Interaction of parasitism and nutrition in goats: effects on haematological parameters, correlations, and other statistical associations

• Published in: Veterinary parasitology Vol. 44; no. 3; pp. 183 - 197
• Main Authors: Blackburn, H.D., Rocha, J.L., Figueiredo, E.P., Berne, M.E., Vieira, L.S., Cavalcante, A.R., Rosa, J.S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.1992
• Subjects: ANALISIS ESTADISTICO; ANALYSE STATISTIQUE; Animal Feed; ANIMAL NUTRITION; Animal Nutritional Physiological Phenomena; Animals; BLOOD; Blood Proteins - analysis; CAPRIN; CAPRINOS; Eating; ERITROCITOS; ERYTHROCYTE; Erythrocyte Count - veterinary; ERYTHROCYTES; Goat Diseases - blood; GOATS; Haemonchiasis - blood; Haemonchiasis - veterinary; HAEMONCHUS CONTORTUS; Hematocrit - veterinary; LEUCOCITOS; LEUCOCYTE; Leukocyte Count - veterinary; LEUKOCYTES; Male; NUTRICION ANIMAL; NUTRITION ANIMALE; PARASITISM; PARASITISME; PARASITISMO; Random Allocation; Regression Analysis; SANG; SANGRE; STATISTICAL ANALYSIS
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/0304-4017(92)90116-Q

Weaned wether goats ( n = 144) approximately 6 months of age were placed in a 2 × 3 factorial experiment to test the effects and interaction of two levels of nutrition (growth + maintenance, NUT1; and twice growth + maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500, and 2000 larvae administered every 2 weeks; W0, W500, and W2000, respectively) on packed cell volume, red blood cell count, total serum protein and leukocytes. The statistical analysis revealed clear and proportionate differences among levels of infection for all variables. A significant ( P < 0.05) nutritional effect was also found associated with all the variables except leukocytes. Nutrition by worm load interactions were found for packed cell volume and leukocytes. The neutrophil/lymphocyte ratio was higher in the NUT1-infected animals, leading to the nutrition by worm load interaction for leukocyte . An analysis for the different leukocyte types revealed significant ( P < 0.05) differences among infection levels for lymphocytes, while nutrition level was found to be a significant effect for basophil count and immature white cells. Several significant correlations were observed between pairs of variables. Faecal egg output could be predicted from actual worm count in three of the four necrospy periods. The clear differences observed for blood parameters were not present in production traits, suggesting that physiological thresholds may play an important role in framing the metabolic activity of biological organisms. Total serum protein was the best indicator of these effects on production parameters.