ANIMAL PEODUCTION. , 71 



may be increased or decreased by the addition of another feed or ration. For 

 example, the addition of porli cracliliugs to rations of ground corn alone, ground 

 corn and tankage, and ground corn and red dog flour, clearly increases the 

 digestibility of the dry substance, the crude protein, and the crude fat of the 

 basal rations. On the other hand, it seems probable that the addition of 

 tankage to a ration consisting of ground corn alone decreases the digestibility 

 of the dry substance and the crude protein in the basal ration." 



As regards the influence of quantity of ration, " there is a significant in- 

 crease in the coefficients of digestibility of the dry substance, the crude protein, 

 and the total carbohydrates of a ration consisting of ground corn, red dog 

 flour, tankage, and pork cracklings, when there is a reduction of 26 per cent 

 in the dry substance consumed. On the other hand, there are no significant 

 differences in the coefficients of digestibility for the nutrients of a ration con- 

 sisting approximately of 10 parts of ground corn and 1 part of pork cracklings 

 when fed as a full-feed allowance and in amounts equal to two-thirds of a full- 

 feed ration." 



A study of the development of growing' pigs with special reference to the 

 influence of the quantity of protein consumed, A. D. Emmett, H. S. Grindley, 

 W. E. Joseph, and E. H. Williams {Illmois 8ta. Bid. 168 (WU), pp. 85-135, 

 figs. 9; abs., pp. 4)- — The object of the investigations of which this bulletin is 

 a partial report was to determine the influence of different quantities of protein 

 upon the nutrition of young growing pigs when the rations were supplemented 

 with an ample amount of calcium phosphate. 



Three lots of four 51-lb. Berkshire pigs were fed during a 174-day period a 

 ration of ground corn, blood meal, and calcium phosphate, all the pigs receiving 

 the same amount of corn protein per 100 lbs. live weight, lot 1 receiving a low 

 protein ration (0.32 lb. of digestible protein per day per 100 lbs. live weight), 

 lot 2 a medium protein ration (0.7 lb. digestible protein), lot 3 a high protein 

 ration (0.94 lb. digestible protein), the blood meal allowance being 50, SO, and 

 86 per cent, respectively, of the total protein received, and the lots receiving 

 3.79, 4.28, and 4.49 therms of metabolizable energy, and 11.09, 9.65, and 8.73 gm. 

 of phosphorus per 100 lbs. live weight per day. The pigs were fed under simi- 

 lar conditions and each pig separately. 



A slaughter test was made of two control pigs at the beginning of the experi- 

 ment and of pigs of each of the three lots. At the close it was noted that the 

 pigs of the low-protein lot were unthrifty and underfed and that three had 

 died. The number of leucocytes in the blood of the remaining ijig from lot 1 

 was possibly somewhat greater than those of the other lots; the kidneys of the 

 animal were distinctly affected with chronic parenchymatous nephritis, and 

 were smaller in length and width than those of the pigs of the other lots, and 

 the liver was abnormal. The dressed carcass was shorter in length, had less 

 fat on the sides, brisket, and flanks, the fat and lean were darker in color, the 

 fat softer and the marrow lighter in color, and while the amount of fat was less 

 the amounts of lean were practically equal. The weights of the intestinal 

 and composite fats were higher, and the weights of the leaf fat, blood, stomach, 

 kidneys, offal, and miscellaneous parts lower than the average for the other 

 lots. 



The fasted live weights, the net live weights, and the weight of the various 

 cuts varied directly with the live weights of the animals when slaughtered. 

 In the weights of the skeleton, the respiratory organs, the small and large in- 

 testines, and the organs of the central nervous system, the corresponding values 

 for the three lots were similar. The pig on the low-protein ration had the 

 highest percentage of leaf fat. the lightest liver, and the heaviest skeleton. 



