EFFECT OF SELENIUM ON WOOL PRODUCTION, BODY WEIGHT AND MORTALITY OF YOUNG SHEEP IN WESTERN AUSTRALIA

The effect of regular selenium supplementation on the body weight, wool production and mortality of young Merino sheep was investigated. Groups of Se-treated and control sheep involving from 260–500 on each of 15 farms were observed from six weeks to 19 months of age. Ten mg Se as sodium hydrogen selenite was administered orally to the treated sheep at two-monthly intervals. Treated and control sheep grazed together throughout the trial period. Statistically significant responses to selenium were recorded in body weight gains on four farms, in decreased mortality on five farms and as an increase in fleece weight on eight farms. The response in fleece weight varied from 2.9-7.6% and could not be explained as a result of increased body weight. The increase in fleece weight was not due to an increase of grease in the wool but appeared to be due to an increase in fibre diameter and to a lesser extent an increase in staple length. A statistically significant decrease in the incidence of tender fleeces as a result of selenium supplementation was also recorded. All farms on which responses to selenium were obtained were in areas with average annual rainfall more than 20 inches. On two farms selenium caused statistically significant depressions in the parameters measured. Both farms were in areas with less than 20 inches average annual rainfall.     

Detection of T. gondii in tissues of sheep and cattle following oral infection.

It has been reported in the literature that cattle are more resistant to toxoplasmosis than sheep. Congenital disease due to T. gondii infection is rarely reported in cattle whereas the parasite is a major cause of abortion and neonatal mortality in sheep. It is believed that sheep remain chronically infected for life. Undercooked meat from infected sheep is an important source of infection for man. In contrast cattle are thought to harbour fewer parasite tissue cysts which may not persist for the lifetime of the host. Therefore, cattle are believed to pose less of a risk for human infection. In this study we examined the presence of T. gondii within a range of tissues in sheep and cattle at 6 weeks and 6 months following oral infection with 10(3) or 10(5) sporulated oocysts of T. gondii. The presence of parasite was determined by bioassay in mice and using polymerase chain reaction (PCR). The results from this study show that T. gondii was more frequently and consistently detected in sheep, in particular within brain and heart tissues, whereas parasites were not detected in the samples of tissues taken from cattle. T. gondii was more frequently detected in sheep given the higher dose of T. gondii. Examination of tissues at either 6 weeks or 6 months after infection did not appear to affect the distribution of T. gondii. The polymerase chain reaction has more specificity and sensitivity when detecting the presence of T. gondii in large animals than histological detection.     

Cross-sectional study of risk factors for the clinical expression of ovine Johne's disease on New South Wales farms

OBJECTIVE: To explore the environmental and management risk factors that promote the clinical expression of ovine Johne's disease on farms in New South Wales. DESIGN: Cross-sectional study. PROCEDURE: A questionnaire about the farm, flock and their management was mailed to all farmers known to keep infected sheep in the area zoned residual for ovine Johne's disease in New South Wales. The resultant data were analysed by multivariate statistical methods, specifically examining the factors associated with farmers reporting some mortality due to ovine Johne's disease; the reported annual incidence of ovine Johne's disease-associated mortality; the youngest age at which sheep die from ovine Johne's disease; whether scouring was a feature of the disease; and the season of peak mortality from ovine Johne's disease. RESULTS: Fine wool Merino sheep were more likely to die from ovine Johne's disease than other sheep types. Mortality was higher on farms with light sandy soils and those with a high proportion of improved pastures containing subterranean clover. Winter shearing was also associated with clinical expression. The time that the infection had been present on a farm was not strongly associated with mortality. Higher stocking density, high rainfall and access to open water, factors that are believed to aid transmission, were not found to be influential. CONCLUSION: Clinical expression appears to be principally associated with light infertile soils and their associated pastures and pasture improvement practices which may lead to micronutrient deficiencies or imbalances. Genetic effects are also important and are likely to be exacerbated by physiological stressors, such as winter shearing.     

