Small Ruminants: Farmers’ Hope in a World Threatened by Water Scarcity

Abstract

The availability and sustainability of suitable and good quality drinking water is a global concern. Such uncertainties threaten livestock production with an attendant ripple effect on food security. Small ruminants, including sheep and goats, appear to be promising to smallholder farmers in solving this problem because of their ability to survive in water-limited areas and harsh environment when compared with large ruminants. Their small body size is also seen as an advantage, because less water will be required for proper digestion and feed utilization. Therefore, this review will provide information regarding the adaptive responses of small ruminants on thermoregulation, blood metabolites, immune status, drug pharmacokinetics, reproduction and hormonal indices during the period of water stress. Adaptable and indigenous breeds are known to be more tolerant to water stress than selected breeds. A drop in feed intake and weight reduced respiratory rate and increased concentration of blood metabolites are the general effects and/or observations that are encountered by small ruminants during the period of water stress. The concept of water tolerance either as deprivation and/or restriction of indigenous and adaptable breeds of small ruminants is gaining ground in research studies around the world. However, more research, however, seeking to explore water tolerance capacity of adaptable breeds especially in arid and water limiting areas are still needed.

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

“…The observed increase in plasma glucose in this study contradicts the unchanged concentrations observed in goats (Alamer 2006;Abdelatif et al 2010), as well as the significant drop, observed in sheep (Li et al 2000) during water deprivation. Such variations in plasma glucose concentration could be as a result of the pattern of dehydration adopted in this study which allows for rehydration for 24 h. Normally, small ruminant adaptively responds to limited water intake by depressing feed intake, and such feed intake depression may affect blood concentration of glucose (Akinmoladun et al 2019). 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.…”

“…Least square means for average daily water intake and average daily feed intake from Nguni goats subjected to varying periods of water deprivation over a four-week period of successive feeding. severe water scarcity by recouping as much water as possible in the rumen during rehydration to counteract weight loss induced by water deprivation (Akinmoladun et al 2019). With an increased length of water deprivation, excessive thirst is induced leading to increased consumption of water during rehydration (Hogan et al 2007).…”

“…This is because goats are imbued with good attributes such as fast growth rate, low production cost, short generation intervals, efficient utilisation of crop residues, adaptability to a harsh environment and the good nutritional profile and acceptability of the meat irrespective of religion and cultural divides (Webb 2014). However, their sustainability alongside other species of livestock is currently under threat due to increasing drought and water scarcity (Akinmoladun et al 2019). The severity of water stress and vulnerability to seasonal drought is further heightened in arid and dry zones of the world.…”

“…Therefore, a suboptimum intake can be critically limiting in terms of performance and productivity of livestock (Alamer 2010). Small ruminants are highly revered for their efficient water use abilities and resilience to limited water intake compared to other species of livestock (Akinmoladun et al 2019). This is attributed to minimal water requirement resulting from their small body size and also the ability to conserve water in their rumen (reservoir) for later use during shortfalls (Shkolnik et al 1980;Silanikove 2000).…”

“…Under a 3-day water deprivation, the Egyptian Baladi goat was still able to maintain about 35% of the control feed intake (Hassan 1989), while a 2-day water deprivation in Aardi goats made them stop eating completely (El-Nouty et al 1990). Therefore, breeds that can adapt to changing climatic condition, including resilience to limited water intake, without seriously compromising production indices are currently advocated as a key research need and focus for sustainability (Akinmoladun et al 2019).…”