Abstract #481
Section: Production, Management and the Environment (orals)
Session: Production, Management, and the Environment 3
Format: Oral
Day/Time: Wednesday 10:15 AM–10:30 AM
Location: Room 264
Session: Production, Management, and the Environment 3
Format: Oral
Day/Time: Wednesday 10:15 AM–10:30 AM
Location: Room 264
# 481
Progesterone based synchronization following Quick-resynch protocol improves cumulative pregnancy rate in lactating dairy cows.
A. H. Shahzad*1, A. Abbas2, S. Abbas1, I. Anwar2, R. Safdar2, 1University of Veterinary and Animal Sciences, Lahore, Pakistan, 2Livestock and Dairy Development Department, Punjab, Pakistan.
Key Words: lactating cows, Quick-resynch, pregnancy rate
Progesterone based synchronization following Quick-resynch protocol improves cumulative pregnancy rate in lactating dairy cows.
A. H. Shahzad*1, A. Abbas2, S. Abbas1, I. Anwar2, R. Safdar2, 1University of Veterinary and Animal Sciences, Lahore, Pakistan, 2Livestock and Dairy Development Department, Punjab, Pakistan.
Objectives of the present study were to evaluate CIDR-estradiol benzoate (CIDR-EB) synchronization protocol followed by Quick-resynch through pregnancy rate (PR). Postpartum cows (n = 396) were assigned to receive standard CIDR-EB protocol. Cows were subjected to timed AI (TAI) and randomly assigned to 1) Quick-resynch group (n = 198), received autoclaved CIDR for d14-d21 following 100 µg GnRH on d 23rd post TAI. Pregnancy was diagnosed on d30 through ultrasonography. Open cows received PGF2α and GnRH of Quick-resynch protocol. 2) Control group (n = 198), subjected to AI after detected estrus from d18–30 post TAI. Pregnancy was confirmed on d60 and d90 in both groups. For progesterone (P4) profile, blood sampling was done on d14, d16 and d30 post TAI and Luteal tissue cross-sectional area was measured on d30 in pregnant animals in both Quick-resynch and Control groups (n = 60). Chi-squared analysis in PROC FREQ of SAS was used to determine the treatment effect on pregnancy rate. Treatment effect on luteal tissue cross-sectional area and P4 profile were analyzed by GLM procedures of SAS (P < 0.05). On d30 post TAI, PR was 51 and 43.40% (P = 0.37) in both Quick-resynch and Control groups, respectively. On d60 and 90, cumulative PR was 72.20 vs. 50% (P = 0.03) and 70 vs. 47.50% (P = 0.02) in Quick-resynch and Control groups, respectively. On d60 pregnancy loss in Quick-resynch group was 4.80% in comparison with 9.30% in Control group (P = 0.34). Overall pregnancy loss was 4.10 and 12.96% in Quick-resynch and Control groups (P = 0.02), respectively. Progesterone profile (ng/mL) was statistically non-significant on d14 (P > 0.05) while on d16 and 30 post TAI, P4 was significantly higher (P < 0.05) in Quick-resynch group as compared with Control group. Luteal tissue area was significantly higher (P < 0.05) in Control group. Parity, cyclicity and BCS did not have any effect on pregnancy neither independently nor in interaction with treatment. In conclusion, cumulative PR was significantly higher in Quick-resynch group and has also been resulted in significantly higher (P < 0.05) P4 profile despite smaller luteal tissue as compared with Control group on d30 post TAI.
Key Words: lactating cows, Quick-resynch, pregnancy rate
