FEEDS FOB SWINE 669 



required in dry lot. Manifestly, when an excess of supplement is thus 

 fed, it does not have as high a value per ton as when wisely used. 



Other trials show a similar advantage in supplying a supplement to 

 pigs fed corn on alfalfa or clover pasture. 123 



But relatively few experiments have yet been carried on to determine 

 just how much tankage or other supplement is needed to balance corn 

 for pigs of various ages which are on good pasture. The trials available 

 show that with pigs on such pasture as alfalfa, clover, or rape, only about 

 half as large a proportion of supplement will be required as in dry lot 

 feeding. For instance, pigs over 100 Ibs. in weight on good pasture need 

 only 5 Ibs. of tankage or less to every 95 Ibs. corn. In general, a safe 

 rule is to feed about half as large a proportion of protein-rich supple- 

 ment as it would take for pigs in dry lot to meet the requirements of 

 the Morrison feeding standards. (Appendix Table V.) 



Pigs on pasture which are self -fed, free choice, corn and in addition 

 tankage, linseed meal, or wheat middlings, or else such mixtures as 

 tankage and linseed meal, or tankage and corn germ meal, will generally 

 balance their own rations fairly well. Sometimes they may take a little 

 more supplement than is needed, but the saving in labor thru this 

 method of feeding is sufficient to offset it. Pigs fed barley require much 

 less supplement than those fed corn, but often pigs on pasture which are 

 self -fed barley and tankage, free choice, will eat more tankage than if 

 they had been fed corn. Therefore the ground barley and the supple- 

 ment had best be mixed in proper proportions. Pigs over 100 Ibs. in 

 weight fed barley or wheat on good pasture need little or no supple- 

 ment. 124 



985. Alfalfa pasture. Wherever it thrives, alfalfa is the best perma- 

 nent pasture crop for pigs. (340) It provides pasturage during a longer 

 season than most other forage crops, starting early in the spring and 

 remaining green and succulent in late summer when bluegrass has dried 

 up and even clover grows hard and woody. Since the heavy pasturing 

 of alfalfa is injurious to the stand, the number of pigs' should be re- 

 stricted and the plants allowed to grow up, being cut for hay 2 or 3 

 times a year. Except in the best alfalfa districts of the West, no more 

 than 17 to 20 spring pigs per acre should usually be grazed on alfalfa, 

 even when they are full-fed on concentrates in addition. If the amount 

 of grain is limited, then less pigs should be carried per acre. Where 

 the winters are severe, care must be taken not to pasture alfalfa too late 

 in the fall, for there is danger of its being killed out unless sufficient 

 growth is left standing to protect the plants. With pigs there is no 

 danger from bloat on alfalfa pasture. 



The following table summarizes the results of 8 trials in each of which 

 one lot of spring pigs has been fed from early summer to market time 



, Iowa Bui. 136; Robison, Ohio Bui. 343; Snyder, Nebr. Bui. 165; 

 Walker, Miss. Bui. 177; Waters et al., Kan. Bui. 192. 



124 Morrison and Bohstedt, Wis. Station, unpublished data. 



