Using soybean hulls to meet dietary energy requirements of gestating cows having restricted access to poor-quality hay

Forage for grazing and hay may be limited during drought years, necessitating alternative feeding options. Co-product feedstuffs, such as soybean hulls (SH), may be a more economical means to maintain cows through such conditions. The objective of this study was to determine if SH could be used to meet the majority of the energy demands for cows in late gestation when access to hay was restricted to 1 h daily. Eighty-six gestating, spring-calving cows (527 ± 7.5 kg initial BW; 4.3 ± 0.27 yr of age) were allocated to 1 of 6 groups for a 68-d study beginning December 6, 2012. Three groups were given ad libitum access to medium-quality bermudagrass [Cynodon dactylon (L.) Pers.] hay. The 3 remaining groups were offered 6.4 kg of SH/cow daily and allowed access to a very-poor-quality, mature, mixed-grass hay for only 1 h daily. Each group was housed in separate 2.02-ha dormant bermudagrass pastures. Birth weight and dystocia scores were recorded, and calf performance was monitored through weaning. Representative bales of each hay were weighed to determine total hay offered. Differences in BW and BCS, and changes in these measurements during the study, were minimal between treatments (P ≥ 0.53). Calf birth weight, weaning weight, BW/d of age at weaning, and birth-to-weaning ADG did not differ (P ≥ 0.11) between treatments. Therefore, SH may be used as the major dietary energy component for cows in late gestation having access to hay for only 1 h daily without having adverse effects on the cows or their subsequent calves.