EFFECT OF VARYING DIETARY LEVELS OF CALCIUM AND PHOSPHORUS ON APPARENT DIGESTIBILITY AND RETENTION OF MACRO AND MICRO-MINERALS IN LACTATING SAHIWAL COWS.

Keywords: Calcium; phosphorus; magnesium; varying levels; apparent digestibility EN Calcium phosphorus magnesium varying levels apparent digestibility INTRODUCTION For optimal performance of dairy animals, appropriate supply of minerals in diet needs to be considered (Kronqvist, 2011). Phosphorus absorption is affected by multiple factors including total P intake, source of P, the Ca: P ratio, and dietary Ca, Mg and fat levels (Ekelund, et al., 2003). Schneider et al. (1985) found that when animals were offered P deficient diets, high levels of Ca reduced the absorption of P, due to reduction in rumen P solubility and also due to less P availability in the lower GIT. In contrast, Feng et al. (2015) reported lowest P digestibility in steers fed 0.15% dietary P. Similarly, Geisert et al. (2010) reported very low P digestibility in steers fed with 0.12% dietary P. Ternouth (1990) explained that slight reduction of P digestibility at very low dietary P levels can be attributed to the compromised microbial P requirements. [Extracted from the article]