title: Calcium and phosphorus absorption in lambs exposed to Trichostrongylus colubriformis.
abstract: Ten lambs (29 +/- 1.2 kg) reared parasite-free and prepared with rumen, duodenal and ileal cannulae were paired and one of each pair was given a daily oral dose of 2500 Trichostrongylus colubriformis larvae for 14 weeks. Untreated animals received the amount of ration consumed by their infected pair-mates the previous day. During weeks 6 and 12 of infection, all lambs underwent a 7 day calcium (Ca) and phosphorus (P) balance. During weeks 7 and 13, duodenal and ileal samples were collected to determine the amounts of Ca and P entering and leaving the small intestine. The infection caused varying degrees of feed refusal in all infected animals. As a result, the data on Ca and P in excreta and the amounts of Ca and P entering and leaving the small intestine were regressed against dry matter (DM) intake for each group at each period. There were no between-period differences in these relationships. Calcium absorption and retention were unaffected by the stress of infection. Infection affected several aspects of P metabolism. Blood P concentrations were markedly reduced. Absorption of P from the small intestine was greater (P less than 0.01) in control lambs (at 1 kg DM intake 6.6 g per day) than in infected animals (2.2 g P per day), but there was a greater (P less than 0.05) duodenal flow rate of P in control lambs which suggested much higher rates of salivary secretion of P than in infected animals. Phosphorus flow rates at the ileum were greater (P less than 0.01) in infected lambs, despite the lower duodenal flow rates, which indicated a major abnormality (P less than 0.01) in small intestine absorption of P in infected animals; this may have contributed to the growth check experienced by these lambs.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000652:urine; D005243:Feces / Q000032:analysis; D007408:Intestinal Absorption; D007411:Intestinal Diseases, Parasitic / Q000378:metabolism / Q000662:veterinary*; D010758:Phosphorus / Q000097:blood / Q000378:metabolism* / Q000652:urine; D012756:Sheep; D012757:Sheep Diseases / Q000378:metabolism* / Q000469:parasitology; D014252:Trichostrongyloidiasis / Q000378:metabolism*; D014253:Trichostrongylosis / Q000378:metabolism*
chemical_list: D010758:Phosphorus; D002118:Calcium