Working with Beltsville White turkeys, Harper (1955) 
found that length of holding period was not critical early in 
the breeding season but that it was later. He had compared the 
fertility and duration of fertility from pooled semen stored at 
about 60 degrees Fahrenheit for one, two, and four hours and 
from fresh semen. 
Carter, McCartney, Chamberlin, and Wyne (1957) studied 
the fertilizing capacity of semen from Lene White turkeys held 
at 10 and 15 degrees Centigrade for 0, 2, 4, and 6 hours. They 
found little difference between results obtained at the two | 
storage temperatures but found a fairly consistent sharp drop in 
the fertility of semen held for two hours or longer. 
b) Effect of diluents on fresh and stored semen. 
Studies under this heading have been aimed almost ex- 
clusively at finding diluents which will give satisfactory re- 
sults in extending the use of fresh semen and diluents which 
will prove satisfactory for storing semen. The literature on 
this subject is too voluminous and detailed to be covered ade- 
quately here. The paper by Wilcox and Wilson (1961) provides a 
bibliography from which a review of the literature on this topic 
might be begun. 
ec) Effect of bacterial contamination. 
Contamination of semen samples with bacteria is a 
major problem in. studies of sperm metabolism. Some research has 
been directed towards finding methods of circumventing the 
problém. Wilcox and Shorbd (1958) found that the addition of 
oxytetracycline and dihydrostreptomycin to stored semen diluted 
with a buffer resulted in improved fertility. 
Although they presented no data as such, Gale and 
Brown (1961) stated that the presence of bacteria in semen and 
their multiplication probably result in deterioration of semen 
samples in vitro. They cultured samples of turkey semen and 
found a great variety of bacteria. Staphylococci were present 
in 78% of the samples and coliforms in 53% of the samples. They 
found that seminal fluid taken aseptically from the vas deferens 
contained no bacteria and concluded that the cloaca was the 
source of contamination. 
ad) Effect of chemicals. 
Reference has been found to one chemical which might 
be regarded as having both beneficial and deleterious effects 
on semen VALE « Blackwood and Harris (1960) found that 
2,5-alkyl benzimidazoles would inhibit almost completely the 
motility of chicken sperm. The exact metabolic processes which 
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