莫能霉素添加剂对湖羊饲养试验

1　材料与方法1.1　试验动物与时间试验于 2 0 0 1年 5月 15日至 6月 2 3日在余杭潘板湖羊场进行 ,试验期共 4 0d。17～ 2 4kg健康生长湖羊 4 9头。1.2　试验分组试验分为 4组 :即空白对照组 :海正产低组 ;每头羊日喂海正产 2 0 %莫能霉素 5 0mg :海正产中组 :每头羊日喂海正产 2 0 %莫能霉素 10 0mg ;海正产高组 :每头羊日喂海正产 2 0 %莫能霉素 15 0mg。试验动物随机均分为 4组。各组体重基本一致。按试验要求 ,将各组添加的莫能霉素分别均匀拌入基础饲料中 ,每日分早、晚 2次饲喂。1.3　饲养试验基础饲料组成棉籽饼 12 % ,菜籽饼 12 % ,…     

农业部修订兽药莫能霉素预混剂质量标准

本刊讯2004年3月1日,农业部发布了第350号公告,组织了有关专家对美国礼来公司在我国注册的进口兽药莫能霉素预混剂质量标准进行了修订,并予以发布,同时废止了原发布的同品种兽药质量标准。详见中国饲料工业信息网www.chinafeed.org.cn(政策栏目)。■农业部修订兽药莫能霉素预混剂质量标准     

森杜拉霉素与盐霉素莫能霉素抗球虫效果比较试验

森杜拉霉素与盐霉素莫能霉素抗球虫效果比较试验Ｌ．Ｒ．ＭＣＤｏｕｇａｌｄ等著魏文康摘译（广东省农科院兽医研究所广州５１０６４０）森杜拉霉素是由玫瑰型放线菌（Ａｃｔｉｎｏｍａｄｕｒａｒｏｓｅｏｒｕｆａ）发酵生成的聚醚类离子载体抗生素。２０～３０ｐｐｍ有抗...     

莫能霉素和盐霉素对肉仔鸡生产性能的影响

材料与方法选用Cobb×Cobb羽毛自别雌雄肉仔鸡进行了两次试验,所用基础饲粮是商品玉米—豆饼型饲粮,其蛋白质和代谢能计算值为21.02％和3256Kcal/kg(应用NRC1984年版营养价值表)。试验1在基础饲粮中添加44、55、66、77、88ppm盐霉素和81、101、     

中草药饲料添加剂在反刍动物养殖中的应用研究进展

笔者结合人类食品安全与健康、环境保护和反刍动物养殖业的现状,介绍了反刍动物饲用中草药饲料添加剂的独有特点和应用方向,讨论了反刍动物饲用中草药饲料添加剂在实际应用和研发中存在的主要问题,并对以后的发展方向和研究趋势进行了展望。     

中草药饲料添加剂在反刍动物生产中的应用

中草药饲料添加剂是一种兼具营养价值和药用价值的新型绿色饲料添加剂,可以促进动物机体生长发育,提高动物生产性能,增强动物机体抗病能力,同时还具有毒副作用小、无残留、无耐药性等优点。阐述了中草药饲料添加剂的特点及其在反刍动物生产中的应用,以期为中草药饲料添加剂的科学、合理利用提供参考。     

在反刍动物中应用酶制剂的研究

酶是由活细胞生产的具有催化活力的一类蛋白质。细菌、真菌等微生物是各类酶的主要来源。自从１９７５年美国饲料工业Ｊｅｎｓｅｎ首次把微生物作为添加剂应用于配合饲料中并在饲料业中取得显著效果后，饲用酶制剂日益受到养殖界的重视（Ｂａｒｒｙ，１９８８），８０年代国外配合饲料中已普遍使用这类新型添加剂。９０年代初，我国才开始该方面的研究，且进展异常迅速。目前，已发现可用于饲料的酶有２０多种。最近，通过基因编码已将不同的酶，如β—葡聚糖酶、木聚糖酶、纤维素酶等进行克隆，并在不同的商业体系中进行表达微生物、…     

缩二脲在反刍动物中的应用

在现代畜牧业中,蛋白质资源是制约其发展的主要因素,国内外都在积极研究、开发各种蛋白质资源,非蛋白氮饲料添加剂便是一类重要的蛋白质资源,常用的非蛋白氮饲料添加剂主要包括缩二脲、尿素、异丁叉二脲、硫酸铵、磷酸二氢铵、氨水、磷酸脲、硬脂酸脲等。由于缩二脲具有独特的理化性能,以及作为反刍动物饲料添加剂具有适口性好、毒性低,且易于消化吸收等优点,所以倍受人们的关注。缩二脲在许多国家,如美国、前苏联等已被指定用作非蛋白氮饲料添加剂,欧共体也正式批准缩二脲作为反刍动物非蛋白氮饲料添加剂,我国对缩二脲的开发应用报道不多,…     

