Fertility after induction of oestrus in anoestrus Jamunapari goats primed with progesterone and eCG treatment

Abstract

Present study was aimed to improve upon life time productivity in adult anoestrus goats (24; 18 parous and 6 non – parous) to resume oestrus cyclicity by hormonal intervention (treatment group, 16; control group, 8). Prior to start of treatment all goats were checked for luteal activity by estimating circulating progesterone (P₄). Goats were implanted @ half crestar implant/goat (1.5 mg norgestomet) subcutaneously and left in situ for 15 days. Concurrently, 1 ml of crestar solution (1.5 mg norgestomet and 2.5 mg oestradiol valerate) was administered to each goat. A luteolytic dose (7.5 mg) of illiren was intramuscularly injected to each goat 24 h prior to implant removal to regress functional luteal tissue, if any. Implants were taken out after 15 days and an amount of 400 – 500 IU eCG/goat was intramuscularly injected to stimulate follicular growth. At induced oestrus each goat received 2.5 ml receptal to enhance ovulation. Goats at induced oestrus were naturally mated twice at 10 – 12 h interval by fertile Jamunapari bucks. Responded does (14 goats, 87.50%) expressed behavioral symptoms of oestrus varying from medium to high intensity. Post treatment oestrus induction period and duration averaged 34.28±3.29 and 29.14±2.07 h, respectively. Progesterone level prior to start of hormonal protocol was at basal level (P ≤ 1.00 ng/ml). A total of 9 goats (65.00%) were confirmed for pregnancy by progesterone assay (14 and 21 days after mating) and real time B- mode ultrasonography at 40 – 60 days of gestation. The kidding rate was 1.88. It is concluded that oestrus can be induced and synchronized in anoestrus (parous and non – parous) by hormonal intervention. It is also possible to augment fecundity in this important but less explored goat breed of India.