The Effect of True Dietary Calcium (Ca) to True Dietary Phosphorus (P) Ratio on Urine Volume in Grower Pigs

Abstract

Water is one of the known essential nutrients required by pigs to optimize their production potentials. However, excessive intake of water by the pig leads to high volume of urine excretions resulting in difficulty in manure management. Inappropriate Ca to P ratio in pig diets is majorly responsible for high volumes of urine excretions. Therefore, the effects of true digestible Ca to true digestible P ratios on urine excretions were investigated. 36 Yorkshire barrows of 24.2 ± 1.9 kg body weight (BW) were used in the study in a randomized complete block design of 6 pigs per block. 6 diets with different ratios of Ca to P were formulated as :0.76:1, 0.98:1, 1.17:1, 1.39:1, 1.60:1 and 1.80:1 for diets 1, 2, 3, 4, 5 and 6, respectively. Animals were fed for 15d consisting of 10d adaptation to their diets and 5d of urine collection. Orthogonal linear and quadratic contrasts were used to separate means and significance level was set at P ≤ 0.05. There were no significant (P > 0.05) differences in the volume of urine for animals on all dietary treatments. Nevertheless, pigs on diet 2 had numerically the least or smallest volume of urine excretions. It was thus concluded that narrower ratio of Ca to P should be employed in reducing urine volumes to ease manure management in the pig farm.