Manganese in forage and in dairy cattle nutrition
1994
Oresnik, A. (Biotechnical Faculty, Ljubljana (Slovenia). Zootechnical Dept.)
A literature review of manganese significance in dairy cattle nutrition and of manganese concentrations in forage and concentrates is presented in the article. Results of obtained manganese concentrations in forage (grass, grass silage, hay and maize silage) produced in years 1986/87 and 1992/93 on six groups of large dairy farms in Slovenia are performed. Forage samples contained in kg of dry matter following concentrations of manganese: grass (n 140) 93.6 +/- 45.9 mg; grass silage (n = 166) 141.5 +/- 58.1 mg; hay (n = 91) 107.3 +/- 46.3 mg and maize silage (n = 119) 38.0 +/- 15.8 mg. Significantly lower manganese content was found in samples of forages produced in dry summer periods of 1992/93 (45.3 % less rainfall then in 1986/87). The differences in manganese content of forage produced on three different locations in the period 1992/93 were not significant. The main conclusion is that in the ratio for dairy cows based on grass, grass silage or hay no additional manganese is necessary. Maize silage ratio demands a supplementation with manganese. On a farm with stated problems in cow's fertility and neonatal deformities in their calves manganese concentration in forage and in whole ration has to be controlled.
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