Responses of Tswana goats to various lengths of water deprivation

Abstract

The aim of this trial was to determine the water intake of Tswana goats and investigate the effects of short term water deprivation in summer or winter (6000 ml water offered either once every 72 h, 48 h, 24 h or ad libitum) on feed intake, dry matter digestibility, growth rate and health. Goats were fed a diet comprising 60% Cenchrus ciliaris hay and 40% Medicago sativa hay. Feed intake per kg metabolic weight was inversely related to water intake. Body weight gains decreased with longer watering intervals, rectal temperatures were unaffected but respiratory rate, packed cell volume, pulse rate, haemoglogin level and mean corpuscular haemoglobin concentration was highest with the 72 h watering interval. Feed intake and daily weight gains were higher in winter than summer, but animals drank more water in summer than in winter, and showed more signs of dehydration in summer. Dry matter digestibilities (%) were 66.8, 66.7, 64.2 and 65.2 for water intake intervals of ad lib, 24 h, 48 h and 72 h respectively; digestibilities of organic matter, crude protein and crude fibre followed the same trend. Urine output, faecal output per kg metabolic weight and faecal moisture content decreased with increased length of water deprivation. It was concluded that Tswana goats are well adapted to semi-arid zones and can be watered once in 72 h without severe dehydration.