Interval between oestrous characteristics and pregnancy rate in synchronised Kedah-Kelantan and crossbred cows

Abstract

The study was conducted to determine the differences in the interval between removal of Controlled Internal Drug Release (CIDR) and standing oestrus (C_ES) interval between CIDR removal and Ovulation (C_OV) interval between oestrus and Ovulation (ES_OV), predetermined Artificial Insemination (AI) and Pregnancy rate following prostaglandin (PGF) treatment and CIDR removal at standing oestrus in Kedah-Kelantan (KK) and KK crossbred cows. A total of 35 KK (n = 11), Brakmas (BK: n = 10) and Charoke (CK: n = 14) cows were inserted with CIDR containing 1.38 g Progesterone (P4) for 7 days and followed with intramuscular injection of 500 μg Cloprosterol of PGF synthetic analogue 2 days prior CIDR removal. The oestrous behaviour was observed for 72 h at 2 h intervals beginning 12 h after CIDR removal. AI was carried out at 6 and 12 h after standing oestrus was detected. Mean interval between CES, CO V and ESOV were 52.97±6.16, 94.42±16.41 and 53.75±25.36 h, respectively. The number of follicles >5 mm in diameter at the time of CIDR removal was significantly lower in CK (p = 0.04) compared to KK. The results of POF size and number of follicle size >5 mm either at CIDR removal or prior ovulation and P4 concentration at day 0, 7 and 14 were found to be not significantly different at p = 0.05. The pregnancy rate was higher (p<0.05) in CK (43.8%) followed by KK (31.3%) and BK (25%). The study provides results which could be used in the development of TAI on oestrous synchronisation protocol of KK and KK crossbred cows. © Medwell Journals, 2012.