Comparison of Estrus Synchronization with Application of Prostaglandin F2α Intrauterine and Intramuscular in Bali and Crossbred-Ongole Cattle

The objective of this study was to compare effects of intramuscular and intrauterine injection of prostaglandin F2α (PGF2α) on estrous synchronization in Bali and crossbred-Ongole cattle. A total of 80 Bali and 70 crossbred-Ongole (PO) cows were used for the study. The average body weighs were 327±9.98 and 355±8.45 kg and were aged 4-8 years (parities 2 to 5) for Bali and PO cattle, respectively. The Bali and PO cows were divided into two treatment groups and to each cow, two injections of PGF2α, 14 days apart were administered. Cows in group 1 (Bali, n=40; PO, n=35) were injected witrh 25 mg Dinoprost® (Glandins, Tad Pharmazeutisches werk Gmbh, West Germany) intramuscularly (i.m). Whereas, for the cows in group 2 (Bali, n=40; PO, n=35), 5 mg Dinoprost® was injected intra uterine (i.u) using a modified AI gun. The percentage estrus after first and second injection with i.m and i.u were non significantly different (P 0.05) between Bali and PO cows. The percentage estrus response was significantly different (P 0.05) between first injection and second injection. The pregnancy rate after first injection with i.m and i.u were non significantly different (P 0.05). Whereas, pregnancy rate after second injection with i.m and iu between Bali and PO cows were significantly different (P 0.05). Thus, differences in breed and method of PGF2α administration were not significantly different (P 0.05). It was concluded that injection of PGF2α via the i.u route resulted in similar estrus response and pregnancy rates compared with the i.m route of administration. Furthermore, the i.u application of the PGF2α or its analogues may reduce the dose requirement of the drug.