The energy and water balance for Bedouin goats before gestation and at different levels of production was worked out. Both gross energy and total water intake were linearly related to their milk production. High producing animals consumed twice as much food (up to 1256kJ/kg body weight/day) and three times more water (290ml/kg body weight/day) as non-lactating ones.
The conversion coefficient of digestible energy to energy in milk ranged from 34% at peak lactation to 25% at the end of the period. No mobilization of tissue was observed even at peak lactation. Black Bedouin goats thus demonstrate ‘superior dairy merits’ throughout their entire lactating period.
Water requirement of a lactating Bedouin goat was lower than reported for other ruminants and amounted to 2·5 l/kg milk produced. This ratio was maintained whether over 2 l of milk was produced or only 0·5 1.
Compared with goats before gestation, lactating Bedouin goats ‘economize’ both their energy and water metabolism and were highly adapted to maintain production in the adverse desert environment.