Performance and ruminal fermentation of second-trimester pregnant beef cows fed short-season high-moisture corn stover or barley greenfeed during winter in western Canada

Abstract

This study evaluated performance and ruminal fermentation for cows fed short-season high-moisture shelled corn stover with corn dried distillers’ grains with solubles (COR) or barley greenfeed (BAR) that was either swathed (S-COR; S-BAR; Experiment 1) or baled (B-COR; B-BAR; Experiment 2) as winter-feeding systems. In Experiment 1, cows were randomly assigned to S-COR or S-BAR and fed for 52 days in the fields where crops were grown. Body weight (BW), subcutaneous rib and rump fat, and body condition score (BCS) were measured, with no differences detected between treatments ( P > 0.05). However, S-COR had a lower estimated dry matter intake (DMI) than S-BAR ( P ≤ 0.03). In Experiment 2, cows were assigned to B-COR or B-BAR for 42 days and fed in field paddocks. Cows fed B-COR had less ( P ≤ 0.01) DMI, final BW, rib fat, rump fat, and BCS than B-BAR, with no differences ( P > 0.05) for ruminal pH. Total SCFA concentration was greater ( P ≤ 0.05) on day 21 for B-BAR than B-COR, but not on day 42. Under western Canadian conditions, COR may reduce DMI and the performance of pregnant cows, suggesting that additional preservation and supplementation strategies should be investigated.