The effect of copper and cobalt supplementation on the rumen ciliate population in sheep

The effect of physiological doses of the sulfate form of copper (12 mg.kg(- 1) DM), cobalt (2 mg.kg(-1) DM) and cobalt + copper (2 + 12 mg.kg(-1) DM) i n two different diets on the rumen ciliate protozoa of four Merino rams wit h rumen cannula was investigated. The total number of ciliates, Entodinia s pp., Trichostomatids (Dasytricha and Isotricha) and large Entodiniomorphids (Polyplastron multivesiculatum and Ophryoscolex caudatus tricoronatus) was counted in the rumen fluid 3 h after feeding the animals. The experiment l asted 30 days; 14 days presented the adaptation period after changing the d iet. The number of Entodinium spp, and thus the total number of ciliates si gnificantly increased with diet A (complete feed ration: meadow hay, feed m ixture, corn, molasses, mineral supplement, treated beech sawdust) without microelement supplementation. The population of Entodinium spp. was decreas ed by 69% with diet B (meadow hay and barley meal). No significant effect o f Co, Cu or Cu + Co supplementation on the growth of Entodinium spp. was ob served with diet A. Supplementation of Cu significantly decreased the numbe r of Entodinium spp. by 45% with diet B. The number of Trichostomatids was significantly decreased by 80% with diet A. It was probably due to feeding molasses. After supplementation with Co their growth was significantly high er with diet A (control values were lower by 87%). No significant effect of Cu or Cu + Co supplementation on the growth of trichostomatids was observe d with diet A or diet B. Neither diet A nor diet B revealed any significant effect of Co, Cu or Cu + Co supplementation on the growth of large Entodin iomorphids.