Effects of dietary fossil shell flour supplementation on a basal diet, relative feed values, in vitro true digestibility, and rumen fermentation parameters of Dohne-Merino wethers

Abstract

The availability of fossil shell flour(FSF) has increased its use as a natural feed additive in livestock diets. Therefore, identifying its optimum inclusion levels in livestock production is essential for animal productivity. This study investigated the effects of various fossil shell flour (FSF) inclusion levels on in vitro digestibility, relative feed values and rumen parameters of Dohne-Merino wethers. Twenty-four fistulated wethers, averagely 20 ± 1·5 kg body weight, were used in a complete randomized design. They were fed a basal diet without fossil shell flour (control, 0%) or with the addition of 2% FSF (T2), 4% FSF(T3) and 6% FSF (T4) of diet DM for 35 days. The results showed that increasing FSF levels had no effect on ruminal T0C or pH, but Ammonia-N increased (P < 0.01) with increasing FSF. The total molar concentrations of volatile fatty acids (VFA) decreased (P < 0.05) with increasing levels of FSF. IVTDDM, IVTDNDF and IVTDADF decreased to 4% FSF inclusion but tended to increase (P = 0.06) at 6% inclusion. Relative feed values of the diets tended to increase (P = 0.07) by adding fossil shell flour. In conclusion, adding FSF to the sheep diet had no adverse effects on the rumen parameters, though in vitro true digestibility could be reduced.

Keywords

• Fossil shell flour
• rumen parameters
• in vitro true digestibility
• and feed quality