Measurement of caprine plasma beta-mannosidase with a p-nitrophenyl substrate

Experimental conditions for measuring caprine plasma beta-D-mannosidase activity are described with p-nitrophenyl-beta-D-mannopyranoside as a substrate. The plasma enzyme was stable for 3 months at -20 C or 1 week at 4 C. The optimal pH for activity was 5.0 in citrate-phosphate or acetate buffer. Enzyme activity was linear with time up to 24 hours at 37 C, but incubation of plasma at 56 C for 5 minutes resulted in loss of all activity. The apparent Michaelis-Menten constant (Km) for the plasma enzyme was 10.0 mM. Plasma beta-mannosidase from clinically normal and beta-mannosidosis carrier goats did not differ with respect to pH optimum, heat stability, or Km. The coefficient of variation for the assay, determined by assaying a plasma pool over a 3-month period, was 10.7% (mean: 115 nmole of p-nitrophenol formed/hour/ml of plasma). The assay described can be used to evaluate plasma beta-mannosidase measurements as a test for detecting carriers of caprine beta-mannosidosis, a newly described lysosomal storage disease.     

Bovine plasma beta-mannosidase activity and its potential use for beta-mannosidosis carrier detection.

Plasma beta-mannosidase activities were determined for Salers cattle from 8 herds as an evaluation of this method for detection of beta-mannosidosis heterozygotes. Several biological factors, such as age, gender, herd, and risk of being a beta-mannosidosis carrier, were considered in this study. The mean enzyme activity for obligate heterozygotes (n = 8) was 55 U/ml (range = 43-65 U/ml), which was 59% of the mean enzyme activity for cattle that were low risk for being a carrier. These data indicate that bovine beta-mannosidosis is characterized by a gene dosage effect. The analytical and biological variation of plasma beta-mannosidase activity that was observed necessitates limiting the test to adult fullblood/purebred Salers cattle within a herd. Plasma beta-mannosidase analysis provides important information for intraherd selection of Salers cattle that are heterozygous for beta-mannosidosis.     

Otic pathology of caprine beta-mannosidosis

Caprine beta-mannosidosis is an autosomal recessive defect of glycoprotein catabolism with a deficiency of tissue and plasma beta-mannosidase activity and tissue accumulation of oligosaccharides within lysosomes. This rapidly fatal genetic disorder of Nubian goats is expressed at birth by a variety of clinical signs including deafness. Affected goats had folded pinnas, and the tympanic cavity was decreased due to multiple, polypoid projections of bone covered by middle ear mucosa which obstructed the view of the cochlear promontory. Numerous cells of the cochlear duct including mesothelial and epithelial cells of Reissner's membrane, mesothelial cells lining the scala tympani, cells of the stria vascularis, numerous supportive cells of the organ of Corti, cochlear hair cells, endothelial cells, perithelial cells, fibroblasts, macrophages, and neurons of the spiral ganglion contained numerous nonstaining intracytoplasmic vacuoles which resulted in distention of affected cells and caused thickening of involved structures. Ultrastructurally, the vacuoles were membrane-bound and consistent with lysosomes. Vacuolated cells were desquamated into the scala vestibuli and scala tympani. This is one of few reports describing light and electron microscopic otic alterations of a storage disease. Goats with beta-mannosidosis appear to be good models of hearing loss in patients with storage disease.     

Caprine beta-mannosidosis: phenotypic features

The clinical features of caprine beta-mannosidosis were evaluated in 10 newborn goats, one stillborn goat and one goat fetus. The phenotypic abnormalities observed in all 10 live affected animals included an inability to rise from a recumbent position, moderate to marked intention tremor, eye movements resembling pendular nystagmus, clinical deafness, bilateral Horner's syndrome, carpal contractures, pastern joint hyperextension, thickened skin and to a varying degree, a dome-shaped skull. Subjective evaluation suggested that most animals had a decreased muscle mass. Together, these characteristics represent a common phenotype which is expressed at birth in caprine beta-mannosidosis.     

