Variability in the fecal egg count and the parasitic burden of hair sheep after grazing in nematode infected paddocks

Abstract

Pesq. Vet. Bras. 33(4): 469-475, abril 2013 469 INTRODUCTIONThe frequent and continuous use of chemical anthelmintic drugs for deworming sheep flocks has resulted in the presence of lateral and multiple anthelmintic resistance in the parasites. This resistance leads to a concerning ineffectiveness of anthelmintics with large economic losses in sheep productivity (Coles et al. 2006, Papadopoulos 2008, Sargison 2011. Twenty-four countries have reported the presence of nematodes resistant to several anthelmintics (Jabbar et al. 2006). This situation has motivated workers around the world to search for alternative strategies to Variability in the fecal egg count and the parasitic burden of hair sheep after grazing in nematode infected paddocks 1Roberto González-Garduño 2 *, Pedro Mendoza-de Gives 3 and Glafiro Torres-Hernández 4ABSTRACT.-González-Garduño R., Mendoza- This study aimed to evaluate the variability in the fecal egg count (FEC) and the parasitic burden of naive hair sheep after grazing in nematode infected paddocks. The research was carried out in Tabasco, Mexico, during two periods (August and December). In each period 32 lambs were grazed for one month on African star grass (Cynodon plectostachyus) contaminated with gastrointestinal parasitic nematodes. FEC, packed cell volume (PCV) and body weight (BW) were recorded. Gastrointestinal worms were recovered at necropsy. Data were analyzed with the MIXED procedure of SAS using a model of repeated measurements over time. A higher number of Haemonchus contortus worms was found in December (2814±838) than in August (1166±305). The opposite occurred with Cooperia curticei (2167±393 and 3638±441, respectively). The FEC and correlation coefficient in respect to the worm burden were higher in December (6516 ± 1599, r=0.83, respectively) than in August (4364±771, r=0.44, respectively). A high variability in resistance-susceptibility to gastrointestinal nematodes (GIN) occurred in Katahdin × Pelibuey lambs after grazing.

Assessment of genetic resistance and abomasal tissues expression of Yichang white goat experimentally challenge with Haemonchus contortus infection

“…The data of FEC were not normally distributed among the samples and exhibited positive skewness. So, a logarithmic transformation [log 10 (FEC+25)] was therefore applied before analysis (Rout et al 2011;González-Garduño et al 2013) to minimize the heterogeneity of variance and increase normality of the FEC distribution. Analysis of FEC carried out using a repeated measures analysis of variance with the GLIMMIX Procedure of SAS version 9.2 (SAS Inst., Inc., Cary, NC, USA).…”

Single nucleotide polymorphisms in candidate genes are significantly associated with resistance to Haemonchus contortus infection in goats

“…The FEC were not normally distributed and exhibited positive skewness. A logarithmic transformation [log 10 (FEC + 25)] was therefore applied before analysis [ 9 , 29 ]. Descriptive statistics (arithmetic means, variances, standard errors, etc.…”

Sheep parasitism and its control by medicinal plants: A review

“…indicum, Trichris sp., Bunostomum sp., F. gigantica and Strongyles sp., (Bangladesh) [47] ; and Bunostomum sp., Haemonchus sp., Trichostrongylus sp., Strongyloides sp., and Oesophagostomum sp., (Ethiopia) [48] . According to Domke et al [49] [50] . Variable prevalences and species of GI parasites reported from different localities of Pakistan and other parts of the world are outlined in tables 1 and 2, respectively.…”