360 Effect of housing beef cows on dry lots vs pasture on cow performance and reproduction

Abstract

Abstract The objectives were to compare the effects of housing cows in dry lots or pasture on cow performance and reproduction. Simmental × Angus (n = 108; 87 ± 11.5 d postpartum), lactating, spring-calving cows were stratified by age, BW, BCS, calving date, and sex of the calves and allotted to six groups. Groups were randomly assigned to 1 of 2 treatments: dry lot (DL) or pasture (PAST). The cows in dry lot were limit-fed a ration consisting of corn silage, dried distillers grains, corn stalks, corn, and soybean hulls to meet their protein and energy requirements. Cows on pasture were rotationally grazed and with free-choice mineral. On d 0, cows were synchronized and artificially inseminated (AI). On d 0, 33, 51, and 87, BW and BCS were measured. Cow AI and overall pregnancy were determined on d 35 and 88, respectively. On d 52, milk production was determined using the weigh-suckle-weigh technique. Body weight, BCS, and milk yield were analyzed using the MIXED procedure of SAS. Reproductive data were analyzed using the GLIMMIX procedure of SAS. On d 0 and 33, BW did not differ (P ≥ 0.38) between cows on in DL or on PAST. On d 51, DL cows tended (P = 0.07) to have greater BW than PAST cows. On d 87, DL cows had greater BW (P = 0.05) than PAST cows. The BCS, milk yield, and reproductive rates did not differ (P ≥ 0.12) between treatments. Housing cows in dry lots compared to pasture increased BW, but did not affect BCS, milk production, and reproduction.