82 FEEDS AND FEEDING 



tankage in such proportions as to provide the same nutritive ratio gained 

 1.75 Ibs., and a lot fed barley and skim milk, 1.71 Ibs. A lot fed barley 

 and whey made still better gains, 1.95 Ibs. per head daily, tho receiving 

 a considerably wider nutritive ratio. With younger pigs more protein is 

 needed than is supplied by whey and either barley or corn, and hence in 

 another trial younger pigs made considerably more rapid gains when fed 

 some protein-rich feed, such as tankage or linseed meal, in addition to 

 grain and whey. 



These trials show clearly that in feeding growing animals not only 

 must an abundance of protein be supplied but also that it must be of 

 the right quality. In time further studies along these lines will un- 

 doubtedly reveal the supplementing relationships of the many feeding 

 stuffs and make possible the more efficient compounding of rations. 

 The methods of determining the amounts of the individual amino acids 

 furnished by different feeds are not sufficiently perfected as yet to enable 

 scientists to ascertain by chemical analysis alone the definite value of the 

 proteins from various sources. Hence, further knowledge concerning the 

 value of the proteins furnished by individual feeding stuffs and by 

 combinations of feeds must come thru actual feeding tests. The chapters 

 of Part III show, so far as data are available, the combinations of feeds 

 which have been most successfully used for various classes of animals. 



119. Mineral matter required for growth. It has already been shown 

 that the young animal, growing rapidly in skeleton and tissues, needs 

 a liberal supply of mineral matter, especially calcium (lime) and phos- 

 phorus. (113) The amounts supplied in the feeds must always be larger 

 than the quantity actually stored in the body, in order to cover the con- 

 tinuous excretion thereof from the body which occurs even in case of a 

 deficient supply. 



The injurious effects of a lack of mineral matter are shown in a trial 

 by Hart, McCollum, and Fuller at the Wisconsin Station 14 in which one 

 lot of 47-lb. pigs was fed wheat bran from which most of the phosphorus 

 had been removed by washing, together with wheat gluten and rice, 

 both of which feeds are extremely poor in mineral matter. Other lots 

 were fed the same ration plus ground rock phosphate or bone ash, which 

 supplied ample calcium and phosphorus. For a considerable period all 

 the pigs 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. 



At present there is little data regarding the minimum amounts of 

 lime and phosphorus which will permit normal development of grow- 

 ing animals. From the available data Kellner 15 concludes that the ration 



14 Wis. Bes. Bui. 1. 15 Ernahr. landw. Nutztiere, 1907, pp. 472, 476, 478. 



