Factors affecting scrotal circumference and semen characteristics of Awassi rams

Abstract EN

The objective of this study was to evaluate the effect of age, body condition score, year of collection and the presence of horns on semen characteristics and scrotal circumferences of Awassi rams.

A total of 93 rams (49 matures and 44 yearlings) were used in this study.

Mature rams were 2 to 6 years old while yearlings were 10 to 18 months old.

Rams were maintained in open-front barns with free access to water, shade and mineral and salt blocks.

Body Weight (BW), Body Condition Score (BCS), Scrotal Circumference (SC) and semen characteristics were evaluated for all rams.

The evaluated semen characteristics included Ejaculate Volume (EV), Ejaculate Appearance (EA), Mass Motility (MM), rate of Forward Movement (FM), concentration (SCM) and percentage of abnormal sperm cells (AP).

Mature rams (75.3 kg) weighed more (P < 0.001) than yearlings (54.9 kg) and had significantly larger (P < 0.001) SC.

Ejaculate appearance was better (P < 0.05) for horned rams than that for polled ones (3.04±0.15 and 2.44± 0.25, respectively).

However, horned yearlings tended to have (P < 0.10) higher abnormal spermatozoa.

Although BCS had significant positive correlation with SC (r = 0.56), it did not affect (P > 0.1) semen characteristics.

Results of this study indicate that ram age had no effect on semen characteristics despite the fact that older rams had larger scrotal circumferences (32.5 and 29.0 cm, for adult and yearlings, respectively).

The presence of horn had positive effects on EA in all rams while having positive effects on MM in adults and negative effects on AP in yearlings.