Epsilon Open Archive

Abstract

Large number of by-products from the agricultural industry can potentially be used as protein sources in diets to dairy cows. The increasing demand for alternative dietary protein supplements in ruminant production systems is due to a growing requirement for a more sustainable food production from the livestock industry. However, use of agro-industrial byproducts in diets to dairy cows and beef cattle have to be efficient in terms of nutrient utilization, be complementary to basal feed ingredients and not impair production. Since in vivo studies are very expensive and laborious, using an in vitro gas production technique enables identification of by-products which can efficiently replace conventional ingredients. Recently, there has been great progress in the development of the automated gas in vitro technique, which enables treatment evaluation of ruminal fermentation profiles, diet digestion rates (Huhtanen et al., 2008), methane (CH4) production (Ramin and Huhtanen, 2012) and estimation of utilizable crude protein (uCP; Edmunds et al., 2012). The aim of this study was to evaluate effects of levels of agro-industrial by-products replacing soybean meal in diets based on silage and barley or beet fibre on neutral detergent fibre (NDF) digestibility, true organic matter (OM) digestibility, uCP, fermentation parameters and CH4 production in vitro.