Identification of lactic acid bacteria isolated from corn stovers

One hundred and twenty‐six strains were isolated from corn stover in Henan Province, China, of which 105 isolates were considered to be lactic acid bacteria (LAB) according to Gram‐positive, catalase‐negative and mainly metabolic lactic acid product. Analysis of the 16S ribosomal DNA sequence of 21 representative strains was used to confirm the presence of the predominant groups and to determine the phylogenetic affiliation of isolates. The sequences from the various LAB isolates showed high degrees of similarity to those of the GenBank type strains between 99.4% and 100%. The prevalent LAB, predominantly Lactobacillus (85.6%), consisted of L. plantarum (33.3%), L. pentosus (28.6%) and L. brevis (23.7%). Other LAB species as Leuconostoc lactis (4.8%), Weissella cibaria (4.8%) and Enterococcus mundtii (4.8%) also presented in corn stover. The present study is the first to fully document corn stover‐associated LAB involved in the silage fermentation. The identification results revealed LAB composition inhabiting corn stover and enabling the future design of appropriate inoculants aimed at improving the fermentation quality of silage.     

Performance and heterosis from crossing local cattle in the Sudan

Summary Local Sudanese breeds were crossbred at Ghazala Gawazat Research Station in western Sudan to utilise the advantage of heterosis. The breeds involved were Kenana (KK), Butana (BB), and Western (WW). Lactation milk yields were 277·7 and 252 kg/210 days from two teats for BB and WW respectively. Offspring from BB and KK sires bred to WW dams had 8·5% and 25% higher lactation milk yield respectively, than straightbred WW cows. The percentage heterosis for total milk yield was 3·3. The reproductive effectiveness of all breed types was below 100%; indicating that most cows did not calve at regular intervals of 365 days. The local crosses (Butana × Western [BW]) had an, earlier age at first calving and shorter calving interval, by 46 and 17% respectively below their respective straightbreds. Weaning weights (205-day) were 66·4, 58·5, 69·5 and 64·8 kg for BB, WW, BW and KW, respectively. The estimated heterosis for weaning weight was 16·1 per cent.

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Resumen En este ensayo, se cruzaron razas locales en la Estación Experimental de Ghazala Gawazat, en el occidente de Sudán, para expresar la heterosis. Las razas involucradas fueron la Kenana (KK), Butana (BB) y la Occidental (WW). Las producciones por lactación fueron de 277·7 y 252 kg en 210 días, tomada la medición de dos pezones, para BB y WW, respectivamente. Las hijas, de toros BB y KK que sirvieron hembras WW, tuvieron 8·5% y 25% producciones de leche mas altas respectivamente, que las vacas WW servidas con toros de la misma raza. El porcentaje de heterosis para producción de leche total fue 3·3. La efectivaded, reproductiva de todos los tipos cruzados fue monor del 100%; indicación ésta de que la mayoría de las vacas no parieron a intervalos regulares de 365 días. Los cruces locales (Butana × Western [BW]) tuvieron una minore edad más temprana a la primera parición e intervalos entre partos más cortos de 46 y 17% respectivamente, por debajo de las respectivas razas puras. Los pesos al destete (205 días) fueron 66·4, 58·5, 69·5 y 64·8 kg para BB, WW, BW, y KW, respectivamente. La heterosis estimada por peso al destete fue 10·1 por ciento.

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Résumé Des races bovines soudanaises locales ont été croisées à la station de recherche de Ghazala Gawazat, au Soudan occidental, pour tirer profit du phénomène d'hétérosis. Les races concernées étaient: la Kenana (KK), la Butana (BB) et la Western (WW). La production laitère, a été de 277,7 et 252 kg en 210 jours avec deux trayons pour la BB et la WW respectivement. Les animaux issus de pères BB et KK croisés avec des mères WW ont produit, respectivement, 8,5 et 25 p 100 de plus que les femelles WW non croisées. Le pourcentage d'hétérosis pour le rendement laitier total était de 3,3 p 100. La production significative, tous types de races confondus, était inférieure à 100p 100, indiquant ainsi que la plupart des vaches n'ont pas vêlé à un age moins avancé au premier vêlage, avec des inter-vêlages plus courts, de 46 et 17 p 100 respectivement inférieurs par rapport aux produits non croisés. Les poids au sevrage à 205 jours on été respectivement de 66,4, 58,5, 69,5 et 64,8 kg pour BB, WW, BW et KW. L'hétérosis estimé pour obtenir un gain de poids est de 10,1 p 100.

     

健康动物肠道源产窄谱细菌素乳酸菌的筛选鉴定

从健康猪、鸡、兔新鲜粪便及鸡肠道内容物等78份样品中分离乳酸菌,以大肠杆菌、李氏杆菌、金黄色葡萄球菌作为指示菌筛选有明显抑菌活性的菌株,同时进行产细菌素的乳酸菌筛选,并测定抑菌谱;进一步通过生化试验,并结合16S rRNA基因测序结果确定菌株的种类,采用溶血试验和动物试验确定分离菌株的安全性。结果表明,在分离得到的30株乳酸菌中,共有8株对指示菌有抑制作用,其中1株为产窄谱细菌素的短乳杆菌。本研究为下一步探讨产细菌素短乳杆菌作为天然防腐剂和抗菌剂提供了材料。     

Biochemical and serological studies on Pasteurella multocida isolated from cattle in the Sudan.

