栄養・飼養2

[I-16-18] Effects of grain vinegar feeding on feed intake, milk production, and milk fatty acids of lactating Holstein cows

*Seongjin Oh¹, Tomohiro Mitani¹, Masahito Kawai², Koichiro Ueda¹ (1. Research Faculty of Agriculture, Hokkaido Univ., 2. Field Science Center for Northern Biosphere, Hokkaido Univ.)

[Objective] In the 128th meeting, we reported that when grain vinegar of 2 different concentrations (4.5% vs. 15% acetic acid) was fed to non-lactating cows (1 mol/d), the rumen liquid volume was greater in 4.5% than 15% and control. The following trial was carried out to investigate the effect of 4.5% vinegar feeding on feed intake and milk yield of lactating cows. [Methods] The lactating Holstein cows (n=19) were blocked into two groups according to body weight, days in milk, parity numbers, and milk yield. Cows were used in 2 periods (3+3 weeks) cross-over design. Cows were fed corn silage and concentrate with or without 4.5% grain vinegar, which was top-dressed on the feed twice a day (1.7 mol/head). The pH, volatile fatty acid, and ammonia-N in the rumen and NEFA, BUN in the plasma were analyzed. The milk composition and milk fatty acid profile were analyzed. [Results] No significant differences were observed in blood, rumen fermentation parameters, water, and concentrate intake, while vinegar feeding decreased corn silage intake and milk yield. The milk fatty acids including iso-C14:0, iso-C15:0, and iso-C16:0 were decreased by vinegar feeding.