Abstract

Mineral supplements differ in their bio-availability, which must be taken into consideration, before the use of any such supplement. Two crossbred fistulated calves housed in individual pens and fed Calcium carbonate (T1) and Calcite powder (T2) were used to study the distribution and disappearance pattern of calcium and its influence on rumen fermentation. The proportion of Ca distributed in soluble, particulate and solid phase of the rumen digesta, pH of the filtrate, Ammonia-N and VFA concentration, rate of disappearance of Ca and rumen flow rate, dry matter intake and other related measurements were used as evaluation parameters. The results obtained showed that there were no significant difference (P<0.05) between the treatments in NH3- N concentration in the rumen liquor of the experimental animals, indicating that replacing CaCO3 with calcite powder did not affect NH3-N concentration in the rumen. There was no significant difference between different sources of Ca fed to animals in total DMI or DMI per 100 kg body weight of animals, suggesting that calcite powder had any adverse effect on the palatability of the diet. Rumen pH and concentration of NH3-N and total VFA in the rumen liquor of animals were similar, indicating that functions of cellulolytic organisms in the rumen were not affected by feeding calcite poweder.