瘤胃素在反刍动物生产中的应用

瘤胃素又称莫能霉素或莫能菌素（monensin），是由链霉菌（Streptomycescinnamonesis）产生的一种聚醚类抗生素。瘤胃素能够调节瘤胃微生物区系，减少革兰氏阳性菌（Russell等，１９８８）和原虫（易建民等，１９９８）数量，抑制乳酸产生菌、氨产生菌和产气菌活性，提高乳酸利用菌活性（Dennis等，１９８１；Callaway等，１９９６；王中华等，１９９９）。饲料中添加瘤胃素可提高饲料转化率和养分吸收率。１９４５年美国正式将瘤胃素列为肉牛饲料添加剂，现已广泛用于肉牛生产中。瘤胃素在奶牛上的研究起步比较晚，试验表明，瘤胃素可提…     

莫能菌素作为饲料添加剂在反刍动物中的应用

我国是抗生素生产和使用大国,莫能菌素属于聚醚类离子抗生素,常被作为离子载体添加剂用于反刍动物饲料中,是应用最广泛的促生长抗生素添加剂。用莫能菌素直接饲喂反刍动物,能通过改善瘤胃微生物区系、提高碳水化合物和蛋白质利用率、减少甲烷产量,最终促进动物生长,效果十分显著。文章将对莫能菌素的作用机制作一综述并对其发展进行展望。     

Comparative toxicology of monensin sodium in laboratory animals

The toxicology of monensin has been studied in several laboratory animal species. There was considerable species variation in acute oral LD50 values. The consistent signs of acute toxicity were: anorexia, hypoactivity, skeletal muscle weakness, ataxia, diarrhea, decreased weight gain and delayed deaths. The 3-mo study in rats fed diets containing 0, 50, 150 or 500 ppm monensin resulted in no effects at the lowest dose level, slight reduction of body weight gain in the middle-dose group and severe depression in body weight gain, skeletal and cardiac lesions, and deaths in the highest dose group. The 3-mo study in dogs given daily oral doses of 0, 5, 15 or 50 mg/kg monensin resulted in no effects at the lowest dose level. Dogs in the 15 and 50 mg/kg groups developed, during test wk 1 to 4, anorexia, weakness, ataxia, labored respiration, body weight loss, increased serum muscle enzyme values, severe skeletal muscle degeneration and necrosis with less severe heart lesions and deaths. Mice fed diets containing 0, 37.5, 75, 150 or 300 ppm monensin for 3 mo had reduced body weight gain in all test groups but no other physical signs. Serum creatine phosphokinase (CPK) values were increased in mice in the two highest dose groups and minimal heart lesions were found in the highest dose group. Dogs given daily oral doses of 0, 1.25, 2.5, 5 or 7.5 mg/kg monensin for 1 yr survived with no evidence of toxicity in the two lowest dose groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accidental monensin sodium intoxication of feedlot cattle

Of 1,994 yearling and 2-year-old cattle in a winter feeding program, 117 died within 42 days of being fed toxic amounts of monensin sodium in a liquid protein supplement. Death losses commenced on the third day after ingestion of a toxic amount in the feed. Clinical signs in cattle that died in less than 9 days included anorexia, pica, diarrhea, depression, mild hindlimb ataxia, and dyspnea. Gross necropsy findings in cattle dying in the acute phase of the illness included hydrothorax, ascites, and pulmonary edema, as well as petechial hemorrhages, edema, and yellow streaking in skeletal and cardiac muscle. Cattle dying after 9 days had gray streaks in heart and skeletal muscle, generalized ventral edema, enlarged, firm, bluish discolored liver, and enlarged heart. Microscopic changes in cattle dying in the acute phase (less than 9 days) consisted of pulmonary edema, congestion, and hemorrhage. Cardiac and skeletal muscle had localized areas of edema, hemorrhage, and coagulative necrosis. In cattle dying after 9 days of illness, the changes included lymphocytic infiltration, sarcolemmal nuclear proliferation, and fibrosis in skeletal and cardiac muscle. Lungs contained increased alveolar macrophages and a few neutrophils. Centrilobular necrosis and mild fibrosis were found in the liver. Changes varied somewhat according to the area of heart or skeletal muscle that was affected. Active muscles, eg, those in the heart ventricles and diaphragm, were altered most severely. Intoxication appeared to be a result of sedimentation of monensin in the molasses carrier to give remarkable concentrations of the substance at the bottom of the holding tank.     

