甘蔗渣的饲用价值评价

为探讨甘蔗渣作为牲畜粗饲料的营养价值评价,本研究以光叶紫花苕、灯盏花秆、蚕豆秆、熟化洋蓟花苞等农副产物作对照,对其常规营养成分及其饲料相对值(RFV)和粗饲料分级指数(GI)进行综合评价。结果表明：甘蔗渣的粗蛋白(CP)含量显著低于熟化洋蓟花苞、光叶紫花苕、灯盏花秆(P<0.01),也低于蚕豆秆(P>0.05);甘蔗渣的粗脂肪(EE)含量明显低于光叶紫花苕、灯盏花秆(P<0.05),而甘蔗渣的钙、磷含量显著低于其他粗饲料(P<0.05)。在测定五类粗饲料中,光叶紫花苕、灯盏花秆和熟化洋蓟花苞的RFV分别为102.90、88.62和94.75,明显低于优质青贮玉米(139.48)(P<0.05),显著高于甘蔗渣(76.09)和蚕豆秆(55.86)(P<0.01),甘蔗渣(76.09)跟稻草糠(73.45)差异不显著(P>0.05)。与之相对应,光叶紫花苕、灯盏花秆、熟化洋蓟花苞的干物质随意采食量(DMI)、产奶净能(NE_L)显著高于甘蔗渣和蚕豆秆的对应值(P<0.05)。RFV排序依次为：光叶紫花苕>熟化洋蓟花苞>灯盏花秆>甘蔗渣>蚕豆秆;而粗蛋白含量高的灯盏花秆GI优于光叶紫花苕(P>0.05)和灯盏花秆(P<0.05),甘蔗渣和蚕豆秆二者极低(P<0.01),表明甘蔗渣饲用价值低下,作为粗饲料利用必须与其他饲料进行混合发酵或膨化后制作颗粒料。

Evaluation on Feeding Value of Sugarcane Bagasse

To evaluate the nutritional value of sugarcane bagasse as livestock roughage, the common nutritional components, RFV and GI of sugarcane bagasse were calculated by comparing with the by-products such as Vicia villosa var. glabrescens, Erigeron breviscapus stems, broad bean stems and cooked artichoke petals. The results showed that the crude protein (CP) content of sugarcane bagasse was significantly lower than those of cooked artichoke petals, Vicia villosa var. glabrescens and Erigeron breviscapus stems (P<0.01), also lower than that of broad bean stems (P>0.05); the ether extract (EE) content of sugarcane bagasse was significantly lower than those of Vicia villosa var. glabrescens and Erigeron breviscapus stems (P<0.05), and the calcium (Ca) and phosphorus (P) content of sugarcane bagasse were significantly lower than those of the other roughages (P<0.05). Among the five types of roughages, RFV of Vicia villosa var. glabrescens, Erigeron breviscapus stems and cooked artichoke petals was 102.90, 88.62 and 94.75, respectively, obviously lower than that of high-quality silage corn (139.48) (P<0.05), while significantly higher than those of sugarcane bagasse (76.09) and broad bean stems (55.86) (P<0.01); and there was no much difference between sugarcane bagasse (76.09) and rice straw chaff (73.45) (P>0.05). Similarly, the dry matter intake (DMI) and milk net energy (NE_L) of Vicia villosa var. glabrescens, Erigeron breviscapus stems and cooked artichoke petals were significantly higher than those of sugarcane bagasse and broad bean stems (P<0.05). In order, the RFVs were as follows: Vicia villosa var. glabrescens > cooked artichoke petals > Erigeron breviscapus stems > sugarcane bagasse > broad bean stems. The GI of Erigeron breviscapus stems with higher CP was prior to Vicia villosa var. glabrescens (P>0.05) and cooked artichoke petals (P<0.05), and the RFV of sugarcane bagasse and broad bean stems were fairly low (P<0.01), indicating lower feeding value of sugarcane bagasse. It is suggested that sugarcane bagasse could be mixed and fermented with other feed types, or puffed for processing feed pellets as roughage resource.