A Case Study of Behaviour and Performance of Confined or Pastured Cows During the Dry Period

SIMPLE SUMMARY: Pasture and freestall systems offer benefits and consequences during lactation but have not been investigated during the dry period. The effect of pasture or confined systems during the dry period on behaviour and milk quality was investigated. Freestall housing resulted in more resting behaviour and less locomotor activity during the dry period compared to pastured cows. At calving, freestall housed cows performed fewer lying bouts and less locomotor activity compared to pastured cows. Pasture resulted in less aggression around feeding but high respiration rates during peak heat times. Pasture during the dry period altered lying behavior, reduced feed bunk aggression and increased heat stress behaviors. ABSTRACT: The objectives of this study were to determine the effect of the dry cow management system (pasture or confined) on: (1) lying behaviour and activity; (2) feeding and heat stress behaviours; (3) intramammary infections, postpartum. Non-lactating Holstein cows were assigned to either deep-bedded, sand freestalls (n = 14) or pasture (n = 14) using rolling enrollment. At dry-off, cows were equipped with an accelerometer to determine daily lying time (h/d), lying bouts (bouts/d), steps (steps/d) and divided into periods: far-off (60 to 15 d prepartum), close-up (14 to 1 d prepartum), calving (calving date) and postpartum (1 to 14 d postpartum). Respiration rates were recorded once weekly from dry off to calving from 1300 to 1500 h. Feeding displacements were defined as one cow successfully displacing another from the feed bunk and were recorded once per week during the 2 h period, immediately after feeding at 800 h. Pastured cows were fed a commercial dry cow pellet during far-off and total mixed ration during close-up, with free access to hay and grazing. Freestall housed cows were fed a total mixed ration at far-off and close-up. Cows housed in freestalls were moved to a maternity pen with a mattress at commencement of labour. Pastured cows calved in pasture. After calving, all cows were commingled in a pen identical to the freestall housing treatment. Cows housed in freestalls laid down for longer during far-off and close-up periods, had fewer lying bouts during the calving period and took fewer steps throughout the study period when compared to pastured cows. Freestall housed cows experienced more displacements after feeding than did pastured cows. Respiration rates increased with an increasing temperature humidity index, more in pastured cows than in freestall housed cows. Pastured cows altered their lying behaviour and activity, suggesting a shift in time budget priorities between pastured and confined dry cows. Pastured cows also experienced less aggression around feeding but may be more susceptible to heat stress.