落叶松树皮单宁组分的研究(凝缩类单宁组分研究之一)

从兴安落叶松(Larix gmelini)树皮提取物中分离出来的水溶性单宁,通过花色素反应、硫解反应、间苯三酚反应、~(13)C-核磁共振、旋光、紫外光谱和红外光谱等方法研究,判定为原花青定。落叶松树皮原花青定的终端单元由(+)—儿茶素及(—)—表儿茶素组成,二者的比例为8:2,延伸单元由(+)—儿茶素及(—)—表儿茶素组成,二者的比例约为3:7,水溶性单宁分子的平均聚合度约为8。     

化学预处理提高酒糟生物质酶解糖化效果

为促进酒糟生物质的酶解糖化,筛选适宜的预处理方法,以脱除木质素,提高综纤维素（纤维素和半纤维素之和）保留率为目标,研究比较了酸-超声波耦合（ultrasound-assisted acid pretreatment,UAAP）、液氨（pretreatment by soaking in aqueous ammonia,PSAA）、碱性双氧水（alkaline hydrogen peroxide pretreatment,AHPP）和酸性亚硫酸氢盐（bisulfite pretreatment,BP）4种预处理法对酒糟化学组分、结构特性和酶解得率的影响。结果表明,与其余3种方法相比,BP法处理后酒糟的纤维素和半纤维素保留率最高,分别为84.59%和84.87%,即综纤维素保留率为84.68%。与未处理酒糟（unpretreatment,UP）相比,4种方法预处理后酒糟的综纤维素酶解得率分别提高了49.12%（酸-超声波,UAAP）、55.48%（液氨,PASS）、92.79%（碱性双氧水,AHPP）和99.15%（酸性亚硫酸氢盐,BP）,其中BP法对酒糟酶解糖化的促进作用最有效。扫描电镜（scanning electron microscope,SEM）和X-衍射（X-ray differaction,XRD）结果显示,酒糟经不同方法预处理后表观结构发生了明显变化,木质纤维网络结构遭到破坏,表面呈现无规则或形状各异的膨松状态,沟壑明显,孔隙率增加,比表面积增大,有利于提高水解酶的可及性。化学组分和结构特性的变化说明酒糟的酶解得率与综纤维素的保留、木质素的去除、表面微观形貌变化以及纤维素结晶度等因素直接相关。总之,酸性亚硫酸氢盐（BP）法是适用于酒糟生物质糖化预处理的一种有效可行方法。     

高山灌木和牧草缩合单宁含量季节变化动态研究

采用香兰素盐酸法分析了高寒草甸几种优势牧草和灌木中的可浸提缩合单宁含量季节变化动态。试验结果表明,线叶嵩草、阴山扁蓿豆、垂穗披碱草和鹅绒委陵菜等牧草和短叶锦鸡儿不含缩合单宁;珠芽蓼缩合单宁含量高,5个月的平均值为77.56g/kg DM,7月高达120.2g/kg DM;苔草显著低于珠芽蓼(p<0.01),最高时也只有6.7g/kg DM(7月);5种灌木缩合单宁含量各不相同,金露梅、红药柳、高山绣线菊、藏沙棘和鬼见锦鸡儿4个月的平均值分别为(g/kg DM):54、3、58、53、29、18、67.08和42.15,且随着季节推移,各灌木缩合单宁含量逐渐下降;而珠芽蓼和苔草从5月到7月逐渐上升,之后又开始下降。同时,分析了缩合单宁含量与植物的进化及家畜利用富含缩合单宁植物时应注意的事项。     

薯莨及红根皮单宁组分的研究(凝缩类单宁组分研究之四)

从薯莨(Dioscorea cirrhosa)块茎及红根(Rosa spp.)根皮提取物中分离出来的单宁,通过各种降解反应及波谱方法研究,均判定为原花青定。其中的终端单元及延伸单元,都由(+)-儿茶素及(-)-表儿茶素组成,但(-)-表儿茶素单元在薯莨原花青定中占大部分,(+)-儿茶素单元在红根原花青定中占大部分。     

Bio‐Ag reutilization of distiller's dried grains with solubles (DDGS) as a substrate for black soldier fly larvae,Hermetia illucens,along with poultry by‐product meal and soybean meal,as total replacement of fish meal in diets for Nile tilapia,Oreochromis niloticus

A feeding trial was conducted in a closed system with Nile tilapia, Oreochromis niloticus, juveniles (mean initial weight, 2.66 g) to examine total replacement of menhaden fish meal (FM) with distiller's dried grains with solubles (DDGS), which had been used as substrate for the production of black soldier fly larvae, Hermetia illucens, in combination with soybean meal (SBM) and poultry by‐product meal (PBM), with or without supplementation of the amino acids (AA) DL‐methionine (Met), L‐lysine (Lys) and a commercial non‐amylaceous polysaccharide enzyme (Enz) product. Fish were fed seven isoenergetic [available energy (AE) = 4.0 kcal g^?1 of diet] and isonitrogenous (350 g kg^?1 protein as‐fed basis) practical diets formulated with equivalent digestible protein levels. Diet 1 was formulated to be similar to a commercial, high‐quality, tilapia diet containing 200 g kg^?1 FM. Diets 2–5 were formulated as a 2 × 2 factorial to replace FM with similar contributions from DDGS (45%), PBM (25%) and SBM (2.1–2.9%), but to differ in supplementation of AA and/or Enz preparation. Diets 6 and 7 were formulated to investigate the effects of a 2/3 and 1/3 reduction, respectively, in DDGS contribution to the replacement protein mix, with concomitant increases in SBM, with respect to diet 3, and were balanced with Lys and Met. After 6 weeks, growth responses were slightly attenuated (P ≤ 0.05) and average daily intake (ADI) and feed conversion ratio (FCR) were slightly higher in tilapia fed DDGS diets 2–5 compared to those of fish fed the FM control diet 1. Growth responses were not significantly affected by the presence or absence of AA or Enz (diets 2–5), or the level of DDGS (diets 3, 7 and 6). Whole‐body proximate composition was not different among treatments. Amino acid profiles of fish fed DDGS diets were not significantly different from those of fish fed the FM control. Evidence of interaction between AA and Enz supplementation was detected in whole‐body amino acid concentrations such that AA content was higher with AA or Enz addition alone, but lower when both were added to the diet. Results suggest that DDGS replacement of FM in tilapia diets can be substantial when diets are formulated on a digestible protein basis and DDGS is combined with highly digestible animal (PBM) and plant proteins (SBM).     

