Abstract

COMPARATIVE ASSESSMENT OF DIFFERENT PARAMETERS IN LACTATION INDUCED REPEAT BREEDING HEIFERS VS. NATURAL LACTATION NULLIPAROUS HEIFERS

Nagaraja K.*, Jagadeesh S. Sanganal, Byregowda S. M., Chandrashekaramurthy V., Shridhar N. B. and Satyanarayana M. L.

Abstract

The induction of lactation were carried out in 30 animals, divided into three groups with 10 animals in each group. Group I, animals which were in first lactation (nulliparous) served as control, not given any treatment. Group II, administered with 17β-estradiol at 0.1 mg/kg body weight and progesterone at 0.25 mg/kg body weight were administered from day 1 to 7 twice daily 12 h apart by subcutaneous route at either side neck region on alternate days. Dexamethasone (20mg/animal/day) was administered for 4 days (day 14 to 17) by intramuscular route. The treatment schedule for Group III, from day 1 to 7 were adopted same as group II and Metoclopramide (0.1 mg/kg body weight) and dexamethasone (20mg/animal) were administered for 4 days from day 14 to 17 by intramuscular route. The relative efficacy of lactation induction protocol employed in group II was 90 per cent and while in the group III it was 100 per cent. In both the treatment groups droping of milk from the teats were noticed on day 18 and 19 in four and five animals in group II and III respectively and milking was initiated on day 20. The first day milk was watery, yellowish to white in colour. The milk secretions in all the animals become normal within 3 to 7 days. The animals reached to peak mean daily milk yield of 4.73±0.15, 4.38±0.16 and 5.06±0.20 liters on day 45, 90 and 60, the mean total milk yield for 90 days were 357.83±4.05, 228.87±4.49 and 349.30±12.95 liters and for 305 days were 1224.92±14.78, 753.07±14.09 and 1156.95±33.39 liters in group I, II and III respectively. The mean total milk yield for 90 and 305 days were significantly higher (P0.05). The peak mean milk fat composition of 5.87 ±0.16, 4.05±0.09 and 4.27±0.10 per cent on day 1, 45 and 90 and the lowest mean SNF composition of 8.18±0.03, 8.55±0.05 and 8.36±0.06 per cent on day 1, 45 and 90 were observed in group I, II and III group respectively.

Keywords: Lactation induction, efficacy, milk yield, 17?-estradiol, progesterone.