Trucking stress at breeding does not lower conception rate of beef heifers

• Published in: Theriogenology 1996-02, Vol.45 (3), p.623-632
• Main Authors: Yavas, Y., de Avila, D.M., Reeves, J.J.
• Format: Article
• Language: English
• Subjects: BOVIN DE BOUCHERIE; conception; ESTEROIDES; ESTRES; GANADO DE CARNE; GENISSE; heifers; NOVILLA; PERFORMANCE DE REPRODUCTION; REPRODUCTIVIDAD; SERUM SANGUIN; STEROIDE; STRESS; SUERO SANGUINEO; transport; TRANSPORT D'ANIMAUX; TRANSPORTE DE ANIMALES; VACA; VACHE
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/0093-691X(95)00408-Z

The goal of this study was to determine whether 1 h of trucking stress before or after artificial insemination (AI) altered the conception rate of beef heifers. Estrus was synchronized in heifers with prostaglandin F 2α.The 3 treatment groups consisted of 1) AI (control heifers, n = 93); 2) Truck + AI (trucked for 1 h immediately before AI, n = 81); and 3) AI + Truck (trucked for 1 h immediately after AI, n = 82). All heifers were artificially inseminated by a single technician with semen from a single ejaculate. Blood samples were collected for cortisol measurement 1 h before AI, immediately before and after AI, and 1 h after AI in the AI (n = 6), Truck + AI (n = 9), and AI + Truck (n = 8) groups Pregnancy in heifers was confirmed either at slaughter or by palpation per rectum. Trucking before AI elevated (P < 0.01) serum cortisol concentrations. Artificial insemination alone increased (P < 0.01) serum cortisol concentrations in AI heifers. The increase in serum cortisol concentrations caused by trucking after AI was not significant (P > 0.05). Areas under the cortisol curves in Truck + AI heifers are greater (P < 0.05) than in AI heifers. The conception rates of AI heifers (50.5%), Truck + AI heifers (51.9%) and AI + Truck heifers (58.5%) are not different (P > 0.05) This study demonstrates that 1 h of trucking stress either before or after AI did not lower the conception rate of heifers