Prevalence, spread and control of caprine arthritis-encephalitis virus in dairy goat herds in New South Wales

SUMMARY A study of the prevalence, spread and control of caprine arthritis-encephalitis virus (CAEV) in dairy goat herds in New South Wales (NSW) during 1986–1988 found that 56.8% of 1484 goats in 14 dairy herds were infected with CAEV. The prevalence of CAEV infection within most herds not implementing control measures increased during the study. At the end of the study, 59.7% of 1322 goats were infected. The prevalence of CAEV increased with age. Differences between breeds were less apparent. Within seven herds with a high standard of identification of goats, 149 of 812 goats seroconverted in an ELISA. Of these newly infected goats, 142 (95.3%) were > 1 yr of age and 96 (64.4%) were > 2 yr suggesting lateral spread of the virus. Most of the goats > 2 yr of age had been in the milking herd for a minimum of 3 to 6 months. The high seroconversion rate within the milking herd suggested that factors other than the ingestion of infected colostrum and milk before weaning were important for the spread of CAEV. Observations indicated that behaviour of goats, particularly reproductive behaviour among lactating does, and milking herd management practices are important in the spread of CAEV. A high density of livestock, poor livestock control and contamination of feed, water, equipment and personnel were implicated in transmission. Poorly functioning milking machines may also be involved. CAEV was eradicated from 3 herds by the implementation of strict control measures.     

Serologic and reproductive findings after a herpesvirus-1 abortion storm in goats

CASE DESCRIPTION: An abortion storm occurred in a goat herd, resulting in 75 aborted kids and 1 neonatal death from December 2004 to February 2005. CLINICAL FINDINGS: Aborted fetuses ranged from being premature to past term. Laboratory findings in 4 of 5 aborted fetuses were consistent with herpesvirus abortion. A virus that yielded positive results with a fluorescent antibody test for bovine herpesvirus-1 was isolated and identified as caprine herpesvirus-1 (CpHV-1) via DNA sequence analysis. TREATMENT AND OUTCOME: Many does that aborted were rebred for kidding in late summer. Most of the young wethers born in 2005 were sold; however, all of the young does were kept for breeding in fall. In November 2005, all 241 goats in the herd were tested for antibodies against CpHV-1 to identify goats that had seroconverted during the outbreak. No complications attributable to CpHV-1 were identified during kidding in 2006. CLINICAL RELEVANCE: On the basis of serologic findings, infection with CpHV-1 was not associated with reduced reproductive success in the subsequent breeding.     

Goats may experience reproductive failures and shed Coxiella burnetii at two successive parturitions after a Q fever infection

Q fever is a zoonosis caused by the obligate intracellular bacterium, Coxiella burnetii. Aborting domestic ruminants are the main source of human infection. In January 2003, an abortion episode occurred in a dairy caprine herd where 18/60 (30%) goats experienced reproductive problems: 4/60 (7%) aborted and 14/60 (23%) had stillbirths. Serological screening for abortion-related infectious diseases suggested Q fever. The diagnosis of C. burnetii infection was confirmed with PCR based on the occurrence of C. burnetii shedding into vaginal mucus, faeces and colostrums taken after kidding from the affected animals. The pregnancy following this episode resulted in one abortion and four stillbirths; three of those goats had already experienced reproductive failure during the previous kidding season. The seroprevalence of C. burnetii infection and the bacteria shedding were investigated using both ELISA and PCR assays, respectively, during the course of the initial and subsequent kidding seasons. Serological testing, performed on the whole herd 6 weeks after the abortion episode, showed 48/60 (80%) of ELISA positive goats. PCR assay performed on both vaginal swab and milk samples showed that the bacterium was shed for almost four months after the outbreak. C. burnetii DNA was also amplified from vaginal swab and milk samples taken from goats after the second kidding season. Furthermore, the bacteria were found into 14 vaginal swabs and 12 milk samples taken from infected females at both kidding seasons.     

Enzootic ataxia and caprine arthritis/encephalitis virus infection in a New England goat herd [corrected

