Influence of BVDV exposure on AI conception and breeding season pregnancy success in beef herds

• Published in: Journal of animal science 2019-07, Vol.97, p.123-123
• Main Authors: Epperson, Kaitlin M, J Rich, Jerica J, Zoca, Saulo Menegatti, Perkins, Stephanie D, Northrop, Emmalee J, Daly, Russell F, Walker, Julie A, Rhoades, Jim R, Perry, George A
• Format: Article
• Language: English
• Subjects: Animal breeding; Animal husbandry; Animal reproduction; Animals; Antigens; Beef; Blood; Breeding; Breeding of animals; Breeding seasons; Breeding success; Cattle industry; Diarrhea; Economic impact; Embryos; Exposure; Females; Pregnancy; Reproduction; Statistical analysis; Statistical methods; Ultrasound; Viruses
• ISSN: 0021-8812; 1525-3163

Bovine Viral Diarrhea Virus (BVDV) causes reproductive and economic losses in cattle. The objective of this study was to evaluate the influence of BVDV exposure on reproductive success (AI and breeding season conceptions). Well vaccinated cows (n = 367) and heifers (n = 540) from 9 different herds were synchronized using the 7-d CO Synch + CIDR protocol and were fixed-time AI (FTAI). On d 28 following insemination, blood samples were collected, and pregnancy status was determined by transrectal ultrasonography and the IDEXX Rapid Visual Pregnancy Test. Non-pregnant animals were resynchronized and FTAI a second time. In six herds bulls were comingled with females beginning 10-15 d after the second AI. Final pregnancy status was determined 33-80 d following the first pregnancy diagnosis. Blood samples were tested for the presence of BVDV antigen using the IDEXX BVDV PI X2 Kit. Positive samples were indicative of animals with an active infection. Herds were determined as having BVDV exposure by the presence of at least one animal having a positive test for active antigen (n = 4 exposed herds, n = 5 non-exposed herds). Statistical analyses were performed using the GLIMMIX procedure of SAS. Herds that had BVDV exposure during the breeding season had significantly decreased (P < 0.01) first service AI conception rates compared to herds that had no exposure (34 ± 2.3% vs. 54 ± 2.3%). Additionally, breeding season pregnancy rates were decreased (P < 0.01) in herds that had BVDV exposure compared to non-exposed herds (69 ± 3.4% vs. 80 ± 3.6%). There was no significant effect of BVDV exposure on embryonic loss (P = 0.42) or percentage of animals which lost a pregnancy and rebred by the end of the breeding season (P = 0.63). In conclusion, BVDV exposure in well vaccinated herds still had a negative effect on both first service AI conception rate and overall breeding season pregnancy success.