微波萃取蓝莓中花青素获取和降解的同步模型

为同步表征微波萃取蓝莓过程中花青素获取和降解过程,揭示微波萃取蓝莓中花青素的传递机理,依据Fick扩散定律和电磁场增强扩散理论,探究微波萃取温度对蓝莓花青素萃取率及降解率的影响,在低温范围内（30~60℃）花青素萃取速度高于降解速度,在高温范围内（60~70℃）花青素降解速度高于萃取速度。建立描述微波萃取过程中花青素获取与降解同步模型,为在生产实践中提高效率、实现对微波辅助萃取有效成分工艺系统的最优控制提供理论依据。     

米糠连续式微波稳定化处理工艺条件优化

采用连续式微波稳化机对米糠进行稳定化处理,以过氧化物酶酶活和脂肪酶活动度为评价指标,通过单因素试验结合正交试验优化米糠微波稳定化工艺。结果表明,最佳工艺条件为,功率4.2 kW、转动速度10 r/min、进料速度180 kg/h、水分含量22%。在此优化条件下,过氧化物酶的平均残余酶活力为4.87%,脂肪酶的平均残余酶活力为14.30%,这4个因素对微波稳定化的效果大小排序为：微波功率>滚筒速度>进料速度>水分含量。加速贮藏试验表明,微波稳定处理后的米糠40℃下储藏30d其酸值仅上升了2.92mgNaOH/g,上升幅度为未处理的16.8%。     

刈割时间对杂交狼尾草成分及厌氧发酵性能影响试验

以杂交狼尾草为原料,采用批式中温厌氧发酵工艺,研究生长期为30、60、91、128、175 d的杂交狼尾草的成分及厌氧发酵沼气产量。研究结果表明:刈割时间对原料成分有较大的影响,原料中C质量分数、碳氮比,干物质(TS)、挥发性固体物(VS)和木质素的质量分数随着刈割时间的延长呈升高的趋势。杂交狼尾草在单位土地面积上的干物质产量随刈割时间的延长先增加而后降低,其中生长128 d时刈割干物质产量最高,可达15.01 t/hm2。原料的产气率也随刈割时间的延长先升高而后降低,其中生长60 d的杂交狼尾草的产气性能最高,其挥发性固体物的产气率和产甲烷率分别为0.68、0.37 L/g。综合干物质产量和原料产气率,杂交狼尾草在不同刈割时间下单位面积土地上的生物质量可产沼气量为848.07~6 279.73 m3/hm2,相应的年产能为165.49~292.66 GJ,可见杂交狼尾草是一种有潜力的厌氧发酵原料。     

添喂气溶胶OT对小尾寒羊采食和消化代谢的影响

利用6只1.0~1.5岁、体重(55.3±3.8)kg、装置永久性十二指肠和回肠瘘管的小尾寒羊公羊,收集十二指肠和回肠食糜试验的同时,进行消化代谢试验,研究在粗料型日粮(玉米秸秆67%)和精料型日粮(玉米秸秆30%)条件下添喂气溶胶OT(0.8 g/kg日粮)对绵羊自由采食和整体消化代谢的影响。结果表明,在粗料型日粮条件下添喂气溶胶OT,绵羊的干物质自由采食量增加30.7%(P0.01),干物质、有机物、粗蛋白(表观)消化率分别提高6.8%(P0.05),7.6%(P0.05),7.9%(P0.05),氮、钙和磷保留量分别增加49.1%(P0.01),30.8%(P0.01),53.4%(P0.01);在精料型日粮条件下添喂气溶胶OT,绵羊的干物质自由采食量增加23.7%(P0.01),绵羊的干物质、有机物、粗蛋白(表观)消化率分别提高3.4%(P0.05),4.1%(P0.05),7.7%(P0.05),氮、钙和磷保留量分别增加29.5%(P0.01),49.3%(P0.01),24.2%(P0.01)。添喂气溶胶OT可以提高绵羊自由采食量,提高消化率,增加氮保留,这种作用在粗料型日粮条件下更显著。     

添喂气溶胶OT对小尾寒羊及策勒黑羊消化代谢的影响

选取平均体重分别为（48.5±2.1）,（47.6±3.2）kg的2.5~3.5岁空怀小尾寒羊和新疆策勒黑羊母羊各6只,自由采食粉碎玉米秸秆占70%的粗料型日粮,以自身对照设计,比较添喂气溶胶OT（0.8 g/kg日粮）对小尾寒羊、策勒黑羊消化代谢的影响。结果表明,添喂气溶胶后小尾寒羊和策勒黑羊的干物质自由采食量分别提高25.2%（P〈0.01）和25.3%（P〈0.01）;干物质表观消化率分别降低12.0%（P〉0.05）和8.3%（P〉0.05）;有机物表观消化率分别降低7.9%（P〉0.05）和6.6%（P〉0.05）;粗蛋白表观消化率分别降低3.2%（P〈0.05）和4.3%（P〉0.05）;能量表观消化率分别降低12.0%（P〉0.05）和8.3%（P〉0.05）;纤维素消化率分别提高1.1%（P〉0.05）和2.3%（P〉0.05）;半纤维素消化率分别提高2.3%（P〉0.05）和6.2%（P〉0.05）;氮保留分别增加13.7%（P〉0.05）和11.1%（P〉0.05）;钙保留分别增加25.2%（P〈0.01）和21.2%（P〈0.05）;磷保留分别增加24.3%（P〈0.05）和18.2%（P〉0.05）。添喂气溶胶OT可提高绵羊自由采食量和消化量,改善绵羊的消化代谢,但在小尾寒羊和新疆策勒黑羊母羊间没有显著差异。     

