氨气熏蒸对柑橘属果实采后腐烂的控制效果及对抑霉唑杀菌剂效果的影响

在初始阶段及2 h后分别两次向柠檬和柑橘的贮藏环境中充入3 000μL.L-1的氨气,并在22℃温度条件下熏蒸处理6 h,可有效抑制由指状青霉菌和意大利青霉菌引起的绿霉病和青霉病。虽然熏蒸后很多孢子仍然存活,但这种处理不伤害柑橘,而会造成柠檬外表皮原有伤口区域的颜色变暗。6 000μL.L-1的氨气熏蒸处理能够略加快柠檬果实由绿变黄的进程。意大利青霉菌的孢子萌发对氨气的敏感程度要高于指状青霉菌。在初始阶段及后2 h两次注入6 000μL.L-1的氨气进行熏蒸处理6 h后,大约有30%的指状青霉菌和10%的意大利青霉菌孢子能够萌发。应用氨气熏蒸处理可抑制一种对抑霉唑(IMZ)有较高抗性的指状青霉菌的生长。本文还研究了氨气熏蒸对这种常见的采后杀菌剂的效果的影响。首先将试验果实浸入10 mg.L-1或30 mg.L-1的IMZ中(大约为常用商业用量的10%),然后用1500μL.L-1的氨气熏蒸处理就可以控制这两种病害的发生,并且这种效果的增长量是叠加的,有时具有协同增效作用。这种作用效果的部分原因可能是由于氨气熏蒸影响了pH的大小,而对于中性的IMZ来说,pH的增加能够显著地提高其抗真菌的活性。1 500、3 000、6 000μL.L-1的氨气熏蒸处理能够使柑橘和柠檬果实上已有伤口组织中的pH值从5.9(±0.2)分别增加0.6(±0.3)、0.9(±0.4)和1.3(±0.3)。IMZ可以在柑橘采后马上应用,将刚采收的果实连同盛装容器一起浸入IMZ水溶液中,在果实运抵包装房之后采用氨气熏蒸处理。由于所有包装房中均有乙烯脱绿室,将其改为密封室后可以用于熏蒸处理。总之,氨气能够取代合成杀菌剂或提高IMZ对柑橘属果实采后腐烂的控制效果,尤其是控制对IMZ有耐药力且在柑橘包装房中广泛存在的指状青霉的能力具有很高的价值。     

喜利康 高质量的犊牛奶粉

本文阐述的是使用喜利康犊牛奶粉的优势。1 成分与犊牛的需要表1反映了喜利康与鲜奶的成分差异。如今的鲜奶成分与犊牛的需要不一致，主要原因是当今的奶牛选育注重提高日后鲜奶中的脂肪与蛋白成分，现在鲜奶中脂肪与蛋白含量远比过去的要高，也远高于犊牛的生长需要。这样不仅会造成犊牛消化系统紊乱，而且，犊牛也并不能够很快地消化全部的脂肪与蛋白，不能消化的脂肪与蛋白则被肠道病菌利用。鲜奶中的脂肪与蛋白成分含量不稳定，而喜利康是稳定不变的，并且，喜利康中的蛋白与脂肪含量是针对犊牛的需要而配制的。另外，铁在鲜奶中的含量…     

European veterinary dissertations

Summary

The purpose of this investigation was to study the incidence and course of Salmonella infections in finishing pig herds in order to asses the stability of a given Salmonella herd status. Five low‐ and 7 high‐seroprevalence herds were followed for seven sampling rounds. Each round, blood and faecal samples were tested in an indirect ELISA and by bacteriological culturing, respectively. In high‐seroprevalence herds a positive Salmonella status was an indication of a long‐term problem and the status was relatively stable over time. The herds experiencing clinical salmonellosis were not necessarily the herds with the highest seroprevalence. It is possible to deliver seronegative finishers to the slaughterhouse, even though these pigs were seropositive as growers. In three out of five low‐prevalence herds, major infection incidents occurred, indicating that changes in the Salmonella status should be anticipated. Low‐prevalence herds can remain negative over a longer period of time as a result feeding a complete liquid feed containing fermented by‐products.     

