The aim of the present study was to investigate the effects of a deoxynivalenol (DON) contaminated ration with a concentrate proportion of 50%, on the performance of dairy cows (Period 1), and to examine the effects when the concentrate proportion was elevated to 60% compared to a ration with 30% concentrates (Period 2). In Period 1, 13 lactating German Holstein cows (Myco group, on average 29 days in milk) were fed the experimental diet (on average 5.3 mg DON/kg DM) as total mixed ration over 11 weeks, while another 14 cows (on average 33 days in milk) received a control diet. Both rations contained 50% concentrates (on DM basis). In Period 2 (18 weeks), the same 27 cows plus five additional cows were divided into four groups: Control-30 (30% concentrates), Myco-30 (30% concentrates, 4.4 mg DON/kg DM), Control-60 (60% concentrates), Myco-60 (60% concentrates, 4.6 mg DON/kg DM). The overall performance level was characterised by a mean daily DM intake of 17.9 kg and a mean daily milk production of 26.7 kg fat corrected milk (FCM) in Period 1 and 17.3 kg DM intake and 24.5 kg FCM in Period 2, respectively. In both periods cows fed the Fusarium toxin-contaminated diets consumed more DM (in Period 2 only significant for group Myco-30) resulting from stimulating effects on the ingesta passage rate of the natural contaminated Fusarium-infected triticale. In Period 1, cows fed the Fusarium toxin-contaminated diet had a significantly higher milk yield, milk urea and somatic cell count, whereas milk fat and protein concentration and fat-to-protein-ratio (FPR) were significantly lower. In Period 2, on a low concentrate level, FCM was significantly higher in group Myco-30. On a high concentrate level, group Myco-60 produced significantly more milk, but milk fat and protein concentration, FPR and milk urea were significantly lower. A concentrate proportion of 60% had a depressing effect on milk fat concentration but was significantly more pronounced in the presence of Fusarium toxin-contaminated and Fusarium damaged-triticale.

中文翻译：

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存在和不存在镰刀菌毒素污染的小黑麦时奶牛日粮的浓缩比例对奶牛生产性能的影响

本研究的目的是调查浓缩比例为 50% 的脱氧雪腐镰刀菌烯醇 (DON) 污染日粮对奶牛生产性能的影响（第 1 期），并检查当浓缩比例提高到60% 与 30% 浓缩物的日粮相比（第 2 期）。在第 1 阶段，13 头泌乳的德国荷斯坦奶牛（Myco 组，平均 29 天牛奶）在 11 周内被饲喂实验日粮（平均 5.3 毫克 DON/kg DM）作为总混合日粮，而另外 14 头奶牛（平均在牛奶中 33 天）接受对照饮食。两种口粮都含有 50% 的浓缩物（以干物质为基础）。在第 2 阶段（18 周），同样的 27 头奶牛加上另外 5 头奶牛被分成四组：Control-30（30% 浓缩物）、Myco-30（30% 浓缩物，4.4 mg DON/kg DM）、Control-60 (60% 浓缩物), Myco-60（60% 浓缩物，4.6 mg DON/kg DM）。总体性能水平的特点是第 1 阶段的平均每日 DM 摄入量为 17.9 kg，平均每日产奶量为 26.7 kg 脱脂奶 (FCM)，第 2 阶段分别为 17.3 kg DM 和 24.5 kg FCM。在这两个时期，饲喂受镰刀菌毒素污染的日粮的奶牛消耗了更多的干物质（在第 2 阶段，仅对 Myco-30 组显着），这是由于对天然受污染的镰刀菌感染的小黑麦的摄食通过率的刺激作用所致。在第 1 阶段，饲喂受镰刀菌毒素污染日粮的奶牛的产奶量、牛奶尿素和体细胞计数显着较高，而乳脂和蛋白质浓度以及脂肪与蛋白质比 (FPR) 显着较低。在第 2 阶段，在低浓度水平下，Myco-30 组的 FCM 显着更高。在高浓缩水平下，Myco-60 组生产的牛奶明显更多，但乳脂和蛋白质浓度、FPR 和牛奶尿素显着降低。60% 的浓缩比例对乳脂浓度有抑制作用，但在存在镰刀菌毒素污染和镰刀菌损伤的黑小麦时更为明显。