Relação entre o periparto e o número de ovos e oocistos de parasitos gastrintestinais em cabras da raça Anglo-nubiana naturalmente infectadas, no Semi-árido brasileiro , Jequié -BA

Abstract

Objective of this study was to analyze possible relationships between the number of eggs of gastrointestinal nematodes and peripartum period in female Anglo-Nubian goats, naturally infected, raised in semi-extensive system. The experiment was conducted between April and July 2007 in Jequié, southwestern of Bahia state (52'23' 13'S, 40 º 07'3''W; altitude: 216m). Rainfall ranged from 0.1 to 1.8 mm during the study period. 63 does with mean body weight of 35.05 ± 6.54 kg were divided into two groups: pregnant and not pregnant, but kept together in the same pasture. Feces collection was performed weekly during the peripartum period (four weeks of gestation to the first four weeks postpartum) and on the same dates in nonpregnant animals. Exams were performed at the Laboratory of Parasitology of the Universidade Estadual de Santa Cruz (UESC) in Ilheus, BA and the highest eggs per gram of faeces (EPG) counts of gastrointestinal nematodes occurred at the time of concentration of parturition, showing a direct relationship between the level of helminthes infection and the proximity of parturition. There was also performed the larvae culture to characterize the helminths population during the experimental phase. The frequency of infective larvae (L3) observed was: Trichostrongylus spp. (58,7%); Haemonchus contortus (32,8%), Oesophagostomum columbianum (6,9%), Cooperia sp. (1,4%) e Bunostomum trigonocephalum (0,2%). In goats, these gastrointestinal helminths are a major cause of economic losses in production systems due to its high pathogenicity causing loss of performance and animal death. The count of oocysts per gram of faeces (OoPG) was also performed in order to identify species of Eimeria sp.; there was an increase of OoPG of Eimeria sp. peripartum, a significant difference between pregnant and non pregnant females. Counts ranged from 100 to 11,200 OoPG. Following species were identified: E. arloingi, E. capriovina, E. alijevi, E. ninakohlyakimovae, E. hirci and E. pallid. E. Ninakohlyakimovae is considered the most pathogenic for goats, however there was not observed clinical symptoms compatible with coccidiosis. Regarding hormone levels, concentrations of progesterone were determined by radioimmunoassay (RIA) at the Laboratory of Endocrinology of the Universidade Estadual Paulista (UNESP) in Araçatuba, São Paulo. There was a high level of progesterone (mean before parturition, 7.04ng/mL and after parturition of 0.05 ng / mL, with a standard deviation of 2.73 ng / mL and 0.049 ng / mL, respectively) as a function of gestation. The increase of gastrointestinal nematode eggs was significant (p = 0.028), only in period between the second week before and the second week postpartum, showing an increased susceptibility to infections by gastrointestinal nematodes in breeding females. Therefore, the peripartum period may cause changes in the course of gastrointestinal helminthiasis in goats.