Nutrition for Draught Power A Review of the Nutrient Requirements of Draught Oxen

NUTRIENTS for any class of livestock are generally divided into four classes: vitamins, minerals, pro-teins and energy-giving nutrients. The requirements for these nutrients have been extensively investi-gated in beef and dairy cattle and tables drawn up in the form of feeding standards which tell one the amount of each type of nutrient required per ani-mal according to its type, sex, age and physiological state. For most nutrients it is customary to divide re-quirements into those for maintenance and those for production, i.e. growth, pregnancy and lacta-tion. Since there is no reason to believe that the maintenance requirements of draught oxen differ from those of cattle kept for other purposes, the rationing of such animals becomes simply a ques-tion of determining the extra nutrients needed for work. Vitamins and Minerals There seem to be no significant extra require-ments for vitamins and minerals in working animals over and above those contained in the extra food needed to supply the animal's increased energy needs. In very hot climates animals may need extra salt to replace that lost in sweat; there is seldom any lack of chloride ions in most diets, but forage crops in some tropical areas tend to contain very little sodium. Protein As in the case of vitamins and minerals, protein requirements seem to be minimal. Exercise seems to have little effect on urinary nitrogen excretion in man (Rennie et al. 1981) or sheep (Clapperton 1964). No work appears to have been done on draught animals, so the matter was investigated a