Malik, R.K.Virendar Singh2017-08-212017-08-212008http://krishikosh.egranth.ac.in/handle/1/5810029152The present study was conducted on twenty four non-cyclic Murrah buffalo-heifers between age of 25 to 38 months and body weight >300kg to investigate the effect of different hormonal regimens in anestrus buffalo-heifers during summer season. All the animals were housed in commercial half covered pucca sheds with asbestos cement sheet roofs. They were stall fed collectively with sufficient quantity of green fodder and concentrates according to their individual requirements. Showering of animals was also done 1-2 times a day during the period of experiment. These experimental animals were randomly divided into four equal groups (A, B, C & D) having six heifers in each group. Group A was kept as control where as Group B received CIDR+Folligon+Chorulon; Group C (Folligon+Receptal-Vet + Vetmate + Receptal - Vet) and Group D (Duraprogen + Progynon depot + Vetmate + Folligon). All (100%) animals in Group B and C exhibited behavioural estrus symptoms whereas majority (66.66%) Group D and only (33.33%) Group A exhibited behavioural estrus symptoms. The estrus induction percentage in Group A, B, C & D was 33.33, 100, 16.66 and 66.66%, respectively. The mean interval to estrus from withdrawal of treatment in three treatment groups B, C and D was 38.40±4.49, 66.00±30.00 and 72.00+19.60 hours, respectively. The duration of estrus was maximum (28.20±6.12) hour in Group B animals, followed by 27.75±7.08, 17.00±2.52 and 16.00±2.00 hours in Group C, D and A, respectively. The pregnancy rate at induced estrus was highest (50.00%) in Group B animals followed by 33.33%, 20.00% and 16.66% in Group D, C and A heifers, respectively. The treatment cost per estrus induction was highest (Rs. 1061/-) in Group B heifers followed by Rs. 1011/- and Rs. 651/- in Group C and D, respectively. Group D treatment was most cost effective (Rs. 1302/-) followed by Rs. 2122/- per pregnancy and Rs. 4042/- per pregnancy in Group B and C, respectively on comparison of the pregnancy rates. From the present study it can be concluded that Duraprogen + Progynon depot+ PGF2α+PMSG (Group D) treatment is cost effective for induction of cyclicity and pregnancy at induced estrus in non-cyclic, post pubertal Murrah buffalo-heifers in summer season. However, it is suggested to extend the present investigation on large number of animals before final recommendation could be made for field application.enThesis