新农生物葡萄保鲜剂1号的应用效果初报

红提葡萄汁多、味浓、口感好,是消费者喜爱的水果,然而在保鲜过程中易受到微生物污染,影响葡萄的商品性。笔者历时5年,研制成新农生物葡萄保鲜剂1号。保鲜试验结果表明,新农生物保鲜剂1号具有抑制红提葡萄保鲜过程中微生物生长的作用,用质量分数为0.1%的该保鲜剂喷施的葡萄,在0~1℃条件下贮藏100d,其果穗和果粒外观优于对照;掉粒率和烂果率显著低于对照;果粒中的可溶性固形物含量高于对照。该葡萄口味浓,不含二氧化硫,无涩味。     

不同配料比对杏果蔬原汁品质的影响

新疆有着丰富的杏子和番茄资源,为了充分利用这2种果蔬的营养物质,将其加工制成杏果蔬原汁。笔者进行了5种配料的杏果蔬原汁的品质测定,结果表明,用杏子、蔬菜番茄、蔬菜黄瓜质量比为1:2:1的配料,制成的杏果蔬原汁色泽和口感好,胡萝卜素、VC和番茄红素含量较高。     

Rheology and Texture Properties of Surimi Gels of Northern Snakehead (Channa Argus) as Affected by Angelica Sinensis (Oliv.) Diels. (Danggui) Powder

Northern snakehead (Channa argus) is very popular freshwater fish in China and is expected to become a new surimi material with therapeutic efficacy. The Angelica sinensis powder is a type of famous Chinese medicine that helps to regulate metabolism and enhance the immune function. Therefore, an upmarket medicated surimi product with hygienic qualities was designed to adapt to the stressful current lifestyle using snakehead and Angelica sinensis powder. The texture, whiteness, rheological properties, and sensory properties were studied to further optimize the dosage of the Angelica sinensis powder used in the surimi processing. The results indicated that the maximum breaking force and breaking distance were obtained at a concentration of 4 g/kg, and the whiteness value and driage were significantly decreased with the increase of the amount of the Angelica sinensis powder. Ultimately, the highest total sensory evaluation score was obtained for samples with the addition of 2 g/kg Angelica sinensis powder. This study shows that the Angelica sinensis powder has the potentiality to become an added ingredient to snakehead surimi products in order to improve the health status of sub-health population.     

CIMMYT牧草与普通玉米杂交后植物学形态变异研究

[研究目的]为发掘利用CIMMYT牧草生长繁茂和抗逆能力强等优良遗传特性,改良普通玉米材料的抗逆性和创制新型饲草材料.[方法]以CIMMYT牧草和4个普通玉米自交系为遗传交配材料,比较研究了CIMMYT牧草和4个杂交(回交)后代材料的植物学形态特征及其与普通玉米的差异.[结果]CIMMYT牧草能将其生长繁茂、分蘖力强、生物产量高的特性遗传给杂交后代材料,并有较强的世代传递能力;该牧草幼苗、植株及其生长习性、花器官、种子特征等与普通玉米差异明显,其与普通玉米的杂交后代基本保持了它的生长发育特性,但花器官和种子特征更偏向于普通玉米;回交后代除保持了一定的分蘖特性、明显的多穗和返祖现象外,其余特征特性与普通玉米基本没有区别.[结论] CIMMYT牧草生长繁茂和生物产量高的特性能遗传给杂交后代,世代传递能力较强,通过遗传改良途径,能将CIM-MYT牧草的优良特性转育到普通玉米中,培育出饲草玉米育种新材料.     

稀土对真空熔结镍基复合涂层组织结构的影响

研究了稀土(Ce La)对真空熔结镍基金属陶瓷复合涂层化学组成和组织结构的影响。结果表明:稀土(Ce La)消除了Ni60 WC涂层中的针状相,改变了陶瓷相的分布形态。稀土还改变了涂层的化学组成,提高了组成相中的镍含量和陶瓷相中的钨含量。含稀土的真空熔结镍基金属陶瓷复合涂层还析出了新的第2相WC和LaNi3。     

人工神经网络在遥感图像森林植被分类中的应用

应用人工神经网络模型对陆地卫星TM多光谱图像进行了森林植被分类的研究 ,共选取了 8种主要植被类型 ,重点是研究在不同背景条件下存在同谱异物现象的云杉、油松和落叶松等针叶林树种的分类方法 .所采用的网络模型为 3层误差后向传播神经网络模型 ,鉴于贺兰山自然植被垂直带谱明显 ,利用误差后向传播网络模型的并行分布式结构 ,研究中引入高程数据作为一个独立波段与 3个多光谱波段一起直接进行分类 ,取得了很好效果 .该方法与常规的最大似然法相比 ,存在同谱异物现象的云杉、油松和落叶松的分类精度平均提高了 2 7 5个百分点 .对存在同物异谱现象的阔叶林的分类精度也有一定程度的提高 .     

