PSIII-16 Use of soybean hulls in diets for drylot beef cows

Abstract

Abstract One-hundred twenty-one Red Angus beef cows were used to evaluate the effects of soybean hull inclusion in beef cow diets throughout gestation and lactation. Cows were stratified by age, body weight (BW), and body condition score (BCS), and were randomly assigned to treatment (n = 4 pens per treatment). Treatments included 1) control diet [CON; consisted of corn silage, modified distillers’ grains plus solubles (MDGS), and wheat straw], and 2) soybean hull diet [SBH; consisted of 26 to 27% soybean hulls (DM basis) replacing portions of corn silage, MDGS, and wheat straw]. Beef cow BW, BCS, average daily gain (ADG), and back fat (BF) measurements were evaluated. Colostrum samples were collected on a subset of randomly selected cows from each pen. Weigh-suckle-weigh technique was used to evaluate milk production. Calf birth weight, weaning weight, and ADG were evaluated. At weaning, calves were ultrasounded for BF, rump fat, and ribeye area. Dam BW, BCS, BF, and ADG were not affected (P ≥ 0.12) by treatment. Colostrum fat, somatic cell count, urea nitrogen, and other solids were not altered (P ≥ 0.13) by treatment; however, colostrum protein was greater (P ≥ 0.09) in CON cows. Milk production at d 60 was greater (P = 0.03) for SBH fed cows. Calf birth and weaning weights were unaffected by treatment (P = 0.30). Ribeye area measurements were greater (P = 0.05) in SBH calves (14.6 vs. 13.7 ± 0.76 cm2), but BF and rump fat were not different (P ≥ 0.58). The present study demonstrates that soybean hulls can be included in beef cow diets at 26 to 27 % of dietary DM. Our data and previous research indicate that soybean hulls can be fed to drylot beef cows during gestation and lactation without negative impacts on cow or calf outcomes.