ANIMAL PEODUCTION. 175 



vidiial is largely a matter of condition, while the type is almost entirely due to 

 breeding. 



Developing- draft colts, W. A. Cochel and B, O. Severson (Pennsylvania 

 Sfa. Rpt. 1912, pp. 126-134, pis. ifi).— This is an amplification of work pre- 

 viously noted (E. S. R., 29, p. 773), with additional data on the rate of growth 

 and change in form of draft colts from weaning until two years of age. 



Cross-section measurements of the heart and paunch girth were made at in- 

 tervals of three months from November, 1910, to April, 1912. It appears that the 

 rate of growth as measured by the increa.se in the length of bones is continuous 

 from birth to maturity, but that the increase in width of body may remain 

 stationary while that in depth increases. This is to a very large extent due 

 to the amount of food that the animal consumes over and above that required 

 for maintenance and growth which is represented by a deposit of fat over the 

 outside of the chest. There was apparently a greater increase in the depth of 

 che.st than in the depth at the middle of the paunch, doubtless due to the colts 

 being " paunchy " at the beginning of the feeding period. 



Lineal measurements were also taken. It was observed that the height of 

 withers was materially greater at weaning time than that of the croup, while in 

 their 2-year-old form the difference was very much less. The depth of the 

 chest increased 32 per cent during the entire period, while the distance from the 

 chest to the ground only increased 9.78 per cent, showing that the foal is much 

 more " leggy " than the mature horse. There was very little change, amounting 

 to only 1.8 per cent, in length of the cannon of the hind leg as indicated by 

 the measurement from the point of hock to gi'ound. There was a very material 

 increase in the length of shoulder and also in the length of back as measured 

 from the scapula to the hip. In all of the measurements, however, the increase 

 in width was proportionately greater than the increa.se in height, so that the 

 body may be said to change in both depth and width to a greater extent than in 

 the length of the long bones of the skeleton. There was apparently a much 

 greater increa.se in the circumference of the girth at the heart than in either of 

 the circumferences at the hind flank or in the middle of the paunch. During the 

 last period, when the grain rations were increased very materially in order to 

 induce fattening, the most noticeable change was in the width of the body 

 throughout. There was practically no additional growth in the depth of the 

 chest or in the length of the cannon during this period. The greatest change 

 was in the rounding out and improvement, in the symmetry, form, and general 

 appearance of the animals rather than any actual change In the form as indi' 

 cated by the change in skeleton. 



Individual characteristics of hens, H. W. Jackson (Pennsylvania Sta. Rpt. 

 1912, pp. 228-241, pis. 10). — Three experiments were conducted to ascertain the 

 difference in individual preference for feed stuffs, and variation in the nutritive 

 ratio preferred by individuals. 



It was noted that hens taken from the same general flock and previously fed 

 on the same or similar rations developed pronounced preferences in feeding, 

 preferences which persisted throughout the entire period of observation. One 

 hen, for example, promptly selected a ration of corn, wheat, and scrap, with a 

 very large proportion of corn, and that ration remained characteristic of her 

 throughout the entire year. The proportions varied and on lighter laying in the 

 second season wheat consumption decidedly increased, but her corn preference 

 persisted to the end. Hens that showed an indisposition to consume enough 

 oyster shell properly to inclose the eggs were given 10 grains of powdered oyster 

 shell daily in capsules. The shells resumed their normal strength, thickness, 

 and texture. 



