Effects of Dietary Addition of Bentonite on Manure Gas Emission, Health, Production, and Meat Characteristics of Hanwoo (Bos taurus coreanae) Steers

A study was conducted to determine the dietary effects of a clay mineral (sodium bentonite, NaB) on manure gas emission, health, production, and meat characteristics of Hanwoo steers. Two diets fed to steers included a control diet (concentrate mix and rice straw) and a treatment diet (control diet+1.0% clay mineral/concentrate mix). Dietary NaB addition considerably reduced concentrations of gases (H2S, SO2 and NH3) in the manure of Hanwoo steers. Growing steers fed NaB had similar blood profiles with the exception of lower (p<0.05) concentrations of blood alkaline phosphatase and lactate dehydrogenase. Dietary NaB addition tended to increase (p = 0.10) live weight by 30 kg at slaughtering and did not affect carcass yield and quality traits. Dietary NaB addition increased concentrations of P (p<0.01), Mg (p<0.01), Na (p<0.01), Zn (p<0.005), K (p = 0.08), Fe (p = 0.08) and Cu (p = 0.07) in the longissimus muscle compared to the control but did not affect (p>0.05) fatty acid composition. The study demonstrated that the dietary addition of a clay mineral could be effective in improving mineral bioavailability to Hanwoo steers, which could be one of the reasons for their improved performance. (