80 Effects of Prenatal Stress on Beef Steer Development

• Published in: Journal of animal science Vol. 100; no. Supplement_3; pp. 37 - 38
• Main Authors: Elder, Kasey A, Fernandez, Rachel, Dunn, Rachel, Green, Kiana, Odhiambo, John F, Coble, Derrick
• Format: Journal Article
• Language: English
• Published: 22.09.2022
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/skac247.073

Abstract Cost-effective growth in beef steers is necessary for limited-resource grass-fed cow-calf operations. Therefore, production goals should emphasize using inexpensive feed sources to maximize growth post-weaning. Maternal stress during gestation can negatively affect this progression. Effects of prenatal stressors such as hurricanes have been overlooked. In this project two groups of steers born from the same lineage in different years were compared: Group 1, dams experienced effects of a category 5 hurricane in their late gestation. Group 2, dams experienced no adverse environmental effects. Body weights were collected at 13 (Period 1), 14 (Period 2), and 20 months of age (Period 3). Blood cortisol concentrations were evaluated in Summer (when Group 1 average age was 31 months, while Group 2 averaged 18 months of age) and Fall (when Group 1 average age was 34 months, while Group 2 average age was 21 months) periods. Data were evaluated by mixed procedures of SAS, and significance was declared at P< 0.05. The results showed a significant group effect on the age-matched body weights (572.96±22.04 vs 735.12±22.04, lbs. for groups 1 and 2 respectively). Period effect was also significant (P< 0.001). However, there was no group by period effect. Group 1 steers were lighter in body weight than Group 2 in periods one and two but were not different thereafter. There was a significant group effect on cortisol concentrations (965.24±38.21 vs 1,282.2±40.53, pg/mL for groups 1 and 2 respectively). Our results showed that the hurricane had detrimental effects on steers, which may impede the growth progression of animals as seen in this study. The observations made in this study indicate the need to investigate further the effects of prenatal stress by natural disasters on beef steer development.