鸡毒支原体PCR检测及特异扩增片断的克隆与测序

根据Ｅ．Ｒ．Ｎascimento等人鸡毒支原体（Ｍycoplasma gallisepricum,ＭＧ）基因文库 分离的种特异性片段fＭＧ－２序列,设计合成一对长２５bp的引物Ｌ１Ｒ１,经ＰＣＲ反 应条伯优化选择,对５株ＭＧＤＮＡ扩增均产生出预期的７３２bp特异扩增片断,而不能扩增滑液支原体（Ｍycoplasma synouiae,ＭＳ）、Ｅ．coli、ＰＵＣ１９质粒ＤＮＡ,符合 设计要求;ＤＩＧ随机引物法标记扩增产物ＤＮＡ探针,与上述菌株ＤＮＡ Ｄot-blot杂交     

Effects of dietary protein levels and 2‐methylbutyrate on ruminal fermentation,nutrient degradability,bacterial populations and urinary purine derivatives in Simmental steers

The objective of this study was to evaluate the effects of dietary crude protein (CP ) levels and 2‐methylbutyrate (MB ) supplementation on ruminal fermentation, bacterial populations, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in Simmental steers. Eight ruminally cannulated Simmental steers, averaging 18 months of age and 465 ± 8.6 kg of body weight (BW ), were used in a replicated 4 × 4 Latin square design by a 2 × 2 factorial arrangement. Low protein (98.5 g CP /kg dry matter [LP ] or high protein (128.7 g CP /kg dry matter [HP ]) diets were fed with MB supplementation (0 g [MB ?] or 16.8 g steer^?1 day^?1 [MB +]). Steers were fed a total mixed ration with dietary corn straw to concentrate ratio of 50:50 (dry matter [DM ] basis). The CP  × MB interaction was observed for ruminal total VFA , molar proportions of acetate and propionate, acetate to propionate ratio, ammonia‐N, effective degradability of neutral detergent fibre (NDF ) and CP , microbial enzyme activity, bacterial populations and total PD excretion (p  < .05). Ruminal pH decreased (p  < .05), but ruminal total VFA concentration increased (p  < .05) with increasing dietary CP level or MB supplementation. Acetate molar proportion increased (p  = .043) with MB supplementation, but was not affected by dietary CP level. Propionate molar proportion decreased (p  < .05) with increasing dietary CP level or MB supplementation. Consequently, acetate‐to‐propionate ratio increased (p  = .001) with MB supplementation, but was not affected by dietary CP level. Ruminal ammonia‐N content increased (p  = .034) with increasing dietary CP level, but decreased (p  = .012) with MB supplementation. The effective degradability of NDF and CP increased (p  < .05) with increasing dietary CP level or MB supplementation. Microbial enzyme activity, bacterial populations and total PD excretion also increased (p  < .05) with increasing dietary CP level or MB supplementation. The results indicated that ruminal fermentation, nutrient degradability, microbial enzyme activity, ruminal bacterial populations and microbial protein synthesis improved with increasing dietary CP level or MB supplementation in steers.     

培养液磷含量和pH值对鸡离体小肠磷吸收的影响

本研究主要探讨了培养液不同pH值和磷含量对鸡离体小肠磷吸收的影响,为体外培养鸡小肠合理选择培养液pH值和用外翻肠囊法评定饲料有效磷时合理选择培养液磷浓度提供参考依据。采用2个单因子随机试验,每个因子4个处理。48只30日龄体重相近的三黄肉公鸡的十二指肠、空肠和回肠肠囊随机分配到8个处理中,每个处理6个重复,每个重复1个肠囊,39℃培养50min。结果表明：pH5．0～7．0时,肠囊的磷吸收量线性增加;pH8．0时,肠囊的磷吸收量降低;与pH5．0比较,pH7．0时,肠囊的磷吸收量极显著增加（P〈0．01）。培养液磷含量在50～200μg／mL时,肠囊的磷吸收量与磷含量呈正相关;当磷含量增加到400μg／mL,十二指肠肠囊和空肠肠囊的磷吸收量开始降低;磷吸收率与培养液磷含量之间呈负相关,不同处理之间差异极显著（P〈0．01）。结果显示：以肉仔鸡为动物模型,用外翻肠囊法评定饲料有效磷时,培养液适宜pH为6．0～7．0;有效磷含量不能超过200μg／mL,以50μg／mL左右为宜。     

A survey of the frequency of aminoglycoside antibiotic-resistant genotypes and phenotypes in Escherichia coli in broilers with septicaemia in Hebei,China

1. The aim of this study was to investigate the occurrence of aminoglycoside resistance and the prevalence of 6 important modifying enzyme genes, i.e. (strA, strB, aph(3?′)-IIa, aac(3)-IIa, aac(6?′)-Ib and ant(3?″)-Ia), in Escherichia coli strains in broilers with septicaemia in Hebei, China.

2. A total of 111 clinical isolates of E. coli were collected from 46 large-scale farms. Antimicrobial susceptibility tests, using the Kirby–Bauer disc diffusion method, were performed on all 111 isolates. In addition, all were screened for the presence of modifying enzyme genes using the polymerase chain reaction (PCR).

3. The results show that the rates of resistance were as follows: streptomycin: 97.3%, kanamycin: 97.0%, gentamicin: 95.5%, neomycin: 50.5%, amikacin: 46.0%, spectinomycin: 22.5%. Of the genes examined, strB (73.9%) was the most frequently identified gene in the phenotypic resistant isolates, followed in order by: ant(3?″)-Ia, aac(3)-IIa, aac(6?′)-Ib, aph(3?′)-IIa and strA.

4. It is concluded that aminoglycoside resistance in E. coli from broilers with septicaemia remains a serious problem in Hebei, China. This emphasises the need to ban the non-therapeutic use of antibiotics, discourage their misuse and to be continually vigilant by providing appropriate scientific and technological support for the poultry industry.