Maintenance of rumen protozoa populations in a dual outflow continuous fermenter
✍ Scribed by Broudiscou, Laurent-Philippe; Papon, Yves; Fabre, Michel; Broudiscou, Anne F
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 191 KB
- Volume
- 75
- Category
- Article
- ISSN
- 0022-5142
No coin nor oath required. For personal study only.
✦ Synopsis
Using a 25h2 fractional factorial design, Ðve factors were screened for their ability to promote rumen protozoa growth in a dual outÑow fermenter and on their inÑuence on fermentation. The tested factors were the addition of bovine serum (BS, 20 ml litre~1) and of a 100 g litre~1 yeast extract solution (20 ml litre~1) to artiÐcial saliva, the addition of diethystilbestrol (15 mg day~1) to fermentation broths, the reduction of shear stresses by lowering the stirring speed from 260 rpm to 230 rpm, and the improvement of ciliate sequestration by the use of a polyurethane foam belt. In the fermentors, the ciliate population density ranged from 10 kl~1 to 58 kl~1. The genus Isotricha was rarely observed, with a population density estimated at \0É7 kl~1 while Dasytricha was not maintained. All the experimental factors markedly inÑuenced total protozoa numbers. Lowering the stirring speed was the sole beneÐcial treatment. Nutritional supplements, in particular BS, were all detrimental to Entodinium. Their association was characterised by a signiÐcant antagonism. The population size of Polyplastron and Eudiplodinium was lowered only by BS addition, possibly through the changes induced in the fermentation pattern.