Mineral Status and Their Retention in Lactating Cows in Relation to Soil, Fodder and Feed in Kamrup District of Assam

A study was conducted in Kamrup district of lower Brahmaputra valley to assess the mineral status of blood in relation to soil, fodders and feeds in crossbred and nondescript indigenous lactating cows. A mineral balance trial was conducted. The purpose of the study was to evolve a suitable strategy for adequate supplementation of deficient minerals. Samples of soil, fodders, feeds and blood were collected from the animals of various farmers of different villages and different elements namely Ca, P, Mg, Fe, Cu, Zn and Mn were estimated. Study revealed that soil P was well below the critical level which Ca was close to the critical level. The other elements like Mg, Fe, Cu, Zn and Mn were observed adequate and above the critical level. Out of the total fodder samples, analyzed 33% were deficient for Ca, 67% for P, 56% for Mg 61% for Zn, 30% for Cu and 29% for Mn. Moderate to high concentration of Fe was observed in different fodders screened and analyzed. Cultivated fodders showed slightly higher concentration of minerals than locally available natural grasses. The different ingredients used for preparation of ration contained adequate Ca P Fe Zn and Mn. Serum Cu and P concentration was below the critical level in crossbred and nondescript indigenous cows respectively Low phosphorus concentration in soil and fodders and low Cu concentration in fodders and feeds are reflected in the blood of the animals suggesting the need of extra supplementation of these two elements to the lactating cows of this district. The mineral balance trial was conducted using crossbred Jersey and Holstein Friesian lactating cows. DM intake and DM digestibility (%) did not vary significantly between the two groups Both the groups showed positive balance for all the elements analyzed viz. Ca P Mg Fe Cu and Zn. The retention percentage of all the elements was higher in crossbred Jersey cows but was significant (P<0.05) only for Mg