The impact of the balanced feeding of cows in the dry period on the content of macroand microelements in colostrum and milk
The article presents the results of the evaluation of the dynamics of microelements in the colostrum and milk, as well as microelements in milk of dairy cows when used in the composition of the rations they are feeding regulators of metabolism (vitamin-mineral premixes P60-3/2 and P60-3/P, propylene glycol, calcium salts of fatty acids) in accordance with the developed scheme of combined use. Less pronounced decrease of calcium and phosphorus content in milk of animals of the second and third groups is established. On day 30 lactation revealed a significant increase in the content of copper and selenium in individuals of the second (respectively 66.2% (P<0.01) and 65.2% (P<0.05)) and third (respectively 67.2% (P<0.001) and 73.0% (P<0.01)) groups. On the 60th day of lactation in animals of the first group the increase of zinc content in milk was significant and amounted to 6.9% (P<0.05). In cows of the second and third groups, the copper content was significantly higher than in animals of the first group by 60.3% (P<0.01) and 62.6% (P<0.01), respectively. In individuals of the third group the content of selenium was significantly higher than in animals of the control group by 94.2% (P<0.01).