Effects of supplementation with sodium caseinate of early lactation diet on performance, digestibility, microbial nitrogen flow, and nitrogen efficiency in Holstein cows

Performance, digestibility of nutrients, microbial nitrogen flow (MNF) and nitrogen efficiency (NE) inearly lactating Holstein cows were investigated by diet supplementation with sodium caseinate (CN).Multiparous lactating Holstein cows (n = 15) with an average body weight of 638 kg and 21 days in milkwere assigned to a completely randomized design (five cows per treatment) and fed a basal diet with different CN levels (treatments 1, 2, and 3, contained 0, 50, and 100, g/d/head CN, respectively). The study lasted 49 days (first 14 days for adaptation and the last 35 days for collection of data). There were no statistical differences in dry matter intake, milk yield, milk lactose yield, and protein yield with CN supplementation. 3.5% fat corrected milk yield was increased by CN supplementation (P