PHOSPHORUS AND BEEF-PRODUCTION IN NORTHERN AUSTRALIA .2. RESPONSES TO PHOSPHORUS BY RUMINANTS - A REVIEW

Results of studies to examine the effect of supplying supplementary P to grazing ruminants are reviewed. Effects on feed intake and digestibility, liveweight change, reproduction rate, milk yield and calf growth rate are considered. Sources of P and delivery systems are presented. Responses to P are contingent on the P level in the diet, P status of the animal, class of animal, physiological state and supply of other nutrients in the diet. Significant responses will occur only when P is the primary limiting nutrient in the diet.