Supply of trace elements to ruminants in the German Democratic Republic. 3. Supply of zinc

Abstract

The supply of zinc to ruminants as influenced by and depending upon the geological origin of soils was investigated using the hair test and the technique of indicator plants. A total of 1276 samples of red meadow clover and 3022 samples of red field clover and 4184 hair specimens from cows were analyzed. The following statistically well-established results were obtained which appear to be generalizable: Red meadow clover contained significantly more Zn than red field clover (48 ppm/38 ppm). Red meadow clover and field clover grown on loamy soils (59%), weathered soils of less (59%), red sandstone (57%) basalt (53%), shell limestone (47%) and Keuper (41%) contained only 59%-41% of the amount of Zn found in indicator plants that were grown in locations were the highest Zn level (weathered soils of porphyry). Zn concentrations in red meadow and field clover grown on soils of the same geological origin correlated with r = 0.87. A positive correlation (B = 0.53) was found to exit between the relative proportions of Zn contained in indicator plants grown on a particular soil and the proportions of Zn contained in hair specimens from Zn-deficient cows (less than 100 ppm of Zn). The largest number of hair specimens containing less than 100 ppm of Zn were found in cows from areas with soils of basalt (17%), and loess (18%), areas with loamy soils (24%), and sandy diluvial soils (25%), or with alluvial pastures (23%), or with soils of Keuper (27%), shell limestone (22%) or red sandstone (29%). Ruminants in these areas are liable to suffer from Zn deficiencies.