LeCompte Lazić Rebecca Ashlee, Nielsen Brian D, Robison Cara I, Schott Harold C, Herdt Thomas H, Larson Connie K
Department of Animal Science, 474 S. Shaw Lane, Michigan State University, East Lansing, MI 48824, USA.
Department of Large Animal Clinical Sciences, 784 Wilson Road, Michigan State University, East Lansing, MI 48824, USA.
Animals (Basel). 2024 Dec 12;14(24):3595. doi: 10.3390/ani14243595.
The 2007 Horse NRC reduced cobalt (Co) requirements from 0.1 ppm to 0.05 ppm in dietary dry matter, though preliminary research suggested increasing dietary-Co enhanced fiber digestion in horses. This study aimed to evaluate fiber digestion with varying dietary Co amounts, as well as to compare serum Co concentrations with dietary Co content. Four geldings (mean body weight [BW] 503 ± 37 kg) were studied in a 4 × 4 Latin square design consisting of four 5-week periods, each comprising a 2-week washout phase followed by a 3-week treatment phase. Supplementing 0.0, 5.6, 16.8, or 28.0 mg of Co daily resulted in total Co dietary concentrations of 0.06, 0.7, 2.0, and 3.0 ppm, respectively. Feces and urine were collected to evaluate fiber digestibility and Co balance. Co supplementation did not affect neutral detergent fiber, acid detergent fiber, or lignin digestibility. Co balance was negative for the control diet but positive for the other three treatments ( = 0.04). Serum cobalamin concentrations slightly decreased (6%) with increasing dietary Co intake ( = 0.003), while folate concentrations were unaffected. Serum Co concentration differed ( < 0.01) with a mean of 4.7 μg/mL for the high treatment and 0.8 μg/mL for the control. Results suggest that serum Co concentrations above regulatory limits are likely due not to higher levels of Co in fortified feeds, but rather to parenteral administration of Co solutions.
2007年的马营养需求推荐量将日粮干物质中钴（Co）的需求量从0.1 ppm降至0.05 ppm，尽管初步研究表明增加日粮钴含量可提高马的纤维消化率。本研究旨在评估不同日粮钴含量对纤维消化的影响，并比较血清钴浓度与日粮钴含量。选用4匹去势公马（平均体重[BW] 503±37 kg），采用4×4拉丁方设计，包括4个为期5周的阶段，每个阶段包括2周的洗脱期和随后3周的治疗期。每日补充0.0、5.6、16.8或28.0 mg钴，日粮总钴浓度分别为0.06、0.7、2.0和3.0 ppm。收集粪便和尿液以评估纤维消化率和钴平衡。补充钴对中性洗涤纤维、酸性洗涤纤维或木质素消化率没有影响。对照日粮的钴平衡为负，而其他三种处理的钴平衡为正（P = 0.04）。随着日粮钴摄入量增加，血清钴胺素浓度略有下降（6%）（P = 0.003），而叶酸浓度不受影响。血清钴浓度存在差异（P < 0.01），高剂量处理组的平均值为4.7 μg/mL，对照组为0.8 μg/mL。结果表明，血清钴浓度高于规定限值可能不是由于强化饲料中钴含量较高，而是由于钴溶液的肠胃外给药。
