UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 996 



- Contribution from the Bureau of Animal Industry 

 JOHN R. MOHLER, Chief 



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Washington, D. C. 



October 12, 1921 



FLUSHING AND OTHER MEANS OF INCREASING LAMB 



YIELDS. 1 



By F. P. Marshall and C. G. Potts, Animal Husbandry Division. 



CONTENTS. 



Page. 

 Extent to which flushing is practiced in the 



United States 1 



Factors influencing size of lamb crop 2 



Results of experiments in flushing ewes 3 



General plan of the experiments 3 



Number of lambs dropped 4 



Relation of weight gainstonumber of twins . 6 



Feed for flushing 6 



Earliness of lambing 6 



Uniformity of lambs' ages 7 



Twin production as affected by age of ewe ... 7 



Twin production as affected by breed of ewe. 8 



Twin production as affected by sire 8 



Breeding for twin lambs 9 



Value of twin lambs in comparison with 



singles 10 



Comparative weights of single and twin lambs 1 1 



Summary 13 



EXTENT TO WHICH FLUSHING IS PRACTICED IN THE UNITED STATES. 



THE BELIEF that extra feeding of ewes at the time they were 

 bred would result in larger yields of lambs has long been held 

 by students of sheep husbandry. Feeding for this purpose is 

 commonly called " flushing." Though flushing has been practiced 

 by a few breeders of purebred sheep, it has not been generally or 

 seriously considered by flock owners producing market lambs. 

 Practically no figures or results of experiments have been obtainable 

 as to the extent of increase in the lamb crop that could be obtained 

 by flushing the ewes. 



This bulletin presents the results of five years' experiments in flush- 

 ing ewes, covering a total of 302 matings. These experiments were 

 conducted on that portion of the Bureau of Animal Industry farm at 

 Beltsville, Md., known as "Sheep Acres," and at the United States 

 Morgan Horse Farm, Middlebury, Vt. There is added a discussion 

 of other matters to be considered in endeavoring to obtain maximum 

 yields of lambs. 



1 R. B. Millin, now of the Montana Agricultural College, assisted in the early development of the experi- 

 ments reported in this bulletin. 

 56405°— 21— Bull. 996 



