Effect of Premix and Seaweed additives on minerals status of Lactating Friesian Cows

Eighteen lactating Friesian cows with average body weight of 534.44±13.04 kg, ranging from 450 to 660 kg, average milk production of 12.16±0.10 kg/day, ranging from 9.52 to 14.80 kg/day and average parity of 2.22±0.33; ranging from 1 to 5 were used during summer season 2011, for 150 days starting with one week after parturition, from June to November. Animals were divided into three similar groups with six cows in each group based on body weight, milk production and parity. All animals were fed the basal ration consisted of 40% concentrate feed mixture + 40% corn silage + 20% rice straw (on DM basis) without additive served as a control (group 1) or with 25 g premix / head / day (group 2) or with 50 g seaweed / head / day (group 3). The obtained results showed that the contents of calcium, phosphorus, copper, zinc and manganese in basal ration were lower than the recommended requirements of dairy cows. Minerals intake expressed as g or mg per day was nearly similar for the different groups except potassium and manganese. Seaweed group showed significantly (P<0.05) the highest apparent absorption and retention of different minerals followed by premix group, while the control group had the lowest values. Seaweed group showed significantly (P<0.05) the highest minerals concentrations in hair, blood plasma and milk followed by premix group, while the control group had the lowest contents.