Methane mitigation potential of 3-nitrooxypropanol in lactating cows is influenced by basal diet composition
Methane mitigation potential of 3-nitrooxypropanol in lactating cows is influenced by basal diet composition
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DOI：
10.3168/jds.2021-20782
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发表时间：
2022-04-26
影响因子：
3.5
通讯作者：
Bannink, Andre
中科院分区：
文献类型：
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作者：
van Gastelen, Sanne;Dijkstra, Jan;Bannink, Andre
本研究的目的是调查 3-硝基氧基丙醇 (3-NOP) 对奶牛的 CH4 缓解潜力是否受到基础日粮 (BD) 成分的影响。该实验涉及 64 头荷斯坦-弗里斯兰奶牛（试验开始时在牛奶中饲养 146 +/- 45 天；平均值 +/- SD），进行 2 个重叠的交叉试验，每个试验由 2 个测量周期组成。根据胎次、产奶量和产奶量对奶牛进行分组，并随机分配到 3 种日粮中的 1 种：由 30% 浓缩物和 70% 草青贮饲料（DM 基础）组成的青贮饲料为主的日粮（GS），由 30% 浓缩物、42% 青贮饲料和 28% 玉米青贮饲料（DM 基础）组成的青贮饲料和玉米青贮饲料混合日粮（GSCS），或以玉米青贮饲料为基础的日粮 (CS)，由 30% 浓缩物、14% 草青贮饲料和 56% 玉米青贮饲料（DM 基础）组成。配制了两种类型的浓缩物，即。 GS 日粮的浓缩物和 CS 日粮的浓缩物，以满足维持和产奶的能量和蛋白质需求。 GSCS 饮食的浓缩物由两种浓缩物以 50:50 的比例混合而成。随后，每种 BD 类型的奶牛在交叉设计中接受 2 种治疗：在一次交叉中使用 60 毫克 3-NOP/kg DM (NOP60) 和含有 0 毫克 3-NOP/kg DM (NOP0) 的安慰剂，在另一次交叉中使用 80 mg 3-NOP/kg DM (NOP80) 和 NOP0。日粮以饲料箱中的总混合日粮形式提供，饲料箱自动记录采食量。额外的浓缩物被注入 GreenFeed 系统，用于测量 CH4 和 H-2 的排放。 CS日粮导致CH4产量（g/kg DMI）和CH4强度（g/kg牛奶）降低。饲喂 3-NOP 会导致 DMI 下降。 NOP60 和 NOP0 之间的产奶量和成分没有差异，而与 NOP0 相比，NOP80 的产奶量和主要成分的产量有所下降。饲料效率不受饲喂 3-NOP 的影响。观察到 BD 和补充 3-NOP 之间 CH4 和 H-2 的产量 (g/d) 和产量 (g/kg DMI) 之间的相互作用，表明 3-NOP 的缓解效果取决于 BD 的组成。所有 BD 补充 3-NOP 后 CH4 排放量均有所下降，但与 GSCS（CH4 产量中 NOP60 为 -35.1%，NOP80 为 -37.9%）和 CS（NOP60 为 -34.8%，CH4 产量为 -41.6%）相比，GS 的 CH4 排放量下降幅度较小（CH4 产量为 -26.2%，NOP60 为 -28.4%，NOP80 为 -28.4%）对于 NOP80 的 CH4 产率），后 2 个 BD 之间没有差异。所有BD补充3-NOP后H-2排放量均增加，但当向GS补充NOP60和NOP80时，H-2产量（g/kg DMI）分别增加3.16和3.30倍，当向CS补充NOP60和NOP80时分别增加4.70和4.96倍。总之，3-NOP 可以有效减少奶牛不同日粮中的 CH4 排放，但与青贮饲料相比，在玉米青贮日粮中添加 3-NOP 的 CH4 缓解水平更高。
The objective of this study was to investigate whether the CH4 mitigation potential of 3-nitrooxypropanol (3-NOP) in dairy cattle was affected by basal diet (BD) composition. The experiment involved 64 Holstein-Friesian dairy cows (146 +/- 45 d in milk at the start of trial; mean +/- SD) in 2 overlapping crossover trials, each consisting of 2 measurement periods. Cows were blocked according to parity, d in milk, and milk yield, and randomly allocated to 1 of 3 diets: a grass silage-based diet (GS) consisting of 30% concentrates and 70% grass silage (DM basis), a grass silage- and corn silage-mixed diet (GSCS) consisting of 30% concentrates, 42% grass silage, and 28% corn silage (DM basis), or a corn silage-based diet (CS) consisting of 30% concentrates, 14% grass silage, and 56% corn silage (DM basis). Two types of concentrates were formulated, viz. a concentrate for the GS diet and a concentrate for the CS diet, to meet the energy and protein requirements for maintenance and milk production. The concentrate for the GSCS diet consisted of a 50:50 mixture of both concentrates. Subsequently, the cows within each type of BD received 2 treatments in a crossover design: either 60 mg of 3-NOP/kg of DM (NOP60) and a placebo with 0 mg of 3-NOP/kg of DM (NOP0) in one crossover or 80 mg of 3-NOP/kg of DM (NOP80) and NOP0 in the other crossover. Diets were provided as total mixed ration in feed bins, which automatically recorded feed intake. Additional concentrate was fed in the GreenFeed system that was used to measure emissions of CH4 and H-2. The CS diets resulted in a reduced CH4 yield (g/kg DMI) and CH4 intensity (g/kg milk). Feeding 3-NOP resulted in a decreased DMI. Milk production and composition did not differ between NOP60 and NOP0, whereas milk yield and the yield of major components decreased for NOP80 compared with NOP0. Feed efficiency was not affected by feeding 3-NOP. Interactions between BD and supplementation of 3-NOP were observed for the production (g/d) and yield (g/kg DMI) of both CH4 and H-2, indicating that the mitigating effect of 3-NOP depended on the composition of the BD. Emissions of CH4 decreased upon 3-NOP supplementation for all BD, but the decrease in CH4 emissions was smaller for GS (-26.2% for NOP60 and -28.4% for NOP80 in CH4 yield) compared with both GSCS (-35.1% for NOP60 and -37.9% for NOP80 for CH4 yield) and CS (-34.8% for NOP60 and -41.6% for NOP80 for CH4 yield), with no difference between the latter 2 BD. Emissions of H-2 increased upon 3-NOP supplementation for all BD, but the H-2 yield (g/kg DMI) increased 3.16 and 3.30-fold, respectively, when NOP60 and NOP80 were supplemented to GS, and 4.70 and 4.96 fold, respectively, when NOP60 and NOP80 were supplemented to CS. In conclusion, 3-NOP can effectively decrease CH4 emissions in dairy cows across diets, but the level of CH4 mitigation is greater when supplemented in a corn silage-based diet compared with a grass silage-based diet.