Animal Science Abstract
Anorexia and food utilization in nematode infected lambs on pasture
S. M. Thamsborg1,A and N. Agergaard2
AE-mail: smt@kvl.dk
1Organic Animal Health and Production, Department of Animal Science and Animal Health, Royal Veterinary and Agricultural University, 2 Grønnegårdsvej, DK-1870 Frederiksberg C, Denmark2Department of Animal Health and Welfare, Danish Institute of Agricultural Sciences, Research Centre Foulum, PO Box 50, 8830 Tjele, Denmark
Abstract
The influence of naturally acquired nematode infections on food intake and utilization was investigated in grazing lambs. It was first demonstrated in a pilot study with penned lambs that the application of chrome-oxide in a ruminal bolus could be used for comparison of food intake in infected and uninfected lambs on grass. In a field trial, repeated in two consecutive seasons, 48 lambs grazed on clover grass in six groups. Three stocking rate groups were grazed on contaminated pastures (I-low, I-medium and I-high) and three groups on clean pastures (U-low, U-medium and U-high). Faecal dry-matter (DM) output of individual lambs was estimated in August each year by the chrome-method. DM intake and food conversion efficiency were calculated based on hand-picked herbage samples and in vitro assessment of digestibility. Substantial worm burdens, increasing from year 1 to year 2, were observed and some lambs had clinical symptoms in the 2nd year. In year 2, lambs on contaminated pastures had significantly lower DM intake (proportionately 0•09 lower), higher faecal protein losses and lower food conversion efficiency compared with the uninfected lambs on clean pastures. The effect of infection on food intakes was eliminated if corrected for body weight. The study showed that if exposure to nematode infections is large enough, increased protein losses in faeces and anorexia may contribute to reduced performance in lambs in late season.
Keywords: anorexia, food intake, nematoda, protein intake, sheep, stocking rate
| Search for papers on a specific subject | |
|---|---|
 |
|