374 VETERINARY PHYSIOLOGY 



capacity of its digestive powers, and concentrated foodstuffs 

 are added to the ration to increase its energy value. A 

 bullock should increase in weight about two pounds per da,y 

 when receiving a ration containiDg digestible nutrients yielding 

 30,000 Calories and '75 to 1'5 lbs. of protein. 



4. Meat Production. — In meat production, the animal before 

 it reaches 'maturity is confined and subjected to intensive 

 feeding. The process of fattening is thus superimposed 

 upon the process of growth, and so muscle formation and 

 deposition of fat proceed simultaneously. Some of the fat 

 is deposited between the muscle bundles, producing the 

 so-called "marbling" of the meat upon which its quality 

 largely depends. 



As in fattening in the adult animal, the object desired is 

 to get as large an increase in weight per da}^ as possible. The 

 animal therefore is allowed to eat as much as it can digest, 

 and concentrated foods are given to increase the energy value 

 of the ration. The total energy of the food given is usually 

 about twice the maintenance requirement. The proportion 

 of protein varies with the rate of growth, being greater the 

 younger the animal. According to Haecker's standard, the 

 ration of meat-producing bullocks should be as follows : — 



Live Weight Digestible Nutrients per 1000 lbs. live weight. 



J 1 = ■ Protein. Carbohydrates. i'ats. 



^- Lbs. Lbs. Lbs. 



200 3-05 11-6 0-55 



500 1-90 11-1 0-60 



1000 1-64 9'5 0-48 



5. Milk Production. — The food requirement in dairy cows 

 depends upon the amount of milk produced. According to 

 Kellner's experiments, after the maintenance requirement is 

 met, from 60 to 70 per cent, of the excess energy of the 

 digested food is recovered in the energy values of the 

 constituents of the milk. The protein is much better 

 utilised for milk production than for fat formation. In some 

 experiments nearly 100 per cent, of the excess above main- 

 tenance requirement has been recovered in the milk. The 

 value of protein for milk production varies with the amino- 

 acid content (p, 276), Casein stands highest. The proteins 

 of maize and wheat are of much less value. 



