Relative effect of temperature and moisture on the development of strongyle eggs to infective larvae in bovine pats in Argentina.

To determine the most efficient microclimatic factors in bovine faeces that could explain the rate of development of parasitic nematode species, experimental pats were deposited in three locations (sun, shade and laboratory) in central-west Argentina during summer, autumn and winter seasons. Faecal water content (FWC) and temperature inside the pats were recorded during the duration of the experimental periods. The mean temperature and minimal values of FWC explained 54% of the variability of the rate of development of Haemonchus (third-stage larvae per 100 eggs) and mean maximal temperature and minimal FWC values were the two main factors regulating Cooperia development (R2 = 0.42). Rainfall was the third factor. No microclimatic component explained the development of Ostertagia in our experiments.