Use of prostaglandin F2 alpha in the treatment of unobserved estrus in lactating dairy cattle
Elmarimi, A.A.; Gibson, C.D.; Morrow, D.; Marteniuk, J.; Gerloff, B.; Melancon, J.
American Journal of Veterinary Research 44(6): 1081-1084
1983
ISSN/ISBN: 0002-9645 PMID: 6575626 Document Number: 215108
73 Holstein-Friesian and 9 Jersey cows in 9 commercial herds were allotted to a treatment or a control group. Silent oestrus was defined as the absence of detected oestrus, by the time of either desired 1st postpartum insemination or pregnancy examination following a 1st insemination. 96% of 46 females in the treatment group and 92% of 36 females in the control group had more than or equal to 1 corpus luteum on the day of treatment. Cows in the treatment group were injected with 5 ml (25 mg) PGF2 alpha ; 50% came into oestrus within 80 h and were inseminated, while the rest were inseminated 80 h after treatment. Cows showing signs of oestrus after 80 h were reinseminated. Controls were inseminated at 1st observed oestrus. The overall pregnancy rate was 57% in treated and 47% in control cows, the difference being non-significant. The intervals from treatment to 1st observed oestrus, 1st service and conception were significantly shorter in the treated group (12.5, 3.5 and 17.0 days resp.) than in controls (22.8, 27.07 and 41.7 resp.).