Reaction of primiparous dairy cows reared in early postnatal period in different systems on milking conditions

Abstract

An experiment was performed in primiparous dairy cows, which were reared as calves in different systems (with own mothers, with nursing cows, in individual hutches) before weaning at day 56. After weaning the animals were kept under similar conditions. During rearing period calves were exposed to some ethological tests except for animals from control group. The aim of the experiment was to determine their milking performance in response to first milking after calf removal and to stressor applied in parlour in the middle of lactation. Responsiveness to milking was monitored during the evening milking on day 8 (first milking after the weaning of calf), and on day 10 (third evening milking). On day 150 of lactation cows were subjected to stressor (unknown human in front of a head in parlour touching the cow). On day 152 of lactation the milking was usual. Rearing conditions and both treatments did not influence the parameters of milking performance. However, both treatments of first milking after calf removal and stressor at 150 day significantly increased residual milk volume (3.94 ± 0.82 vs. 1.13 ± 0.82 kg, P = 0.0218, 0.58 ± 0.30 vs. 0.11 ± 0.30 kg and P = 0.0294, respectively). In conclusion, the rearing conditions of heifers during the period before weaning could influence their response to milking conditions as primiparous cows fall in the range that is not of high importance for milking performance. However, higher residual milk volume indicates that heifers reared under own nursing cows express higher sensitivity to stressor during whole production life.