Interpretive Summary: Performance, heat tolerance response, and blood metabolites of water-restricted Xhosa goats supplemented with vitamin C
By Anne Wallace
Goats are important in pastoral farming, especially for rural communities with limited resources. However, excessive heat and limited freshwater are physiologically stressful events that negatively impact performance. Given the importance of these animals to the small communities they sustain, a significantly reduced performance can be devastating.
In this April 2020 Translational Animal Science study, researchers looked at the Xhosa ear-lobed goat, indigenous to the Eastern Cape of South Africa. They hypothesized that supplementing vitamin C during heat stress and water restriction would limit negative impacts on performance.
Goats were given no water restriction, water restriction to 50% of ad lib intake (W50), or water restriction to 70% of intake (W70). Four additional groups were given either 3 grams of vitamin C daily with reduced water (W70 and W50), or 3 grams of vitamin C daily plus 5 g every 8 days with reduced water (W70 and W50). The growth performance, heat tolerance, and blood metabolites of all groups were evaluated.
In water restricted goats, blood urea, total protein and ALT were increased, but less increased in goats supplemented with vitamin C. There was also decreased body weight and dry matter intake, most pronounced in the W50 group. Vitamin C attenuated the negative effects of water restriction on body weight, dry matter intake, and blood levels of urea, total protein, and ALT. There was no difference in tested parameters for goats given the extra vitamin C.
Overall, the results of this study confirm that water restriction and heat stress impact the growth and performance of Xhosa ear-lobed goats. Supplementation with vitamin C limited negative impacts on performance. In-depth studies evaluating how vitamin C biochemically improves blood and health parameters of Xhosa ear-lobed goats under conditions of water restriction and heat stress is justified.