The effect of cassava foliage (Manihot esculenta) on gastrointestinal parasites of small ruminants in Cambodia(2009) The effect of cassava foliage (Manihot esculenta) on gastrointestinal parasites of small ruminants in Cambodia. Doctoral diss. Dept. of Biomedical Science and Veterinary Public Health, SLU. Acta Universitatis agriculturae Sueciae vol. 2009:43. Full text available as:
AbstractThe overall aim of this project was to evaluate whether cassava foliage mitigates gastrointestinal (GI) nematode infections in young goats in Cambodia. The nematocidal activity of fresh cassava foliage was investigated in four trials with experimentally infected pen-fed goats. In the first experiment, the activity on incoming larvae and established adult worms were tested following short-term feeding of fresh foliage for three weeks. Goats (4-6 months) were first treated with ivermectin. After six weeks, they were re-infected with ~2000 mixed infective third-stage GI nematode larvae (L3). There was only a slightly reduction in the faecal egg counts (FEC) during the cassava feeding periods. In the second experiment, the effects of prolonged feeding of fresh (CaF) or ensiled (CaS) cassava foliage for ten weeks using the same type of set up as in experiment one. The inoculations were in accordance with the first trial, except that 3000 L3 were administrated. It was found that CaF only reduced worm fecundity, while feeding CaS also reduced the worm burdens, but only of Haemonchus contortus. Although this was promising, it was realized that the possible effects of a high protein content in cassava silage was a confounder. Accordingly, a third trial was conducted. The aim was to compare the antiparasitic effects in goats fed CaS, and a supplement of urea molasses and soybean meal (UM). The results indicated that the UM supplementation supported only resilience (weight gain, anaemic state) against GI parasite infection, whereas parasite fecundity and worm burden were more or less unaffected. In the final experiment special attention was paid on the antiparasitic effects of CaS. Both cassava foliage and paragrass (Brachiaria mutica) were ensiled with two fermentative additives (sugar palm syrup or rice bran) and were then fed in a similar fashion to the previous experiments. CaS still provided consistent results irrespective of the fermentative additive used. It is concluded that cassava foliage can be used to reduce the adverse effects of GI nematode infections in goats, in particular when offered as silage.
|
