In India, 65 million dairy buffaloes produce about 60% of the country's milk, but high-yield dairy cows and their crosses with indigenous cattle represent a rapidly expanding portion of the national herd. Their feed consists of cereal crop residues, supplemented with grazing and/or cut grasses and tree leaves. However, forage availability from sources other than crop residues is often scarce, limiting productivity because of imbalance of nutrients and low digestibility of the available feed.

Earlier ACIAR projects on increasing the efficiency of straw utilisation by cattle and buffaloes (8203, 8601) demonstrated the benefit of using multinutrient blocks to supplement cereal crop residue diets. They also showed how catalytic nutrients that bypass fermentation in the rumen and are absorbed lower down in the gastrointestinal tract increase efficiency of feed utilisation and productivity. Following this research, molasses--urea nutrient blocks are now used widely in India to improve the efficiency of the rumen, while oil-seed meals are fed in catalytic amounts to provide bypass nutrients.

This project will continue the collaborative nutritional research between scientists at the University of New England (UNE), Armidale, Australia, and Indian scientists at the National Dairy Development Board (NDDB). It will extend the earlier work to include further assessment of the benefits of non-protein nitrogen, minerals and bypass protein supplementation and to apply findings at the village level. The roles of critical bypass nutrients (particularly proteins) will be investigated in terms of response relationships (for both growth and milk production) and cost effectiveness, and the resulting strategies will be field tested, validated and evaluated. The University of New England has well- established facilities for studying rumen microbiology and special competence in isotope dilution techniques.

Rumen manipulation to increase bacterial cell production and digestibility through components in the multinutrient blocks and the provision of appropriate bypass nutrients could result in large enough responses to warrant their adoption by small farmers. After the basal diet has been optimised, the research team intends to develop a 'balanced' bypass feed to provide the exact amounts of nutrients needed to boost milk production still further in cows and buffaloes with the best genetic potential.

By increasing milk yields, the project will help improve the standard of living of small farmers, who make up 75% of India's population. It will provide more milk for better balanced diets for both rural and city people. (It has been estimated that an average increase in milk yield of only 0.5 litres per day per head would provide the extra milk needed to meet the minimum needs of essential amino acids for the whole population of India.) Improved nutrition of cattle and buffaloes will also improve growth and reproduction rates.

There will be close cooperation between the research groups in India and Australia, and Indian scientists will visit Armidale for research and training. The Australian Project Leader will make a number of visits to India to assist the coordination of the work, and Australian Research Fellows will make periodic visits to establish technology, development and feeding trials.

NDDB will carry out feeding trials based at Anand, India,to develop response relationships to molasses/urea blocks and bypass protein in buffaloes and cows on local diets. This work will be aimed at assessing new sources of bypass protein. The Board will also develop a protected fat/maize/protein feed and test this as a supplement for milk production over and above that obtained with the optimum level of bypass protein, and study forage trees with high protein leaves as potential sources of forage, fermentable nitrogen and bypass protein.

At the same time, parallel studies will be done at UNE of microbial interactions using animals fitted with rumen cannulas. The team will develop methods to produce a bypass feed, test its protection against rumen degradation, and provide glucose, long-chain fatty acids and protein direct to the animal. The testing and validation phase will be undertaken at both institutional and village levels.