Effect of Trypanosoma vivax infection on energy and nitrogen metabolism of west African dwarf goats.

Abstract

A study was conducted using 32 mature 22-kg West African Dwarf Goats to measure the effect of Trypanosoma vivax infection on energy and nitrogen metabolism. Sixteen goats were infected intravenously with 14 X 10(6) T. vivax. Sixteen control goats were sham-injected. Digestibility and metabolizability of energy and N balance were measured for each goat. Heat production and energy balances were measured per treatment group from 1 wk before infection to 6 wk after infection. Goats were fed alfalfa pellets (10% above maintenance). Treated goats had a reduced (P less than .05) packed cell volume (38 to 40% before infection vs 20 to 25% 6 wk after infection) and an increased (P less than .05) rectal temperature. Log parasitemia/ml was about 6.0 to 6.2. Parasitized goats showed increased urine creatinine excretion at wk 2 postinfection. After infection, feed intake was reduced (about 15%; P less than .05) and greater variability in intake was noted. Treated and control goats had similar N output and energy output in urine. Metabolizability of energy intake was similar at 42.7 vs 42.1% in treated vs control goats, respectively. Heat production in infected goats was increased by about 15%. Treated goats lost more weight and had a lower N balance than control goats (P less than .05). The calculated maintenance energy requirement for infected goats (464 kJ ME/kg.75) was 25% greater than for control goats (375 kJ ME/kg.75).

Evaluation of animal performance, feed intake, and economic losses in sheep experimentally infected with Trypanosoma vivax

“…Instead, an effect also occurs in the chronic phase, with a possible cumulative effect, which resulted in a weight loss for the IG of 24% by the end of the experiment. This percentage resembles the maintenance value observed by Vertegen and Zwart (1991), who evaluated the effect of T. vivax infection on energy metabolism and nitrogen balance in goats and found that the energy requirement for maintenance increased by 25% after infection. According to these authors, the increase was associated with a negative nitrogen balance, serum urea increase, urinary creatinine excretion, reduction in nitrogen retention, and greater weight loss in the group of infected animals.…”

Social factors affecting seasonal variation in bovine trypanosomiasis on the Jos Plateau, Nigeria

“…Malnutrition and high stress increase both susceptibility to trypanosomiasis and promote negative outcomes of infection [28]. Nutrition is one of the key factors determining outcomes of trypanosomiasis infections since the degree of anaemia and growth retardation in infected cattle depends on protein and energy intake [29-31]. …”

The effects of pathogen challenges on the performance of naïve and immune animals: the problem of prediction

“…It has been observed that during pathogen challenges heat production was increased, while food intake and energy retention were reduced e.g. Verstegen et al (1991) and Zwart et al (1991). This effect, however, appears to be both pathogen and dose specific.…”

“…There appears to be highly specific pathogen differences, with the greatest energetic cost occurring for pathogen or antigen challenges that lead to a fever e.g. Verstegen et al (1991), Zwart et al (1991) and Demas et al (1997). Local pathogen challenges may cause less of an effect as was demonstrated by Van Diemen et al (1995) who considered the effect of atrophic rhinitis on heat production in pigs.…”