Factors affecting the metabolizable energy content of poultry feeds. 7. The effects of grinding, pelleting and grit feeding on the availability of the energy of wheat, corn, oats and barley. 8. A study on the effects of dietary balance
Mcintosh, J.I.; Slinger, S.J.; Sibbald, I.R.; Ashton, G.C.
Poultry Sci 41(2): 445-456
Three experiments were conducted to determine the effects of grinding, pelleting, dietary balance, and grit feeding on the metabolizable energy (M.E.) content of cereal grains and on the weight gains and feed efficiencies of chickens. No consistent increase in M.E. resulted from the grinding or pelleting of cereal grains. In 2 experiments, whole wheat yielded more M.E. than either ground or pelleted wheat. However, in the remaining trial little difference was evident between ground, pelleted or whole wheat. Similarly, the grinding or pelleting of barley, oats or corn exerted no consistent effect on the M.E. values of these grains. Evidence indicates that the size of the grit may be a factor influencing its effect on energy availability. Feeding hen-size grit in 1 experiment did not influence the M.E. contents of the grains, whereas in 2 other trials grower-size grit enhanced the M.E. values. The birds consumed much more of the smaller sized grit which may have been a factor in explaining the difference. The results suggest that grit has an action(s) in enhancing energy availability, in addition to that of grinding feed in the gizzard. One experiment involved the feeding of "balanced" and "unbalanced" diets. The balance of the diet did not influence the M.E. values of the cereal grains in a significant manner. However, the results suggest that the balance of the diet may have exerted a variable effect on M.E. depending upon the type and physical form of the grain studied.