Abstract #25

# 25
Association among health and fertility and survival of high-producing dairy cows in three geographic regions of Chile.
Pablo Pinedo*1,2, Pedro Melendez3, Sushil Paudyal4, Felipe Arias5, Ricardo Krauss5, Hernando Lopez6, Alejandro Luco5, Cristian Vegara5,6, 1Texas A&M AgriLife Research, Amarillo, TX, 2Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University System, College Station, TX, 3Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, MO, 4West Texas A&M University, Canyon, TX, 5ABS Chile Ltda, Santiago, Chile, 6ABS Global Inc, DeForest, WI.

The objective was to analyze the association between disease occurrence during early lactation and reproductive performance and survival of dairy cows in high-producing herds, under different management practices in 3 geographic regions of Chile. Data included 30,157 lactation records of cows calving between January, 2013 and June 2014, maintained under different production systems: Dry lot (DL; n = 3,881 cows in 6 herds); freestall (FS; n = 21,421 cows in 13 herds); grazing (G; n = 1,211 cows in 3 herds); and freestall/grazing (FG; n = 4,244 cows in 5 herds). Cows were also classified according to geographic location: central area (C, n = 6,375 cows); south-central area (SC, n = 17,073 cows); and south area (S, n = 7,309 cows). Logistic regression and ANOVA were used for the analyses (PROC GLIMMIX and PROC GLM, SAS), considering cow as the experimental unit. Covariables offered to the models included lactation number, cow, and herd milk yield. Average milk yield (305 ME) per cow was 11,793, 12,632, and 6,876 kg for C, CS, and S regions, respectively and 10,603, 12,270, 6,899, and 9,261 kg for DL, FS, G, and FG systems. The odds (95% CI) of pregnancy at 150 DIM (P150) and the odds of survival until 150 DIM (S150) for cows that had at least 1 disease event within 50 DIM were 0.82 (0.77- 0.88) times the odds of pregnancy and 0.21 (0.17–0.26) times the odds of survival for healthy cows. The odds (95% CI) of P150 for cows under grazing systems were 1.48 (1.24–1.77), 1.07 (0.9–1.28), and 1.29 (1.09–1.52) times the odds of P150 for cows under DL, FG, and F systems, respectively. The odds (95% CI) of S150 for cows under grazing were 5.15 (3.0–8.8), 3.18 (1.88–5.40), and 2.0 (1.19–3.33) times the odds of S150 for cows under DL, FG, and F systems. The odds (95% CI) of P150 and S150 for cows located in the S area were 1.03 (0.95–1.11), and 1.11 (1.03–1.19) times the odds of P150 for cows in C, and SC areas and 1.42 (1.23–1.66), and 1.37 (1.20–1.60) times the odds of S150 for cows in C, and SC areas. Data suggested that cow’s health status, geographic location, and production system had a significant association with reproductive performance and survival in this population of Chilean high-producing cows.

Key Words: dairy, health, fertility