title: Effect of different milking routines on milking-related release of the hormones oxytocin, prolactin and cortisol, and on milk yield and milking performance in Murrah buffaloes.
abstract: Milking-related release of oxytocin, prolactin, and cortisol was studied following three premilking treatments. Six Murrah buffaloes were treated with direct application of milking cluster (O), a 1-min pre-stimulation (M), and combined feeding and pre-stimulation (MF). Machine milk yield, stripping yield and milk composition were recorded. Milk ejection occurred significantly earlier with MF than M and O (P<0.05; 2.50, 5.10 and 6.33 min, respectively). In all treatments, milk ejection occurred with small increases >3-5 ng/l in oxytocin concentration. Increase in oxytocin concentration over a threshold level and milk ejection occurred simultaneously and were closely correlated (r=0.83, P<0.05). There was a positive correlation between total time oxytocin concentration remained elevated over threshold levels and machine yield (r=0.86, P<0.05). For treatment O, milk ejection was inhibited during machine milking, while a marked increase in oxytocin occurred during hand stripping (6 and 16 ng/l, respectively). For treatment M, mean oxytocin concentrations remained unchanged during prestimulation but increased during subsequent machine milking and hand stripping (6.38, 18.06 and 12.36 ng/l, respectively). For treatment MF, although there was a 3.6-fold increase during pre-stimulation, oxytocin increased by 10-fold and 3-fold during machine milking and hand stripping, and was significant for machine milking (P<0.05, 17.32, 47.86, 18.13 ng/l, respectively). Milk-ejection-related cortisol release was visible only in treatment MF. For treatments O and M, prolactin concentration increased prior to the increase in oxytocin. The stripping yield was higher, and fat content in the stripping yield significantly lower, for treatment O indicating incomplete milking. Thus buffaloes are easily disturbed even by small changes in milking routines.
authors.affiliation: Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Kungsangens Research Centre, SE-753 23 Uppsala, Sweden.
authors.forename: Chirathalattu S
authors.initials: CS
authors.lastname: Thomas
authors.forename: Rupert M
authors.initials: RM
authors.lastname: Bruckmaier
authors.forename: Karin
authors.initials: K
authors.lastname: Ostensson
authors.forename: Kerstin
authors.initials: K
authors.lastname: Svennersten-Sjaunja
mesh_terms: D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D003612:Dairying / Q000379:methods; D005260:Female; D006854:Hydrocortisone / Q000032:analysis / Q000097:blood; D007774:Lactation; D008892:Milk / Q000737:chemistry / Q000378:metabolism*; D010121:Oxytocin / Q000032:analysis / Q000097:blood; D011388:Prolactin / Q000032:analysis / Q000097:blood
chemical_list: D010121:Oxytocin; D011388:Prolactin; D006854:Hydrocortisone