在体外模拟瘤胃发酵条件下N-乙酰-DL-蛋氨酸稳定性的研究

通过两个试验,研究在体外模拟瘤胃发酵条件下N-乙酰-DL-蛋氨酸的降解率。试验1:N-乙酰-DL-蛋氨酸在pH值6.5、温度为39℃的缓冲液中孵育9h,其降解率为3.3%。试验2:运用瘤胃体外发酵技术研究N-乙酰-DL-蛋氨酸不同添加量对pH值、氨态氮、微生物蛋白动态变化的影响。结果表明,添加0.4、0.6gN-乙酰-DL-蛋氨酸发酵3～6h,均能够显著降低体系的pH值;添加0.6gN-乙酰-DL-蛋氨酸发酵12h能够显著提高氨态氮的浓度;N-乙酰-DL-蛋氨酸在发酵过程中不影响微生物蛋白产量。以上结果显示,N-乙酰-DL-蛋氨酸在体外模拟瘤胃发酵的条件下可以稳定存在。     

巴氏杀菌牛乳和UHT牛乳的差别

研究了巴氏杀菌、超高温灭菌对牛乳中各种成分的影响，结果发现此两种热处理方式对牛乳中蛋白质、维生素、矿物质和产品风味产生不同影响，而对脂肪的影响不大。     

犬附红细胞体病的诊治体会

犬附红细胞体病是由附红细胞体寄生于犬的血液、游离在血浆中或附着在红细胞表面所引起的一种血液寄生虫病。临床上以发热、贫血、黄疸等为主要特征。2004年以来,笔者诊治了8例病犬出现持续高热为主要特征的疾病,经临床与实验室诊断,确诊为犬附红细胞体病,经治疗5天后恢复正常。现举1例报道如下：     

Effect of Fermentation Bed with Spent Mushroom Substrate of Pleurotus eryngii on Weaning Piglets

[Objective] The paper was to investigate effects on fermentation bed temperature,growth performance,diarrhea rate and digestive en-zyme activity of weaning piglets by using spent mushroom substrate of Pleurotus eryngii as padding.[Method] A total of 120 weaning piglets(Duroc × Landrace ×Yorkshire) with average initial body weight of(8.0 ±0.5)kg were allocated to five dietary treatments in a randomized complete block design for 42 d,each of which was replicated three times with eight piglets per replicate(half male,half female).The padding for control group was(50% sawdust +50% rice husk);experimental group Ⅰ 100% spent mushroom substrate;experimental group Ⅱ(15% sawdust +15% rice husk +70% spent mushroom substrate);experimental group Ⅲ(25% sawdust +25% rice husk +50% spent mushroom substrate);experimental group Ⅳ(35% sawdust +35% rice husk +30% spent substrate).[Result] There was no significant difference in surface temperature of fermentation bed between experimental groups and control group(P0.05).Compared with the control group,the temperature under 20 cm of fermentation bed in ex-perimental groups I,Ⅱ and Ⅲ increased significantly(P0.05).Except for experimental group Ⅳ,other three experimental groups had higher aver-age daily gain(P0.05) and experimental group Ⅰ had higher average daily feed intake(P0.05) compared to the control group.The diarrhea rate and mortality of weaning piglets in experimental groups Ⅱ,Ⅲ and Ⅳ were significantly decreased compared with the control group(P0.05).Compared with the control group,other three experimental groups had higher digestive enzyme activity in duodenal contents except for experimental group Ⅳ(P0.05).[Conclusion] Spent mushroom substrate of P.eryngii can be used as fermentation bed padding,and the optimal proportion was experimental group Ⅲ.     

基质对黑果腺肋花楸幼苗生长的影响

以黑果腺肋花楸(Aronia melanocarpa)为试验材料,选用田园土、泥炭土、珍珠岩和黄沙,采用正交试验设计,研究不同基质配比对黑果腺肋花楸成苗率以及幼苗形态指标和生理指标的影响。结果表明,不同育苗基质对黑果腺肋花楸出苗率、苗高、地径、主根长、侧根数和高径比等形态指标以及根系活力、可溶性糖、淀粉和蛋白质等生理指标的影响差异显著,综合分析各项指标,筛选出适合黑果腺肋花楸容器育苗的栽培基质为田园土(40%)+泥炭土(30%)+黄沙(30%)、田园土(40%)+珍珠岩(30%)+黄沙(30%)、田园土(40%)+泥炭土(30%)+珍珠岩(30%)和田园土(60%)+泥炭土(20%)+黄沙(20%)。     

