Size of Litters 



111 



Size of litter. 



In Table XXV are figures collected by W. J. Carmi- 

 chael * on the relation of the size of the litter to the birth 

 weight of the individual pigs. The large number of pigs 

 involved in this study makes the data here presented 

 especially valuable. 



TABLE XXV. EFFECT OF SIZE OF LITTER ON BIRTH WEIGHT 



OF PIGS 



According to these figures, as the number of pigs in 

 the litter increased, the size of the individuals quite 

 regularly decreased. 



Vigor of sow and boar at breeding time. 



That there is a causal relation between the vigor of the 

 parents at breeding time and the vigor and development 

 of their offspring is attested by the observation of stock- 

 men and the results of laboratory experiments. Animals 

 which are in a state of vigorous health at breeding time 



1 Master thesis : Univ. of 111., 1916. 



