22 MASS. EXPERIMENT STATION BULLETIN 339 



These data cover the period from 1920 to 1934 and indicate that more em- 

 phasis has been placed upon the general subject of nutrition than upon the 

 general subjects of breeding, physiology, and meats. 



Progeny Performance in Sheep. (C. H. Parsons, R. C. Foley, and J. 

 C. Hillier.) A cooperative project with the U. S. D. A. was started in 1932, 

 using the Southdown and Shropshire flocks of sheep, in order to determine the 

 inherent capacity of specific families or strains of sheep for the utilization of 

 feed and the production of meat and wool, and to improve them by a study of 

 the manner in which they transmit these characters. 



Accurate records are kept on all sheep, including lambing records, gains in 

 weight, type scores made on all lambs at 140 days of age, and carcass grades of 

 all sheep slaughtered. The wool on each sheep is graded and weighed yearly, 

 and samples are analyzed by the Bureau of Animal Industry of the U. S. D. A. 

 A specialist from the Bureau visits the college at least once each year to counsel 

 with a committee from the college in grading the mutton and wool character- 

 istics of the flock. This contact helps to keep the records uniform and com- 

 parable with similar records at other institutions. 



Sufficient records have now accumulated to give valuable information on 

 the offspring of the sires used in recent years. As an example, the body scores 

 for four Southdown rams are given below. The figures are expressions of the 

 difference between the average scores of lambs and their dams; a positive figure 

 indicates improvement on the part of the offspring, and a negative figure indi- 

 cates that they did not score as high as their dams. The scoring system em- 

 ployed was on the basis of 1 as perfection and grading down to 5 as the lowest 

 possible score. For example: the ewes to which Ram A was bred had an aver- 

 age score for type of 1.25, the corresponding score for their lambs was 1.09, 

 showing an improvement of .16 which is the figure given in the table. 



Body Scores 



No. Ofl- Birth 



spring com- Con- Weight 



pared to dams Type dition Back Rump Leg Head Pounds 



Ram A 5 +.16 +.50 —.33 +.16 +.08 



Ram B 5 +.13 —.60 —.07 —.20 —.20 +.27 +2.2 



Ram C 11 —.41 —.81 —.33 +.11 —.37 —.07 +.4 



Ram D 8 —.13 —.07 —.13 +.40 +.13 —2.28 



It is felt that the type of ewes to which these rams were mated was unusually 

 high and that as the level of the flock improves it becomes progressively more 

 difficult for a ram to improve or even hold the type of the ewes. It should be 

 noted that with the exception of the birth weights, all scores are the combined 

 opinions of a scoring committee. It is doubtless the unconscious tendency of 

 the scorers to grade more severely the nearer the level of the flock approaches 

 perfection. 



Similar information is now available on three Shropshire rams. In addition 

 the weight, length, and characteristics of the wool for all sheep have been 

 recorded and tabulated. 



