ICAR Technical Series no. 7 - Nitra Proc.

Marnet et al.Comparative study of physiologicalresponses of cows to classical versusautomatic system of milkingP.G. Marnet, H. Aupetit , J.F. Combaud, J. Portanguen & J.M. AubryENSAR/INRA, Research on milk production,65 rue de S t Brieuc, 35000 Rennes, FranceE-mail: marnet@roazhon.inra.frEight cows were controlled during 2 weeks of classical milking techniquein a side by side parlor and the first 4 succeeding weeks of adaptation toan automatic milking system (AMS). Milk production and composition,milk emission kinetics, oxytocin release and teat end reaction weremeasured 4 times per week during all the experiment. The milk productionand lactation persistency, the milk composition and the C.C.S are notsignificantly affected during the adaptation period to the AMS. There is agood massaging of the teat during milking. That suggests a normal functionof the liner in the special cup of the AMS. The mean flow rate have just atendency to be lowered by AMS that confirm the good quality of themilking machine of the AMS. Therefore, there is a significant reduction ofthe oxytocin release when cows are milked by the AMS with acorresponding increasing number of bimodal milk emission kinetics. Thisresult remain significant even when we take only in account the goodmilking procedures in the AMS (without any failure, delay in cupattachment or cluster fall). That suggests a poor efficiency of the udderpre-stimulation in our AMS. Additionally, we cannot eliminate a potentialchronic inhibition of the milk ejection reflex by the robotic surroundingsduring the 4 weeks despite a clear improvement of the AMS efficiencywith a reduction of more than 15% of the second, third and fourth trialsfor attachment procedures of the teat cups.SummaryKey words: Machine milking, milk production, milk flow, teat reaction, oxytocin.It is well known that the most important stimuli are pre-milkingpreparation and the action of the machine milking (Woolford, 1987). In anAMS, the pre-milking preparation consists in mechanical cleaning of theteats and foremilking by the machine. When the udder or the teat arebrushed, a positive effect on milk let down and oxytocin release have beendescribed (Shuiling, 1992, Macuhova and Bruckmaier et al., 2000). However,no data exists about the stimulation efficiency of foremilking with waterIntroductionICAR Technical Series - No 749