FLUSHING TO INCREASE LAMB YIELDS. 3 
mum lamb yields: (1) The ewes that are in the best nourished condi- 
tion and therefore more likely to produce two ova are also those 
first to come in heat and get in lamb, or, (2) the feed and pasturage 
are more nutritious early in the season and cause production of more 
ova by the ewes bred at that time. 
In the Bureau of Animal Industry experiments the use of rams 
began about September 7 to September 10, but in most cases only 
one or two ewes were bred during the first 10 days. It therefore 
seems that the ewes ordinarily bred first are those that owing to 
their better physical condition first come in heat at the beginning 
of the breeding season, and that their condition is at once the cause 
of their showing heat earlier and their producing twins. 
An overfat condition may derange the normal action of the ova- 
ries even more seriously than a thin condition. It seldom occurs 
except in stock fitted for show or in ewes that have missed getting in 
lamb and grown fat while running dry. In our experiments there 
have been some rather fat dry ewes which got in lamb as readily as 
other ewes. They were not allowed grain, however, and had plenty 
of exercise. 
RESULTS OF EXPERIMENTS IN FLUSHING EWES. 
GENERAL PLAN OF THE EXPERIMENTS. 
The experiments were made with purebred Southdown ewes, all 
of which had been bred in the Bureau of Animal Industry flocks. 
The number of animals was 302, divided into 17 lots, of which Lots 
1, 2, 5, and 6 were at the Morgan Horse Farm, Middlebury, Vt., 
and Lots 3, 4, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and 17 at the bureau 
farm, Beltsville, Md. The ewes were usually in good condition com- 
pared with general farm flocks, which it is thought would tend to 
lessen the effect of flushing. 
In all the tests the lots of ewes were divided with careful regard to 
age, number of lambs dropped in previous years, gain in weight prior 
to experiment, and the rams to which bred. As it was necessary to 
use a number of different rams in each flock, hand breeding 3 was 
followed, which with the use of teasers 4 made it possible to record 
the date of each service and at the same time mate each ewe to the 
ram desired. Approximately the same number of ewes in each lot 
were bred to each of the rams used that season. In one case the 
proportion was disturbed because one of the rams was not a sure 
breeder and some of the ewes booked to him did not get in lamb. 
Such cases were eliminated from the experiment. The data given 
are in all cases for ewes having lambs. The matter of dry ewes and 
the influence of rams upon the lamb yield are discussed separately. 
3 " Hand breeding" is a term applied to the individual mating of a ram and ewe outside the flock. 
4 "Teaser" applies to a ram used in a flock for the purpose of indicating the ewes which are in heat. Copu- 
lation is prevented by an apron tied around the ram's body. 
