Zaros, Lilian GiottoCoutinho, Renata Maria Alves2014-12-172012-09-172014-12-172012-02-28COUTINHO, Renata Maria Alves. Phenotypic markers to characterizeE goats with different levels of resistance to gastrointestinal nematodes. 2012. 62 f. Dissertação (Mestrado em Sistemas de Produção Sustentáveis no Semi-árido; Caracterização, conservação e melhoramento genético) - Universidade Federal do Rio Grande do Norte, Natal, 2012.https://repositorio.ufrn.br/jspui/handle/123456789/17171The aim of this study was to evaluate and characterize phenotypically goats with different levels of resistance to gastrointestinal nematodes. For a period of 93 days, 60 F2 goats originated from ½ Saanen and ½ Anglo- nubian animals were kept in the same area of pasture. Every seven days, feces and blood were collected for eggs per gram counts of feces (EPG) and cultures of feces and to determinate the number of eosinophils, packed cell volume and total plasma protein, respectively. On the same day, the animals were weighed and submitted to body score condition and FAMACHA method to worm control. Based on the average of EPG, the twelve animals with the highest average (susceptible group) and the twelve animals with the lowest average of EPG (resistant group) were selected, slaughtered and necropsied to recovery, counting andparasites identification. The resistant animals present lower EPG mean (P <0.0001) and 4.7 folder less parasites than susceptible animals. The resistant group presented higher mean packed cell volume (26.48%) and total plasma protein (6.24 g / dl) than susceptible one (24,04% e 5,82g/dl, respectively). The average number of eosinophils was similar in both groups The Haemonchus sp. was the most prevalent in the culture of feces, followed by Trischostrongylus sp. and Oesophagostomum sp.. The counting of nematodes in the abomasum of susceptible group was higher than in resistant one. The species identified were H. contortus in abomasums and T. colubriformis in small intestine. It can be concluded that EPG, packed cell volume and total plasma protein were useful phenotypic markers to identify animals as resistant and susceptible to gastrointestinal nematodes infectionsapplication/pdfAcesso AbertoCaprinosFAMACHANematoidesOPGResistênciaVolume globularGoatsEPGFAMACHANematodePacked cell volumeResistancemasterThesisCNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA::COMPORTAMENTO ANIMAL