ICP-MS法测定沙棘果油中13种微量元素含量

沙棘果油样品经微波消解处理,采用电感耦合等离子体质谱法测定所得样品溶液中铁、硒、锌、钾、钠、钙、镁、铜、锰、铅、砷、汞、镉等13种微量元素的含量。使用动态反应池技术消除了多原子离子对部分被测元素的干扰。方法快速准确、灵敏度高,加标回收率在96.1%～101%之间,相对标准偏差小于3%。     

农业有机废弃物两相厌氧消化影响因素的稳定性调控

两相厌氧消化工艺受产氢调酸、反应温度、底物滞留时间、活性污泥的形成及其颗粒化程度调控,其工艺参数的选取直接关系到系统运行的成败和处理效果的优劣。     

莫能菌素对牛日粮养分代谢和甲烷排放的影响

为研究莫能菌素饲喂肉牛后对日粮养分消化代谢及瘤胃甲烷排放的影响,选用12月龄左右、健康、发育正常的西门塔尔牛48头,按随机设计分成4组,对照组试验牛饲喂由混合精料与玉米秸秆所组成的基础饲粮,其精粗比45∶55,处理1、处理2和处理3组分别在基础日粮基础上添加100、200和300 mg·d-1的莫能菌素,进行为期70 d的试验。结果表明,处理2和处理3的粗蛋白消化率和采食氮显著高于对照组(P0.05),甲烷能显著低于对照组(P0.05);处理2和处理3的粪氮和尿氮显著低于对照组和处理1(P0.05),而可消化氮和沉积氮显著高于对照组和处理1(P0.05);处理组的氮排泄/采食氮、磷排泄/采食磷显著低于对照组(P0.05)。综合以上各项指标,当莫能菌素的添加量为300 mg·d-1时,日粮中粗蛋白的消化率、氮利用率提高,氮、磷和甲烷排放降低。     

Effect of physical training on nutrient digestibility and faecal fermentative parameters in Standardbred horses

This study aimed at evaluating, in previously inactive Standardbreds horses, the effect of 5 weeks of an exercise training programme on nutrient digestibility and faecal fermentative parameters (FFPs). As an increase in digestibility had previously been reported in trained endurance horses, we hypothesized that similar results would be found in horses being trained for other types of exercise on a different type of diet. After 3 weeks of dietary adaptation, a digestibility trial (DT1) was undertaken, over 3 days, in eight untrained Standardbreds with a fresh faecal sample being collected on the second day for FFP determinations. Six of the eight horses undertook a training programme, and after 5 weeks of exercise, the DT and the FFP measurements were then repeated (DT2). DT2 began after 3 days of inactivity. The same natural meadow hay (H) and pelleted complementary feed (CF) were fed throughout. For 5 days before the DTs, horses were fed 2.1% BW on a dry matter basis (55:45 ratio H:CF). Body weight and body condition score remained constant. Apparent digestibility of dry matter, organic matter, neutral detergent fibre, hemicellulose, crude protein and gross energy, as well as faecal total volatile fatty acids (VFA), acetate and propionate concentrations were significantly (p < 0.05) higher at DT2 than at DT1. A 5‐week exercise programme had a positive impact on nutrient digestibility and FFP. Training may improve dietary energy supply, in particular via increased hindgut VFA production. The potential improvement of digestive efficiency with training should be taken into account when formulating nutritional recommendations for the exercising horse, particularly when performing light work, which is low‐intensity exercise for 1–3 h per week.     

The effect of mixing and changing the order of feeding oats and chopped alfalfa to horses on: glycaemic and insulinaemic responses, and breath hydrogen and methane production

The aim of this study was to investigate the effects of feeding oats alone before or after feeding chopped alfalfa or, in admixture with the alfalfa on the glycaemic and insulinaemic responses of horses as well as post-prandial breath hydrogen and methane excretion. Horses were fed in a randomized order, chopped alfalfa as a source of dietary fibre and unprocessed oats as a source of starch. Chopped alfalfa intake was adjusted to a crude fibre intake of 0.5 g/kg bodyweight (BW) per meal and the oats intake was adjusted to a starch intake of 2 g/kg BW per meal. The feeds were offered in three different ways: (i) alfalfa followed by oats (A/O), (ii) oats followed by alfalfa (O/A) or (iii) a mixture of alfalfa and oats (A + O). Oats alone were used as a control. Blood and breath were collected after the test meal was fed at the end of a 11.5-h overnight fast following a 10-day acclimatization period. The highest glycaemic and insulinaemic responses were measured when the A/O and O/A diets orders were fed, whereas most hydrogen was produced after feeding oats alone. It was concluded that adding alfalfa chaff to a meal of oats prolonged the pre-caecal digestion of starch, but there was no evidence for any effect on pre-caecal starch digestibility.