Quality Analysis of Farm-Made Feeds

Feeds and harvesting methods are known to affect the milk yield. This article introduces an in-depth nutritional analysis of various feeds for highyielding cows in the Arkhangelsk Region. Modern cow feeds with optimal chemical composition and digestibility can improve the milk yield and cows’ health. A quality diet depends on a number of factors and requires a regular analysis of proteins, fats, carbohydrates, fiber, and metabolizable energy content. In the local feeds, only annual grass silage with protein-rich legumes demonstrated a high nutritional value (9.01 MJ metabolizable energy; 12.33 % crude protein). We used the method of artificial rumen in vitro to determine the solids digestibility, with the best results belonging to annual grass silage (63.14 %). The research also included the effect of fiber and protein content on digestibility and milk yield. It revealed an inverse correlation between the fiber content in silage and the solids digestibility: hay (r) = –0.55 ± 0.2 (P ≥0.95), haylage (r) = –0.33 ± 0.25 (P ≤0.95), silage (r ) = –0.61 ± 0.18 (P ≥0.99). The feed quality correlated with the plant vegetation phase: younger plants provided better feed quality and digestibility. Between tillering and the end of flowering, cereals lost 23.2 % digestibility, 27.7% protein, 26.1 % fiber, and 28.9 % fat. Crude protein degradability in feeds depended on the harvesting time, the feed type, and the harvesting method. The average rumen protein degradability was 39.7 % for mixed-grass hay, 50.9 % for haylage (trench haylage – 48.8 %, packaged haylage – 52.6 %), 60.2 % for mixed-grass silage, and 60.0 % for annual grass silage. Advanced methods of feed analysis and harvesting proved able to increase the milk yield and improve the domestic dairy industry.