Effects of Processing on the Nutritional Value of Feeds ( AVAILABILITY AND NUTRITIONAL VALUE OF VITAMIN)

Prolonged heat treatment can destroy the fat soluble vitamins and the water soluble vitamins thiamine, pantothenic acid, folic acid, and biotin. Such heat treatment can occur during the drying of protein supplements of plant and animal origin. For example, meat and bone meal contains little or no thiamine as a result of processing. The water soluble B vitamins are removed to some extent during the processing of fish into fish meal. The B vitamin content of fish-stick - water is higher than that of fish meal.
The pelleting process can alter the vitamin content of feeds. If insufficient anti-oxidants are present in the feed, pelleting may destroy Vitamins A, E, and K. On the other hand, pelleting may increase the availability of nicotinic acid and biotin, which are often present in feeds in a bound form.
Certain trace minerals act as pro-oxidants in feeds and can hasten the oxidative destruction of Vitamins A, D, and E. Manganese and iron are examples of such minerals. Non-nutritive feed additives, such as bentonite, which are added to feeds as binding agents, may interfere with the availability of riboflavin and certain divalent cations, such as zinc.
Some commercial methods for processing grains and oilseed meals result in decreased levels of certain vitamins in the final product. For example, coarse wheat flour grinders lose less Vitamin E than fine grinders. Germinated wheat may have a Vitamin E level as low as 30 percent of ungerminated wheat. Solvent extraction of soybean meal results in the removal of some of the Vitamins E and K and, thus, lower levels in the product.