I- 



*^>i 



.7^, 



-s 



A nuwiy farrowed litter of Chester White pigs gets an excellent start In life from its mother's 

 milk. In two or three weeks, however, the pigs may be entirely weaned and placed on a 

 sow milk repiacer reinforced with antibiotics. Photo hxj John 11. Vondill 



sheep) . Here an additional "boost" 

 was evidenced in the yoimg just 

 lielore the develo]:)inent of the 

 paimch, which is dependent upon 

 rumen bacteria for its effective 

 ftmctioning. 



Claims of 10 to 15 percent in- 

 crease in growth and weight attrib- 

 utable to antibiotics were made by 

 many workers in the field of animal 

 nutrition. This additional gro^vth 

 stimulus has tremendous conmier- 

 cial significance and is being widely 

 accepted throughout the livestock 

 Avorld. 



Best Response from Runt Pigs 



In January, 195-^ nineteen Ches- 

 ter \\'hite weaned pigs from the 

 University swine herd were divided 

 into three groups: Group 1 in- 

 cluded seven normal pigs, averaging 

 49 pounds each; Group 2 was made 

 uj) of six rinit J^igs, averaging -51 

 jjounds each; and Group 3, six nor- 

 mal pigs, averaging Hi pounds each. 

 Ail groups received the same ration. 



but Groups 2 and 3 each had ter- 

 ramycin (TM5) added at the rate 

 of 2 pounds to a ton of feed. In six 

 Aveeks the runts in Group 2 had 

 outgained the other two groups 

 ancl had required less feed for every 

 pound of grain. Group 3 was the 

 second best to gain and made the 

 second most efficient utilization of 

 feed. 



Other Tests Under Way 



Other tests in progress concern a 

 sow milk repiacer with antibiotic 

 incorporated to permit ^veaning of 

 pigs at two weeks or less, a foal 

 feeding trial in the raising of Mor- 

 gan horses, and a calf feeding ex- 

 periment to test the effectiveness of 

 an antibiotic-reinforced calf starter. 



The application of antibiotics to 

 fight or Avard off disease organisms 

 is knoAvn almost universally. But 

 the strange power of these newly 

 discovered substances to stimulate 

 growth will not be understood until 

 more evidence is brought to the 

 fore. 



13 



