Response of age and reproductive stage on plasma cobalt concentration with and without feeding mineral mixture

Abstract

The experiment was conducted on crossbred prepubertal heifers (Frisian x Hariana) of 10 to 13 months, 18 to 21 months and 27 to 30 months, cycling heifers and cycling lactating cows to study the plasma cobalt concentration with and witho~t feeding mineral mixture. The pretreatment plasma Co concentration ranged from 0.21 ppm to 0.31 ppm, 0.28 ppm to 0.36 ppm, 0.38 ppm to 0.51 ppm, 0.89 ppm to 1.08 ppm and 0.99 ppm to 1.25 ppm respectively in above age group ofanimals. The plasmaCo concentration increased significantly on seventh day following of mineral mixture and peak concentration reached in all heifers on day 35. The observation revealed that the Co concentration in circulation is positively correlated with the increasing age and cyclicity in crossbred heifers and is associated with the activation of intrinsic mechanism responsible to bring the animal in eyelicity.