Adenovirus infection in lambs. II. Experimental infection of lambs.

Adenovirus strain GY/14 isolated during a natural outbreak was used in experimental infection. Three weeks old lambs responded with temperature rise, respiratory symptoms and diarrhoea to the infection. Infection spread to a contact animal, too. Reisolation of the virus was successful from the nasal discharge and feces from the 3rd to 10th, and the 3rd to 5th day following infection, respectively. In the killed experimental animals the pathological and histological changes observed were similar to those observed in natural cases. On comparing the natural outbreaks with the experimental infection the only difference appeared in the severity of the changes. Following the experimental infection characteristic nuclear inclusions appeared in the nasal and bronchiolar epithelium, in the alveolar septal cells and in the reticular cells of the lymph nodes. Epizootiologic observations and experimental results confirm the assumption that our adenovirus strains isolated from natural cases are pathogenic for lambs.     

Prevalence of Sarcocystis spp. in water buffaloes in Vietnam.

Muscles from heart, tongue, oesophagus, neck and abdomen from 502 adult water buffaloes (Bubalus bubalis) slaughtered in Ho Chi Minh City, Vietnam, between 1996 and 1997 were examined for Sarcocystis cysts by a combination of ocular and histological examination. Sarcocysts were present in 396 (79%) of the animals and the prevalence increased with age from a 57% infection rate among 2-3 year old animals to 93% among 6-7 year olds. The prevalence was higher in animals originating from the northern part (89%) than in those from the southern part (69%) of the country. Four species of Sarcocystis were identified. S. levinei (74%) was the most common species found, followed by S. fusiformis (41%), S. buffalonis (33%) and S. dubeyi (12%). All four species were present in 8% of the infected animals. The most common site for sarcocyst location was oesophagus, followed by cervical muscles, tongue and heart.     

Prevalence of Sarcocystis spp. in meat-producing animals in Iraq.

The prevalence of Sarcocystis spp. infection was investigated in 605 sheep, 826 goats, 1080 cattle, 580 water buffaloes and 36 camels slaughtered from 1992 to 1996 in the Baghdad area (Iraq) using naked eye examination for macroscopic sarcocysts, and peptic digestion, muscle squash, squeezing methods and indirect fluorescent antibody test (IFAT) for microscopic types. The intestinal stages of the parasite were also studied in dogs experimentally fed with tissues containing microscopic cysts. The percentage prevalence of macroscopic cysts were 4.1, 33.6, 0.2, 15.6 and 0, and of the microscopic type, 97.0, 97.4, 97.8, 82.9 and 91.6 for the above-mentioned hosts, respectively. Among the different organs examined, macroscopic cysts were found to be highest in the oesophagus and the lowest in the heart. Peptic digestion method gave the highest rate (93.3%) followed by indirect fluorescent antibody test (IFAT) (88.6%), squeezing (81.3%), and muscle squash (81.2%). Each infected dog shed a total of about 150-200 million sporocysts. Histologically, developmental stages of the parasite were detected in the small intestinal mucosa of the dogs on Days 7 and 13 post-infection.     

Strongyle infections in ponies. II. Reinfection of treated animals.

Five of seven ponies whose strongyle worm burdens had previously been removed or markedly reduced by repeated thiabendazole treatments were reinfected with doses ranging from 100,000 to 500,000 small strongyle infective larvae. Reinfection of ponies resulted in the development of clinical signs characterized by abnormal feces, marked loss of weight and delayed shedding of winter hair coats. An abrupt increase in circulating eosinophils occurred during the first three weeks following reinfection. Patent infections developed in all ponies with worm eggs appearing in the feces from 12 to 15 weeks after receiving infective larvae. Worm egg outputs followed a cyclic pattern with approximately four to five peaks in egg output per year. There was an abrupt drop in the high worm egg counts in two untreated ponies approximately two and a half years after reinfection. No worms were recovered in the feces of these animals when they were subsequently treated, suggesting that a depletion in the number of inhibited larvae present in these ponies might have occurred.     

The current position of A.I. in horse breeding.

This short review article describes the various techniques currently available for artificial insemination in the horse. The collection and use of raw and extended semen is discussed together with the more recent developments in freezing semen. The expected conception rates with both fresh and frozen semen are quoted. The possible benefits in disease control and stud management are discussed, as well as the difficulties in controlling the use of A.I. from the Breed Registration Authorities point of view.     

太湖地区蚕桑生产发展分析

本文分析了太湖地区蚕桑生产布局和现状布局格局,供因地制宜制定发展对策参考。文章对本地区蚕桑生产的进一步发展进行了可行性分析,认为本地区蚕桑生产的进一步发展,不仅有可能,也有必要。实现进一步发展目标的宏观对策是:调整蚕桑生产布局,加强技术开发和应用,改革蚕茧经营管理体制。     

美国肉牛饲料添加剂科学使用概述

饲料添加剂是肉牛日粮的重要组成部分,不同种类的添加剂作用效果不同,且添加剂的使用剂量尤为重要。综述了美国肉牛饲料添加剂的使用剂量和用途,旨在通过了解美国肉牛饲料添加剂的使用情况,为我国肉牛养殖领域中饲料添加剂的科学、合理选择和使用提供参考。     

The involvement of polymorphonuclear leukocytes in the pathogenesis of bronchopneumonia in calves. IV. Myeloperoxidase activity.

Stable oxidant and hypochlorous acid production in neutrophils of bronchopneumonic calves was investigated. The production of these compounds was much more intense in neutrophils of diseased calves than in the control cells. The production of stable oxidants and hypochlorous acid was restrained by free radical scavengers. Functional response of neutrophils was inhibited by cyclooxygenase products and stimulated by lipoxygenase products of the arachidonic acid cascade. Superoxide anion production is not connected with the degranulation process (beta-glucuronidase release), and the two events are under different control mechanisms.