62 MAINTENANCE RATIONS OF FARM ANIMALS. 



equivalent to the necessary demand for internal work. Even if we 

 follow Wolff in regarding the energy of the fiber-free nutrients as 

 an approximate expression of the available energy, his computation 

 of the fiber-free nutrients required for maintenance simply shows the 

 amount of available energy (in this sense) present in a maintenance 

 ration, but gives no indication of how much of this may have been 

 consumed in simple heat production. 



MUNTZ'S EXPERIMENTS. 



Miintz, 1 in 1878-79, attempted to determine the maintenance ration 

 of the horse by a different method, viz, by starting with an insufficient 

 ration and gradually increasing it until an equilibrium between food 

 and live weight was secured. His experiments were made upon 

 horses of the Paris Omnibus Co. whose work ration was known from 

 previous experiments. Upon one-third of their regular working 

 ration four horses lost in from one to one and a half months an aver- 

 age of 1.02 pounds per day and head. The ration was then increased 

 to one-half of the work ration. Upon this nine horses, including the 

 four used in the previous experiments, gained on the average 1.08 

 pounds per day and head. Upon decreasing the ration to five- 

 twelfths of the work ration, six other horses gained 0.46 pound per 

 day and head. The amount of total organic matter consumed by 

 the animals is recorded. Estimating from this the total digestible 

 nutrients and computing the metabolizable energy of the latter at 

 the rate of 3.96 calories per gram, the last two rations afforded the 

 following results : 



Metabolizable energy in rations of horses — Miintz. 





Average 

 gain in 

 weight 



per day. 



Average 



live 

 weight. 



Digesti- 

 ble nu- 

 trients. 



Metabolizable en- 

 ergy. 



Per head. 



Per 1,000 

 pounds 



live 

 weight. 



One half of work ration 



Kilos. 

 +0.49 

 +0.19 



Kilos. 

 545 

 523 



Grams. 

 4,102 

 3,417 



Therms. 

 16. 24 

 13.53 



Therms. 

 14.37 

 12. 31 



Five-twelfths of work ration 





GRANDEAU AXD LE CLERC'S RESULTS. 



Grandeau and Le Clerc, 2 in addition to the experiments recorded 

 in connection with Wolff's results, fed five cab horses a daily ration 

 of 8 kilograms of hay during a total of 14 periods of a month each 

 (1 to 5 periods for each animal), during each of which the digesti- 

 bility of the ration was determined. The animals had only a small 



1 Annales de l'lnstitut National Agronomique, Tome 3, 1878-79. 



2 L' Alimentation du Cheval de Trait, 1883, III. 



