CHAPTER ONE
1.0 INTRODUCTION
Previous studies (Aboud et al, 1992) clearly indicate the value of selective feeding. Sheep were shown to perform better and consume more digestible matter through selective intake of leaf and sheath fractions of sorghum stover as a result of liberal offers. This observation is of practical value for small ruminants in the tropics because the traditional feeding systems depend largely on crop residues. However, there is little evidence in the literature that the approach adopted by Aboud et al (1992) would be as effective for goats as it was for sheep. Results from comparative studies between sheep and goats of selective efficiency are generally conflicting (Huston, 1978; Devendra and Bums, 1983). Goats in the tropics are more able than sheep to consume feed fractions of higher nutritional quality when offered the opportunity to eat selectively (Devendra and Burns, 1983; Hoppe et al, 1977; Huston, 1978). This observation does not agree with studies carried out in temperate countries, where sheep have been shown to perform better than goats under most practical feeding systems. A comparative feeding and performance study on Small East African goats and the Red Maasai sheep in Tanzania (Shoo, 1986) was inconclusive, although sheep appeared to perform better than goats when offered a basal diet of Chlorisgayanahay with Leucaenaas a supplementary forage. However, observations in Shoo’s (1986) study did not include an assessment of selective feeding ability between the two species. The inclusion of a supplementary forage may have confounded the results, as it is known that goats would preferentially consume browse species (Lu, 1988). Most of the comparative studies in the tropics were made under grazing conditions, whereas those in the temperate countries involved comparisons under stall-feeding conditions in which feed was offered at restricted levels, usually at 35 g dry matter M(D)/kg live weight per day or to achieve 10-20% rate of refusal. Comparative studies under grazing or in stalls at restricted levels of offer may give misleading results (Demment and Van Soest, 1983). Restricted levels of offer do not usually provide sufficient opportunity for selective feeding (Aboud et al, 1993). This is particularly serious where low-quality crop residues are used in comparisons.