June, 1939] Agricultural Research in N. H. 15 



Agriculture was conducted as usual. During the year 443 samples of 

 seed were handled in the laboratory. Of this number 392 were col- 

 lected by the state inspector and are reported in Bulletin 309 ; the 

 remaining 51 samples were sent in by private individuals. The 

 referee work was done as usual. The work was in charge of Mrs. 

 Bessie G. Sanborn, seed analyst, assisted by students. {Miscella- 

 neous Income) 



Studies in Animal Metabolism and Nutrition 



During the past nineteen years of cooperation with the nutrition 

 laboratory of the Carnegie Institution of Washington, E. G. Ritzman 

 has carried out metabolism experiments with many animals of differ- 

 ent species of farm livestock. With the retirement of Dr. F. G. 

 Benedict of the Carnegie Institution last year, the results of the 

 cooperative researches on cattle have been published in Washing- 

 ton under the title "Nutritional Physiology of the Adult Ruminant." 



The summary of nineteen years of experiments is as follows: 

 13 with horses, including a thoroughbred stallion with a notable turf 

 record, a blue-ribbon Percheron stallion weighing over a ton, a 

 Percheron mare, a standardbred or trotting gelding, a range pony 

 and a very small Shetland pony weighing about 300 pounds ; about 

 300 experiments with 18 beef steers ; 4 experiments with bulls ; over 

 50 experiments with 12 dairy cows ; over 200 experiments with about 

 100 sheep; about 30 experiments with 13 goats and 20 experiments 

 with pigs, ranging from a boar weighing 600 pounds down to suck- 

 ling pigs weighing less than 10 pounds. 



These studies have been devoted to a determination of the needs 

 of the animal organism for its own maintenance (i. e. basal metabo- 

 lism) in support of life under various conditions of season and cli- 

 mate, and particularly to the comparative efficiency of the different 

 species of farm livestock. It has been found that the horse has the 

 highest basal metabolism per unit of size of any animal so far meas- 

 ured. The adult dairy cow has an extremely variable basal metabo- 

 lism, and lactation has an extraordinary effect on increase in metabo- 

 lism. This renders the concept untenable that basal heat production 

 is conditioned solely by the rate of heat loss to the environment. 



A study of metabolism during growth was begun during this year, 

 experiments being carried out with eight Holstein heifer calves from 

 purebred ancestry. Previously only adult cows have been used. This 

 first year's results have already demonstrated that basal metabolism 

 during growth is nearly double that of the adult dry and farrow cow 

 and compares more nearly with that of the adult when lactating. 



In a series of experiments carried out monthly throughout the 

 year on an adult Chester White pig, a considerable variation in basal 

 heat production was obtained although the food and the experi- 

 mental temperature were maintained constant. The highest basal 

 metabolism occurred during March, April and May ; the lowest, dur- 

 ing June, July and August with an extreme difference of about 35 per 

 cent. As with cows, pregnancy raised the basal metabolism 

 markedly, and lactation in the pig increased metabolism 62 per cent 

 above the original basal level. This indicates the tremendous inter- 

 nal stimulus to which the tissue cells of the body are subjected in 

 the process of milk formation. 



