GROWTH AND FATTENING 67 



throve fairly well, but as time went on those fed the ration poor in 

 mineral matter fell behind the others. They had no appetite and 

 disliked to stand up ; later they lost control of their hind quarters and 

 had to be carried to the trough at feeding time. When the pigs were 

 slaughtered, it was found that those fed insufficient phosphorus had 

 light, weak bones, while those receiving ground rock phosphate or 

 bone ash had strong, heavy ones. 



Since the common feeds which are high in protein are also rich in 

 phosphorus, probably plenty of phosphorus will be furnished when 

 rations are balanced according to the usual feeding standards. The 



Fig. 19. — Pigs Fed a Ration Low in Phosphorus 



These young pigs, fed a ration very low in phosphorus at the Wisconsin Station, 

 are stunted and have lost control of their hind quarters. Pigs fed the same ra- 

 tion with ground rock phosphate in addition grew thriftily. (From Hart, Wis- 

 consin Station.) 



calcium supply for calves and lambs will usually be ample when hay 

 and the cereals form the greater part of the ration. Deficiencies may 

 occur in regions where the roughages are unusually low in calcium, or 

 when large amounts of such roughages as wheat straw, barley straw, 

 or timothy hay are fed. Where pigs are fed exclusively on the cereal 

 grains, especially corn, the calcium supply will usually be too low. 

 As shown in the preceding chapter, when calcium alone is lacking, 

 it may be supplied in legume hay or in the form of ground limestone. 

 If only phosphorus, or if both calcium and phosphorus are lacking, 

 these may be furnished in ground rock phosphate, ground bone, or 

 bone ash. 



Utilization of food by young animals. — The gains made by thrifty, 

 well-fed young animals are much larger and more economical, based 

 on live weight and food consumed, than those of mature animals. For 

 example, an unweaned calf may gain 2 to 3 lbs. daily for each 100 lbs. 

 of body weight, while a daily gain of 0.3 to 0.4 lb. per 100 lbs, of 



