Feeding and Handling the Herd 19 



ing and farrowing. Recent accumulations of data, 

 however, indicate that the average time is more nearly 

 114 days than it is 112. Breeding and farrowing records 

 of 488 litters in the Illinois University herd l showed 

 114f days to be the average time which the sows carried 

 their pigs, the longest observed being 124 days and the 

 shortest 98 days. A study of these records did not reveal 

 any tendency for mature sows to carry their pigs longer 

 than did gilts. The average length of seventy- seven 

 gestation periods in the Purdue University farm herd 

 was 113i days. In this herd, sows with their first litter 

 went, on the average, 113.2 days; those with their second 

 litters, 113.4 days ; those with their third, 114.5 days ; and 

 with the fourth, 113.6 days. It is the common opinion 

 among breeders that gilts and old sows lacking thrift 

 farrow a few days earlier than the average, while mature 

 vigorous sows tend to carry their pigs a few days longer. 



Age to breed the gilt. 



A gilt should take her place in the breeding herd as 

 soon as her growth has reached the stage where the 

 demands of maternity will not materially affect her own 

 development or her future usefulness in the breeding 

 herd. Just where this stage is in the life of the gilt is 

 a question of development rather than of age. The gilt 

 that is well grown is more reliable as a future mother 

 when bred at seven months of age than the gilt of ten 

 months whose development has been retarded by in- 

 sufficient nourishment. 



Experience has established the important fact that 

 reasonably early breeding tends to establish reliable 

 breeding habits, while late breeding frequently results 



1 W. J. Carmichael : Master's thesis, Univ. 111., 1916. 



