The effect of rearing conditions during the milk-fed period on milk yield, growth, and maze behaviour of dairy cows during their first lactation

Abstract

p The objective was to find whether cow growth, milk performance, and behaviour are affected by (1) rearing conditions until weaning after a milk-fed period of 84 d and (2) the sire lineage. Thirty-five Holstein heifers were assigned to one of three treatments: SM, span classCombining double low line inline-formula i n /i Combining double low line13 , pen with mother to 21st day, then group pen (they received a maximum of 6 kg of milk daily); SN, span classCombining double low line inline-formula i n /i Combining double low line9 , after 3 d with own mother in pen with nursing cow (they received a maximum of 6 kg of milk daily); H, span classCombining double low line inline-formula i n /i Combining double low line13 , in hutch from the 2nd to 56th day (6 kg of milk replacer daily), then loose housing pen to weaning (6 kg of milk replacer daily). After weaning at the 84th day, all heifers were kept in pens with the same ration as during calving. During lactation, live body weight (LBW) was measured each month and milk yield each day. Maze learning was evaluated in the fifth month of lactation. The data were analysed using a general linear model ANOVA. At the 30th day, the LBW tended to be the highest in SN (SM 528.2 span classCombining double low line inline-formula 11.4 kg, SN 571.7 span classCombining double low line inline-formula 15.3 kg, H 533.2 span classCombining double low line inline-formula 12.3 kg). When lactation ended, the highest LBW was in SN and the lowest in H (SM 612.6 span classCombining double low line inline-formula 12.2 kg, SN 623.1 span classCombining double low line inline-formula 16.4 kg, H 569.8 span classCombining double low line inline-formula 13.2 kg; span classCombining double low line inline-formula i P /i 0.05 ). The SN tended to have the highest production of milk (SM 7143.9 span classCombining double low line inline-formula 241.5 kg, SN 7345.1 span classCombining double low line inline-formula 319.0 kg, H 7146.7 span classCombining double low line inline-formula 234 kg), and the H for FCM (SM 6290.3 span classCombining double low line inline-formula 203.2 kg, SN 6307.6 span classCombining double low line inline-formula 268.4 kg, H 6399.3 span classCombining double low line inline-formula 197.1 kg) for 305 d lactation. Group SN crossed the maze fastest (SM 1141.4 span classCombining double low line inline-formula 120.5 s, SN 810.3 span classCombining double low line inline-formula 160.5 s, H 1120.8 span classCombining double low line inline-formula 118.6 s). The vocalization number differed significantly (SM 32.3 span classCombining double low line inline-formula 5.7, SN 20.8 span classCombining double low line inline-formula 4.4, H 9.9 span classCombining double low line inline-formula 2.6; span classCombining double low line inline-formula i P /i 0.01 ). The results indicated that the rearing method up to weaning may have an impact on dairy cows' performance and behaviour.