Objectives: Achai cattle are found in hilly terrains of northern Pakistan. Accessibility of the veterinary practitioners for insemination of estrous cows at the herds, is difficult. Therefore, this study evaluated the efficiency of two different estrus synchronization protocols for estrus expression and overall conception rate.
Methods: Twelve lactating Achai cows (n=12) were divided into two groups with equal numbers and subjected to POP (Presynch Ovsynch) or MSS (Modified 7 day Select Synch) protocol. In POP protocol animals were administered with PGF2-α injections on day -38, -24 and -3. GnRH-1 was given on day -10 and 0 followed by TAI 16 hours later. Animals in MSS group were administered with a CIDR insert on day -7 concurrent with PGF2-α, GnRH-1 at day -5, removal of CIDR at day 0, concurrent with two doses of PGF2-α at 8 hr interval, GnRH-2 on day 3, followed by TAI after 16 hrs.
Results: Higher E2 and lower P4 concentrations were observed for MSS than POP group. Cows having higher level of E2 and lower level of P4 concentrations at the time of estrus, become pregnant (P<0.05). E2 concentrations varied among pregnant and nonpregnant cows in both protocols (P<0.01). Highest concentration of E2 was observed in pregnant cows in POP group. The P4 concentration of pregnant cows in MSS was lowest at the time of insemination followed by pregnant cows in POP group compared to the nonpregnant cows in both the protocols (P<0.05). Maximum cows exhibited estrus in POP than MSS. Conception rate in TAI cows was higher in MSS than POP group. Overall conception rate was higher in MSS than the POP (66.66% vs 33.33; P<0.01).
Conclusion: It may be suggested that efficiency of MSS protocol was almost double as compared to POP; for estrus synchronization and conception in Achai cows.