Byproducts of high energy value but low in nitrogen
The byproducts of the sugar industry (molasses, sugar beet pulp), the horticultural industry and products such as stock feed potatoes and bakery waste products are in this category. Because of the rapid rate of their digestion, there is usually a substantial requirement for supplementary sources of readily available nitrogen to be given to balance the excess of energy. With monogastric animals this may take the form of skim milk, blood meal, fish meal, soybean meal or dried yeast. In ruminants where the need in for a highly degradable source of nitrogen in the rumen, heat treated proteins are unsuitable.
Fats and oils are the best examples of byproducts in this category. Animal fat canbe included in the diet of pigs and poultry but at levels, which are usually less than 5% of complete diet. At higher levels of use, these may be problems of physical structure and adverse effects on carcass composition. In the case of pigs and poultry, the use of vegetable oils containing linoleic acid may lead may lead to soft fat, particularly if the linoleic acid content of the diet exceeds 16g/kg. With ruminants, there may be problems of maintaining cell wall digestion in the rumen if the proportion of fat in the complete diet exceeds five %.
Mango (Mangifera indica) seed kernel: It is a waste product of mango fruits canning industry which is available to the extent of one million tones annually in India. Mango seed kernels constitute about 15% of weight of the mango fruit. It contains 5.9-8.5% CP, about 75% NFE and about 2.5% crude fibre, which indicate that kernels are good source of energy. Mango seed kernels are palatable although it contains around 4% tannic acid. Mango seed kernel feeding to lactating cows has not shown any adverse effect on quality and quantity of milk produced. Ruminants have been shown to tolerate concentrates having upto 50% mango seed kernels without any adverse effects. They are recommended for use in the rations of ruminants only and that also at a level not exceeding 10% and with other feed ingredients which do not contain high levels of tannins.
Tomato pomace: Dried and ground pomace contain 22.36% CP, and 28.11$ CF with a nutritive value of 13.7-15.8% DCP and 60.8-73.3% TDN. Tomato waste can be incorporated upto 35-40% of the concentrate mixture in the complete diet of cattle and buffaloes.
Bakery wastes: The use of bakery waste as animal feed has been reported in India and abroad as a substitute for comparatively high priced cereal brans. The replacement upto 35% in the concentrate mixture by bakery waste in place of wheat bran is safe, effective and economical for raising of lambs for meat and wool production.Byproducts of category B are therefore well suited to being used in mixture with those of category C. They are also suitable for use with other feeds of high energy content but which are low in N, such as cereal grains.