Mortality of sheep exported by sea: evidence of similarity by farm group and of regional differences

OBJECTIVE: To determine whether mortality of sheep exported by sea is similar for sheep from the same farm exported in different years or is associated with the region of origin. DESIGN: Mortalities were monitored in farm groups of sheep exported from the southwest of Western Australia under normal commercial conditions. PROCEDURE: Mortalities were monitored on commercial shipments from 1985 to 1996. For each consignment, the mortality rate was assigned its percentile ranking within the month and year of loading of the ship. A mortality rate was high if its percentile ranking was above a selected cut-off value. Five cut-off values were used in separate analyses. The spatial distribution of farms with high mortality was compared between and within zones of rainfall and length of pasture-growing season. RESULTS: A total of 479 groups of sheep from 405 farms was monitored. Mortality rates ranged from nil to 28.2%. Half of all deaths were from 14.2% of the consignments. There was a significant association (P < 0.05) between the category of mortality (high or low) in the first and second years of monitoring for four of the five cut-off values. The spatial analyses indicated that there were more high-mortality groups, and the average mortality was higher, in the zones of higher rainfall and longer pasture-growing season (P < 0.001). CONCLUSION: Mortality data can be used to identify regions and groups of sheep that are at risk of suffering high death rates when exported by sea.     

Paratuberculosis in Iceland: epidemiology and control measures, past and present

Paratuberculosis as well as the slow virus infections maedi/visna and jaagsiekte came to Iceland in 1933 when 20 sheep of the Karakul breed were imported from Halle, Germany. At least five of these sheep were subclinical carriers of paratuberculosis. Within 16 years paratuberculosis together with the other Karakul diseases (maedi/visna and jaagsiekte) almost ruined sheep farming, the main agricultural industry in Iceland. The first clinical case of paratuberculosis in sheep was confirmed in 1938, and in cattle in 1944. The first cattle cases of paratuberculosis appeared on farms where the disease had been prevalent in sheep for years. The virulence in cattle appeared to be considerably lower than in sheep. Extensive measures were used to control the spread of paratuberculosis in sheep. Hundreds of kilometres of fences were put up and used together with natural geographic borders to restrict the movement of sheep from infected areas. Serological and other immunological tests were also used to detect and dispose of infected individuals. These measures proved inadequate and the disease could not be eradicated. Culling and restocking of uninfected sheep in endemic areas eradicated maedi/visna and jaagsiekte but not paratuberculosis. Experiments showed that vaccination against paratuberculosis could reduce mortality in sheep by 94%. Vaccination of sheep in endemic areas has been compulsory in Iceland since 1966 and as a result losses have been reduced considerably. Today, serology is used to detect and control infection in cattle herds. Furthermore, serology is used to control vaccination of sheep and screen for infection in non-endemic areas. The complement fixation (CF) test for paratuberculosis has been used until now, but recently we have started comparing the CF test with the CSL absorbed ELISA test.     

Relationship of body condition score, live weight, stocking rate and grazing system to the mortality of Angora goats from hypothermia and their use in the assessment of welfare risks

Body condition scoring is widely used for sheep and cattle but the practice is included in only one Code of Practice for the welfare of goats in Australia. There is no published scientific evidence to support or defend its use in the assessment of welfare risks to farmed goats. PROCEDURE: The significance of stocking rate, grazing system, body condition score (CS) and live weight were investigated in explaining the risk of mortality of individual and flocks of grazing Angora goats from hypothermia following a severe weather event in April. This event occurred 5 weeks after shearing the goats. Angora goats and Saxon Merino sheep were grazed alone, or mixed together in equal numbers at each of three stocking rates. RESULTS: There was no mortality amongst Angora goats provided they grazed at the lowest stocking rate even when their CS was < or = 2.0. Mortality in flocks of Angora goats was most related to the CS reached during the preceding 2 months. For flocks of Angora goats there was no mortality at CS > or = 2.5 and mortality increased sharply at mean CS < 2.0. For individual Angora goats, mortality increased as CS declined and stocking rate and grazing combinations were additive in effect on mortality. Grazing with sheep increased mortality of Angora goats at higher stocking rates. The individual goat mortality rate was not dependent on individual plot effects suggesting that these results are applicable widely. Live weight loss was not related to mortality rates of goats once CS had been accounted for. CONCLUSION: It was concluded that CS and stocking rate were highly significant determinants of welfare risk in Angora goats.     

