| dc.description.abstract | 'Ibis study sought to determine experimentally if any differences exist
in the susceptibility of different breeds of pig to trypanosomiasis caused
by T. simiae. Four breeds were used: pure Large White, Large White X
Landrace, Landrace X Large Black and pigs belonging to an undetermined breed
and bought from farms in Nderi, Muguga. Pigs of both sexes aged 2-3 months
were used.
Following needle or tsetse challenge, the rectal temperatures of the
pigs and the haematological changes during the course of infection were
measured. Parasites were detected by examination of the buffy coat using the light microscope after sping the blood in a microhaematocrit
centrifuge. The parasites were quantified using the wet blood method of
Walker (1968).
Differences in the prepatent period occurred between
the pure Large White and the Landrace X Large Black Pig had prepatent period of 3 days. The Large White X Landrace crossbreed pigs had a mean prepatent period of 3.73±O.23 days. After tsetse challenged the Large White X
crossbreed pigs
and the pigs from Nderi had mean prepatent
6. 27±1. 26 ~ and 5. 88±O. 86 days ) respectively. All the pure
large white pigs and some individuals from the other breeds exhibited no
ability to control or remit parasitaemia. These animals became anaemic
rapidly and died during the first peak of parasitaemia. In terms of
survival, the pure Large White pigs were the least resistant to
trypanosomiasis. The Large White X Landrace crossbreed pigs, the Landrace X
Large Black crossbreed pigs and the pigs from Nderi showed marked
heterogeneity in their trypanotolerance. Some animals were resistant and
survived more than two weeks of patent infection following needle or tsetse
Challenge some had no resistance) while others were intermediate. One Large
White X Landrace crossbreed pig lost the infection spontaneously. The
resistant animals possessed a superior capacity to control parasitaemia and
developed less severe anaemia.
It is concluded that a degree of resistance to T. simiae infection
exists in the Large White X Landrace crossbreed pigs and in the pigs from
Nderi, Muguga. | en |
