Performance, heat tolerance response, and blood metabolites of water-restricted Xhosa goats supplemented with vitamin C1

Abstract

Water restriction in small ruminants is usually accompanied by a drop in feed intake, body weight, and disturbances in the normal internal milieu. However, attempts to lessen the burden of water stress with vitamin C (VC) supplementation have been greeted with conflicting reports. Therefore, this experiment was conducted to evaluate the effect of single and/or multiple VC supplementations in water-restricted Xhosa goats by evaluating their performance, heat tolerance, and blood metabolites. In total, 42 does, 12 mo old and with an average weight of 15.92 ± 2.12 kg were evaluated for 75 d. The does were distributed according to a complete randomized design into seven groups of six comparable animals: W0, without water restriction (control); W70, water restriction of 70% of ad libitum water intake (WI); W50, water restriction of 50% ad libitum WI; W70+, water restriction of 70% of ad libitum WI plus 3 g VC daily; W50+, water restriction 50% of ad libitum WI plus 3 g VC daily; W70++, water restriction of 70% of ad libitum WI plus 3 g VC and extra 5 g VC given every eighth day; and W50++, water restriction of 50% of ad libitum WI plus 3 g VC and extra 5 g VC given every eighth day. Goats under the W50 group were the most affected (P < 0.05) and the effect was more pronounced in their body condition scores (BCs). Weight loss due to water restriction was reduced by VC supplementation in treated groups. Changes in body thermal gradient, rectal temperature, cholesterol, and bilirubin were similar (P > 0.05) across the various experimental groups. The attenuation effect of VC was significant (P < 0.05) in responses to respiratory rate, Na+, K+, Mg2+, Cl−, Ca2+, and urea. Supplementation of VC (either single or multiple) did not significantly (P > 0.05) improve the effect of water restriction on BCs, FAMACHA, glucose, globulin, alanine aminotransferase, and high-density lipoprotein. The additive effect of multiple VC significantly influenced (P < 0.05) Na+ and Mg2+. Limited WI affects growth and other physiological parameters in Xhosa goats. However, supplementation of VC may be beneficial at modulating the stressful stimuli imposed by water stress.

Effect of hydric stress on intake, growth performance and nutritional status of Nguni goats

“…This could be attributed to the water deprivation regimen adopted. A similar response was reported in a 75-d water restriction study on Xhosa goats (Akinmoladun et al 2020b). Besides, the correlations from the current study indicate that an increase in water deprivation periods results in low body condition scores and large faecal egg counts.…”

“…In a similar study, the body weights of Saudi Arabia goats were reduced by 21% when deprived of water for 3 days (Alamer 2006). A similar decrease in body weight was observed in a 75-d water-restriction study in Xhosa goats (Akinmoladun et al 2020b). Giving the correlation between body weight and body condition (Rumosa-Gwaze et al 2010), the decreased body condition with increasing period of water deprivation in this study was expected.…”

“…The decreased energy intake during water deprivation and/or restriction requires that fat be mobilised from adipose tissues (Jaber et al 2011), thus increased plasma cholesterol concentration. Similar increased level of plasma cholesterol induced by limited water intake was reported in goats (Akinmoladun et al 2020b) and sheep (Jaber et al 2004).…”

“…water stress, and attempts to maintain energy needs normally result in fat mobilisation from adipose tissues (Jaber et al 2013). In a similar study, Akinmoladun et al (2020b) reported an increasing loss of body condition in Xhosa goats' water restricted by 70% and 50% of ad libitum intake for 75 days. This decline in body condition scoring and body weight in the current study proved the negative correlation that exists between water deprivation period together with body condition scoring and body weight.…”

“…The increased blood constituents due to limited water intake agree with the report of Alamer (2006) who observed increased plasma concentrations of creatinine, urea and plasma osmolality in Saudi Arabia indigenous goats subjected to a 3-day water deprivation study. The haemo-concentration of blood constituents resulting from limited water intake has also been documented in goats and sheep (Nejad et al 2014;Akinmoladun et al 2020b).…”