CHAPTER XXVIII. 



GENEKAL INVESTIGATIONS IN CAKE AND MANAGEMENT OF 



SHEEP. 



715. Period of gestation. Below are given the findings of Tes- 

 sier 1 of France, and Carlyle, Humphrey, and Kleinheinz of the "Wis- 

 consin Station, 2 showing the gestation period of ewes. The Wiscon- 

 sin data cover 17 years of the records kept by Kleinheinz, the sta- 

 tion flock master. 



The gestation period of ewes. 



The Wisconsin ewes, mostly grades of the English breeds, carried 

 their lambs for an average of 147 days, while the French ewes, doubt- 

 less of the Merino breed, yeaned in 152 days. At the Wisconsin Sta- 

 tion the grade Merinos and Cheviots carried their lambs longer than 

 those of the English breeds under observation. 



716. Breeding studies. Studies of the Wisconsin Station flock, 

 covering 5 years, by Humphrey and Kleinheinz show: 3 The length 

 of the gestation period does not influence the birth size of the lamb. 

 The average weight of ram lambs at birth is about 0.5 Ib. greater, and 

 the gestation period somewhat longer, than in the case of ewe lambs. 

 The per cent of male lambs is practically the same as females. The 

 age of the ram appears to have no effect on the sex of his offspring, 

 but as the age of the ewe increases, the per cent of ram lambs she 

 bears increases. The size of the lamb is determined by the size of the 

 ewe and not of the ram. Six-year-old ewes produced the largest per 

 cent of increase, while young ewes have more singles. The size of the 

 ram appears to have no effect on the number of lambs yeaned by 

 the ewes. The larger the ewe of a given breed the greater is the per 

 cent of her increase. 



1 Coleman, Sheep of Great Britain. 

 1 Ept. 1907, Bui. 95. 



3 Wis. Sta v Ept. 1907. 



442 



