%0 Journal Article %T Diurnal variations in milk macro-mineral concentrations in Holstein dairy cows in Urmia, Iran %J Veterinary Research Forum %I Faculty of Veterinary Medicine, Urmia University %Z 2008-8140 %A Nozad, Shahram %A Ramin, Ali-Gholi %A Asri Rezaie, Siamak %D 2012 %\ 12/01/2012 %V 3 %N 4 %P 281-285 %! Diurnal variations in milk macro-mineral concentrations in Holstein dairy cows in Urmia, Iran %K Milk %K Cows %K Milking time %K Holstein %K Macro-minerals %R %X Milk samples from high and low milk producer Holstein cows, were obtained during the morning and afternoon milking over a one week period. Overall, 1064 samples were tested within 14 times sampling in Urmia, Iran. Milk macro-mineral concentrations in the morning milking and in low producers were greater than in the afternoon and in high producers. The highest and lowest concentrations were observed in Na+ and Mg++, respectively. Mean milk values between low and high producers in the morning, afternoon and daily milking times were different (p < 0.05). The individual comparison of milk parameters between both groups in the different milking times were also different (p < 0.05). The results of correlation among macro-minerals in the morning, afternoon and overall milking showed significant and positive correlations among all macro-minerals except for Na+ and K+, in which there was a significant negative correlation (p < 0.05). The highest and lowest correlations were found between Ca++ and inorganic phosphorus (IP) (r=0.37, p < 0.05) and Na+ and IP (r=0.10, p < 0.05), respectively. It is concluded that the concentration of macro-minerals in different producers varied between milking times. The sodium concentration was the highest while Mg++ was the lowest among macro-minerals. The correlation between Ca++/ IP was the highest, while Na+/K+ revealed a negative correlation. Therefore, by organizing the appropriate macro-minerals in the ration, it would be possible to achieve an optimal purpose from animal husbandry. %U https://vrf.iranjournals.ir/article_1603_23180f572729efc8aa819d80c515b961.pdf