Effects of different estrous synchronization protocols on estrus and subsequent fertility in cycling cows

Title: Effects of different estrous synchronization protocols on estrus and subsequent fertility in cycling cows

Authors: Amit Kumar, JS Mehta, Swati Ruhil and GN Purohit

Source: Ruminant Science (2018)-7(1):83-86.

Cite this reference as: Kumar Amit, Mehta JS, Ruhil Swati and Purohit GN (2018). Effects of different estrous synchronization protocols on estrus and subsequent fertility in cycling cows. Ruminant Science 7(1):83-86.


Present study was conducted on 53 healthy cyclic cow of 2-5 parity and >90 day postpartum to evaluate the efficacy and subsequent fertility of three estrus synchronization protocols i.e. CIDR-PG (n=13), Ovsynch (n=15), Heatsynch (n=15). The animals of control group (n=10) remained untreated. After end of the protocol all the treated cows were observed daily morning-evening for 7 days for the occurrence of signs of estrus and inseminated artificially 12 to 18 hrs after the onset of estrus. Cohort development of developing follicles (5 mm) was monitored by ultrasonography and revealed that mean total no. of follicles on the left, right and both the ovaries recorded were not significantly different between the protocols. The mean diameter of the dominant follicle showed significant difference between the groups. Mean duration of onset of estrus post protocol was shortest in ovsynch protocol (27.46±0.97 h) whereas mean duration of estrus was significantly longer in CIDR-PG protocol (23.53±0.96 h). All the inseminated but not returned cows were scanned ultasonographicaly or examined manually through rectum for the confirmation of pregnancy at 35 and 60 days of pregnancy and revealed 60  conception rates in the heatsynch and ovsynch protocol whereas 54.54  in CIDR-PG based protocol.  It was concluded that among these estrous synchronization protocol heatsynch protocol was most effective for induction of estrus and expression of signs of estrus while ovsynch protocol as most effective in term of conception rate.


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