The Bulletin. 59 



The symptoms of cottonseed meal poisoning which generally have been 

 observed may be briefly stated as follows: When the pig begins to refuse 

 cottonseed meal, he usually shows very rapid, short, shallow breathing, an 

 anaemic condition which shows in the paleness of the mouth, skin and else- 

 where, imperfect vision, and even blindness, and a weakening of the muscles 

 of the legs. If the pig is exercised very violently, death usually ensues 

 quickly. A post-mortem examination always shows an (Edematous condition 

 of the lungs, and sometimes there is inflammation of the digestive tract. 



Many investigators in America and abroad have studied the problem with 

 a view to ascertaining the cause of toxicity and means for overcoming it. 

 The various theories which have been advanced as to what the poisonous 

 substance is, have all been discarded. Lest you throw aside as erroneous the 

 explanation and remedy which we have to offer, I shall endeavor, without 

 going too much into the technical side, to give you an outline of the steps 

 involved in our work, so that you may know the facts which we observed and 

 draw your own conclusions from them. 



These experiments were conducted jointly by the Chemical, Veterinary, and 

 Animal Husbandry Divisions of the Agricultural Experiment Station. As 

 Belgian hares, or rabbits, are killed by cottonseed meal in about two weeks, 

 our preliminary experiments were conducted with them instead of with swine, 

 as it takes about twelve weeks to kill the latter. There is also a saving in 

 expense by using the hares. 



A feed may be deleterious or harmful to an animal from several causes: 

 (1) from purely mechanical action such as stopping the intestines, lacerating 

 them, etc.; (2) by not having in it the constituents which are necessary for 

 maintaining the life of the animal; or (3) by having in it some true poison, 

 that is some substance which may be taken into circulation in the blood of 

 the animal and thereby interfere with the physiological processes of the body. 

 We may quickly dismiss the idea of injury in a mechanical way, as there has 

 not been an indication of stoppage of the intestines or of irritation by me- 

 chanical means. The remedy for an incomplete or improperly balanced feed 

 would be to increase the missing constituent, and the remedy for a poison 

 would be to remove it before feeding or to change it into an insoluble form so 

 that it would be inert in the body of the animal. 



Coming back to the symptoms exhibited by the animals fed on the cotton- 

 seed meal, we find that they compared fairly well with those exhibited by 

 animals that have had some soluble sulphide added to their feed. These pro- 

 duce death by acting upon the blood, and diminishing its power of carrying 

 oxygen until death ensues. Some soluble iron salt naturally suggests itself 

 as an antidote. In our experiments with rabbits, we fed one gram of cotton- 

 seed meal daily for each 100 grams of live weight. This corresponds to one 

 pound daily for each 100 pounds of live weight of swine, or 10 pounds daily 

 for each 1,000 pounds of live weight of beef or dairy cattle. This will be 

 recognized as rather heavy feeding. The meal was mixed with molasses to 

 make it more palatable. Green feed was given one each day in the form of 

 cowpea vines or cabbages. The rabbits were confined in galvanized iron 

 cages, so as to keep them under close observation. 



We began feeding five rabbits with the cottonseed meal. At the end of 14 

 days, two had died, one was sick, and all had lost in weight. At that time 

 we began adding a solution of citrate of iron and ammonia to the feed. The 

 sick rabbit recovered and all three rabbits gained in weight for the next 14 

 days, at which time the experiment was discontinued. We took another rab- 

 bit which had only eaten 75 grams of cottonseed meal during five weeks and 

 added iron solution to his feed. This rabbit at once began to eat the meal, 

 and after the first week continued to eat all the meal supplied him and 

 gained in weight for five weeks, at which time the experiment was stopped. 

 These four rabbits testify that an iron salt will make them well after they 

 have been made sick by cottonseed meal. 



We took 22 rabbits and fed them with cottonseed meal at the rate referred 

 to, and all died after an average of 13 days, some of them going as early as 



