To move or not to move: when should dairy cows be moved to maternity pens

Cows are often moved from a group to an individual maternity pen just before calving. However, moving cows too soon before calving may alter their behavior and delay labor. The aim of this study was assess if moving cows to a maternity pen at different time periods before calving would influence labor or cow behavior. Thirty-six multiparous Holstein dairy cows were moved from a group to 1 of 10 maternity pens adjacent to the group pen. Cows were moved either 3d before calving, or when signs of calving were present. The time of moving relative to calving was determined retrospectively and cows were assigned to 1 of 3 treatments: "very late" (2.5 ± 1.2 h (mean ± SD) range 1.5 to 5 h; n = 12), "late" (12.9 ± 4.0 h, range 8 to 20 h; n = 12) or "early" (83 ± 23 h, range 37 to 122 h; n = 12). Calves were weighed within 12 h of birth. Using video, behavioral data collected 4 h before calving was used to approximate the length of the second stage of labor (the time between first 'expulsive' contractions, recorded when the cow's abdo-men engaged in rhythmic movements, to the delivery the calf). During the 1h before calving we recorded the total time of contractions, lying time and number of position changes made by the dam. The effect of treatment on these variables was tested with ANOVAs (Proc GLM in SAS); treatment was a fixed effect and calf BW and cow parity were covariates. There was an effect of treatment and calf BW on the length of the second stage of labor; cows with heavier calves (P = 0.01) and those moved very late took longer to expel the calf (very late = 76.6 ± 6.9, late = 56.9 ± 5.6, early = 58.3 ± 6.6 min; P = 0.02). Cows with heavier calves spent more time having contractions 1 h before calving (P = 0.03), but there was no effect of treatment (P = 0.42). Cows moved very late spent twice as much time standing 1h before calving (very late = 25.5 ± 4.5, late = 12.4 ± 3.6, early = 11.6 ± 4.3 min; P = 0.01), but there was no effect of treatment on the number of position changes (P= 0.85). Results suggest that moving cows within 5h of calving from a group to a maternity pen prolongs the second stage of labor, and this may partly be driven by a longer time spent standing during the final hour before calving.