Effect of additional feeding with rye grass silage on mineral metabolism in grazed cows
2000
Gallo, M. | Sommer, A. | Mlynar, R | Rajcakova, L. (Research Institute of Animal Production Nitra, (Slovak Republic)) | Knotek, S.
We studied the effect of additional feeding with rye grass silage on mineral metabolism in grazed cows. The experiment was performed with 12 cows of Pinzgau breed divided into 2 groups with 6 animals. The first group was given no silage, the second group got 4 kg dry matter rye grass silage daily. Concentrates and mineral supplement was given according to efficiency. The real intake of individual feeds and mineral substances in feed ration (Table 2) covered Na need and exceeded the Ca, P, K and Mg standard need. Content of mineral substances in blood (Table 3) showed higher P values, average Mg values and substandard Ca and K concentrations. Na content varied in groups and in grazing cycles. Values of studied substances in urine (Table 4) signalize higher Ca, P and K excretion, lower Mg excretion and very low Na excretion. The results of this experiment show that introduction of rye grass silage into feed ration of grazed cows did not change their mineral metabolism. Greater differences were caused by changes in quality of the grass stand and its various intakes between the cycles than by introduction of rye grass silage into the feed ration. Ca and P excess in feed ration showed itself in their higher excretion. K and Mg excess resulted in higher K excretion and lower Na and Mg excretion with required Na amount
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