Supplementation of corn dried distillers grains plus solubles to gestating beef cows fed low-quality forage: I. Altered intake behavior, body condition, and reproduction.

To investigate the effects of corn dried distillers grains plus solubles (DDGS) supplementation to cows fed corn stover and silage during late gestation, 27 multiparous beef cows (674 ± 17 kg; BCS, 5.6 ± 0.1) were divided randomly into 2 pens equipped with electronic feeders. For 10 wk, both groups were fed the basal diet for ad libitum intake while 1 group was supplemented (SUP; = 12) with DDGS at 0.3% of BW (DM basis). Following parturition, all cows received the same diet for an additional 8 wk. During gestation, SUP cows gained BW ( < 0.01), and there was no change in BCS ( 0.79). Nonsupplemented (CON) cows tended to lose BW ( 0.06) and lost BCS ( < 0.01) during gestation. Supplemented cows consumed more forage ( 0.01) and total feed than CON cows. An interaction of treatment and day was observed for time spent consuming forage ( < 0.01); SUP cows consumed forage faster than CON cows ( ≤ 0.01) early in gestation. Control cows ate more meals than SUP cows ( = 0.06) from d 201 to 218 of gestation. Supplemented cows tended ( = 0.09) to consume larger meals than CON cows and spent more ( < 0.01) time eating than CON cows around d 240 of gestation. Calves born to SUP cows tended ( = 0.06) to be heavier than calves born to CON cows. During lactation, both groups gained ( < 0.01) BW. Body condition score was less ( < 0.05) in CON cows than it was in SUP cows at the end of the study. Dry matter intake during lactation increased ( < 0.01) over time but was not influenced ( = 0.44) by treatment. Supplemented cows spent more time ( < 0.01) eating than CON cows after wk 4 of lactation, and they ate faster than CON cows until wk 3 of lactation whereas CON cows ate faster than SUP cows after wk 6 of lactation ( 0.01). The number of meals increased with advancing lactation ( < 0.01) and CON cows averaged more meals daily than SUP cows ( = 0.01). Conversely, meal size decreased as lactation advanced ( < 0.01), and SUP cows consumed larger meals than CON cows ( = 0.05). Supplementation with DDGS during gestation influenced intake behavior during gestation and lactation as well as the maintenance of maternal BW and BCS and calf birth BW.