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ARS Home » Southeast Area » Booneville, Arkansas » Dale Bumpers Small Farms Research Center » Research » Publications at this Location » Publication #187494
Title: ESTROUS BEHAVIOR AND INITIATION OF ESTROUS CYCLES IN POSTPARTUM BRAHMAN INFLUENCED COWS AFTER TREATMENT WITH PROGESTERONE AND PROSTAGLANDIN F2A

Author
item FLORES, R - UNIV OF ARKANSAS
item Looper, Michael
item KREIDER, D - UNIV OF ARKANSAS
item POST, N - UNIV OF ARKANSAS
item ROSENKRANS, JR, C - UNIV OF ARKANSAS

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2006
Publication Date: 6/16/2006
Citation: Flores, R., Looper, M.L., Kreider, D.L., Post, N.M., Rosenkrans, Jr, C.F. 2006. Estrous behavior and initiation of estrus cycles in postpartum Brahman influenced cows after treatment with progesterone and prostaglandin F2a. Journal of Animal Science. 84:1916-1926.

Interpretive Summary: Anestrous beef cattle are not pregnant at the end of the breeding season and reduce profitability of beef production. Exposure to progesterone can induce estrous cycles in anestrous European cattle breeds but no data are available on the effects of progesterone on initiating estrous cycles in Brahman-influenced cows. ARS scientists from Booneville, AR and the University of Arkansas investigated the effects of progesterone via a controlled internal drug-releasing (CIDR) device and prostaglandin F2alpha (PGF2alpha) on initiation of estrous cycles, synchronization rate, estrous behavior, and pregnancy rate of Brahman-influenced cows. Treatment of cows with a CIDR for 7 d with PGF2alpha at CIDR removal improved synchronization and first service conception rates, decreased interval to first estrus, and was effective at inducing estrous cycles in anestrous Brahman-influenced cows. This information is important to livestock producers and extension personnel.

Technical Abstract: Spring-calving, crossbred (1/4 to 3/8 Brahman) primiparous (n = 56) and multiparous (n = 102) beef cows were used to evaluate the effects of progesterone (P4) via a controlled internal drug-releasing device (CIDR) and prostaglandin F2alpha (PGF) on initiation of estrous cycles, synchronization rate, estrous behavior, and pregnancy rate during 2 yr. Treated cows received a CIDR for 7 d beginning on d -7 of the breeding season. On d 0, CIDRs were removed, and cows receiving CIDRs were administered PGF; control cows received no treatment. Cows were exposed to bulls and estrous activity was monitored using a radiotelemetry system for the first 30 d of the breeding season. Synchronization of estrus was increased (P < 0.001) in cows treated with CIDR-PGF (56%) compared to untreated controls (13%) during the first 3 d of the breeding season. More (P < 0.05) cows without LA and treated with CIDR-PGF were in estrus during the first 3 d (59 vs. 12%) and 30 d (83 vs. 63%) of the breeding season than untreated, control cows without LA. First service conception rate was increased (P < 0.02) in CIDR-PGF-treated cows compared with untreated control cows. Treatment with CIDR-PGF increased (P = 0.01) the mean number of mounts received (22.5 ± 3.0 and 13.7 ± 4.4) during the first 30 d of the breeding season compared to untreated, control cows. Cows with LA at initiation of the breeding season had increased (P = 0.04) pregnancy rate than cows without LA. We conclude that treatment of Brahman-influenced cows with P4 via a CIDR for 7 d with administration of PGF at CIDR removal improves synchronization rate and conception rate, and may be effective at inducing estrous cycles in anestrous Brahman-influenced cows.