Ataxia was diagnosed in kids from a New England goat herd. Concurrent infection with the caprine arthritis/encephalitis (CAE) virus contributed to the development of hind limb ataxia and weakness in one of the kids. Six kids from this herd had signs of hind limb ataxia and paralysis. Detailed evaluation of 2 of the affected kids revealed low liver and serum copper concentrations and spinal cord demyelination. One kid also had histologic changes in the CNS and lungs, compatible with a diagnosis of CAE. Serum copper concentration was determined in affected goat kids and their dams and was compared with serum copper concentration in clinically normal kids and their dams from the same herd. Serum copper concentration also was measured in dams and kids in a control herd that had no history of ataxia. The mean serum copper concentration in affected kids was 0.125 microgram/ml, compared with 0.45 microgram/ml in unaffected kid herdmates. Kids from the control herd had mean serum copper concentration of 0.6 microgram/ml. Mean serum copper concentration in dams of kids with neurologic signs also was low (0.25 microgram/ml), compared with that (0.5 microgram/ml) in dams of clinically normal kids of the affected herd and that (0.95 microgram/ml) in dams of kids of the control herd. Results of a serologic survey (by use of agar gel immunodiffusion) of the affected herd for CAE indicated that 69.5% of the goats were seropositive. Dietary copper intake was determined to be adequate in this goat herd; therefore, copper deficiency appeared to be conditioned by an interfering substance. However, a search for interfering substances was unrewarding.     

An outbreak of vulvovaginitis in goats caused by a caprine herpesvirus

A caprine herpesvirus related to infectious bovine rhinotracheitis virus but immunologically distinct from that virus was isolated from an outbreak of vulvovaginitis in a herd of Saanen goats. The morbidity rate was 52.5%, with 21 of 40 does showing clinical signs. The lesions healed rapidly with only two goats showing lesions two weeks after the disease was first detected. No effect on subsequent reproductive performance was observed. The mode of transmission of the virus was believed to be venereal.     

An outbreak of vulvovaginitis in goats caused by a caprine herpesvirus

A caprine herpesvirus related to infectious bovine rhinotracheitis virus but immunologically distinct from that virus was isolated from an outbreak of vulvovaginitis in a herd of Saanen goats. The morbidity rate was 52.5%, with 21 of 40 does showing clinical signs. The lesions healed rapidly with only two goats showing lesions two weeks after the disease was first detected. No effect on subsequent reproductive performance was observed. The mode of transmission of the virus was believed to be venereal.     

Copper toxicosis in a dairy goat herd

CASE DESCRIPTION: A closed herd of 400 mixed-breed dairy goats was examined because of a decrease in milk production and increase in mortality rate. Nine animals had died within a 1-month period. CLINICAL FINDINGS: Clinical signs were evident only in lactating goats and included anorexia and recumbency. In the most severely affected goats, signs progressed to neurologic abnormalities and death. Serum aspartate aminotransferase activity, gamma-glutamyltransferase activity, and total bilirubin concentration were high in clinically affected does, but no evidence of hemolysis was found. A diagnosis of copper toxicosis was made on the basis of high liver and kidney copper concentrations and histologic evidence of hepatic necrosis. Goats were found to have been fed a mineral mix containing 3,050 ppm copper for 9 months prior to the onset of copper toxicosis. Overall, there was no consistent relationship between serum hepatic enzyme activities, serum copper concentration, and liver copper concentration. TREATMENT AND OUTCOME: Clinically affected goats were treated with penicillamine, ammonium molybdate, sodium thiosulfate, and vitamin E. Penicillamine increased urine copper excretion in treated does versus untreated control animals. An increased incidence of infectious disease was identified in the herd 9 months later. Liver vitamin E concentration was low in 10 of the 12 goats that underwent necropsy. CLINICAL RELEVANCE: Findings suggested that penicillamine may be an effective treatment for goats with copper toxicosis. Production losses months after the diagnosis was made suggested that the intoxication had a prolonged animal welfare and economic impacts.     

Serological evidence of lack of contact with caprine herpesvirus type 1 and bluetongue virus in goat population in Poland

Investigation into herd-level seroprevalence of caprine herpesvirus type 1 (CpHV-1) and bluetongue virus (BTV) was conducted in 2007 in Poland. It involved the entire population of goats covered by a milk recording program in 2007, which included 49 goat herds. The number of goats examined in each herd was determined statistically in order to detect the presence of at least one seropositive animal in a herd with a 95% probability and simple random method of sampling was applied. No antibodies to CpHV-1 or BTV were detected. Further calculations were carried out to determine the herd-level true seroprevalence, taking into account sensitivity and specificity of the test as well as several other factors. It can be concluded that till the middle of 2007 population of Polish goats covered by the milk recording program remained negative with respect to CpHV-1 and BTV.     

Reproductive failure in goats in Norway: an investigation in 24 herds.

