120 Report of Department of Animal Industry. 



improve the ration from the cow's point of view. At first the amounts 

 refused were small and irregular, but as the experiment progressed, 

 they became increasingly larger and occurred every day, so that it 

 was deemed advisable to decrease the rations in the fourth period. 

 The lack of appetite was at first considered as a natural aversion 

 on the part of the animal to the ration. But as she ate the ration 

 during the first week with relish such aversion must then have 

 developed from monotony. It is more probable, however, that 

 there was no real dislike for the food but a decreased appetite due 

 to physiological disturbances. Certain remarks of Professor 

 Mendel in a recent public lecture suggested this idea. These 

 were based on his observations on experiments with rats and the 

 data reported by Hart and McCollum. In Science for November 

 24, 1911, the following sentences occur in Mendel and Osborne's 

 article: ''And whereas nutritive decline has commonly been 

 attributed to the anorexia consequent upon the monotony of diet, 

 we are more than ever inclined to shift the explanation in many 

 such cases to malnutrition as a primary cause. From this 

 point of view improper diet and malnutrition may be the occa- 

 sion rather than the outcome of the failure to eat • — a distinction 

 perhaps not sufficiently recognized heretofore." The interesting 

 and significant data obtained by Mendel and Osborne are published 

 in Carnegie Institution Publications No. 156. Hart & McCollum's 

 data are published as Research Bulletin No. 17 of the Wisconsin 

 Agricultural Experiment Station. The addition of calcium phytate 

 did not mitigate the situation. Up to the fifth period, the animal 

 showed no outward signs of constitutional disturbance except this 

 constant decrease of appetite but by the close of this period untoward 

 symptoms resulted from the protracted malnutrition. It is interest- 

 ing to note that the weight of the cow increased eleven kilos during 

 the last period, which, judged by her appetite, was the least promising 

 period in the whole experiment. The increase in weight during the 

 first two periods was almost at the rate of one kilo per day; for the 

 next thirty-four days, i. e., to the end of the fourth period, the 

 weight remained approximately constant, in the last period, the 

 average weight was nine kilos more than in the two preceding periods. 

 Of the total increase in weight during the whole experiment, less 

 than half can be accounted for by the nitrogen balance. From 

 the eightieth day, the animal began to develop pathological con- 

 ditions, difficult to describe, but perfectly apparent to the men on 

 the farm familiar with live stock. She seemed in good flesh 

 and showed a glossy coat but refused to eat, manifesting positive 

 distaste for her food. Her limbs became stiff and somewhat enlarged 

 about the joints, and her movements were decidedly awkward. 

 She was prone to lie down and had difficulty in getting upon her 

 feet. There was no disturbance of the oestrum throughout the 



