Effects of short and long-term dietary protein restriction on the rumen fermentation activity in growing lambs
2002
Simunek, J. | Krejci, P. (Akademie Ved, Prague (Czech Republic). Ustav Zivocisne Fyziologie a Genetiky) | Wojcik-Gladysz, A. | Wankowska, M. | Polkowska, J.
The aim of the present study was to compare the rumen fermentation pattern of growing lambs fed restricted protein diet lasting for a short or a long time. Merino lambs (n=10) were fed for 24 weeks two isocaloric diets containing either 8 % (R) or 18 % (E) of proteins. Ammonia (determined colorimetrically), volatile fatty acids (VFA, determined by gas chromatography) and numbers of protozoa (counted in a Fuchs-Rosenthal counting chamber) were estimated in the rumen fluid collected 18 h after feeding at 0, 12 (short-term) and 24 (long-term) weeks of experiment. The ammonia concentration in the rumen was significantly (P0.05) decreased by both short- and long-term feeding of R diet. The number of protozoa increased with the age of lambs (P0.05) in both groups and neither the short nor long feeding of R diet had a significant effect on this parameter. The long-term R diet affected the total concentration of VFA which were significantly lower (P0.05) in R than in E groups. This decrease was caused mainly by low acetate and butyrate concentrations. In conclusion, inadequate protein concentration in the diet of growing lambs disturbs the rumen fermentation but this phenomenon depends on feeding duration.
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