Effects of supplementing methionine hydroxy analogue in soybean meal and distiller's dried grain-based diets on the performance and nutrient retention of rainbow trout [Oncorhynchus mykiss (Walbaum)]

Two experiments were conducted to evaluate the effects of supplementing methionine hydroxy analogue (MHA) on the performance, body composition, and nutrition retention of rainbow trout. In experiment 1, a 2×4 factorial arrangement with two MHA supplemental levels (with and without) and four fish meal replacement levels (25%, 50%, 75%, and 100%, replaced with soybean meal (SBM) and wheat gluten) was used. A fish meal diet was included as a control. Results showed that fish meal replacement levels had significant effects on fish weight gain (WG), feed conversion ratio (FCR), body moisture, crude protein, crude fat, and ash (P<0.05). In experiment 2, a fish meal reference diet and seven other diets were made using SBM and distiller's dried grain with solubles supplemented with 0, 0, 0.55, 1.1, 1.65, 2.2, and 2.75 g MHA kg^?1 diet to replace 50% of fish meal. WG, FCR, and apparent retention of crude protein and phosphorus were significantly improved in rainbow trout fed the diet containing 1.65 g MHA kg^?1 diet compared with fish fed an equivalent diet without MHA.     

玉米酒精粕基木材胶黏剂的制备及其性能

以玉米酒精粕(DDGS)为原料、聚酰胺环氧氯丙烷树脂(PAE)为交联剂、水溶性豆粕(SM)为增强剂制备玉米酒精粕基木材胶黏剂,对比了DDGS与SM蛋白质含量及其氨基酸种类与含量,测试了胶黏剂黏度与制备胶合板的胶合强度,表征了固化胶黏剂功能性基团、热稳定性、断面形态,解析了DDGS基胶黏剂组分对性能的影响规律与增强作用机...     

Storage time and condensed tannin content of high-moisture sorghum grains: Effects on in vitro fermentation and mold populations

Silage of high moisture sorghum grains is a highly relevant source of energy in cattle production systems in South America. There is little information related to the chemical characteristics, the kinetics of fermentation and the toxic fungal populations of these feedstuffs. The aim of this study was to evaluate the effect of storage time and condensed tannins content of the grain on chemical composition, in vitro fermentation parameters, and toxicogenic fungal populations of moist sorghum grain stored in silo-bags. Samples of 2 varieties of sorghum grains (high-tannin [HT] and low-tannin [LT]), were obtained during the grain harvest before silage making and after 30, 90, and 180 d of storage (n = 16). High-tannin grains had higher acid detergent fiber, tannins, gas production (P < 0.05) and lower starch and rate of gas production (P < 0.01). Interaction variety × storage time were observed for all chemical parameters (P < 0.01), except for neutral detergent fiber assayed with a heat stable amylase and expressed inclusive of residual ash (aNDF) and pH. Starch and protein content increased in both varieties, tannins decreased in HT and LT, and organic matter (OM) increased in HT and declined in LT (P < 0.05). The rate of gas production increased with the storage time for HT and LT (P < 0.01). A linear reduction in the Aspergillus number of colonies in the HT varieties was observed (P < 0.01), whereas a linear increase in Penicillium isolation was detected in the LT sorghums (P < 0.01). The storage time was beneficial in terms of decreasing the condensed tannins, increasing fractional rate of gas production and minimizing fungal contamination, particularly on HT grains.     

红曲米酒糟对山羊生长性能与脂质代谢的影响

本试验旨在研究红曲米酒糟对山羊生长性能及脂质代谢的影响,并以此确定山羊饲粮中红曲米酒糟的适宜添加水平。选取28只体况良好、体重一致的贵州白山羊,按照随机区组设计将其分为4组,每组7个重复,每个重复1只羊。对照组饲喂不含红曲米酒糟的基础饲粮,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组分别饲喂含10%、20%和30%红曲米酒糟的试验饲粮。试验持续38 d,包括预试期10 d,正试期28 d。结果显示:各组山羊的干物质采食量(DMI)、末重(FW)、平均净增重(ANG)、平均日增重(ADG)和料重比(F/G)差异均不显著(P>0.05),但从数值上看,以试验Ⅰ组的生长性能最佳。试验Ⅲ组血浆甘油三酯(TG)含量显著高于对照组(P<0.05);试验Ⅱ组与试验Ⅲ组血浆总胆固醇(TC)含量显著高于对照组(P<0.05);血浆低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)含量各组间差异不显著(P>0.05)。综上可知,在本试验条件下,饲粮中添加一定量(10%~30%)的红曲米酒糟对山羊的生长性能没有负面影响,并能有效改善脂质代谢状况,综合来看,以红曲米酒糟添加量为10%时饲喂效果最佳。