Relative Influence of Three Gastro-intestinal Nematodes of Cattle on the Concentrations of Haemoglobin and Serum Protein in the Host

Abstract

PURE infections of three species of gastro-intestinal nematodes have recently been established in this laboratory in worm-free calves, which were fed chaffed lucerne hay and infected when 3–4 months old. Seven calves each received a single oral dose of 50,000 infective larvae of Haemonchus placei, ten calves each an oral dose of 7,500 larvae of Oesophagostomum radiatum, and seven were each exposed to percutaneous infection by 10,000 larvae of Bunostomum phlebotomum. A further seven worm-free calves were each subjected to daily phlebotomy for periods of eight to fourteen weeks to induce a state of chronic anaemia due to haemorrhage. A volume of blood varying from 200 to 500 ml. was removed each day from the jugular vein. The concentrations of blood haemoglobin and total serum protein were determined weekly in all calves throughout the treatments.