Increased efficiency of straw utilisation by cattle and buffalo

• National Dairy Development Board, India

Despite increasing livestock numbers, animal production has failed to increase in the last 30 years in many African and Asian countries, especially India, due largely to severe overgrazing of the grasslands and fall in available forage production. Nutrition is expected to continue as the major limitation to milk production in India, where most milch animals are found in village communities that average one animal per household and have little or no forage. Consequently, cereal straws will remain the basal diet of these cattle and buffalo.
The major aim of this project is to maximise the efficiency of utilisation of straw or alkali-treated straw by lactating animals, thereby substantially lifting milk production in India.
Treating straw with alkalis increases the amount that animals will eat and also its digestibility. However, present methods are expensive and unsuitable for village farming. The project will seek and test more suitable methods, including ensiling straw with urea or treating it with gaseous ammonia, but even alkali-treated straw needs considerable supplementation.
In a more important approach, therefore, the scientists will try to increase intake and digestibility using fermentable nitrogen in a molasses/urea block and/or adding bypass protein. Because of the shortage of concentrates in India, any manipulation that leads to their more efficient use has obvious benefits. In recent preliminary trails, replacing expensive concentrate will fermentable nitrogen and bypass protein doubled the profit per cow without reducing milk production, and reduced the concentrate needs by half. The molasses/urea block, is successful, could also be used in future as a means of administering anthelmintics and other drugs.
The team at the University of New England will work mainly with cattle and sheep given diets based on rice straw. Using these animals, they will establish techniques for measuring bypass protein in a meal, for assessing response and for administering urea/molasses to cattle. One question of concern is whether ruminants can sense their need for fermentable nitrogen and can be relied upon to take sufficient from a block.
Concurrently, the Armidale team will cover another major area of research to determine the effects of modifying the rumen microbes through manipulating the protozoal and bacterial populations and enhancing the growth of anaerobic fungi. The will investigate the role of protozoa in the rumen of cattle and sheep on straw-based diets, establish techniques to examine anaerobic fungi and to quantify their effects in the rumen and study manipulation of the fungal biomass to increase output of nutrients from the rumen.
Scientists in India will concentrate on the responses of buffaloes and cattle to supplementation with molasses/urea blocks, with bypass proteins and with various combinations of the two, especially under village conditions.
Since it could eventually apply to some 60 x 106 milch animals in India alone, even the slightest improvement in nutrition brought about through any of the research in the project could have an enormous impact on productivity in Asia and Africa.
Project Leader:
Professor R. Leng, University of New England, Armidale, NSW.
Collaborators:
Mr Kurien, National Diary Development Board, Anand, India.
Related ACIAR Project:
8373 Utilisation of Fibrous Agricultural Residues as Ruminant Feeds.
Commencement Date: February 1983.
Estimated Expenditure: $407.609/3 years.