Levels of micro-nutrients in soil, feed, fodder and animals of north east transition and dry zones of Karnataka

The Calcium (Ca), Phosphorus (P), Magnesiun (Mg), Copper (Cu), Zinc-(Zn) and Iron (Fe) content in soil (n = 10) were well above the critical levels In north east transition zone and north east dry zone. Ca (63.44 ppm), P (0.3S ppra) and Mg (40.77 ppm) content in water in north east dry zone were higher than in north east transition zone. Paddy straw and jowar kadbi, the main dry roughage sources in these zones, were low in most of the minerals screened. Cultivated green fodders (maize, jowar and green gram) and grasses were good sources of Ca, Cu, Zn and Fe. Green gram fodder showed high content of Ca (2 - 2.6%) and Mg (0.85%). Tree leaves like glyricidia, neem and subabul (n = 12) were good sources of Ca (0.8 - 3.1%). Amongst the concentrate feeds, grains were low in most of the micro-nutrients except iron. Groundnut cake and rice bran contained high levels of P (>1.0%). Some of the unconventional feeds like groundnut haulms, gram husks had high levels of Ca (1.75%) and iron (1600 - 3000 ppm). About 49% of the crossbred cattle (n = 40) showed low blood plasma Ca (7.07 mg%) and P (3.51 mg%) values in north east transition zone and 75% of the animals in north east dry zone showed low Zn values (0.72 ppm). Most of the animals were found to have reproductive problems which could be attributed to micro-nutrient deficiency. Providing region specific mineral salts or supplementing top feeds, green fodder, oil cakes and brans which are good sources of these minerals would help in overcoming the mineral deficiency.