Dynamics of gastrointestinal strongyle infesting larvae in grazing sheep

Abstract

A study was conducted for two years, with the objective of characterizing the dynamics of the larval populations in
“refuge” of gastrointestinal nematodes, as well as its interrelation with the meteorological variables in three sheep
production farms in Matanzas province, Cuba (Dos Mercedes, LABIOFAM and the EEPF “Indio Hatuey”). Larvae of
gastrointestinal strongyles were monthly collected from pasture and identified by means of a pasture washing technique from previously selected sentinel paddocks. The third stage larval population’s dynamics in pasture showed a similar trend in the three farms; however, there were differences in the amounts of L3, per kg DM of pasture. A significant effect of month of the year and season on larvae availability was recorded. In the rainy season (RS) a higher quantity of L3 was collected due to the favorable effects of rainfall and temperature. Haemonchus spp. was the prevailing species, followed by Trichostrongylus colubriformis and Oesophagostomum columbianum. The larval populations showed higher quantity during the RS
and their dynamics was related to the environmental variables and the factors related to the production system in each unit.