Assessing the modulatory role of ascorbic acid and L-glutamine on daily rhythms of rectal temperature of Red Sokoto goats during the early rainy season

Rhythmic changes in the rectal temperature of goats, an important health indicator, can be influenced by nutrient supplementation and seasonal environmental conditions. This study evaluates the effects of ascorbic acid and L-glutamine on the daily rhythms of rectal temperature in Red Sokoto goats during the early rainy season. Twenty-four male Red Sokoto goats (6.0–15.0 kg) were divided into four groups: a control group, an ascorbic acid (AA) group, an L-glutamine (L-GLU) group, and a combination group (AA + L-GLU), with six goats in each group, housed separately. Supplementation lasted 21 days. Dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were measured every 2 h for 24 h on days 0, 2, 5, and 8 post-supplementations. Rectal temperature (RT) was recorded at the same intervals. Results indicated that while DBT was within the acceptable range, RH and THI were often outside the thermoneutral zone for goats. Ascorbic acid significantly reduced RT during the light phase (P < 0.05), while L-glutamine increased RT during the dark phase. Ascorbic acid also decreased (P < 0.05) the baseline, amplitude, and phase shift of RT cycles. The phase shift was delayed in goats receiving both AA and L-GLU. In conclusion, ascorbic acid and L-glutamine affected the circadian rhythms of rectal temperature in Red Sokoto goats during the early rainy season.