133 



Seekles: Trace Elements in Pastures and Animals 



heavy clay with high pH values. The intake of manganese is 

 very low in those cases. Also, it seems doubtful whether there is 

 complete absorption of manganese in the gastro-intestinal tract. 



If sterility, due to absolute or relative manganese deficiency, 

 does occur in the Netherlands, this disorder may be expected to 

 occur in other areas of clay soil with an alkaline reaction. These 

 investigations are being continued. 



30 

 25 

 20 

 15 

 10 

 5 

 



r 



-I — I I ■ 



10 20 30 40 50 



Textfigure 25.— Manganese content of pasture grass and hay 

 without considering the type of soil, manuring or the condition 

 of the pasture.— BoZi line: grass (386 samples') —Light line: hay 

 (259 samples).— Afcscissa: mg Mn per 100 g (dry matter basis). 

 —Ordinate: percentage of samples.— Prepared in cooperation with 

 J. T. L. B. Rameau. 



The occurrence of inangcmese in pasture grass and hay in the 

 Netherlands.— A general survey of the occurrence of manganese 

 in 386 samples of young pasture grass and of 259 samples of hay 

 originating from different regions of the country and in 60 sam- 

 ples of hay originating from the province of Friesland is given in 

 Figures 25, 26, and 27. 



Figure 25 shows that in about 50 per cent of the grass sam- 

 ples examined a manganese content between 5 and 15 mg per 

 cent (dry matter basis) was observed. About 30 per cent of the 



