Some biochemical changes following Trypanosoma congolense infection in Djallonke ewe lambs and breeding ewes fed on two levels of nutrition

The effects of artificial Trypanosoma congolense infection and dietary leve l on biochemical changes were observed in 24 ewe lambs (Experiment 1) and 4 2 breeding ewes (Experiment 2). All animals belonged to the Djallonke breed which is known to be trypanotolerant. For both experiments, there were fou r treatment combinations, of which two were kept on a restricted diet (L), the other two on an at libitum diet (H). Half of each dietary group was inf ected with T. congolense (LI, HI), while the remainder served as uninfected controls (LC, HC). Artificial T. congolense infection took place at the ag e of 200 +/- 7 days in Experiment 1 and at the peak of oestrus in Experimen t 2. Irrespective of dietary levels offered, total proteins in lambs and ew es and albumin in lambs declined significantly (P < 0.001) post infection. Plasma glucose concentration was reduced by the low dietary level and not b y infection. Although plasma urea concentrations were slightly increased in the infected ewe lambs, adult ewes in the HI group demonstrated increased plasma urea concentrations (P < 0.05) due to an interaction between infecti on and diet. Neither infection nor the imposed diet induced significant cha nges on plasma creatinine concentrations. Transitory peaks in non-esterifie d fatty acids (NEFA) and beta-hydroxy butyric acid (BHBA) levels in infecte d ewes on low dietary level indicated temporary changes in the energy metab olism of the host. It was concluded from this study that, inspite of their trypanotolerance, Djallonke lambs and ewes demonstrated an infection effect on host metabolism pattern due to I: congolense infection. These changes r eflected to some extent trypanosome-induced alteration of the nutrient meta bolism, which could not always be negated by diet supplements. Nutrition, a s an independent factor, did confer added benefits against the debilitating effects of trypanosomosis under the conditions of the present study. (C) 2 000 Elsevier Science B.V. All rights reserved.