GROWTH 



397 



479. Total increase in normal growth at different ages. 



The feed requirements of the growing animal as regards protein 

 and energy depend in the first place on the amounts which such 

 an animal is capable of storing up in normal growth. From the 

 data regarding the rate of growth recorded in i of this chapter, 

 even though they are somewhat fragmentary, it seems possible to 

 derive average figures regarding the storage of protein and energy 

 in growth at different ages which may be of some value as a guide 

 in estimating the feed requirements of the growing animal. 



As regards protein, it was shown that the rate of gain per 

 1000 live weight apparently does not vary widely as between 

 cattle, sheep and swine, and an empirical formula (463) was 

 given by which its amount at any age may be approximately 

 estimated. As regards energy, fewer data are available, es- 

 pecially for farm animals, but the graphic representation in Fig. 

 39 of the results recorded in Table 81 (464) shows a diminish- 

 ing rate of gain of energy as the animal grows older. 



In the following tabulation the daily gain of protein at differ- 

 ent ages has been calculated by means of the formula just men- 

 tioned and the gain of energy estimated from the smoothed graph 

 of Fig. 39. The two together may be taken as an approximate 

 expression of the normal increase in growth at different ages. 



TABLE 91. DAILY INCREASE IN GROWTH PER 1000 POUNDS LIVE WEIGHT 



