Effects of experimental subclinical fasciolosis on the feeding behaviour of sheep

Abstract

Ten female Churra breed sheep were experimentally infected with 25 Fasciola hepatica metacercariae daily during six days. The animals were offered pelleted lucerne and water ad libitum. Feed and water intake was automatically recorded by computer monitoring of electronic balances. Liver damage caused by flukes was ascertained by measuring the activities of aspartate amino transferase, glutamate dehydrogenase and gamma-glutamyl transferase. Serum bile acids and glucose concentrations were also measured. Maximum plasma enzyme values were found at 10 weeks post infection. Plasma bile acid concentration increased from six to 13 weeks post infection. Glycaemia was decreased from the fourth week post infection until the end of the experiment. Total daily food intake decreased maximally between six and 12 weeks post infection. The number of meals per day and time spent eating and drinking decreased along the experimental infection. The rate of eating and drinking increased progressively. An association between anorexia and liver damage is suggested.