Of 42 strains of Pasteurella meltocida isolated from different outbreaks of hemorrhagic septicaemia and from healthy cattle in various parts of the Suden, 38 belonged to Carters' type B and four to type E. The strain used for vaccine production was type E. With respect to somatic antigen determination, there was some correlation between the results of the gel diffusion and the agglutination tests as most strains reacted with 0 groups 6 antisera in both tests. However, some antigens cross-reacted with antisera of different 0 groups in the gel diffusion test. No correlation was observed between the pattern of biochemical reactions and the serological types.     

Clinical zinc and copper deficiencies in cattle of western Sudan

Clinical cases of both Zn and Cu deficiencies are reported in a cattle farm in Kordofan Region of the Sudan after drought. The animals showed general weakness, stunted growth, infertility, parakeratosis and achromotrichia. There was macrocytic hypochromic anaemia and low Cu and Zn concentrations in sera. The condition was more prevalent in zebu-Friesian crosses than the local breeds. Drought and marginal or low Cu and Zn content in pasture may be the predisposing factors.     

添加乳酸菌制剂青贮饲料饲喂奶牛效果试验

以乳酸菌青贮和常规青贮两种处理对16头泌乳牛进行了40天的饲喂对比试验。结果表明：添加乳酸菌制剂的青贮比常规青贮品质高，适口性好。试验组比对照组多产奶426.0kg，头日增加收入1．39元，试验期内多增怍444．85元，具有明显的经济效益。     

Haemorrhagic lesions resulting from Trypanosoma vivax infection in Ayrshire cattle

Infection of Ayrshire cattle with a stock of Trypanosoma vivax from the Galana Ranch, Kenya, resulted in an acute disease characterised by profound anaemia and haemorrhage, which reached maximum severity between 3 and 5 weeks after infection. Bleeding from the ears, nose and rectum occurred. At necropsy, petechial and ecchymotic haemorrhages were widespread, but were particularly severe in the gastrointestinal tract. In confirmation of the gross findings, congestion, haemorrhage and degenerative changes in most tissues and organs were found histologically. Thrombi were seen in the lymphatic vessels and clots of fibrin were present in the ventricles of the brain. The anaemia was a consequence of frank blood loss through haemorrhaging, exacerbated by erythrophagocytosis of deformed red blood cells, whose occurrence was indicative of microangiopathic changes. Animals were euthanised between 23 and 36 days after infection when they became recumbent with PCV values as low as 9%. There is no doubt that animals affected by this syndrome in the field would die within a few weeks of infection, if left untreated.     

乳酸菌Ⅱa类细菌素抗菌机制的研究

从细胞及分子水平上就乳酸菌Ⅱa类细菌素抗菌机制及其在动物体内的抗菌作用研究作一综述。     

Bacteria in enteric lesions of cattle

Thirty-nine species of bacteria were isolated from or demonstrated in the abomasal and small and large intestinal mucosa of 23 adult cattle and 41 calves and identified. The bacteria isolated were related to the gross and microscopical lesions. Campylobacters, Clostridium perfringens type A, C sordellii, Actinobacillus lignieresii, Fusobacterium necrophorum, Mycobacterium paratuberculosis, Aeromonas hydrophila and Escherichia coli were all associated with specific lesions. The relationship of other bacteria such as Bacillus licheniformis, Branhamella catarrhalis and Bacteroides vulgatus to lesions in which they were found was discussed. It was concluded that some of the bacteria could be responsible for the lesions in which they were found. However, proof of this supposition could only be obtained by experimental infections of non-immune cattle with pure cultures.     

Susceptibility of Sudanese sheep to a bluetongue virus isolated from apparently healthy cattle in the Sudan

This study intends to clarify the role of apparently healthy cattle as a reservoir of bluetongue (BT) virus to sheep in the Sudan. It confirms earlier work and establishes that cattle can harbour bluetongue virus to which sheep are susceptible in the country. Experimental transmission of BT virus between the two species suggests that the best indicator to determine viraemia in apparently healthy cattle is to inoculate susceptible sheep with suspected cattle virus. The condition of the viraemia and the virus survival in the field are discussed.     

Prevalence of caseous lymphadenitis and usage of caseous lymphadenitis vaccines in sheep flocks

OBJECTIVE: To estimate the prevalence of caseous lymphadenitis (CLA), determine the current usage of vaccines against CLA and to measure the effectiveness of these vaccines on sheep farms. DESIGN AND POPULATION: A survey was undertaken on 223 sheep flocks in New South Wales, Victoria and Western Australia. METHOD: The prevalence of CLA was measured by conventional inspection techniques at abattoirs in lines of sheep that could be traced back to a farm. Managers of the flocks were sent a questionnaire about their vaccine practices, management practices and knowledge of CLA. RESULTS: The average prevalence of CLA in adult sheep in these flocks was 26% and varied from 20% in Western Australia to 29% in New South Wales. About 43% of sheep producers used CLA vaccines; only 12% used them as recommended. Awareness of CLA was highest in Western Australia. More producers would use CLA vaccine if they knew the prevalence of CLA in their flock and producers obtained most information about CLA from vaccine resellers. CONCLUSIONS: Only 10 to 15% of producers are currently achieving effective CLA control through the use of recommended CLA vaccination programs. In Western Australian flocks more than 25% of effectively vaccinated ewes will be sent to abattoirs in the 2 to 3 years after this study. However, large decreases in the prevalence of CLA can be achieved by about 70% of producers by either making adjustments to their vaccination programs or buying a vaccine with a CLA component. Two or three key facts on effective CLA vaccination could be made available at the point of sale of vaccines and from abattoirs that reported the prevalence of CLA to farmers.