Summary and Conclusion
The composition of wheat, oat and paddy straws can be profoundly changed by soaking them in the cold in a 1-25 per cent caustic soda solution for 20-24 hours. By this alkali treatment of straws, the percentage composition of crude protein, ether extract , nitrogen-free extracts, ash, potassium, phosphorus and chlorine is lowered and that of crude fibre, calcium, magnesium and sodium is increased. During the treatment, dry matter is lost to the extent of 25 to 35 per cent.
It has been found that about 40 per cent of the alkali present in the solution is used up after one treatment. By regenerating the strength of the residual liquor with a suitable addition of caustic soda, two more batches of straw can be treated with good results.
Digestibility and metabolism experiments carried out with wheat and paddy straw on Sahiwal heifers show that the digestibility coefficient of total carbohydrates in either straw is markedly improved be the alkali treatment. This also increases the S.E. value of wheat straw from 21.3 lb. to 34.1 lb. and that of paddy straw from 24.4 lb. to 35.9 lb. per 100 lb. of dry material. The nitrogen, calcium and phosphorus balances are considerable improved when the animals are fed on the treated straw. The alkali treatment has a special significance in the case of paddy straw. It appears to remove some of the factors which effect the absorption and utilization of nitrogen, calcium and phosphorus from rations containing this straw.
The increased nutritive value and the better physical texture brought about by the alkali treatment suggest that the treated straw can be used in place of poor quality average hay in the feeding of horses.
From a comprehensive study of the problem of alkali treatment of cereal straws, we have thus come to the conclusion that poor quality roughages in India can be remarkable improved. The improvement lies in the better utilization of the carbohydrate, protein and minerals a ration in which treated straw forms the main roughage. It is also possible to meet the protein requirement of the animals at a lower level of concentrate intake than that commonly prescribed. The method of treatment and the results obtained are of special interest to those areas where paddy straw forms the staple feed for cattle.
In conclusion it may be stated that a separate investigation upon the economic aspect of the alkali treatment of straws is being planned.