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ii) Consistency<br />
The normal consistency is thick which is however, variable. It may be classified as dense,<br />
medium, thin and watery. It appears that there is very little direct evidence about the value of<br />
density and motility determinations in rams semen.<br />
iii) Volume<br />
Volume obtained on an average from 0.5 to 2.0 ml. Wiggins et al., (1953) observed that,<br />
volume of ejaculates gives a low but significant positive correlation with fertility.<br />
iv) Motility<br />
When a fresh drop of ram semen is examined under the microscope at body temperature<br />
very brisk dark grey whirls are noticed.<br />
The swirling motion is very rapid and dense in appearance. The grading is done as for bull<br />
semen. A drop of semen is diluted in Ringer's or Sodium citrate solution and examined under<br />
high power. Gradation of motility is done as for bull semen.<br />
v) pH<br />
The pH of ram semen varies between 5.9 and 7.3 with an average of 6.4 (Emmens, 1959).<br />
vi) Sperm concentration<br />
The average sperm concentration in a single ejaculate of ram semen contains on an average<br />
3 to 5 billion spermatozoa per ml. In a good sample about 90% of the sperms are alive. Ram<br />
semen with high sperm concentration is slightly acidic in reaction, while with low sperm<br />
concentration it is slightly alkaline. Semen with alkaline reaction is often associated with poor<br />
quality and low ferdlity (Anderson, 1945).<br />
ii) Morphology<br />
A normal ejaculate may contain 5 to 15% of abnormal spermatozoa. A greater proportion<br />
of abnormal spermatozoa may lead to poor fertility. The most common for ns of the abnor nal<br />
type are tailess and deformed. Other morphological abnormalities found are : tapering heads,<br />
enlarged middle pieces, coiled or bent tails. It is usually observed that head abnormalities cause<br />
low fertility. The types of morphological abnormalities are of more importance than the total<br />
sperm count. High percentage of pyriforms or narrow heads are particularly associated with<br />
poor fertility.<br />
Ram semen with sprem concentration of less than one billion per ml with a pH of 8.00 or<br />
higher, with slow sluggish motility and with more than 25% abnormal type and more than 1%<br />
abnormal sperm heads are of doubtful fertility and should not, therefore be used for<br />
insemination.<br />
The percentage of live sprems omay be estimated by the vital stains (Lasley et al., 1942) or<br />
by direct counting. A stain containing congored and nigrosin gives satisfactory results for ram<br />
semen and it is preferred to Eosin and Nigrosin stain (Blackshaw, 1958). The percentage of live<br />
sperms is not significantly correlated with fertility in a ram but the percentage of live normal<br />
spermatozoa has a significant correlation (Wiggins et al., 1953).<br />
viii) Biochemical Parameters of Ram Semen<br />
In the ram semen, lt3 portion is made up of sper natozoa and<br />
2/3 by the seminal plasma. There is marked difference in composi-tion between the sperm and<br />
the seminal plasma. Nucleic acid is confined to spermatozoa. The spermatozoa contain more of<br />
iron, zinc, copper, haematin chiefly as cytochrome and plasmalogen than the seminal plasma<br />
(Table 7.2). Acid soluble phosphorus compunds are present in the sprem and also in the<br />
seminal plasma. Fructose and citric acid are present in large concentrations in ram semen and<br />
these are derived from the seminal vesicle secretions (Mann, 1964).<br />
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