Udder size and milk production potentials of goats and sheep in the south west of Nigeria
Twelve adult lactating goats and sheep (2 to 2½ years old) comprising three groups of four each of West African Dwarf (WAD) goats and sheep and Yankasa ewes were used for a nine week trial. The animals kidded and lambed between January and March. During these periods, the udder sizes of the dams were measured weekly before hand milking thrice a week to determine the milk yield. Samples of the milk were analysed for th.eir composition. The results showed that the udder size increased with increasing milk yield (112 - 248ml) up to the peak of lactation which was between weeks 3 and 4 after parturition. Thereafter it decreased in size till the end of the experiment. The coefficient of variation (CV) of the udder size was influenced by breed. Udder size was positively correlated with milk yield. Milk yields were generally low or and ranged between 39 and 70ml and this was dependent on the behaviour of the lactation curve. The milk protein and ash contents for the three breeds were comparable to those of the temperate breeds. Though Yankasa sheep exhibited the highest milk production potential, yet the peculiar characteristics of goat milk cannot be overlooked.
Key Words: Udder size, milk yield and composition, West African Dwarf, (WAD) Yankasa, WAD goat, sheep.