A study was conducted to evaluate the impact of continuous exogenous use of oxytocin in Nili Ravi breed of buffaloes on the physicochemical composition of milk. A group of animals (n=12) were injected with oxytocin (20IU) daily at morning and evening while the other group of buffaloes (n=12) were kept as control and injected with normal saline. Morning and evening milk samples were pooled for analysis. Analysis was made on fortnight basis starting from January to the end of June. Appropriate statistics was applied. Overall milk pH was lower (P≤0.05) while proteins, lactose and SNF of oxytocin injected buffaloes were significantly higher as compared to control animals. These differences were due to a significant lower pH during 8^th and 9^th fortnights, higher milk proteins during 9^th fortnight, a higher (P≤0.05) lactose and SNF during 5^th and 9^th fortnights of oxytocin injected buffaloes during the experimental periods. Milk fat, proteins and sold not fat was significantly higher during the months of March and May. Milk pH was higher (P≤0.05) while milk fat was lower during January and February. During April and May, pH was lower (P≤0.05) and milk fat was higher (P≤0.05) in oxytocin treated buffaloes as compared to control animals. During winter season, milk fat concentration from oxytocin injected buffaloes was significantly lower, however during summer seasons fat concentration was higher (P≤0.05) than controls. In conclusion, long term use with a high dose of oxytocin significantly alters the composition of milk and these changes are also significant during different months and with different seasons.

Key words: Buffaloes, Milk composition, Oxytocin, Seasons