Effects of ambient temperature and scrotal fleece cover on scrotal and testicular temperatures in rams

The objective was to determine scrotal and testicular temperatures in rams and how they are affected by ambient temperature (10 degrees C vs 25 degree s C) and scrotal fleece (densely fleeced vs shaved). Scrotal surface temper atures (SST) of the caudal aspect of the shaved hemi-scrotum at 10 degrees C vs 25 degrees C were (mean, degrees C) 28.9 and 30.5 (P < 0.03), 28.2 and 29.6 (P < 0.04), and 26.1 and 27.6 (P < 0.06) at the top, middle and botto m of the testis, respectively. Scrotal subcutaneous temperatures (SQT) on t he fleeced vs shaved side were 33.5 and 32.0 (P < 0.02), 32.2 and 31.1 (P < 0.06), and 31.7 and 30.8 (P < 0.09) at the top, middle, and bottom at 10 d egrees C; they were 33.9 and 32.1 (P < 0.02), 33.1 and 31.9 (P < 0.05), and 32.5 and 32.0 (P < 0.15) at 25 degrees C. Intratesticular temperatures (IT T; measured only at 25 degrees C) on the fleeced vs shaved side were 35.3 a nd 35.0 (P < 0.5), 35.5 and 35.2 (P < 0.4), and 35.4 and 35.0 (P < 0.3) at the top, middle, and bottom. Temperature gradients (difference from top to bottom) were greatest for SST (2.8 degrees C), moderate for SQT (1.8 to 0.1 degrees C), and not significant for ITT (-0.1 and 0.1 degrees C). The SST was approximately 1.5 degrees C warmer at all 3 locations at 25 degrees C v s 10 degrees C. Increased ambient temperature affected SQT more at the bott om than at the top. Conversely, the difference in SQT between the fleeced a nd shaved sides was greatest at the top. The difference in ITT (0.3 degrees C warmer on the fleeced vs the shaved side at all locations) was not signi ficant. Therefore, the magnitude of temperature increase associated with am bient temperature or scrotal fleece was affected by both depth and vertical location.