208 Pork Production 



It will be noted that there is a considerable range in the 

 proportion of supplement recommended for a given 

 group of forages and for pigs of a given weight and system 

 of feeding. This is because of the normal variations 

 which occur in the abundance and quality of forage 

 supplied by a given crop in different years, as well as the 

 normal differences in composition which exist between 

 the forages of the same group. It frequently happens 

 that the crop is so much below average that the de- 

 sired rate of gain can only be secured by a larger pro- 

 portion of supplement even than the maximum figure 

 recommended in the table. On the other hand, when 

 the forage is abundant and palatable, the smaller pro- 

 portions will be sufficient because of the larger quantity 

 of the protein-rich forage eaten. 



Another reason why exact quantities cannot be stated 

 is because of the variations which may occur from year 

 to year in the relation of the price of corn and the price 

 of supplements in general. When grain is cheap and 

 supplements relatively high, a smaller proportion of 

 supplement to grain will be more profitable than when 

 grain is high and the commercial supplements cheap. 

 When barley, rye, wheat, or oats, or any mixture of these 

 is fed, a slightly smaller proportion of the protein supple- 

 ment is required than when corn is used. 



FEEDING A GRAIN RATION TO PIGS ON FORAGE 



The digestive apparatus of the pig is so limited in 

 capacity that he is unable to make even moderate gains 

 on green forage alone. Pigs weighing less than 100 

 pounds fail to maintain their weight on ordinary pastures, 

 especially if they have previously been fed some grain. 