Twenty-four flocks comprising 2370 breeding goats were examined. Three hundred-and-sixty-nine (15.6%) of the goats either aborted or delivered dead kids at full term, or were barren. In 23 of the herds the rate of reproductive loss ranged from 2% to 36%, whereas in one herd all of 54 mated goats had live kids. A loss of greater than or equal to 20% was found in 9 herds comprising 799 goats. In 11 herds comprising 946 goats the rate of reproductive failure was less than or equal to 10%. The incidence of reproductive failure was higher in older goats than in those in their first or second pregnancy. The causes were identified in only about 3% of the goats that aborted. It is concluded that reproductive failure in many flocks probably is associated with non-infectious causes such as nutritional and environmental factors.     

Prevalence of anti-Yersinia outer protein antibodies in goats in lower saxony

Little is known about the prevalence of caprine yersiniosis in Germany. Only few cases are reported every year. The intention of the survey was to provide representative data on the seroprevalence of anti-Yersinia antibodies in goats in the German state of Lower Saxony. A commercially available Western blot kit was used to identify caprine and ovine anti-Yersinia antibodies against five proteins [YopM, H, D, E and V-antigen (V-Ag)]. Of the 681 investigated goat sera, 449 (66%) had anti-Yop/V-Ag antibodies. Only two of 28 animal holdings housed sero-negative goats. Boxplot analysis showed that the number of non-reactive animals is correlated to the size of a herd and the fact of milk production, respectively. A tendency was observed that various management factors may influence the anti-Yersinia antibody status. No statement was possible on the impact of keeping additional carrier animals such as pigs, cows or sheep on a farm or the type of husbandry on the seroprevalence of anti-Yersinia antibodies. This study provides trend-setting data for yersiniosis in goat-holdings. The impact on consumer health, i.e. especially for risk groups-like people allergic to cow milk and the impact on the profit of a farm will have to be elucidated in further studies.     

Leptospirosis in sheep and goats under tropical conditions

Inadequate management practices and poor reproductive performance have been reported as fundamental factors on reducing the levels of productivity in livestock. Different pathogens have been reported in small ruminants' herds/flocks with reproductive failures. The aim of the present study was to review aspects of leptospirosis in small ruminants, mainly its impact on reproduction and consequently on productivity of the herds/flocks under tropical conditions. Leptospiral infection in goats and sheep is common in several countries, and those species can also act as carriers of leptospires. Severe disease is often associated to young animals and is frequently associated to incidental serovars. In contrast, subclinical infection is mainly characterized by reproductive problems, such as infertility, abortion, occurrence of stillbirths, and weak lambs/goat kids. Moreover, laboratorial tests are essential to achieve an accurate diagnosis of the infection. Microscopic agglutination test is the most common indirect test of leptospirosis, being used worldwide. In small ruminants, PCR consists on a recommendable method for diagnosing animals that carry leptospires. Control of leptospirosis in small ruminants involves measures such as the identification and treatment of the carriers and other sources of infection, quarantine in acquired animals, and systematic immunization with commercial vaccines containing the circulating serovars in the herd/flock. Productivity of small ruminant breeding can dramatically increase with adequate sanitary conditions and control of leptospirosis. Immunization of all the animals combined to the treatment of carriers may successfully control the infection and importantly reduce the economic reproductive hazards that are observed under tropical conditions.     

Influence of chronic caprine arthritis-encephalitis virus infection on the population of peripheral blood leukocytes

The influence of caprine arthritis-encephalitis (CAE) virus infection on the population of peripheral blood leukocytes in goats was evaluated. For this purpose two groups of adult dairy female goats were formed. The experimental group consisted of 17 goats, which had been naturally infected for many years. The control group comprised 29 non-infected goats, which originated from CAE-free herd. All goats were clinically healthy. Whole blood was collected and tested in hematological analyzer and light microscope to assess the total number of leukocytes and the percentage of four leukocyte populations--neutrophils, eosinophils, monocytes and lymphocytes. Then, flow cytometry with monoclonal antibodies against several surface antigens (namely CD14, CD2, B-B2, CD4, CD8h, TCR-N6, WC1-N2 and WC1-N3) was performed to assess the proportion of lymphocyte subpopulations. Statistically significant differences (alpha < or = 0.01) were observed only in the subpopulations of T lymphocytes--percentage of all subpopulations were significantly higher in the group of seropositive goats. No statistically significant differences were revealed with respect to the total number of blood leukocytes, the average percentage of blood leukocyte populations and proportions of both T and B lymphocytes.     

