Effect of milking behavior on circulatory hormones and milk production in lactating Murrah buffaloes

The effect of milking temperament on plasma hormones, metabolites, milk yield and composition in lactating Murrah buffaloes was studied. Animals were selected from the institute herd and grouped as docile and nervous buffaloes, based on temperament score before and during milking. Blood sampling times were; before milking (-20 min.), after concentrate intake, after teat massage, during milking and 20 min. postmilking. Plasma prolactin (PRL), growth hormone (GH) and cortisol (CORT) concentrations were measured by enzyme-immunoassay procedures. Milk yields of individual buffaloes were recorded and milk composition (fat, protein, lactose, SNF, SCC) determined. Milk yield was significantly lower (P<0.05) in nervous buffaloes in comparison to docile buffaloes. Mean fat, protein, lactose and SNF varied non-significantly between the groups. Milk SCC and plasma NEFA concentration was more (P<0.05) in nervous buffaloes than in docile buffaloes. Milking temperament significantly influenced plasma PRL (P<0.01) and CORT release (P<0.05) but GH was unaffected. Concentrate feeding prior to milking induced release of plasma PRL and CORT without affecting GH and oxytocin levels. Teat stimulus further enhanced release of PRL, oxytocin and CORT hormone in both the groups. Plasma PRL, cortisol, oxytocin and GH varied significantly (P<0.01) before, during and after milking (P<0.01). Basal PRL, GH and CORT were attained 20 minutes after the completion of milking in both the groups. The results show that the behavior of buffaloes at milking influenced release of galactopoietic hormones (PRL, CORT, GH and oxytocin), milk yield and SCC, while milk fat, protein, lactose and SNF remain unaffected.