Jan. 14, i9i8 Gossypol, the Toxic Substance in Cottonseed 97 



acid) as a finely crystalline powder mixed v/ith the feed in place of gossypol 

 evaporated on corn meal. The pig ate it for one day, and then refused it 

 as before. By using com meal only the animal ate one more feed, but 

 refused it when repeated. During the last few days of the experiment 

 the goss3^1 animal seemed to be growing weaker and very preceptibly 

 thinner. In the last week the animal lost 3 pounds^ while the control 

 gained 2 pounds. This experiment was discontinued on the fifteenth 

 day because of the refusal of the animal to eat. 



In both of these cases of feeding gossypol it was very evident that the 

 animals were physiologically afifected at an early date. All told not 

 over 15 gm. of gossypol were eaten in the first case and not over 22 gm. 

 in the second case. These amounts of gossypol are equivalent to about 

 4 and 6 pounds of oil-free cottonseed kernels, respectively. 



Besides the direct proof of the existence of a toxic substance in cot- 

 tonseed meal, we have a strong argument against the deficiency theory 

 in the results of feeding rabbits on cottonseed meal treated with boiling 

 alcoholic alkali. This treatment, which would be expected to destroy 

 the natural vitamines present, so changes the meal that it becomes non- 

 toxic to rabbits. This change in toxicity we have shown is explained 

 by the ease with which gossypol undergoes oxidation in alkaline solution. 

 This was confirmed by feeding to rabbits the products formed by oxida- 

 tion of gossypol in alkaline solution by air. 



CAN COTTONSEED-MEAL POISONING BE OVERCOME IN A FAVORABLE 

 DIET UNDER FARM CONDITIONS? 



The two largest and oldest pigs (No. 5 and 6) were fed in a turf lot 

 about 50 feet square. Grass was abundant, and a good part of the time 

 there was water in the lot from frequent rains which also kept the turf 

 soft. These pigs were fed on a mixture of equal parts of cottonseed 

 meal, corn meal or com, and wheat bran, with a pint of milk apiece each 

 day. The cottonseed meal fed each day was about 1.33 per cent of body 

 weight, rather higher than has been the practice at this Station. It was 

 thought that for a while, about the fiftieth day, the pigs acted somewhat 

 suspiciously. One showed a lack of appetite for the mixture. Its eyes 

 seemed partly closed and somewhat watery. The pigs also seemed rather 

 short-winded. They retained, however, perfect control of their limbs 

 and were able to mn very well at all times. Finally, after 160 days of 

 high feeding of cottonseed meal, these pigs were put under cover in a 

 small pen. The pigs were soon eating sparingly and losing weight. The 

 pig which had acted somewhat queerly at times in the experiment 

 became sick and died on the one hundred and ninety-eighth day, show- 

 ing typical symptoms, although there was also a pneumonic appearance 

 of the lungs. The experiment with the other pig was then discontinued. 

 On changing this pig's feed to corn, he began to regain weight. This 

 animal was later fed corn, wheat bran, meat scraps, etc. (Table IX.) 

 27805°— 18 5 