棉籽饼粕脱毒方法研究进展

棉籽饼粕含有丰富的蛋白质,但同时也含有对畜禽有毒害作用的游离棉酚。研究适宜的脱毒方法脱除或钝化棉籽饼粕中的游离棉酚,使之变成优质的蛋白质饲料,对缓解我国蛋白质饲料资源不足和促进饲料工业的发展具有重大的现实意义。本文从棉酚的结构、中毒症状谈起,综述了目前棉籽饼粕主要脱毒方法的效果和优缺点,同时对研究中存在的一些问题提出了看法和改进建议。     

镇海巨高长毛兔体重与产毛性能相关的研究

利用原全国家兔育种委员会2000年长毛兔性能测定数据,分析研究了镇海巨高长毛兔12月龄时体重与产毛性能的相关。结果表明:母兔的体重、标准含水率产毛量、单次产毛率和估测年产毛率均显著或极显著地高于公兔;随着体重的增加,标准含水率产毛量相应地提高,单次产毛率和估测年产毛率相应地下降;体重与标准含水率产毛量、单次产毛率的相关系数分别为0.225、-0.324(P<0.01);标准含水率产毛量与单次产毛率的相关系数为0.845(P<0.01)。     

国外的饲料堆码技术

在饲料厂的包装系统中。继自动秤重打包设备之后。堆码机也许是下一个最受欢迎的升级换代设备，因为用人工将成品装上常用的运送托盘可装10—12包的塑料小托盘，是饲料厂劳动强度最大的工作之一。由于拖码包劳动强度大，它就可能使产品质量不稳定，而且工人经常要举起成品。所以它也是最易受伤的工作之一。即使劳动力便宜、不计工人受伤或停工的花费，自动包装和堆码还是有它的优势，它能改善产品质量，因为它可以减少破包和加快袋装饲料的分发。[第一段]     

应用夏洛莱、利木辛肉牛开展三元杂交效果试验

经过20年的努力，凉州区黄牛改良工作取得了显著的成效，黄牛冻配点由最初的10个发展到现在的145个，年授配母牛3万头。为建立适合凉州区的最佳肉牛生产模式，进一步提高该区肉牛生产水平，凉州区从1998年开始，引入夏洛莱、利木辛、德国黄牛、皮埃蒙特等著名肉牛品种与当地西杂母牛进行三元经济杂交，取得了较好的效果。我们于2000年9月20日至2001年1月6日，在凉州区新华乡开展了应用夏洛莱、利木辛肉牛分别与当地西杂牛三元杂交效果试验。现将结果报告如下。     

Effects of inulin on performance, egg quality, gut microflora and serum and yolk cholesterol in laying hens

1. The present study was conducted to investigate the effects of inulin on laying hens. A total of 360 Brown Nick laying hens were divided randomly into 6 groups of 60 with 6 replicates of 10 hens and fed on diets containing 0 (control), 0·1, 0·5, 1·0, 1·5 or 2·0% inulin during the 4-week trial. 2. Dietary supplementation of inulin reduced cholesterol concentration (mg/g yolk) and content (mg/egg) in eggs. Cholesterol content in eggs decreased linearly with increasing levels of dietary inulin level. 3. Supplementation of inulin in diets decreased coliform bacteria counts and pH in the caecum. The lowest coliform bacteria counts (6·30 ± 0·03 log10 cfu/g) and pH (6·47 ± 0·01) were obtained in the 2·0% inulin group, the two indices decreasing by 21·6% and 3·0% respectively, compared with the control group. Coliform bacteria count and pH were changed linearly in accordance with increasing levels of dietary inulin level. Caecal Bifidobacteria counts were increased in the 2·0%-inulin group. 4. Inulin supplementation of layer diets did not appear to have any adverse effects on laying rate, egg weight, feed intake, feed conversion efficiency, cracked-egg rate, eggshell thickness or Haugh unit compared with the control laying hens. 5. Therefore, dietary supplementation with inulin may lead to the development of low-cholesterol chicken eggs as demanded by health-conscious consumers.