Protection of protein meals or bypass protein
The protein of oil cakes, having higher protein degradability, such as groundnut cake, mustard cake are utilized in the rumen less efficiently because of release ofammonia at faster rate, thereby resulting in its inefficient utilization by bacteria and causing economic losses. To improve the protein efficiency, a technology was developed to protect the protein of such meals from ruminal degradation, which allowed its degradation in the lower tract into amino acids. These amino acids along with those available from the microbial protein synthesized in the rumen from the degradable protein of other dietary sources including NPN compounds are absorbed and thus results into higher availability of amino acids for higher productivity of animals. Proteins can be protected from ruminal degradation either by heating the oil cakes or by chemical treatments such as tannins and formaldehyde. Amongst various treatments, formaldehyde treatment of oil cakes was found to be economical and effective way. In fact, the protein meals treated with formaldehyde in sealed chambers formed complexes as a result of reaction with aldehyde group and amino groups of lysine of oil cakes, which is capable of resisting the microbial degradation in the rumen but this complex is hydrolyzed in the lower digestive tract because of lower pH.
The optimum protection of protein meals by treating the oil meals with 1.0 to 1.2 g formaldehyde/ 100 g CP was achieved in 9 days of incubation period. Different protein meals were studied for optimum protection with different levels of formaldehyde. Various feeding trials conducted at the National Dairy Research Institute, Karnal and National Dairy Development Board, Anand have shown the utility of this technology even under field conditions to overcome the nutritional deficiency in ruminants. In view of benefits of this technology, commercial plants to manufacture the protected protein have been established in Itola (Vadodra) and Godhra in Gujarat by the National Dairy Development Board having the capacity of 150 kg batches of bypass protein meal with 75% rumen undegradable protein at a time. Replacing the 1 kg of untreated meal/ animal/day with protected protein meal resulted in increase milk yield from 0.7 to 1.1 kg/ day depending on the byproducts used in feed and the type of milch animal. The additional income per animal including that of bypass protein costs in buffaloes, indigenous cows and crossbred cows was estimated to be Rs 12, 9 and 7(base year?), respectively, which indicated that buffaloes were most responsive for this technology. In an impact assessment of increasing efficiency and productivity of ruminants in India by the use of protected protein technology, Australian Centre for International Agricultural Research (ACIAR) demonstrated that the overall benefit: cost ratio for the project was 123.6:1, which gave an internal rate of return of 43.8%.