夏季饲料要防霉

<正>霉菌污染饲料后,产生大量的孢子和毒素,会给动物造成严重危害。夏季高温高湿,霉菌特别容易繁殖,生产上必须采取有力措施,严格保存饲料,避免霉菌污染饲料,控制霉菌在饲料上生长和繁殖,及时破坏霉菌产生的毒素。     

双乙酸钠防霉效果的试验

霉菌在自然界分布广泛,饲料原料在收割、加工、储藏和运输过程中,均会受到霉菌的污染。饲料中的霉菌在适宜条件下,在饲料贮藏期间会不断繁殖,因而导致饲料品质劣变,大大降低饲用价值。陈必芳等(1996)对全国28个省、区、市86家规模化饲料加工厂和18家饲养场的27份饲料及原料调查发现,配合饲料霉菌污染率为100%,饲料原料为99%。L.Russell等(1991)对美国中西部7个州的82家饲料厂调查发现,饲料中广泛存在着霉菌和霉菌毒素的污染。据联合国粮农组织估计全世界每年大约有5%～7%的粮食、饲料等农作物产品受霉菌污染,每年由于霉变损失的粮食约占总产量的10%左右。饲料霉变及霉菌毒素严重影响饲料工业和畜牧生产。因此为了保证饲料品质及保存饲料产品,有必要对饲料进行防霉处理。     

双乙酸钠用于饲料防霉的研究

<正> 在正常情况下,饲料本身就带有各种各样的微生物。当水分超过14％时,饲料中霉菌便开始迅速生长繁殖。由于饲料中的谷粒已经粉碎,失去了谷粒表皮阻止霉菌入侵的作用,且表面积增大,霉菌极易繁殖。饲料中生长的霉菌为感染整粒谷物的5倍。饲料霉变后,其营养成分被破坏,营养物质平均要损失15％左右,且适口性差,转化率降低。用霉变饲料喂养禽畜,会使禽畜免疫力降低,容易罹患各种疾病或生长发育不良。当霉变饲料中有真菌毒素时,还会引起禽畜中毒,甚至死亡。其体内残留的霉菌毒素还可随食物进入人体,影响人类健康,甚至急性中毒。防止饲料发霉变质的关键是控制饲料水分。在南方高湿多雨气候下,难以保持饲料适度的干燥,所以在饲料中使用防霉剂十分必要。     

夏季饲料防霉技术

霉菌污染饲料后,会产生大量的孢子和毒素,给动物造成严重危害.夏季高温高湿,霉菌特别容易繁殖,生产上必须采取有力措施,严格保存饲料,避免霉菌污染饲料,控制霉菌生长和繁殖,及时阻止霉菌产生的毒素.夏季保存饲料,防霉措施主要有如下几条:     

夏季饲料防霉措施

霉菌污染饲料后,会产生大量的孢子和毒素,给动物造成严重危害.夏季高温高湿,使霉菌容易繁殖,生产上必须采取有力措施,严格保存饲料,避免霉菌污染饲料.现将夏季保存饲料的防霉措施综述如下.     

饲料如何防霉

1控制贮存温度危害谷物的霉菌孢子在7℃时就可以生长,在24℃～32℃时生长最快,温度高于40℃霉菌就会被杀死进入孢子阶段。因此饲料的理想贮存条件是低温干燥。饲料加工后如果散热不充分即装袋、贮存,其中的水分会因温差凝结,易引起饲料霉变。2控制仓库的相对湿度和饲料的含水量     

饲料防霉去毒20种方法

用发霉饲料喂畜禽,轻者会引起畜禽发病,停止生长,降低其机体免疫能力,影响繁殖性能,重者会导致其中毒死亡.为了防止畜禽中毒,必须将饲料中的霉菌毒素去除后才能饲喂.     

谈饲料的发霉与防霉

<正> 一、引起饲料发霉的原因饲料发霉的现象是由于霉菌的作用产生的。霉菌是种多细胞维生物,属真菌,广泛地存在于自然界的各个角落里。霉菌种类繁多,有曲霉、青霉、根霉、木霉等。对畜禽危害较大的主要是曲霉菌。当饲料受潮热时,霉菌就容易生长繁殖,特别是霉雨季节,雨水连连,环境阴暗潮湿,给霉菌生     

饲料的防霉技术

动、植物为霉菌的良好宿主,霉菌通过水和空气传播,与田间作物或储藏的饲料接触.影响饲料感染霉菌及其程度的因素包括水分、温度、氧气、昆虫、谷物饲料的完整性和饲料作物对霉菌的易感性等.每种霉菌都需有一个理想的环境条件,在该条件下霉菌生长和增殖.虽然一些霉菌可在极高或极低温度下生长,但多数霉菌在中等温度下才能增殖.若氧气含量少于1～2%时,则多数霉菌不能生长.一般认为,在料仓内,环境条件维持在以下范围,霉菌生长可被抑制:空气相对湿度低于70%;饲料水分含量低于14%;温度低于-2.2℃;氧气含量少于0.5%.     

饲料防霉去毒措施

<正>1饲料发霉的原因饲料发霉由霉菌引起,致霉菌主要包括黄曲霉素、青霉菌、镰刀菌等。如果饲料饲草未晒干、未晾干便包装入库,或堆积贮存过久等,使饲料中的霉菌在空气温度、湿度适宜时大量繁殖,引起饲料霉烂。梅雨高温季节饲料饲草易霉烂变质。在低温季节,只要饲料饲草含水量超标,或饲料存放环境潮     

A Review of Systemic Antifungal Agents

Résumé— Cet article est une revue des antifongiques systémiques communément utilisés. Sont présentés les origines des diverses substances, leur pharmacocinétique, leur mode d'action, leurs effets secondaires et enfin, leurs indications en médecine vétérinaire. [Hill, P.B., Moriello, K.A., Shaw, S.E. A review of systemic antifungal agents (Antifongiques systémiques: une revue).
Abstract— This paper is a review of commonly used systemic antifungal antibiotics. Included is a review of the origins of the drugs, pharmacokinetics, modes of action, adverse effects and clinical uses in veterinary medicine.     

