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 aim of the study was to investigate the effect of stimulating milk protein and milk yield in dairy cows fed a diet providing an additional influx of amino acids and glucose into metabolic pool. Experiments were conducted on two groups of first calved Holmogor cows, 4 animals each, on 3 mo of lactation, whose carotid artery was put under the skin to obtain arterial blood. During one month before and two months after calving the cows received diet composed of grass-legume hay, diverse grassy silage, fodder beet and concentrate. Then cows in treatment and control groups received diets with different levels of low-degradable protein and starch: the percentage of soybean meal in treatment and control groups was 23 and 7%, that of corn grain − 30 and 5% respectively and these diets did not differ in the percentage of crude protein and metabolizable energy. After 30 days after the change of diet, the daily average milk yield in treatment group was higher by 15.8% (P<0.01), milk protein production by 18.3% (P<0.05), and urea content in milk was lesser by 11.4% (P<0.05) compared with control. The data obtained suggest that the feeding of cows diet providing additional influx of amino acids and glucose into metabolic pool does provoke an increase in production of milk protein and efficacy of using amino acids for productive purposes.
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