<i>In vitro</i> Assessment of Adsorbents to Counteract Lead Toxicity in Ruminal Fermentation

Abstract

An <em>in vitro</em> gas production technique was used to evaluate the effects of different adsorbents on the gas production parameters of lead-exposed diet. Ruminal fluid, obtained from fistulated sheep (3-4 years of age and 40±5 kg BW), and experimental diets samples, 200 ± 0.2 mg DM, were incubated in 100 mL glass bottles. To each bottle, one of the following treatments was applied: 1) control (no Pb and adsorbent), 2) 15 mg/kg DM Pb as Pb acetate and no adsorbent, 3) 15 mg/kg DM Pb as Pb acetate and 3% activated carbon, 4) 15 mg/kg DM Pb as Pb acetate and 3% nanoclay and 5) 15 mg/kg DM Pb as Pb acetate and 3% bentonite. Supplementation of ruminal medium with 15 ppm Pb significantly (P<0.01) decreased total and rate of gas production at all incubation times. Rate and total gas production were significantly (P<0.05) higher for nanoclay compared to control and the other adsorbents treatments. Lead inclusion decreased organic matter digestibility (OMD), net and metabolizable energy contents and short chain fatty acids production (P<0.01). Among the adsorbents, nanoclay showed to be more effective on ruminanl fermentation parameters and improved rate and total gas production.