Antifungal sensitivity testing for equine keratomycosis

We evaluated 31 fungal specimens obtained from equine corneas over a 10-year period, 1973 to 1983. More than half were received in late summer and early autumn, and the number tended to increase in frequency during the 1980s. These isolates included 13 different genera and 20 different species. The prevalent genus was Aspergillus (35%). On the basis of examinations for tube-dilution minimal inhibitory concentrations and minimal fungicidal concentrations of 16 fungal isolates, the imidazole antibiotics such as miconazole and ketoconazole consistently showed the lowest geometric mean titers for filamentous fungi. Because fungal sensitivities varied considerably among different species in vitro sensitivity testing is suggested as an aid in the determination of optimal therapy.     

Antifungal agents of use in animal health--practical applications

The purpose of this paper is to provide an overview of antifungal agents currently in use in veterinary medicine. The practical applications and the therapeutic regimens that have proved successful in the treatment and prevention of fungal infections in dogs and cats, cattle and sheep, horse, pig, poultry and other birds, rodents, rabbits and fur animals are summarized.     

青蒿素母液体外抗真菌试验

用5%青蒿素母液、苯甲酸、水杨酸、6%青蒿素渣煎剂和青蒿素渣粉剂对3种霉菌及酵母菌进行体外生长抑制试验;再用2%、1%、0.5%、0.25%、0.125%的青蒿素母液及苯甲酸,采用平皿纸片扩散法对3种霉菌及酵母进行体外抑菌试验,并与空白和溶剂对照。结果表明青蒿素渣粉剂和煎剂对部分真菌有不同程度的抑制作用,5%母液对所试真菌抑制作用均很强,与5%苯甲酸和水杨酸相当。青蒿素毒母液在浓度高于20%时对所试真菌有较强抗菌作用,其作用苯甲酸相当(P>0.05),而低于20%时抑菌效果不明显。     

Antifungal activity of enilconazole on experimental Aspergillosis in chickens

Day-old chickens were infected with various inoculum sizes of airborne spores of Aspergillus fumigatus, which caused high rates of mortality and morbidity. Fumigation with enilconazole smoke pellets was highly successful in preventing mortality, in reducing morbidity, and in neutralizing growth inhibition of infected chickens. No side effects were observed.     

Antifungal activity of ketoconazole with emphasis on zoophilic fungal pathogens

The antifungal activity of ketoconazole was studied against fungal pathogens associated with various mycotic infections in animals. A concentration of 10 micrograms of ketoconazole/ml of medium proved fungicidal to Trichophyton verrucosum. The same concentration acted as a strong fungistat against the majority of the tested dermatophytes. Yeasts were generally more sensitive than yeast-like pathogens. Ketoconazole also proved fungicidal against Pityrosporon canis and strongly inhibitory on Cryptococcus neoformans and Torulopsis famata at the lowest used concentration. Candida albicans, Candida tropicalis, and Aspergillus fumigatus required a higher concentration in order for the drug to demonstrate some gross changes. However, variable serious microscopic effects were detected. The most marked effect of ketoconazole was in connection with the dimorphic fungi. The action was fungicidal or strongly inhibitory on both the mycelial form and the tissue phase, respectively. The effect of the drug involved both gross morphologic and microscopic changes of the fungi. The mechanism of action of the drug is described in detail. The results are promising and encouraging for the use of ketoconazole in veterinary medicine.     

抑真菌的乳酸菌在酸奶生产中的应用

为了提高酸奶的防霉效果,本研究采用抑真菌的乳酸菌进行酸奶发酵生产。通过对比保加利亚乳杆菌、嗜热链球菌的单菌发酵及添加抑真菌乳酸菌的混菌发酵发现,添加抑真菌乳酸菌的发酵酸奶,在凝乳时间、pH值、色泽、滋味和气味、组织状态等方面变化不显著(P>0.05);而在坚实度、稠度、黏度和黏性指数方面因菌株的不同而有所差异。向发酵后的酸奶中添加霉菌孢子悬液,结果发现添加抑真菌乳酸菌组的霉菌长出时间明显长于对照组。所以,将抑真菌乳酸菌应用于酸奶发酵,在不改变(或优化)原有酸奶特性的前提下可延长酸奶的保质期,但安全性方面还有待评估。     

昆明抗真菌肽Thanatin基因的合成及原核表达

斑腹刺益蝽（Podisus maculiventris）抗真菌肽Thanatin是目前发现的6种昆虫抗真菌肽之一，对真菌具有广谱的免疫诱导杀菌活性，由21个氨基酸残基组成，对革兰氏阳性和阴性细菌也有一定的杀菌作用。根据已报道的抗真菌肽Thanatin基因的氨基酸序列，推导出cDNA序列，采用基因片段合成结合PCR扩增的策略，获得大量完整的Thanatin基因片段，通过T－A克隆法克隆至pGEM-T Easy载体，进行测序，结果证实合成的Thanatin基因与预期设计的完全一致。然后将其亚克隆至表达载体pET-21d中。经IPTG诱导表达后，采用RNA－DNA点杂交和RT－PCR检测具Thanatin基因插段的RNA转录表达活性，初步结果显示该融合表达产物对烟曲霉菌（Aspergillus fumigatus）和绿色木霉菌（Trichoderma riricle）2种病原真菌均有一定的抑菌效果。