Protein feed additive in the diet of fresh cows

An important reserve for eliminating protein deficiency is its rational utilization in animal feeding. Besides the content of total or crude protein in feeds, important indicators include its solubility and degradability, as well as the amino acid composition of the rumen-undegradable protein. Knowing the content of the soluble and degradable fractions of feed protein is necessary for rationing nitrogen available for microbial synthesis, while the amount of feed protein that does not break down in the rumen serves as a source of amino acids from the original feed. Determining the optimal level and combination of feeds in the diet, considering the transformation of feed protein in the gastrointestinal tract of ruminants, is crucial. The studies investigated the inclusion of the protein supplement ForaProtein S in the concentrate part of the diet of cows during the fresh period, replacing 100% and 30% of the crude protein from sunflower cake. The experimental groups showed an increase in the digestibility of dry and organic matter, crude protein, crude fat, crude fiber, and nitrogen-free extract by 3.2–7.8 percentage points. Furthermore, a significant increase in the digestibility of crude protein (73.8%) and crude fiber (62.5%) was noted in the third experimental group, and of crude fat (65.6%) in the second experimental group (P < 0.05). According to the research results, cows in the fresh period showed a tendency towards increased milk productivity in the experimental groups. When replacing 100% of the sunflower cake with the ForaProtein S additive, the average daily milk yield increased by 1.5%, and when replacing 30% of the sunflower cake, it increased by 3.9% compared to the control. The total yield of milk fat and milk protein in the third experimental group was on average 4.3% and 3.55% higher per cow than in the control. The concentrate consumption per 1 kg of milk in the second and third experimental groups was 333 g and 340 g, respectively, which is 4.1% and 2.1% lower than in the control group. The biochemical blood parameters of the cows in the control and experimental groups were within the physiological norm.