Pregnancy loss in beef cattle: A meta-analysis

Reese, S. T. and Franco, G. A. and Poole, R. K. and Hood, R. and Fernadez Montero, L. and Oliveira Filho, R. V. and Cooke, R. F. and Pohler, K. G.

Anim Reprod Sci (2020) 212: 106251

DOI: 10.1016/j.anireprosci.2019.106251

Abstract

Pregnancy loss in beef cattle causes both management and economic challenges to a producer. A meta-analysis was conducted to quantify reproductive failures that occur during fertilization, early embryonic development, and late embryonic/early fetal development periods of gestation in beef cattle. The meta-analysis included more than 56,000 diagnostic records in 159 studies from 48 papers with 12 studies included in fertilization and pre- blastocyst loss analysis (FERT; days 1-7 of gestation), 107 in early embryo (EEM; days 7-32), and 40 in late embryo/early fetal period (LEF; days 32-100) analysis. Although fertilization rates are reportedly high in beef cattle, significant developmental failure occurs within the first 7 days of gestation. Approximately 28.4 % of embryos will not develop past day 7 of gestation with most embryonic losses occurring before day 4. By the conclusion of the first month of gestation, 47.9 % of cows submitted to a single insemination at day 0 will not be pregnant. Overall, LEF between days 32-60 and 100 was 5.8 %. Bos indicus animals had greater (P =  0.001) EEM compared to Bos taurus, but there was no difference (P =  0.39) for the LEF period between subspecies. Primiparous cows had greater EEM (P =  0.002) compared to nulliparous heifers and multiparous cows; and nulliparous heifers had a greater LEF compared to primiparous and multiparous cows (P =  0.048). Collectively, these cumulative findings provide a baseline assessment of pregnancy loss specific to beef cattle.

Citation

Reese, S. T., Franco, G. A., Poole, R. K., Hood, R., Fernadez Montero, L., Oliveira Filho, R. V., Cooke, R. F., & Pohler, K. G. (2020). Pregnancy loss in beef cattle: A meta-analysis. Anim Reprod Sci, 212, 106251. https://doi.org/10.1016/j.anireprosci.2019.106251 Animals, Female, Pregnancy, Risk Factors, Cattle, Beef cattle, *Cattle Diseases, Abortion, Veterinary/*etiology, Embryo mortality

Keywords

• Animals
• Female
• Pregnancy
• Risk Factors
• Cattle
• Beef cattle
• *Cattle Diseases
• Abortion
• Veterinary/*etiology
• Embryo mortality