Effects of supplementing spring-calving beef cows grazing barley crop residue with a wheat-corn blend dried distillers grains with solubles on animal performance and estimated dry matter intake1

A 2-yr study was conducted to determine the effects of supplementing wheat-corn blend dry distillers grains with solubles (DDGS) on beef cow performance and estimated DMI of barley crop residue. Each year, 25 ha of forage barley (cv. Ranger) was seeded and managed for weed control. In fall, the crop was swathed and combined to collect straw-chaff crop residue in 13-kg piles. The field was further subdivided into six 4-ha paddocks for grazing using portable electric fence. Forty-eight spring-calving Black Angus beef cows (BW = 598.2 ± 4.2 kg) were stratified by BW and days pregnant and randomly allocated to 1 of 3 supplement treatments (2 replicates): (1) 100% DDGS (70:30 wheat:corn blend; WCDDGS); (2) 50% WCDDGS plus 50% rolled barley grain (50:50); or (3) 100% rolled barley grain (control; BAR) while winter grazing barley strawchaff piles [TDN = 45.4, CP = 8.6 (% DM)]. Cows were allocated crop-residue piles on a 3-d basis. Cow BW, BCS, and rib and rump fat were measured at the start and end of the trial, and cow BW was corrected for conceptus gain based on calving data. Supplementation strategy did not influence (P > 0.1) forage intake. Supplementation of 100% WCDDGS or a 50:50 blend of WCDDGS and barley grain resulted in greater (P < 0.01) positive BW change compared with supplementation of100% barley. Because forage intake was not affected, the difference in cow BW was the result of supplement type. Results from this experiment indicate that wheat-corn blend DDGS can be used as a supplement for beef cows consuming barley straw-chaff piles to improve beef cow performance.