Soremouth in sheep and goats at the Mankon Animal Research Station, Cameroon.

Between 1980 and 1989, a survey was carried out to appreciate the prevalence of the soremouth (orf) disease among sheep and goat flocks at the Mankon Research Station (Cameroon). The results showed that orf is enzootic at the station and is more a goat (85.5%) than a sheep disease (51%) with kids showing a higher susceptibility rate (53%) than adult goats. Orf has a high mortality (80-90%) with a negligible mortality rate (2%). Both sexes were affected while more incidences of orf were recorded during the dry season than in the rainy season.     

Enteritis in sheep and goats due to Yersinia enterocolitica infection

Yersinia enterocolitica biotype 5, serotype 02,3 was isolated from the intestine of 38 sheep and 8 goats submitted to the laboratory for disease diagnosis. Infected animals were usually young, had diarrhoea and were in poor condition or emaciated. A number were moribund or dead when submitted. Characteristic microabscesses were demonstrated in the intestine of 5 of 38 sheep and 3 of 8 goats and no alternative cause of morbidity or mortality was established in these animals. Of the 33 sheep and 5 goats infected with Y. enterocolitica in which microabscesses were not demonstrated, a number of other diagnoses were made, including internal parasitism (18), selenium deficiency or white muscle disease (6) and cobalt deficiency (2), so that morbidity and mortality were possibly unrelated to Y. enterocolitica infection. Five of 6 sheep exposed experimentally by mouth to Y. enterocolitica biotype 5, serotype 02,3 developed an intestinal infection. Although infected sheep showed no clinical evidence of disease and haematological and biochemical indices remained normal, multiple intestinal microabscesses typical of yersiniosis were demonstrated in 3 of 5 infected sheep. It is concluded that Y. enterocolitica biotype 5, serotype 02,3 is an enteropathogen of sheep and goats. Since sheep and goats may be the specific hosts of this bacterium, its virulence for these species is apparently low. Morbidity and mortality may, therefore, be unusual manifestations of infection.     

一起绵羊痘的诊治

2007年3月,固原地区某养羊户饲养的绵羊发生羊痘疫情,发病率22.8%,病死率17.8%.发病初期被饲养户误诊为湿疹,曾用醋酸铅液和氧化锌软膏对患处涂抹,对病重的羊用抗生素进行治疗,效果不明显.笔者对此次疫病进行了流行病学调查、临床症状和病理变化观察、实验室诊断.根据羊体皮肤、黏膜上发生的典型痘疹和实验室诊断结果确诊为绵羊痘.采用对症治疗和羊痘弱毒疫苗接种,使病情迅速得到了控制.     

Field observations during the Bluetongue serotype 8 epidemic in 2006. II. Morbidity and mortality rate, case fatality and clinical recovery in sheep and cattle in the Netherlands

Data collected in the Netherlands during the Bluetongue serotype 8 (BTV-8) epidemic indicated that in outbreak cattle herds, predominantly dairy and nursing cows were clinically affected and not young stock, beef cattle, beef calves, or breeding animals. In outbreak sheep flocks, mainly ewes and - if present - rams, were clinically affected and not the lambs. Median morbidity rate in outbreak herds was 1.85 per 100 sheep-month at risk and 0.32 per 100 cattle-month at risk for sheep and cattle, respectively. The mean proportion of BT-affected animals in outbreak herds that recovered from clinical disease was approximately eight times higher for cattle compared to sheep in the Netherlands. Median mortality rate in outbreak herds was 0.5 per 100 sheep-month at risk of dying and 0 per 100 cattle-month at risk of dying for sheep and cattle, respectively. Median recovery time of both sheep and cattle that recovered from clinical disease in outbreak herds was 14 days. Median case fatality was 50% in sheep outbreak flocks and 0% in outbreak cattle herds. It is concluded that morbidity and mortality in outbreak cattle herds was very limited during the BTV-8 epidemic in the Netherlands in 2006. In outbreak sheep flocks, morbidity was limited, with exceptions for a few flocks. However, almost 50% of the clinically sick sheep died in outbreak sheep herds.     

