Stability of milking rank in a newly formed group of goats

The aim of the present study was to assess: i) if milking order of a new group of goats constituted for experimental reasons was stable over period, and ii) if milking rank was affected by age, milk yield, milk quality, and morphometric measurements. In a dairy goat farm (NW Italy), 21 Camosciata goats were housed indoors and fed a diet based on fresh grass and concentrate. Goats were machine-milked twice a day in a 12-stall milking parlour and their milking order was recorded. Eleven goats were selected from the flock on the basis of their stage of lactation, milk yield and composition. They were moved to a pen and fresh grass was replaced with mixed hay. The goats were daily monitored at morning milking for 17 days after group formation. The entrance order in the milking parlour, milk yields, and milk samples (for determining fat, protein and somatic cell count) were collected everyday. Body weight, trunk length, height at withers, rump width, chest girth, hornedness, length and maximum diameter of horns of each goat were measured at the end of experimental period. The consistency of milking order of the goats was calculated using the Kendall’s concordance coefficient. The correlations between mean milking order vs. age, days in milk, milk yield, milk traits, and morphometric traits were calculated using the Spearman correlation coefficient. The Kendall’s coefficient showed a significant consistency of entrance in the milking parlour (W = 0.69; P ≤ 0.001). Milking order was significantly correlated with rump width (R = 0.70; P ≤ 0.01) and trunk length (R = 0.59; P ≤ 0.05). The results demonstrated that milking order of goats was not random and it was consistent during the trial. Moreover, the milking rank showed in the original flock was preserved in the experimental group. These results suggest that goats, including subjects involved in experimental trials, should always freely enter the milking parlour in order to avoid possible stress.