108 Pork Production 



TABLE XXI. EFFECT OF SEX ON BIKTH WEIGHT OF PIGS 



All available American statistics on the proportion of 

 the sexes in pigs would indicate a slight preponderance 

 of males. In Circular 112, Bureau of Animal Industry, 

 Rommel reports the results of an extensive inquiry on this 

 point. From eighty-two breeders in twenty-four states 

 he obtained a record of the proportion of males to females 

 in 1477 litters containing 13,285 pigs, which was, ap- 

 proximately, 201 boars to 200 sows, or 6660 boars and 

 6625 sows. Carmichael reports in thesis studies the pro- 

 portion of 2560 boars and 2420 sows. Combining both 

 sets of data we have : 



Boars 9220 



Sows 9045 



Ratio 100 boars to 98 sows 



Age of sow. 



The pigs produced by young sows or gilts in their 

 first litters are supposed to be smaller than those borne 

 by mature sows in their prime, when under the same 

 conditions as to feeding and care. In the following table 

 some figures with reference to this point are shown. The 

 record is here given of the birth weight of pigs farrowed 

 by young sows twelve to eighteen months of age, and the 



