WASTE MINIMIZATION IN CATTLE FEEDLOTS BY RATION MODIFICATION

Public pressure to prevent pollution of the environment is increasing. Cattle feedlots can partly achieve this by adopting a waste minimizat ion strategy which either reduces the quantity of waste produced or th e pollution potential of waste. We analyzed the chemical and physical properties of feces produced by cattle fed six different rations: dry- rolled sorghum, dry-rolled sorghum + Actigest(R), dry-rolled sorghum Hoechst(R) product, steam-flaked sorghum, dry-rolled barley, and stea m-flaked barley. Animal performance was also monitored We found that t he chemical, physical, and biological characteristics of manure, the m ain waste product of feedlots, can be modified beneficially by changin g the feed ration. This may be possible whenever producers have a choi ce of ration types, as do most Australian lot feeders. Further, the po tential for water pollution may be reduced by having less nitrogen, ph osphorus, salt, and volatile solids in the manure. We also suspect tha t a high starch content, a low pH, and the concentration of sodium, po tassium, calcium, magnesium, iron, and other minerals in manure may al l influence odor generation from the manure that accumulates on the fe edlot surface. (This accumulated manure is known as the feedlot pad). Ration type influences these characteristics. Thus, intensive cattle f eeding enterprises that have particular environmental concerns may be able to reduce them through ration modification. However, waste minimi zation can be widely adopted only after animal nutritionists recognize that animal performance is not the only criterion by which ration sui tability should be assessed.