Parasitic helminths in the digestive tract of six species of owls (Strigiformes) in Spain

A survey was carried out in Catalonia, Spain to determine the prevalence of parasitic helminths infesting the digestive tract of nocturnal raptors (Strigiformes). One hundred birds belonging to six owl species were examined. The number of birds examined ranged between three and 30. The overall level of infestation was 65% and the most frequent helminths present were nematodes, followed by trematodes, cestodes and acanthocephalans. Strigiformes showing the highest levels of infestation were little owls (Athene noctua), 86.7% of which were infested. Helminths with the highest prevalence were Synhimantus spp., intestinal capillarids, Brachylaima spp., cestodes and Centrorhynchus aluconis.     

Immunohistochemical analysis of the distribution of desmoglein 1 and 2 in the skin of dogs and cats

OBJECTIVE: To compare the distribution of desmoglein (Dsg) 1 and 2 in skin specimens obtained from dogs and cats to provide information about the possible role of the density of Dsg 1 and 2 in the localization of lesions attributable to pemphigus foliaceus in these 2 species. SAMPLE POPULATION: Skin biopsy specimens obtained from 4 dogs and 4 cats. PROCEDURE: Biopsy specimens were collected from the muzzle, bridge of the nose, ear, dorsum, abdomen, area adjacent to the teats, and footpads of each animal. Immunohistochemical analysis was performed on formalin-fixed, paraffin-embedded skin samples by use of a biotinylated mouse monoclonal anti-Dsg 1 and 2 antibody raised against bovine muzzle. Color development was performed by use of the streptavidin-biotin-peroxidase method with a chromogenic substrate. RESULTS: Immunohistochemical staining yielded a positive reaction in skin samples obtained from all anatomic sites. The intensity and distribution of staining were related to the number of layers of the stratum spinosum. No differences were detected between samples obtained from dogs and cats. CONCLUSIONS AND CLINICAL RELEVANCE: No differences in intensity of Dsg 1 and 2 antigen were observed in the stratum spinosum between skin samples obtained from dogs and cats. Analysis of this result suggests that factors other than the distribution of Dsg may be responsible for the differences in localization of primary clinical lesions in dogs and cats with pemphigus foliaceus.     

Differences and similarities among experts' opinions on Salmonella enterica dynamics in swine pre-harvest

A workshop was conducted to elicit expert opinion on infection status and transmission of salmonella in pigs at the farm of origin, during transport and during lairage. A second objective was to compare opinions regarding risk factors for salmonella introduction and control at the farm level between experts from different countries. Thirty-six experts from 11 countries filled in a paper-and-pencil questionnaire during an international conference. Experts from all countries agreed on the risk of salmonella introduction related to live animals and the importance of general hygiene and all-in/all-out management for salmonella control. However, workshop participants from Denmark put more weight on factors related to feed while experts from USA rated factors related to rodents and people contact higher. The experts believed that 21-33% of pigs coming from a chronically infected farm would be infected with salmonella, but only one-third of the infected pigs would be shedders. Regarding transport and lairage, the US participants believed that contamination was occurring in the majority of pigs regardless of initial infection status and particularly during lairage; in contrast, the Danish experts were more optimistic with respect to the contamination and infection risk. US experts believed that the incidence of salmonella shedding would be high among pigs infected during transport and lairage and that an important proportion of 'carrier' pigs would start shedding.Our results reflect the differences in the level of salmonella infection and implemented control strategies between countries as well as the different philosophies that professionals have. The differences in opinion regarding salmonella dynamics could be due either to true differences in risk as a consequence of distinct management and transport practices in Denmark and USA or to a difference in perception.