Metabolic and Endocrine Indexes in Cattle vis-à-vis Physiological Status and Seasonal Variation

For sustained and efficient livestock production adequate dietary intake of essential nutrients is imperative. Requirement for most minerals, influenced by physiological factors (age, sex, type and level of production) need to be studied thoroughly. Blood samples (110) were collected in 4 different seasons of the year from cattle having varied physiological demands in Sumbal-Hajin area (District Bandipora) of Kashmir valley. Metabolic indices like plasma macro-minerals (Ca, P_i and Mg) were measured using standard kits while as micro-minerals (Cu, Zn and Fe) were estimated using atomic absorption spectrophotometer. Endocrine indices like plasma thyroid hormones (T₃ and T₄) were estimated by Radioimmunoassay technique. The results revealed suboptimal levels of Ca; adequate P_i in all animals throughout the year; Mg level just above the critical concentration in calves, heifers and lactating cows especially during spring and winter; marginal Cu and Zn in all categories; high Fe concentration in all categories in all seasons except spring in which it was adequate; and adequate T₃ and T₄ values irrespective of the physiological status and/or season of the year. The experimental findings advocate Ca, Cu and Zn supplementation in all categories round the year, and Mg supplementation in spring and winter especially in calves, heifers and lactating cows.