Nov. i8, 1918 



Further Studies on Brisket Disease 



411 



Lots 2 and 7 were not included in the summary for the following 

 reasons : 



Lot 2 consisted of only four animals, of which No. i had a carcass 

 weight of 539 pounds, with a heart weight of 6.5 pounds. The heart 

 was clearly pathological; therefore it was not thought proper to include 

 the lot. 



Lot 7 included 9 cows from Falcon, Colo. This lot is of some interest 

 because the hearts averaged lower than either those from San Francisco 

 or Fort Worth, but since the animals were neither from an extremely 

 high nor a very low altitude they were not included in the summary. 



It will be seen from Table I that heart weighings were made on 224 

 cattle raised at high altitudes and 138 raised near sea level. The animals 

 from high altitudes averaged 9 pounds heavier in carcass weight and 

 had hearts averaging 0.542 pound heavier. On the basis of i ,000 pounds 

 of carcass weight the only proper one for comparison, there was a dif- 

 ference of 0.879 pound in favor of the animals from high altitudes. This 

 number of weighings is probably too few on which to base a conclusion, 

 but the results seem to be in accord with the observations of others made 

 on the subject, and also with what one may reasonably expect, that 

 these animals have heavier hearts than those raised near sea level. 



Heger and Meyer, working with guinea pigs and rabbits kept at known 

 air pressures, found the weights of the hearts as shown in Table II. 



Table II. — Weights of hearts of guinea pigs and rabbits, according to Heger atid Meyer 



Animal. 



21 guinea pigs. 

 15 rabbits 



Air pressure. 



Mm. 



765 

 580 

 500 



765 

 500 

 217 



Average 

 weight of ani- 

 mals. 



Gin. 



529 



448 



445 



892 



870 



,224 



Average 

 weight of heart. 



Gm. 



3-85 

 3-42 

 4.92 

 5-76 

 9-75 



Weight of 

 heart per i .000 

 gm. of body- 

 weight. 



Gm. 



7-334 

 8.594 

 7.686 

 5-528 

 6. 620 

 7-965 



They conclude in the following language : 



From the experiment it appears that the thinning of the air had the effect of increas- 

 ing the weight of the lungs and heart, which was especially true of the rabbit. The 

 increase of weight is, in several cases, considerably more for the heart than the limgs. 



EFFECT OF FEED ON BRISKET DISEASE 



In order to determine whether the feed or anything in it was the 

 causative factor in the brisket disease, several animals were shipped to 

 the Colorado Experiment Station, where they were fed on hay that had 

 been raised in the high altitude of the South Park district. This hay 

 was of the typical South Park wire-grass, and was obtained from a Den- 



