Efeitos da Leucaena leucocephala (Lam.) de Wit sobre a concentração de protozoários ciliados no rúmen de ovinos

Abstract

Two completely randomized trials with sheep we re run to study the feeding Leucaena leucocephala on concentration of rumen ciliate protozoa. In trial 1, ten sheep were subjected to two frequencies (twice or four times daily) being the Leucaena hay fed as sole diet. In trial 2, nine sheep were subjected to three treatments: a) 100% Rhodes grass hay (Chloris gayana kunth); b) 30:70%; c) 50 : 40% Leucaena hay and Rhodes grass hay, respectively. The animals were adapted for 21 day period, and after that, rumen fluid samples were taken from each sheep via stomach tube before first feeding. Increasing the feeding frequencies from 2 to 4 times/ day resulted in a decrease in total and ciffsrental numbe'rs of protozoa, excet for genus Epidinium spp. which was not present. The levels 30% and 60% of Leucaena hay in diet on dry matter bases did not result in a significant change in concentration of rumen ciliate protozoa, excet the genus Dasytrich a spp. which showed significant decrease (P < 0,05). Differential protozoa counts revealed that Entodinia species predominanted when sheep were fed only Leucaena (30.0%). From those rindings, it may be made an hypotesis of “protozoocid' action of mimosine or DHP "per si" or products of mimosine metabolism, facilitated for feeding frequencies of microrganisms in the rumen with increase in number of bacteria species breacKdown these compounds due to the decrease of the engulfment process of bacteria by protozoa.