Objective: To examine the effects of giardiasis on production and carcass quality, using growing lambs as a domestic ruminant model.
Design: Randomized block.
Animals: Giardia-free lambs: 23 in infected group, 24 in control group.
Procedure: Six-week-old, specific-pathogen-free lambs were infected with Giardia trophozoites; control lambs received saline solution. Clinical signs of infection, body weight, and feed intake were determined for 10 weeks. Carcass weight and quality were determined at slaughter weight of 45 kg.
Results: Giardia infection persisted from weeks 7 to 16. For 5 weeks after challenge exposure, abnormal feces were more frequently observed in infected lambs. Giardia infection was associated with a decrease in rate of weight gain and impairment in feed efficiency. Time to reach slaughter weight was extended in infected lambs, and the carcass weight of Giardia-infected lambs was lower than that of control lambs.
Conclusion: Giardiasis has a negative effect on domestic ruminant production.
Clinical relevance: Giardiasis in domestic ruminants is an economically important disease, thus necessitating control or elimination of the infection.