long-effect相关论文
选用24头肉用改良牛,分为长效瘤胃丸组、常规相应剂量(拌料)组、低剂量组和对照组,每组6头牛,进行微量元素不同添加方式的试验。试验设7......
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Factors leading to rise of prices of agricultural products mainly include tension of supply-demand relationship,promotio......