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UNITED STATES DEPARTMENT OF AGRICULTURE 
WW- BULLETIN No. 996 1 
Washington, D. C. 
Issued October 12, 1921 
Revised January 8, 1924 
FLUSHING AND OTHER MEANS OF INCREASING LAMB 
YIELDS. 1 
By F. R. Marshall and C. G. Potts, Animal Husbandry Division, 
Bureau of Animal Industry. 
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 gains to number of twins 6 
Feed for flushing 6 
Earliness of lambing 7 
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 9 
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 six years' experiments in flush- 
ing ewes, covering a total of 352 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. * 
i R. B. Millin, now of the Montana Agricultural College, assisted in the early development of the experi- 
ments reported in this bulletin. 
109305°— 24— Bull. 996 
