Silage fermentation profile, chemical composition and economic evaluation of millet and soya bean grown in monocultures and as intercrops

Abstract

AbstractIn recent years, dairy farmers in semi‐arid regions have shifted from maize (Zea mays L.) as their primary source of feed to drought‐tolerant crops, such as millet (Pennisetum glaucum L.), due to lack of water for irrigation. However, millet alone may not provide feed of sufficient quality and crude protein content for dairy cows. A field experiment was conducted in 2 years to evaluate (i) whether intercropping millet with a relatively drought‐tolerant soya bean cultivar (Glycine max Merr, cv. Williams) could improve silage quality with minimum yield penalty, and (ii) if the application of molasses could further enhance the nutritive value of silage of millet–soya bean intercrops. There were three intercropping ratios (60% millet with 40% soya bean, 50% millet with 50% soya bean, 40% millet with 60% soya bean) and monocultures of millet and soya bean. Mixed forages were treated with three levels of molasses: M0 (without molasses), M1, and M2 (2·5 and 5% fresh matter respectively). Inclusion of soya bean in millet crops resulted in decreased silage yield compared with millet alone. The highest yield was obtained from the ratio of 60% millet with 40% soya bean. Molasses‐treated silage had higher lactic acid, lower pH, and lower acid detergent fibre (ADF) and neutral detergent fibre (NDF). Silage produced from millet–soya bean intercrops exhibited enhanced fermentation, indicated by lower pH (3·64) and higher lactic acid (16·63 g kg−1 DM) than silage from monocultures. Intercropping ratios had lower water‐soluble carbohydrate, ADF and NDF than millet monoculture. Overall, an intercropping ratio of 60% millet with 40% soya bean was advantageous over other ratios in terms of higher yield, nutritive value and economic value.