EXPERIMENT STATION BULLETINS. 271 



DIGESTER TANKAGE FOR SWINE. 



R. S. SHAW. 



Bulletin No. 237. 



The following report contains a brief statement of the results of in- 

 vestigations on the value of digester tankage as an adjunct to the 

 ration in certain phases of swine feeding. The value and use af this 

 material has been the subject of investigation elsewhere heretofore, in 

 several ways, and has been reported on. One of the main objects in 

 taking up this work was to secure a substitute for skim milk for young 

 pigs from the time of weaning on to that stage of development where 

 they are capable of using less concentrated rations containing smaller 

 amounts of protein. An enormous quantity of milk leaves our Michi- 

 gan farms annually to supply condensories, cheese factories, and city, 

 town and village trade. Thus, many producers are left without skim 

 milk for rearing young calves and pigs. It is generally conceded that 

 the use of skim milk greatly simplifies the process of pig feeding from 

 weaning time on; in fact, its use in the ration at this time is regarded 

 by some as being indispensable. In the absence of skim milk probably 

 the next best food factor for the young pig is middlings, but the supply 

 and demand are frequently such that even this foodstuff is not avail- 

 able. These are some of the factors that led us to look for a substi- 

 tute for skim milk for the young growing pig. While this work was 

 in progress it also became possible to make some tests with tankage 

 for the fattening hog. The tankage used had a guaranteed content of 

 G0% protein, 10 /o fat and Gfo phosphates. The price paid for it was 

 $32.50 per ton. The question is frequently asked, what is tankage? 

 It consists of refuse materials from slaughtering, such as digestive 

 organs and their contents, flesh scraps and some blood, and condemned 

 carcasses which cannot be used for human food. These materials are 

 cooked under steam pressure and then dried and ground until almost as 

 tine as middlings. 



The prices charged for the foods used in this experiment are as fol- 

 lows, viz. : Corn meal $20.00 per ton, middlings |20.00, tankage |32.50, 

 and skim milk 20c per hundred pounds. 



The data given in this report shows that the work in each case was 

 repeated a number of times. This duplication demonstrates marked 

 uniformity of results in the comparative data. Our readers cannot help 

 but note the fact that, in general, the average daily gains of the experi- 

 mental pigs were not large. It is not reasonable to expect that gains 

 from experimental animals should always reach the maximum for some 

 rations are satisfactory and others less so. In order to test the com- 

 parative efficiency of rations, changes cannot be made in them, often 

 for weeks at a time, whether the animals like them or not. In feeding 

 for big gains only, the appetite of the animal can be catered to. In 

 the case of some of these lots the pigs were on test from ten to four- 



