State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
J Anim Physiol Anim Nutr (Berl). 2021 Sep;105(5):849-860. doi: 10.1111/jpn.13519. Epub 2021 Mar 25.
Two trials were carried out to study the effects of copper sulphate (CuSO ) on detoxifying glucosinolates (GLS) in rapeseed cake (RSC) and compare the effects of feeding CuSO -treated and untreated RSC on nutrient digestion and nitrogen (N) metabolism in steers. In Trial 1, different concentrations of CuSO solution (1.6 vs. 3.2 g CuSO ·5H O L ), soaking temperatures (25 vs. 60°C) and drying methods (air drying at 60°C vs. freeze drying) were allocated in a 2 × 2 × 2 factorial arrangement in vitro. In Trial 2, six steers and dietary inclusions of untreated RSC (control), CuSO -treated RSC and CuSO -added RSC were assigned in a replicated 3 × 3 Latin square design. CuSO treatment in vitro decreased the contents of GLS and thiocyanate (TC) in RSC (p < 0.001). The total amount of GLS and TC decreased by 62.7-68.5% for all treatments. The animal trial showed that CuSO -treated RSC inclusion decreased ruminal concentration of valerate (p < 0.01), whereas it did not affect ruminal pH, ammonia N and total volatile fatty acids. Compared with the control, feeding CuSO -treated or CuSO -added RSC had no effect on plasma concentrations of triiodothyronine and thyroxine, N excretion and N retention. CuSO -treated RSC tended to increase neutral detergent fibre digestibility (p = 0.072) and urinary excretion of urea (p = 0.056). Urinary excretion of purine derivatives (p = 0.076) and rumen microbial N supply (p = 0.084) tended to decrease when feeding CuSO -treated RSC versus control. TC was found to be the only metabolite of GLS in rumen fluid, plasma and urine. It was feasible to detoxify GLS in RSC using low CuSO at room temperature. However, feeding CuSO -treated or CuSO -added RSC had minor effects on rumen fermentation, nutrient digestion and N metabolism in steers. CuSO treatment on RSC for feeding steers seems to be unnecessary.
进行了两项试验来研究硫酸铜（CuSO ）对油菜籽饼（RSC）中硫代葡萄糖苷（GLS）解毒的影响，并比较了饲喂硫酸铜处理和未处理的 RSC 对育肥牛养分消化和氮（N）代谢的影响。在试验 1 中，采用 2×2×2 析因设计，在体外分配不同浓度的硫酸铜溶液（1.6 与 3.2 g CuSO 5H O·L -1 ）、浸泡温度（25 与 60°C）和干燥方法（60°C 下空气干燥与冷冻干燥）。在试验 2 中，将 6 头育肥牛和未处理的 RSC（对照）、硫酸铜处理的 RSC 和添加硫酸铜的 RSC 饲粮纳入重复 3×3 拉丁方设计。体外硫酸铜处理降低了 RSC 中 GLS 和硫氰酸盐（TC）的含量（p＜0.001）。所有处理的 GLS 和 TC 总量降低了 62.7-68.5%。动物试验表明，饲粮中添加硫酸铜处理的 RSC 降低了瘤胃戊酸盐浓度（p＜0.01），但不影响瘤胃 pH、氨态氮和总挥发性脂肪酸。与对照相比，饲喂硫酸铜处理或添加硫酸铜的 RSC 对血浆三碘甲状腺原氨酸和甲状腺素浓度、N 排泄和 N 保留没有影响。硫酸铜处理的 RSC 有增加中性洗涤纤维消化率的趋势（p=0.072）和尿液中尿素排泄量（p=0.056）。饲粮中添加硫酸铜处理的 RSC 时，尿液中嘌呤衍生物（p=0.076）和瘤胃微生物 N 供应量（p=0.084）有降低的趋势。在瘤胃液、血浆和尿液中发现 TC 是 GLS 的唯一代谢产物。在室温下使用低浓度的硫酸铜解毒 RSC 中的 GLS 是可行的。然而，饲喂硫酸铜处理或添加硫酸铜的 RSC 对育肥牛瘤胃发酵、养分消化和 N 代谢的影响较小。在育肥牛饲粮中添加硫酸铜处理 RSC 似乎没有必要。
