LAUSR

The objectives were to analyze the effects of housing cow-calf pairs in drylots (DL) or pasture (PAST) on cow performance and reproduction as well as calf performance and behavior through feedlot receiving. Simmental × Angus (2 yr; 108/yr; 81 ± 15.3 d postpartum) spring-calving cows were stratified by age, body weight (BW), body condition score (BCS), and calf sex and allotted to 6 groups/yr. Groups were randomly assigned to 1 of 2 treatments: DL or PAST. Cows in DL were limit-fed at maintenance and calves had ad libitum access to the cow diet in an adjacent pen. Pairs on PAST were rotationally grazed and calves received creep ad libitum three weeks prior to weaning. On d 110 calves were fence-line weaned and behavior was observed on d 111 and 112. On d 116 calves were transported 272 kilometers to a feedlot for a 42-d receiving period. Behavior was evaluated again on d 117 and 118. Data were analyzed using the MIXED procedure of SAS except reproductive data which was analyzed using the GLIMMIX procedure. Cows on DL had greater (P ≤ 0.01) BW and BCS at weaning. There were no differences (P ≥ 0.42) detected in reproductive data. Cows on DL had greater (P = 0.02) milk production. Calves on DL had greater BW (P ≤ 0.01) on d 55 and at weaning and greater preweaning average daily gain (ADG). There were treatment × time effects (P = 0.01) for lying and eating on d 111 and 112. More DL calves were eating in the morning and lying in the evening. More (P < 0.01) PAST calves were walking on d 111. Pasture calves vocalized more (P ≤ 0.01) on d 112. On d 117, more (P ≤ 0.05) pasture calves were lying and eating, and DL vocalized more. On d 118, treatment × time and treatment effects were detected (P ≤ 0.02) for lying and walking. More PAST calves were lying and more DL calves were walking. Drylot calves had greater (P ≤ 0.02) BW at the beginning and end of the receiving phase. Pasture calves had greater (P < 0.01) ADG and tended (P = 0.10) to have greater gain efficiency during feedlot receiving phase. In conclusion, housing cow-calf pairs in drylots improved BW, BCS, and milk production of cows but did not affect reproductive performance. Drylot calves had increased BW and ADG during the preweaning phase. Calf behavior at weaning and receiving was influenced by preweaning housing. Pasture calves had improved receiving phase ADG and feed efficiency but were still lighter than drylot calves after 42 d receiving phase.