Henry D D, Ruiz-Moreno M, Ciriaco F M, Kohmann M, Mercadante V R G, Lamb G C, DiLorenzo N
J Anim Sci. 2015 Jul;93(7):3539-50. doi: 10.2527/jas.2014-8844.
Chitosan was evaluated as a feed additive to mitigate in vivo CH4 emissions in beef cattle. Twenty-four crossbred heifers (BW = 318 ± 35 kg) were used in a randomized block design replicated in 2 periods. The design included a 2 × 3 factorial arrangement of treatments, which included diet (high concentrate [HC] or low concentrate [LC]) and 0.0, 0.5, or 1.0% of chitosan inclusion (DM basis). Diets were offered ad libitum and individual intake was recorded. An in vitro experiment to analyze chitosan’s effect on fermentation parameters and gas production kinetics was performed. A diet effect (P < 0.01) was observed for CH4 emissions expressed as grams/day, grams/kilogram of BW0.75, and grams/kilogram of DMI. Heifers consuming the LC diet produced 130 g of CH4/d vs. 45 g of CH4/d in those consuming the HC diet. Incubation fluid pH increased linearly (P < 0.05) when chitosan was included in HC substrates. In vitro CH4 production was not affected (P > 0.10) by chitosan in HC substrate; however, when incubated with the LC substrate, CH4 production increased quadratically (P < 0.01) as chitosan inclusion increased. A digestibility marker × diet interaction occurred (P < 0.05) for DM, OM, CP, NDF, and ADF digestibility. Diet × chitosan interactions (P < 0.05) occurred for DM, OM, NDF, and ADF digestibility when Cr2O3 was used. When TiO2 was used, diet × chitosan interactions (P < 0.05) were observed for NDF and ADF. However, using indigestible NDF as an internal marker, DM and OM digestibility were improved (P < 0.05) by 21 and 19%, respectively, when chitosan was included in LC diets. In conclusion, feeding up to 1% of chitosan (DM basis) to heifers consuming a LC diet increased apparent total tract digestibility of nutrients. Enteric CH4 emissions were not affected by chitosan feeding, regardless of type of diet, and heifers consuming a 36% concentrate diet produced 2.6 times more methane per day than those consuming an 85% concentrate diet.
壳聚糖作为一种饲料添加剂，被评估用于减轻肉牛体内的甲烷排放。选用24头杂交小母牛（体重=318±35千克），采用随机区组设计，分两个阶段重复试验。试验设计包括2×3析因处理安排，其中包括日粮（高精料[HC]或低精料[LC]）以及0.0%、0.5%或1.0%的壳聚糖添加量（以干物质计）。日粮自由采食，并记录个体采食量。进行了一项体外试验，以分析壳聚糖对发酵参数和产气动力学的影响。以克/天、克/千克体重0.75和克/千克干物质采食量表示的甲烷排放存在日粮效应（P<0.01）。采食低精料日粮的小母牛每天产生130克甲烷，而采食高精料日粮的小母牛每天产生45克甲烷。当壳聚糖添加到高精料底物中时，培养液pH呈线性增加（P<0.05）。壳聚糖对高精料底物中的体外甲烷生成没有影响（P>0.10）；然而，当与低精料底物一起培养时，随着壳聚糖添加量的增加，甲烷生成呈二次增加（P<0.01）。对于干物质、有机物、粗蛋白、中性洗涤纤维和酸性洗涤纤维的消化率，消化率标记物×日粮存在交互作用（P<0.05）。当使用三氧化二铬时，日粮×壳聚糖在干物质、有机物、中性洗涤纤维和酸性洗涤纤维消化率方面存在交互作用（P<0.05）。当使用二氧化钛时，在中性洗涤纤维和酸性洗涤纤维方面观察到日粮×壳聚糖交互作用（P<0.05）。然而，以不可消化中性洗涤纤维作为内部标记物，当壳聚糖添加到低精料日粮中时，干物质和有机物消化率分别提高了21%和19%（P<0.05）。总之，给采食低精料日粮的小母牛饲喂高达1%（以干物质计）的壳聚糖可提高养分的表观全消化道消化率。无论日粮类型如何，壳聚糖饲喂对肠道甲烷排放均无影响，采食36%精料日粮的小母牛每天产生的甲烷比采食85%精料日粮的小母牛多2.6倍。
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