Oestrus induction and conception in buffaloes after hormonal treatment during summer

Experiment was conducted on 24 Murrah buffaloes during summer maintained at livestock production research farm of the institule. All the buffaloes were in anoestrus condition, but some had small sized corpus luteum. whereas others possessed smooth ovaries after rectal palpation on 3 successive occasions. Buffaloes (10) which had corpus luteum, were given 25 mg first PG injection i/m (5.0 ml lutalyse), whereas buffaloes received 5.0 ml normal saline solution to serve as control. Buffaloes were detected in oestrus by teaser bull twice a day. Animals not observed in oestrus after first PG. were further given 5.0 ml lutalyse at an interval of 10 days. Blood was collected from each buffaloes at the time of PG injection as well as at oestrus for estimation of progesterone. in plasma. In another group, remaining 8 buffaloes with smooth ovaries were treated with progesterone and oestradiol regimen. Buffaloes (5 and 3) expressed oestrus activity after first and second PG treatment respectively. Out of 5 buffaloes in first PG group, only 2 expressed standing oestrus symptom and remaining 3 had uterine tone. No buffalo was observed in standing oestrus in second PG treated group. Only 2 buffaloes become pregnant and that to in first PG treated group. Conception was nil in second PG and in control group. Progesterone estimation revealed that PG was effective only in those buffaloes, which had more than 1.0 ng/ml blood progesterone concentration at the time of treatment. Progesterone concentration was lower then 1.0 ng/ml of blood in all control and non-pregnant treated buffaloes. In other experiment, oestrus was induced in 75% (6/8) buffaloes, when progesterone and oestradiol was injected. Four buffaloes were observed in standing oestrus and 2 expressed mucus discharge after 48 hr to treatment. Conception rate was 50% (418) in this treatment group. Findings of above experiment suggest that supplementation of exogenous progesterone is essential for oestrus induction and pregnancy in acyclic buffaloes during summer.