4*42 Feeds and Feeding. 



Patrick, at the Iowa Station, 1 where .58 per cent, more fat was 

 found in the milk of cows getting sugar meal than was found in 

 the milk of the same cows when fed corn and cob meal. Amer- 

 ican findings do not generally show any marked permanent change 

 in the fat content of milk brought about by feed; indeed, when 

 Patrick 2 again fed sugar meal, only a slight difference was found 

 in its favor, some cows giving adverse results. We may conclude 

 in this case, then, that these results were accidental, or rather 

 that they were due to other than the assigned cause. 



675. Danish experiments. The experiments with cows by the 

 Copenhagen Station 3 furnish reliable data on this important sub- 

 ject, because of the large number of animals employed and the 

 character of the feeds supplied. Friis, treating of this subject, 

 writes: "In the comparative feeding trials with milch cows now 

 conducted for several years by this Station, in which 1,639 cows 

 have been included (separated into 161 lots on ten estates in dif- 

 ferent parts of our country), it has been repeatedly found that 

 the changes made in the feed of the lots have practically had 

 no influence on the chemical composition of the milk. In these 

 experiments grain has been fed against roots, against oil cake, 

 and against wheat bran or shorts; grain and oil cake have been 

 fed against roots, or roots have been fed as additional food.' 7 



676. Possible exceptions. It is possible that a cow which has 

 long been illy nurtured and is in poor condition will give milk 

 abnormally low in fat, and that the milk will increase in richness 

 of fat with increased feed supply and the approach of the body 

 to normal conditions. When a cow is fed a starvation ration the 

 milk may be richer or poorer in fat than the normal, the quantity 

 decreasing rapidly. There is little known that is definite or sat- 

 isfactory on these points. 



(d) Changes in Character or Composition of One or More of the 

 Components of Milk. 



677. Effect of feed on composition of butter-fat. It is gener- 

 ally agreed that feed affects in some way the character of the 

 fat of milk, which is shown practically by the varying character 



* Bui. 14. 2 Bui. 15, Iowa Sta. 8 Kept. 1894. 



