Micro-Nutrient Profile of Blood Plasma in Relation to Age Reproductive Status of Holstein Friesian Cattle

To evaluate micromineral profile in blood plasma of HF cattle of different age groups and reproductive status. 72 female animals (6 in each group) selected at random from the HF herd according to their age, viz. 1–2 weeks, 2.5–3.0 months, 5–6 months, 8–9 months, 11–12 months and 17–18 months old, and of varied reproductive status, viz. cyclic/early pregnant heifers (22–24 months old), advanced pregnant heifers (30–36 months old), freshly calved cows (0 day), cyclic/lactating cows (2 months postpartum), anoestrus cows (5–6 months postpartum) and repeat breeder cows, were bled in heparinized vials once and plasma samples were utilized for microminerals assay following wet oxidation. The mean values of different microminerals (ppm), viz. zinc, iron, copper, cobalt and manganese varied between different age groups/reproductive status from 1.17±0.10 to 1.70±0.12 (P<0.05), 1.45±0.26 to 2.52±0.31, 0.60±0.04 to 0.98±0.07 (P<0.01), 0.25±0.01 to 0.60±0.05 (P<0.01) and 0.109±0.002 to 0.121±0.005, with an overall means of 1.50±0.04, 1.95±0.08,0.81±0.02, 0.44±0.02 and 0.115±0.003, respectively. Zinc level was significantly low in lactating and anoestrus animals compared to young growing calves, cycling and pregnant heifers; iron was lowest in repeat breeders and highest in pubertal and pregnant heifers; copper content was low in parturient and lactating cows compared to young calves, pregnant heifers and repeat breeding cows, and copper was also low in lactating cows and in heifers around one year of age. This trend of low micronutrient content of blood plasma particularly in lactating and anoestrus cows and growing heifers is indicative of their nutrient drain in milk and deficient feeding, whereas higher levels in very young milk-fed calves may be due to their higher intake through milk.