April - June 2007 - Kasetsart University

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Mohammed et al. (1989) who reported that
weight gains of Arsi sheep improved by an
average of 19±8 g/day when fed with natural
mineral lick as free choice. The low body
weight gain observed might be due to the fact
that Bole soil had lower Mn, Zn and Cu but
higher in pH, sand and clay than the other soils
(Table 1). The imbalance mineral content of the
soil might result in depressing effect on
feed intake which in turn affects the body weight
gain. Allen et al. (1986) observed a decrease
in weight gain when 1000 mg/kg of Fe were
included in the diet of sheep. Hodgson (1962)
reported that because of large quantities in the
soil, animals are also likely to augment their
Fe supplies through direct ingestion of soil or from
soil contaminated herbage Moreover, in
New Zealand it was reported that the amount of
soil ingested annually reach 75 kg for sheep
(Healy, 1978).
The average monthly intake of different
mineral soils is illustrated in Figure 2. During the
first month of the experimental period, there was
Mineral intake (gram/month)
700
650
600
550
500
450
400
350
300
Kasetsart J. (Nat. Sci.) 41(2)
a steady increase in mineral intake of sheep in all
the treatment groups. This was followed by a
nearly constant intake over the period from second
to third month. This decline coincided with
seasonal summer rain and emergence of green
grasses after which an increase was observed until
the end of the fourth month. According to
McDowell (1997), energy and protein supplies
from emerging forages during the wet season are
higher, livestock gain weight more rapidly
resulting in high mineral requirements.
Mean monthly body weight gain of the
sheep fed different mineral sources during the
experimental period is shown in Figure 3. Sheep
supplemented with the complete mineral mixture
tended to gain more live weight than others
through out the experimental period. Sheep
receiving complete mineral lick were less heavy
than that of control animals during the 1st and 2nd
month. However, it was observed that they attained
2 kg weight more than the control group by the
4th month. Sheep fed with Bole soil were found
to loose weight during the 2nd to the 3rd months
July August September October
Experimental period (months)
Jair Hermokale Arabi Bole
Figure 2 Average monthly intakes of different mineral soils over the four months period