CONICET | Buscador de Institutos y Recursos Humanos

Gastrointestinal parasitism in dairy cattle is important in grazing herds and has been shown to decrease milk production. In this study we wished to evaluate the prevalence of diseases during lactation in relation with parasitism. The study was performed in the dairy farm at the Experimental School of Inchausti, 25 de Mayo, Province of Buenos Aires, Argentina (35°36 S, 60°32 W). Cows were individually sampled for rectal feces during their first month after calving. Some cows were also sampled during the prepartum period. Nematode eggs (EPG) were counted in feces by the Mc Master method adapted by INTA. Individual daily milk production was recorded by means of the Alpro-Milking computerized system, and reproductive items, endometritis, foot disease and mastitis events, were recorded and processed with the DairyCOMP 305 Program (Valley Agricultural Software). Cows with positive EPG in early postpartum (between day 0 and 29) suffered twice more feet events (p < 0.0001), and 2.5 times more endometritis events (p < 0.05) than cows with null EPG. Cows with positive EPG prior to partum (days -20 to -1) and during postpartum (days 0 to 29) showed more mastitis events compared to cows with null EPG in both samplings (p < 0.05). Abortion rates were not different between groups. Total milk production was lower in cows with positive EPG during the peripartum in comparison to cows without nematode egg counting during the same period. We conclude that parasite infection during peripartum influences milk production; high parasite burden during early pospartum is associated with increased endometritis and foot disease, while infection before partum and during postpartum increase endometritis and foot disease occurrence. Further research is needed to establish the relationship between peripartal immunity drop and diseases, their causality and relative importance with respect to milk production.