Agro-industrial by-products in Southeast Asia are available in plenty, due to the emphasis on crop cultivation. By-products of agro-industries represent an important source of feedstuffs for ruminants and non-ruminants. Interest in their utilization is stimulated by their potential value for feeding farm livestock and, more recently, by the energy crisis. However, it is doubtful that the bulk of these by-products are incorporated efficiently into feeding systems which ensure maximum livestock response and therefore productivity. The use of these byproducts for supplementary livestock feeding is justified when the forage supply is inadequate for the animals’ needs, either in terms of quantity or quality, or when the cost of the supplementation is less than the value of increased animal production achieved. Supplementary feeding is also justified in times of drought or other feed shortages when the importance of providing the animals immediate nutrient requirements to keep them alive sometimes outweighs other considerations, including the cost of the feed. Concentrate supplements are crucial in such crisis situations, though their quality need not be high. Agro-industrial by- products for feeding livestock present a number of advantages, such as:
- availability in substantial quantities
- relatively low or no cost
- low feeding value of tropical forages
- justification for supplementation
- feed shortage during periods of scarcity and uneven distribution
- scope for import substitution
- improved efficiency of the stall feeding system.
The by-products obtained from grain processing (brans), oil seed processing (oil meals), pulses processing (chunni) are the major and important feed ingredients to Indian livestock. Almost all the quantities of these by-products produced in the country are utilized as livestock feed except the quantities exported to other countries. These by-products are considered as traditional or conventional feedstuffs. The brans are the main source of concentrate feeds accounting to 40 to 47 % of the total concentrate feeds produced in the country. Another important source of concentrate feeds are oil meals constituting 26 to 31 % of the total concentrate feeds produced. Thus, these two industrial by-products cover more than 70 % of the total concentrate feeds fed to Indian livestock.
The available by-products can be grouped into two categories: primary by-products that form the main base in a feeding system, and secondary by-products which supplement a diet. Concerning the former, particular attention is focused on the utilization of by-products from rice, sugarcane, oil palm and coconuts. Additional to these are the by-products from wheat, rubber, tapioca and sago. Secondary by-products include inter alia rice hulls; pineapple and cocoa waste; pulse straws; tapioca leaves; cottonseed, soybean and groundnut cakes; sal seed and guar meals; mango kernels; meat and bone, blood and feather meals and poultry litter. Approximate extraction rates of certain by-products are tabulated.
Amongst the primary by-products that form the major component in the diet, particular attention is focused on rice bran, molasses, oil palm sludge, palm press fibre and coconut cake. Excluding molasses, the general conclusion that emerges concerning efficient utilization of each by-product and good animal performance is that inclusion at rates of 30 to 40% is optimal. Implicit in this performance is the value of molasses (20 to 30%) in enhancing palatability, serving as a carrier of non-protein nitrogenous (NPN) sources like urea, and as an energy supplement. It is suggested that for more intensive utilization of these byproducts where available, 50 to 70% of the total diet should be made up of the byproduct plus molasses