Reticulo-rumen Fermentation in Dairy Cows Fed 12 Times Daily with 4 types of Roughages Supplemented with Straw and Concentrates

Abstract

Abstract The aim of the experiment was to compare the effect of the roughage type on the reticulo-rumen fermentation when included in rations having the same physical properties expressed as chewing time and the same content of energy. The design of the experiment was a 4×4 latin square with 4 types of roughages and 4 dairy cows fed 3 times maintenance. The 4 roughages compared, were fodder sugar beet, beet top silage, beet pulp silage and grass silage. Each ration contained about 6 kg dry matter of one of the 4 roughages. The rations were balanced to the same chewing time of 800 min daily with ammonia-treated barley straw and to the same nutrient content by means of selected concentrates. The cows were fed every 2 hours. The rumen fluid samples were taken at 08.00, 12.00 and 18.00 hours for determination of the content of volatile fatty acids (VFA), ammonia nitrogen and pH. The four experimental cows differed in terms of the concentration of propionate (p<0.04), isovalerate (p<0.04) and of ammonia nitrog...