Abstract Two consecutive trials were carried out to study the effects of dietary supplementation with inorganic sulfur (S) on nitrogen (N) metabolism and nitrous oxide (N2O) emissions of urine from steers. In Trial 1, six castrated Simmental steers [449 ± 19 kg liveweight (LW)] were used as the experimental animals. Three levels of Na2SO4, i.e., 0 (control), 20 and 40 g/d were added to a basal ration [S content 1.15 g/kg dry matter (DM)] as experimental treatments. The animals and the treatments were randomly assigned to a replicated 3 × 3 Latin square design. Each experimental period included 15 days for adaptation and 5 consecutive days for sampling. The results of Trial 1 indicated that dietary supplementation with Na2SO4 linearly decreased the urinary excretions of N (P = 0.05) and urea (P = 0.03), and linearly increased rumen microbial N flow (P = 0.04), and tended to increase N retention rate (P = 0.06) in a linear manner. Supplementing Na2SO4 also linearly increased the excretions of fecal S (P = 0.02), urinary S (P

中文翻译：

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通过添加无机硫来平衡日粮中氮与硫的比例，可改善氮保留，从而减少公牛尿液中一氧化二氮的排放

摘要 连续进行了两项试验，研究膳食补充无机硫 (S) 对公牛尿液中氮 (N) 代谢和氧化亚氮 (N2O) 排放的影响。在试验 1 中，六头阉割的西门塔尔公牛 [449 ± 19 公斤活重 (LW)] 被用作实验动物。将三种浓度的 Na2SO4，即 0（对照）、20 和 40 g/d 添加到基础日粮 [S 含量 1.15 g/kg 干物质 (DM)] 作为实验处理。动物和治疗被随机分配到一个重复的 3 × 3 拉丁方设计。每个实验期包括 15 天的适应和连续 5 天的采样。试验 1 的结果表明，饮食中添加 Na2SO4 会线性降低 N（P = 0.05）和尿素（P = 0.03）的尿排泄量，和线性增加瘤胃微生物 N 流量（P = 0.04），并倾向于以线性方式增加 N 保留率（P = 0.06）。补充 Na2SO4 还线性增加粪便 S (P = 0.02)、尿 S (P