April - June 2007 - Kasetsart University

considered responsible for low productive and
reproductive performance of grazing ruminants in
the tropics (McDowell et al., 1997). Mineral
deficiencies are considered to be one of the
nutritional constraints to animal productivity. Poor
body conditions, slow live weight gain, low
fertility and high mortality are normally observed
in mineral-deficient animals (McDowell et al.,
1983; Vijchulata, 1995).
The main sources of mineral for animals
in the Somali region are salty water, shrub plants
and natural mineral soils. The soil mineral known
as Carro is found in vast area of Afder,
Degehabour, Gode, Jijiga, Liben and Shinile
zones. It is commonly observed that pastoralists
in these zones feed natural mineral soils to animals.
Considerable use is being made of the natural
mineral licks since they are relatively free and are
easily obtained as compared to complete mineral
mixture. Supplementation with multi-nutrient
blocks and local mineral soils such as Bole and
Megadua in some parts of Ethiopia may provide
an adequate or even excess amount of most of the
essential minerals except phosphorus (Tolera and
Said, 1994).
Studies regarding mineral supplementation
have not been conducted in the region.
Moreover, attention has not been paid to its effect
on Black Head Somali (BHS) sheep. The main
objective of this study was, therefore, to determine
the mineral composition of these soils, and to
evaluate the effect of their supplementation in
comparison to Bole soil and complete mineral
mixture on body weight and liver mineral
concentrations of BHS.
MATERIALS AND METHODS
Animals and management
The study was conducted in Jijiga Somali
Region from July to October 2004. Forty eight
males BHS sheep about 12 months of age
weighing 20–25 kg were randomized by weight
Kasetsart J. (Nat. Sci.) 41(2) 289
assigned to six groups of eight sheep each. Prior
to the commencement of the experiment, the
animal were kept for 15 days for adaptation and
to observe their health status. All animals were
ear-tagged. They were also provided with neck
strips of six different colours for group
identification. All the animals were drenched with
a broad-spectrum antihelmentic and vaccinated
against Anthrax, Pasteuriolosis and Blackleg
diseases.
The natural mineral soil Arabi soil, Jair
soil and Hermokale soil were collected from Jijiga
and Shinile districts, Somali region, Bole soil was
collected from Zeway district, Oromiya region and
complete mineral lick from Thailand (Phosrich
Rockie: Phillips International Co. Ltd.). Six
treatment groups were randomly assigned to
mineral supplementation. Group I (control) was
not supplemented. Group II, III, IV, V were
supplemented with Arabi soil, Jair soil, Hermokale
soil and Bole soil, respectively. Group VI was
provided with complete mineral lick.
Sheep barn was constructed using
eucalyptus wood with 19 m × 5 m dimension and
was divided into 48 equal pens (1m × 0.8m) for
individual feeding of the minerals and to
accommodate the animals at night. Sheep were
allowed to graze together in flock on the same
pasture from 8:00 am to 6:00 pm. Between 12:30
pm and 1:30 pm and 6:00 pm to 8:00 am the
animals were driven into their pens where they
were fed individually with their respective mineral
supplements. Mineral soils were offered ad libitum
in the boxes which were fixed at the corner of
individual sheep pen. Mineral residues were
weighed on weekly basis and intakes for each
sheep were calculated. The animals were weighed
on monthly basis through out the experimental
period. All the experimental animals were
provided ad libitum with water in the pens.
Soil sampling and analysis
To study the mineral content of different