Harrison G A, Dawson K A, Hemken R W
Department of Animal Science, University of Kentucky, Lexington 40546.
J Anim Sci. 1992 Apr;70(4):1188-94. doi: 10.2527/1992.7041188x.
The inhibitory effects of iron- and sulfate-containing compounds on the in vitro digestion of a balanced forage diet by mixed populations of ruminal microorganisms were examined in batch cultures. Compounds containing ferrous and ferric cations consistently inhibited DM digestion by up to 36% when added Fe concentrations in cultures were between 100 and 1,000 mg/L. Increased sulfate concentrations of up to 200 mg/L or chloride concentrations of up to 635 mg/L were not associated with decreased DM digestion. Ammonium sulfate additions that provided 200 mg/L of added sulfur increased (P less than .05) digestibility by 10%. Sulfate-containing iron salts tended to be less inhibitory than chloride salts and were associated with increased gas production during digestion. Ferric chloride inhibited (P less than .05) microbial activities at lower concentrations than ferrous chloride. Data suggest that excessive iron supplementation or contamination of feeds with iron-containing pollutants may decrease microbial activities in the rumen.
通过分批培养研究了含铁和含硫酸盐化合物对瘤胃微生物混合群体体外消化平衡饲粮的抑制作用。当培养物中添加铁的浓度在100至1000mg/L之间时，含有亚铁和铁阳离子的化合物始终抑制干物质消化，抑制率高达36%。硫酸盐浓度增加至200mg/L或氯化物浓度增加至635mg/L与干物质消化率降低无关。添加提供200mg/L添加硫的硫酸铵可使消化率提高10%（P<0.05）。含硫酸盐的铁盐的抑制作用往往比氯化物盐小，并且与消化过程中气体产生增加有关。氯化铁在比氯化亚铁更低的浓度下抑制（P<0.05）微生物活性。数据表明，过量补充铁或饲料被含铁污染物污染可能会降低瘤胃中的微生物活性。
