| Popis: |
The main sources of protein in the rations of lactating cows in the farms of our country are waste products of the oil extraction industry. Using them in the rations of highly productive cows in high amount is fraught with loss of productivity and deterioration of animal health due to the high level of digestible protein. With an increase in milk production the role of by-pass protein in feeding cows increases. By-pass protein in the market of feed products of our country is mainly represented by processed beans and fi shmeal. They are an excellent source of protein, which is slowly digest in the rumen, but due to its high cost, deterioration of quality, seasonality of supply the search for alternative sources of protein is relevant. The article contains practical material on the use of protein concentrate in the rations of lactating cows of Ayrshire breed. It has been noted during the studies that the inclusion of protein concentrate in the ration in the amount of 1,0 and 1,5 kg/head/day instead of other protein feeds increased the level of bypass protein. The introduction of the maximum amount of protein concentrate into the ration contributed to a change in the nitrogen balance in cows during the increasing the milk yield period. Thus, the inclusion of protein concentrate in the ration of the nitrogen balance in the experimental groups was positive, and in the control it was negative. According to the degree of use of nitrogen in the ration, the best values have been observed in cows of the 2nd and 3rd experimental groups, which had protein concentrate “Agro-Matic” in the ration, where the nitrogen retention was 189,6 and 201,2 g, respectively. The use of protein concentrate did not have a negative eff ect on the biochemical parameters of the blood. The level of total protein in the blood serum when feeding protein concentrate in the amount of 1,0–1,5 kg increased by 11,7 (P > 0,95) and 5,9 %. The level of urea decreased both when using 1,0 kg of protein concentrate (P > 0,95) and 1,5 kg, which was lower than the level in animals from the control group. |
