Evaluation of barley silage with varying ruminal in vitro fiber digestibility on lactation performance and chewing activity of lactating dairy cows in comparison with corn silage

There is limited knowledge on the effect of barley silage (BS) with different ruminal in vitro neutral detergent fiber digestibility (ivNDFD) on dairy cow performance and chewing activity. The objective of this study was to assess the effects of BS varieties selected for varying rates of ivNDFD on lactation performance and chewing activity of high-yield dairy cows in comparison with a new corn silage (CS) hybrid. A 4 x 4 Latin square design was applied in this study with four mid-lactating multiparous Holstein cows. The cows were fed diets containing 49% barley-based concentrate and 51% forage (dry matter basis). The results show that cows fed CS produced more milk (P < 0.05) and had greater (P < 0.05) feed efficiency than cows fed BS. Cows fed BS with relatively higher ruminal ivNDFD did not show significant difference from the cows fed other BS varieties in milk yield and total chewing activity. The preliminary results indicated that a univariate approach with only one factor consideration (ivNDFD) might not be a satisfactory method for evaluating and ranking BS quality. However, a large-scale animal study with different stages of lactation (early, mid, late) is warranted to confirm this finding. This new corn forage hybrid may be an appropriate option as forage source for high-producing dairy cows in western Canada.