Standard for Haemonchus contortus "pathogenic worm burden" in sheep

• Autor(a) principal: Baroni, João Marcos
• Data de Publicação: 2014
• Outros Autores: Santiago, Marco Aurelio Miranda
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/15473
• topic: nematodes; worm burden; nematódeos; carga patogênica

Twenty-four Corriedale sheep, worm free, were used in this experiment. The animals were divided into six groups of four animals each. Five groups received, respectively, 1,000, 2,000, 3,000, 4,000 and 5,000 L3 Haemonchus contortus larvae per sheep, and one group remained as control. The animals were fed daily with 250 grams of balanced ration and 250 grams of packed alfalfa for 25 days. Afterwards, this ration was reduced in 50%. The animals were controlled every seven days by means of eggs/gram count in faces. Packet cell volume, hemoglobin and RBC counting and total plasma protein and individual weight. The alterations in the parameters in relationship with the degree of infestation and feeding system led to conclude: 1. The pathogenic worm burden of Haemonchus contortus cannot be measured by the number of worms or eggs per gram of faces, without having in mind the nutritional state of the parasited animals. 2. The relationship between feeding and parasitism can be measured by the blood parameters. 3. The average number of eggs per gram of faces was proportional to the number of worms in all the infested animals. 4. The average abomasal pH increased proportionally to the number of worms in all groups.