Digestion of a dehydrated lucerne/barley diet (70:30) in defaunated, Isotricha-monoinoculated and mixed-fauna-inoculated rumen in sheep

Abstract

Summary ― Two adult Texel sheep fitted with permanent rumen fistulae were defaunated for 12 weeks in a preliminary experiment. They were then reinoculated with Isotricha sp for 11 weeks, and finally with a mixed fauna (Entodinium, Epidinium, Eudiplodinium and Isotricha) for 10 weeks. They were fed a diet composed of dehydrated lucerne (700 g/d), pelleted barley grain (300 g/d), grass hay (100 g/d) and wheat straw (50 g/d) in one daily meal. Isotricha and the ciliates of the mixed fauna developed rapidly, reaching a maximum concentration 9-17 d after inoculation. Their concentration then fell for 2-3 d and finally stabilized at values close to 10 4 /ml for Isotricha, Eudiplodinium and Epidinium and 2.5 x 10 5 /ml for Entodinium. The estimated ciliate biomass in the rumen was 1.8 g I-! for a volume of 10.2 mll-1 in the /sotricha-monoinoculated sheep and 4.7 g I-! for a volume of 25.0 mll-1 in mixedfauna-inoculated sheep. The concentration of Isotricha was unaffected by the inoculation of mixed fauna during the third part of the experiment. No difference in total rumen bacteria counts was observed between defaunated, monoinoculated and completely refaunated animals. The total adenylic nucleotide concentration in filtered rumen juice was 4 times higher in faunated sheep just before feeding and 4-9 times lower after feed intake as compared to defaunated animals; the energy charge was always higher in faunated animals. These results are discussed in relation to the digestive activity and biomass of the protozoa. The in situ degradation of lucerne stems was the highest in the mixed-faunated sheep over a retention time interval of 6-18 h.

Effects of defaunation and dietary coconut oil distillate on fermentation, digesta kinetics and methane production of Brahman heifers

“…The protozoal population in heifers after refaunation from a previously defaunated state was well established by day 7 and reached 7.38 × 10 5 cells/mL by day 21, comparable with that found by Sénaud et al. () who re‐inoculated defaunated ruminants with Isotricha and ciliates of mixed fauna and found that the maximum concentration of protozoa was reached 9–17 days after inoculation. The maximum population then decreased for 2–3 days before stabilising.…”