Sheep pox disease outbreaks in Madras Red and Mechery breeds of indigenous sheep in Tamilnadu, India

Sheep pox disease outbreaks were recorded among Madras Red (n=145) and Mechery (n=80) breeds of indigenous sheep on three farms in Tamilnadu. Over both breeds, adult mortality rate ranged from 2.66% to 37.5% and lamb mortality ranged from 10% to 17.33%. However, mortality was more in Mechery sheep (50% overall; 37.5% adults, 12.5% lambs) than in Madras Red sheep (24.28% overall; 10.34% adults, 13.79% lambs). The clinical signs observed were high fever, anorexia, respiratory distress, mucopurulent nasal discharge and in a few cases diarrhoea. Cutaneous lesions were mainly observed around nostrils, eyes, lips, ears and in the abdomen. Most of the lesions were covered with purulent materials and on cleaning with sterile swabs, fresh wounds were observed. Dry scabs were also observed over the oral commissure and maxillary areas, which on removal exposed fresh wounds. Important observations on necropsy were severe nodular lesions in the lungs and intestine. The disease was diagnosed as sheep pox by agar gel immunodiffusion test, isolation of virus and its neutralization in BHK(21) cells by specific antiserum and by electron microscopy.     

绵羊痘的诊断

绵羊痘是由绵羊痘病毒引起绵羊的疾病,其特征为发热、全身皮肤痘疹,内脏(特别是肺脏)黏膜结节,是危害养羊业最为严重的传染病之一。该病经常引起绵羊的大批感染或死亡,病死率可达50%以上,羔羊可达100%,不仅给养羊业带来巨大的经济损失,还严重阻碍了养羊业的发展。文章针对2011年1月份新疆某地区部分养羊户饲养的卡拉库尔羊发生的羊痘疫情进行了流行病学调查、临床症状、病理变化观察和实验室诊断,结果确诊为绵羊痘。     

鄂尔多斯细毛羊冬春季保育接羔技术体系研究

介绍了鄂尔多斯细毛羊妊娠母羊的饲养管理技术、接羔保育技术和羔羊的断奶技术。通过上述各项技术措施的应用和实施,不但提高了羔羊的日增重,又大大降低了羔羊的死亡率和鄂尔多斯细毛羊的不合格率,同时也提高了鄂尔多斯细毛羊母羊的繁殖率,既保证了鄂尔多斯细毛羊产业的生产水平和鄂尔多斯细毛羊的繁育,又使鄂尔多斯细毛羊的生长繁殖能完整准确地体现出遗传基因的表型性状,以便于选育提高,为做大做强鄂尔多斯细毛羊产业奠定了坚实的基础。     

Perinatal lamb mortality in the central sierra of Peru

Perinatal lamb mortality is one of the major factors in impairment of productivity on sheep raising enterprises around the world. In this study, perinatal mortality on one of the largest sheep raising enterprises in Peru was measured over a 10-year period. Between 1971 and 1980, a total of 603 694 lamb births was recorded. Mortality during the first 3 days of life was 36.94/1000 births and for the period from 4 to 30 days mortality was 5.87/1000.

Non-infectious conditions predominated as causes of mortality. The weak lamb syndrome, accidents, injuries and starvation were the leading causes of mortality. Diseases of infectious etiology were second in importance, but may have been under-reported. Variation in mortality between years, did not appear to affect the patterns of mortality by cause.

Approximately 86% of mortality occurred in the first 3 days of life. During this period, nutritional, environmental and management factors resulting in weak lambs and starvation accounted for approximately a third of total mortality. Infections (22%), accidents (22%), and stillbirths (16%) followed in order of importance. During the remainder of the first month of life, deaths from infections predominated, accounting for 60% of mortality from 4 to 30 days.     

