Buffaloes occupy an important role in agricultural economy of Pakistan as a triple purpose (milk, meat and draught) animals. Total population of buffalo in Pakistan is 21.6 million. '1'oal milk production in the Pakistan is 24,874 metric tons, out of which 16,665 in Punjab and the share of buffalo is 72.12%.

In buffalo husbandry seasonality in breeding is a problem of great importance, because seasonal variation in breeding, as its effects on calving profoundly affects the economy of milk production also.

The appearance of oestrous in buffalo is at the maximum (37.56%) during October to December. Therefore, population of the country parturate from July to October. Eventually, during the summer months there is a marked decline in total milk production but demand of milk escalates.

To device ways and methods to overcome summer shortage of milk we designed this project to change the breeding pattern of buffaloes by oestrous cycle synchronization in a way to have maximum milk yield during summer months.

In this study 30 non-suckling postpartum Nili-Ravi buffaloes were used having average age 2592.66±127.41 days and average weight 464.7U,±8.27 kgs. The 30 buffaloes were randomly divided into two groups viz group A and B, having 15 animals in each group respectively. The buffaloes in group A (n=15) received intramuscular injection of Dalmazine, analogue of PGF2 a 2CC, without palpation at 11 days interval.

In group B (n=15) received intramuscular injection of Dalmarelin, Analogue of GnRH 2CC without palpation at 11 days interval.

All the animals were observed for (a) Response of treatment (b) interval to the onset of oestrous post-treatment (c) Numbers of buffaloes showing symptoms of oestrous (d) duration of oestrous (e) conception rate (0 cost comparison of both injections per animal.

From the present experiment it was observed that, the response of oestrous in group A was 86.66% and in group B was 80%, the interval of oestrous in group A was 3.53±0.32 days while in group B was 12.5±0.34 days. The duration was 21.69±0.53 hours in group A and 20.9±0.67 hours in group B. The symptoms was frequent urination, bellowing, segregation from the herd, acceptance of teaser bull, vulvular sniffing, vulvular swelling and mucous discharge in both groups. The conception rate was 76.92% and 75% in group A and B respectively. The cost comparison was Rs.420 in group A and Rs.452/animal in group B which was more in group B, I .e. Rs.32/animal. It was concluded that PGF2 is more effective for oestrous synchronization, by less time, high conception rate, high percentage of response. However, a detailed study is required to determine the blood hormonal levels after the induction of both the injections, for better improvement.