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Content of Manganese in Biological-Materials of Dairy-Cows

SVIATKO P
Veterinarni Medicina 38, 1993, 539-546

Manganese in serum, hair and excrements of 2,720 dairy cows was determined under the practical conditions of animal husbandry. Mn content in the above-mentioned materials indicated the state of sufficient supply in 1,480 dairy cows and Mn deficiency in 1,240 dairy cows. The results of Mn content in the followed materials obtained from dairy cows in a different state of organism supplying are presented in Tabs. I - III. Sufficiently supplied dairy cows (Tab. I, Ist group) displayed a significantly higher (P < 0.01) content of Mn in serum equal to 0.042 mg/l with 95 % interval of reliability, of the mean value (95 % IR) 0.039 - 0.046 mg/l compared with the pooled group of deficient dairy cows (K) with the content of Mn in serum 0.037 mg/l and 95 % IR in the range of 0.034 - 0.040 mg/l of serum. Mn content in hair (Tab. II) of sufficiently supplied dairy cows (Ist group) exceeds the limit value 7.0 mg/kg DM as for both the mean value and the 95 % IR. The content of this element in dairy cows in the state of primary and secondary deficiency (groups II and IV) lies below the limit value within the range. The IIIrd group of dairy cows, which was in the state of depletion, contained Mn above the limit value. The dynamic process of deficiency development is in progress in this group of dairy cows, indicated by a reduced content in serum and excrements and for time being a still sufficient content in hair which is expected to decline with time and further growth and eventually lead to primary deficiency. Mn content in hair of sufficiently supplied dairy cows (Ist group) was significantly higher (P < 0.01), reaching the value 17.17 mg/kg DM and the range of 95 % IR 15.17 - 19.17 mg/kg DM, in comparison with dairy cows in different states of Mn deficiency (IInd, IIIrd and IVth group) in which the mean values varied in the range 5.09 - 13.28 mg/kg DM and 95 % IR ranged from 4.74 to 14.51 mg/kg DM. Differences in Mn content in hair between the deficient groups were statistically significant. Mn content in excrements (Tab. III) of sufficiently supplied dairy cows (Ist group) amounted to 312.6 mg/kg DM with 95 % IR in the range 287.8 - 337.4 mg/kg DM. This content was significantly higher (P < 0.01) in comparison with Mn deficient dairy cows (IInd, IIIrd and IVth group) in which the mean values varied in the range 126.7 - 230.7 mg/kg DM and 95 % IR ranged from 118.9 to 251.6 mg/kg DM. Differences in Mn content between the deficient groups of dairy cows were also significant. The results indicate a marked difference in Mn content in excrements with regard to the state of supplying of dairy cows. Manganese content in dairy cows in the state of sufficient supply exceeded the limit value 265.0 mg/kg DM, and in cows in different deficiency states Mn content below limiting value was recorded. Our results confirmed that the content of Mn in excrements can serve as a reliable indicator of Mn supplied by feed and indirectly of the state of its supplies to the organism. The results indicate the occurrence of Mn deficiency in dairy cows under practical conditions. Out of the total number of examined dairy cows, 46 % were in the deficiency state. Our results confirm that the content of manganese in serum, hair and excrements reflect the state of manganese supply to the dairy cow organism. In order to evaluate correctly the state of organism supply in dairy cows or to diagnose the manganese deficiency, one must consider all three indicator materials simultaneously


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