羊消化道寄生虫种类及防治措施

羊消化道的寄生虫病较多,不仅能不同程度地影响羊只的生长发育,降低生产性能,严重的还能造成羊只死亡,对养羊业危害较为严重。笔者概述了羊消化道寄生虫种类及不同地区、季节、年龄羊消化道寄生虫的感染情况,并介绍不同羊消化道寄生虫常用的驱虫药及防治策略。     

COBALT PELLETS AND HELZOTROPIUM EUROPAEUM POISONING IN PENNED SHEEP

Twenty-five sheep in single pens were fed for up to 16 months a ration containing up to 40% (air dry weight basis) of Heliotropium europaeum. Thirteen of these sheep had two cobalt pellets administered into their rumen before commencement of feeding. The other twelve sheep constituted the control group and were not treated in any way. The sheep in both groups developed the characteristic live pathology of chronic pyrrolizidine alkaloidosis to varying degrees. The median chronic lethal oral dose of Heliotropium europaeum alkaloids for sheep was found to be 23–33 g/kg body weight, expressed as heliotrine equivalent. This is 15–20 times the established mean total lethal parenteral dose of heliotrine when chronically administered to rats. Prior administration of cobalt pellets did not reduce morbidity or mortality rate. Thus it is concluded that cobalt pellets are unlikely to be an effective prophylactic agent for sheep exposed to H. europaeum grazing. This finding is discussed in relation to present knowledge of pyrrolizidine alkaloid metabolism in the rumen.     

Goat smallpox in Chad: study of the pathogeny of the virus in sheep and goats]

A local strain of goat pox virus was tested in goats and sheep. The results showed that 65% of goats and 20% of sheep reacted positively. Only goats died few days after the inoculation (55%) and no mortality was recorded in the sheep. The strict species specificity of this strain was not observed. The difference of sensitivity between sheep and goats was statistically significant.     

The efficacy of acetamide for the treatment of experimental Dichapetalum cymosum (gifblaar) poisoning in sheep

High mortality of livestock is caused annually by the plant, Dichapetalum cymosum (gifblaar), in the Northern Transvaal. So far no therapeutic measures have been developed for the prevention or treatment of this poisoning. In this presentation, the efficacy of acetamide as therapy for experimental gifblaar poisoning was tested in 18 sheep. When 2.5-5 g/kg of acetamide was dosed to sheep at various intervals before and sometimes after the administration of 5 g/kg of gifblaar, 1 out of 5 survived, compared with 0 out of 2 controls. Dosing of 2 g/kg of acetamide before and/or simultaneously with or after 1 g/kg gifblaar prevented mortality as 5 out of 5 treated sheep survived compared with none of the 5 controls. The experiments indicate that acetamide has demonstrable therapeutic value as an antidote for the prevention of experimental gifblaar poisoning in sheep. Further investigations should determine the feasibility and applicability of these findings under field conditions in sheep and cattle.     

Some aspects of tick-borne diseases of British sheep

The significance of tick-borne fever (TBF) and other tick-borne diseases of British sheep are reviewed. Experimental and field studies were carried out to clarify the role of TBF as a pathogen per se and as a predisposing factor in other diseases. Experimental TBF infection caused anorexia and depression in two- to three-week-old lambs, which under the stress of a hill environment could alone be a cause of mortality. Nine out of 10 lambs experimentally inoculated with Staphylococcus aureus during the febrile phase of a TBF reaction developed pyaemic lesions compared with four out of 20 lambs inoculated with S aureus alone. Specific pathogen-free lambs inoculated with an aerosol of Pasteurella haemolytica serotype A1 during a TBF reaction showed more severe clinical signs and had more extensive pathological changes at necropsy than control lambs given P haemolytica alone. Dual infection with TBF and louping-ill virus showed that not only were dually infected sheep more susceptible to louping-ill but almost all of them succumbed to a haemorrhagic syndrome involving a systemic mycotic infection with Rhizomucor pucillus. None of eight sheep given louping-ill virus alone developed this syndrome. Field studies indicated that morbidity and mortality in lambs in south-west Scotland could be markedly reduced by dipping and long acting antibiotic prophylaxis. Lamb groups in which both of these were carried out incurred losses of only 0.6 per cent compared with 10.3 per cent in control groups. In addition antibiotic-treated lamb groups demonstrated significantly better weight gains than untreated groups.(ABSTRACT TRUNCATED AT 250 WORDS)