| dc.description.abstract | A survey was carried out in order to find out (a) the
prevalence of cobalt-related vitamin B12 deficiency in
goats, (b) the effect of the deficiency on body condition and
reproductive performance and (c) to describe the
management practices of the farmers in the area and see
how they predispose the goats to Vit. B12 deficiency. The
survey was conducted in small farming communities of the
endemically cobalt deficient area of the Rift Valley of
Kenya.
The survey area was divided into ten clusters each with
80 female goats. Approximately 800 female goats owned by
small scale farmers were used in the study for
determination of management practices and reproductive
performance. Sixteen to twenty female goats in each
cluster were used for body condition determinations and
blood sampling for the analysis of, serum Vit. B12,
hematology and blood qlucose.
Goats were found to have a wide range of serum Vit. B1 2
levels, from 20.2 pg/ml to 937.5 pg/ml. The overall mean
serum 81 2 .concentration was 205.5±9.37 pg/ml. Only 22
(10.1 %) out of 218 goats had serum Vit. 812 levels higher
than 370 pg/ml which is considered adequate for sheep. The
rest 196 (89.5%) goats had serum Vit. B12 levels less than
370 pg/ml. Of these, 122 (56.4%) .had serum Vit. B12 levels
less than 180 pg/ml, the deficiency level in sheep while 74
or 33.5% of the goats had Vit. B12 levels in the marginal
deficiency range for sheep, 180-370pg/ml.
The mean serum Vit. B1 2 levels of the goats which
received mineral supplements was 385.9±26.16 pg/ml. This
was significantly different (P< 0.001) from the mean of
136.2±8.59 pg/ml. for the goats were not given mineral
supplements.
Cases of overt anaemia were found in every farm and
cluster as demonstrated by RBC counts, Hb concentration,
and haematocrit levels which were below the lower limit of
the normal range for goats.
Very low reproductive and weaning rates were found
throughout the region of study. Cluster mean reproductive
rates ranged from 0.6 kids per doe per year to 1.4 kids per
doe per year and were far below the expected 2 kids per doe
per year. Except one cluster which had comparatively better
management, all the other clusters mean reproductive rates
were <1.0 kid per doe per year. The weaning rates ranged
from as low as 0.4 to 0.9 weaners, per doe per year.
It is concluded that cobalt deficiency is widespread in
goats in the study area. The deficiency is characteristically r
marginal with many goats tending towards the clinical
form. The clinical form is demonstrated by the prevalent
anaemia, very low reproductive performance, poor body
conditions, in some cases severe unthriftness and a
tendency towards low blood glucose levels especially when
goats are left to rely on pasture cobalt alone. The incidence
of occurrence of cobalt deficiency in the area is reduced by
free grazing and mineral supplementation.
It is recommended that effective control would require
very strict management measures. This can be achieved
through adequate extension advice particularly to the small
scale farmers in the cobalt deficient areas. | en |
