juiy23. I9I7 Effect on Growth and Reproduction of Rations 195 



overabundance of a material like wheat straw in a ration, owing to its 

 low salt content, becomes an important factor in premature birth. 



An observation in our experimental work of interest to veterinarians 

 was the low resistance to other diseases of the mothers fed the wheat 

 ration. In an outbreak of anthrax in the university herd the only 

 losses to occur from this diease in our experimental herd were among 

 the wheat-grain fed animals. 



The principle (5, 12) laid down as to what factors must be present in 

 a ration of natural origin in order that it become efficient for both growth 

 and reproduction is well supported by these data. This principle postu- 

 lates that there must be present efficient proteins, adequate energy, 

 proper salt mixture, fat-soluble A and water-soluble B (vitamines) and 

 an absence of toxicity, or a toxicity of such mildness as to become inocu- 

 ous in the presence of the other normal factors of nutrition. The 

 presence of toxicity in the wheat kernel as the explanatory factor for 

 these records rests not only upon the evidence secured with swine and 

 rats but also on that presented here. It is not a deficiency phenomenon. 

 A corn-grain and corn-stover ration is physiologically adequate, while a 

 wheat-grain and corn-stover ration often failed not only when used 

 alone but when there was added to it the most likely limiting factor, 

 fat-soluble A, as butter fat. 



The recognition of these normal factors of nutrition and the further 

 recognition of the occurrence in apparently normal foodstufifs of sub- 

 stances of mild toxicity will be of immense advantage in arriving at 

 an understanding of the oft-reported troubles with farm animals, which 

 to-day are either not understood or their etiology is wrongly assigned; 

 and in the field of human nutrition the same principles will apply. 



When a few years ago the corn crop of Nebraska failed to mature 

 because of drought, and early rains had produced a bumper wheat crop, 

 it left many farmers with little to feed their breeding stock but wheat 

 grain and certain roughages. In many cases where this was done the 

 calves were born either dead or weak, with great financial losses to many 

 breeders. No one would have suspected that the ration was a factor 

 in these disasters, but it undoubtedly was the direct cause of the trouble. 



When Dakota farmers, with their only roughage as wheat straw, try 

 to build up an aninal-husbandry industry, there is likely to arise trouble 

 in reproduction with this class of animals, unless other roughages with 

 better salt mixtures are brought into the ration. We are informed that 

 there is already much trouble with reproduction by cows in the Dakotas 

 wherever much wheat straw is fed. Such facts as these must emphasize 

 the importance of an understanding of all the factors of animal nutri- 

 tion and in addition an understanding of all the factors contributed by 

 any particular foodstuff. It should further emphasize how such studies 

 can furnish the facts which will aid the animal feeder in avoiding the 

 danger zones of his art. We need more effort placed on the accu- 