Prophylactic effect of monensin sodium against experimentally induced paratuberculosis in mice.

Monensin sodium (0, 15, or 30 mg/kg of complete feed) was fed ad libitum for 1 week to female mice (strain C57BL6/J) that were genetically susceptible to infection with Mycobacterium paratuberculosis. Ten mice in each of the 3 groups were inoculated intraperitoneally with M paratuberculosis (10(9) organisms). Sterile saline solution was injected intraperitoneally into 10 other mice in each group. Rations were continued for 50 days, then mice were euthanatized, and body weight, splenic weight, and hepatic weight for each mouse were recorded. Ratios of body weight to splenic weight and of body weight to hepatic weight were calculated for each mouse. Hepatic granulomas in 50 light microscopic fields were counted, and presence of acid-fast organisms in those granulomas was recorded. Infected mice given monensin had higher body weight and fewer hepatic granulomas than did mice not given monensin. Although hepatic granulomas were fewer in these mice, they contained acid-fast organisms. Effects of 15 mg of monensin and those of 30 mg of monensin/kg of complete feed were not different.     

Effect of increasing monensin sodium levels in diets with virginiamycin on the finishing of Nellore cattle

This study evaluated the effect of increasing levels of monensin sodium (MON) in diets with virginiamycin (VM) on the finishing of feedlot cattle. Two hundred and eighty intact male Nellore cattle (348 ± 32 kg body weight, 22 months) received one of the following five diets: control diet (without additives); diet containing VM (25 mg per kg dry matter) combined with 0 (MON0), 10 (MON10), 20 (MON20) or 30 (MON30) mg MON per kg dry matter. During adaptation (28 days), the MON0 diet increased dietary net energy for maintenance and gain compared to the control diet (P = 0.04). The combination of additives linearly reduced dry matter intake, body weight and average daily gain (P < 0.01). Considering the total study period (110 days), there was a trend of greater net energy intake for maintenance (P = 0.09) and hot carcass weight (P = 0.06) for animals fed MON0 compared to the control diet. The combination of additives linearly reduced dry matter intake (P = 0.04) and linearly increased gain : feed and dietary net energy for maintenance and gain (P < 0.01). The combination of VM with MON at a dose of 30 mg/kg dry matter is recommended for Nellore feedlot cattle because it improves the efficiency of energy utilization.     

Long‐term assessment of horses and ponies post exposure to monensin sodium in commercial feed

Reasons for performing study: Acute monensin intoxication in equids is well described; however, the long‐term effects of sublethal intoxication and ability to return to previous use are less well understood. Long‐term observations may allow improved estimation of prognosis in cases of sublethal intoxication. Objectives: To assess horses and ponies exposed to sublethal amounts of monensin for evidence of chronic sequelae and ability to return to prior/intended use. Methods: Twenty‐nine horses and 8 ponies were assessed utilising serum biochemistry, treadmill exercise stress testing, electrocardiography, and pre‐ and post exercise echocardiography ≥6 weeks after ingestion of monensin‐contaminated feed. Animals with evidence of monensin‐induced cardiomyopathy were re‐examined after a period of rest of ≥11 months. Follow‐up information was obtained by owner telephone interview ≥52 months after exposure. Results: During resting echocardiography, 11 animals had reduced/low‐normal left ventricular fractional shortening (FS); an increase in FS in 8 of these animals was measured ≥11 months later. Six animals had reduced or low‐normal FS during post exercise echocardiography. Two horses had ventricular premature depolarisations during exercise. Follow‐up information was available for 35 animals: 21 returned to athletic/reproductive use, 13 were retired immediately and one died. Mean FS increased significantly (P<0.001) between initial and second examination in 15 animals that underwent resting echocardiography on 2 occasions. Conclusions: Some equids exposed to sublethal doses of monensin may not develop permanent myocardial disease and a return to athletic/reproductive use is possible. Potential relevance: Exercise stress testing, echocardiography and electrocardiography may be useful for detection and monitoring of cardiac dysfunction in equids exposed to monensin and determining whether a return to athletic/reproductive use is possible.