 0.05) or were allowed > 12h before cow-calf separation (OR = 0.4; 95% CI: 0.2–0.8; P = 0.01). The odds of metritis were higher if cows had RP (OR = 16; 95% CI: 8.6–30.3; P < 0.01), if farms had a dirty holding area (OR = 2.2; 95% CI: 1.1–4.3; P = 0.03), and lower if cows had BSC between 3 and 3.5 (OR = 0.45; 95% CI: 0.2–0.7; P < 0.01). Management factors related to calving were associated with RP and environmental cleanliness was associated with metritis on pasture-based farms. Further research on the causal relationship between these management practices and their effects on disease could help in the design of improved disease prevention protocols.

Key Words: health, transition period, reproductive disease