604 FEEDS AND FEEDING 



prietary preparations sell for extravagant prices, considering the actual 

 cost of the ingredients of which they are composed. Also exaggerated 

 and even entirely false claims have in some instances been made in adver- 

 tising such mixtures. Any farmer can provide at small expense a simple 

 home-prepared mineral mixture which, so far as is known, will be just 

 as effective as the best proprietary mixtures, and will certainly give 

 better results than some of those on the market. 



From the preceding discussions it is clear that the mineral nutrient 

 which, in addition to common salt, is most apt to be lacking in the rations 

 of swine is calcium and next to this comes phosphorus. Calcium can be 

 supplied very cheaply indeed by using finely ground limestone, air- 

 slacked lime, chalk, or wood ashes. When there is a possibility of phos- 

 phorus being lacking as well as calcium, it is best to supply both these 

 minerals in such forms as steamed bone meal, spent bone black, or even 

 ground rock phosphate, tho experiments by Forbes and colleagues at 

 the Ohio Station 5 show that the latter is not utilized as well as are bone 

 products. Other ingredients are also often incorporated in mineral 

 mixtures, especially charcoal, sulfur, Glauber's salts (sodium sulfate), 

 Epsom salts (magnesium sulfate), and copperas (iron sulfate). While 

 some of these ingredients may perhaps be useful as tonics or cor- 

 rectives for animals which are "off feed" or in poor condition, there is 

 no positive evidence to show that there is any benefit from giving them 

 to an animal which is thrifty and making normal gains. 



If one is feeding ground grains or other ground concentrates, the 

 mineral supplement may be mixed directly with the concentrates. There 

 will then be no question but that the pigs will eat the desired amount. 

 One-half to one pound of any of the calcium-rich mineral supplements 

 previously mentioned to each 100 Ibs. of concentrates should ordinarily 

 be an ample amount for pigs or brood sows. 



When shelled corn or ear corn is fed, the mineral supplement can 

 not be mixed with the feed, but should be fed separately in a suitable 

 box or self-feeder. Such mineral supplements as ground limestone, wood 

 ashes, ground rock phosphate, and bone meal are not very palatable to 

 pigs, and hence they may not eat enough of the supplement to have the 

 desired effect. To increase the palatability of the mineral supplements, 

 salt may be mixed with them. Forbes has found recently at the Ohio 

 Experiment Station 6 that "the one unrivalled perfume and appetizer" 

 for mixing with such supplements is tankage or meat meal. Accordingly 

 he advises that one pound of tankage be added to each nine pounds of 

 mineral supplement when it is not to be mixed with the feed. 



There are insufficient data available to show definitely whether a 

 complex mineral mixture including several of the ingredients previously 

 mentioned will produce any better results than merely such simple com- 

 binations as the following: 



"Ohio Bui. 347. 

 "Ohio Mo. Bui. 55. 



