Всероссийский научно-исследовательский институт физиологии, биохимии и питания животных – филиал Федерального государственного бюджетного научного учреждения «Федеральный научный центр животноводства – ВИЖ имени академика Л.К. Эрнста»
ABSTRACT. The trial duration 2 months was performed on 3 groups of Kholmogor bulls with an initial live weight 280 kg at the age of 10 months, 3 bulls each. The basic ration consisted of 6 kg of feed and 16 kg of grass pastures. With the aim to increase the level of metabolizable protein, dry protein feeds from technical food industry waste were included in rations, in group I − on the basis of sunflower cake, in group II − on the basis of a brewer's grain, in group III − on the basis of alcohol grain stillage. At the end of the trial period, balance measurements were conducted and sampling the ruminal fluid was performed 3 h after the morning feeding. In ruminal fluid samples were determined pH value, the ratio of volatile fatty acids, ammonia nitrogen concentration and cellulolytic activity. Intergroup differences observed in the consumption of crude protein, crude fiber and crude fat in the absence of influence of high level of protein supply on feed dry matter intake. Values of рН rumen fluid were in the range of 7.0-7.1, between-group differences in concentrations of ammonia, volatile fatty acids and cellulolytic activity were not reliable. In bulls of group II, the digestibility of dry and organic matter, crude protein, crude fiber and fat was above these indicators in I and III groups. There were no significant intergroup differences in the value of the average daily live weight gain (1150 g on the average in groups). In general, the used unconventional sources of feed protein did not have a negative effect on the processes of ruminal fermentation; when feeding feed based on brewer's grain, a higher positive effect on the digestibility of nutrients was noted, compared with an additive based on alcohol grain stillage.
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