Beta-mannosidosis in twelve Salers calves

A diagnosis of beta-mannosidosis, a lysosomal storage disease caused by a deficiency of beta-mannosidase, was made in 12 purebred Salers calves. Affected neonatal calves were unable to rise and had intention tremors, hidebound skin, slightly domed calvaria, slight prognathism, and narrow palpebral fissures. Postmortem findings included variable dilatation of the lateral cerebral ventricles, marked pallor and paucity of white matter of the cerebrum and cerebellum, and mild to marked bilateral renomegaly. Microscopic lesions consisted of clear, intracytoplasmic vacuoles, which were especially prominent in neurons, thyroid follicular cells, proximal renal tubular epithelium, and reticuloendothelial cells. By ultrastructural examination, the intracytoplasmic vacuoles were identified as membrane-bound lysosomes distended by lucent material. The serum of affected calves was profoundly deficient in beta-mannosidase. Oligosaccharides, principally a trisaccharide with a terminal hexose in the beta-anomeric configuration, accumulated in tissues of affected calves. The percentage (37.2) of affected calves from groups of siblings, the approximately equal sex ratio, and the phenotypic normalcy of the parents of affected calves are compatible with an autosomal recessive mode of inheritance typical of other glycoproteinoses.     

Active immunization against leptin fails to affect reproduction and exerts only marginal effects on glucose metabolism in young female goats

Approximately 150 days before expected breeding time, 12 female goats (3 months of age) were actively immunized against ovine leptin. Booster injections were given throughout the following year. Control animals (n = 6) were sham-immunized. After the first observed oestrus, a buck was introduced and goats were mated. Blood samples were collected twice weekly and frequent blood sampling series were performed on days -15, 76, 153 and 286 relative to the first immunization. Nine of the immunized goats developed titres within 3 months and had elevated serum concentrations of leptin compared with controls (p < 0.0001). Hematological parameters and blood chemistry were not affected by the immunization. No differences were detectable in all reproductive parameters recorded. Serum insulin was higher in immunized goats during the frequent blood sampling series of day 287 after the first immunization. Glucose metabolism was investigated during pregnancy using hyperglycaemic and euglycaemic/hyperinsulinaemic clamps. None of the parameters derived from the clamp studies was different (p > 0.05) between the two groups. During the hyperglycaemic clamp there was a trend (p < 0.15) towards increased insulin concentrations in immunized animals whereas glucose infusion rates were not different between the groups. This indicates decreased insulin sensitivity in immunized goats. Our study describes the ontogenesis of serum concentrations of leptin during growth, puberty and first pregnancy and parturition for the caprine species. The effects of the immunization were not detectable or only marginal and the approach aimed at therefore not effective to investigate leptin action in detail.     

Administration of hCG 5 days after Breeding and Reproductive Performance in Nulliparous Dairy Goats

The objective of this study was to investigate the effect of hCG administration 5 days after breeding on plasma progesterone (P4) concentration and reproductive performance of oestrous-induced nulliparous dairy goats. A total of 59 nulliparous goats (36 Alpine and 23 Saanen) received intravaginal sponges with 60 mg medroxyprogesterone acetate for 9 days plus 200 IU equine chorionic gonadotrophin (eCG) and 22.5 microg d-cloprostenol 24 h before sponge removal. After detection of oestrus (day of oestrus = day 0) and breeding, 49 females were randomly assigned, according to the breed, into two treatments (T1 and T2). In T1 (n = 25) and T2 (n = 24), animals received intramuscular injection of 1 ml of saline solution (control) or 250 IU hCG, respectively, 5 days after breeding. Plasma P4 concentration (ng/ml) was determined from blood sampled on days 0, 5, 7, 13, 17, 21, 28 and 45 after breeding. Animals were scanned by transrectal ultrasound (5 MHz probe) on days 35 and 70 after breeding for detection of pregnancy. Plasma P4 concentration did not differ (p > 0.05) between treatments in all days, but it was increased (p < 0.05) in Saanen than in Alpine goats from days 13 to 45. Pregnancy and parturition rates, litter size and gestation period were similar (p > 0.05) to treatments and breeds. Results of this study indicate that human chorionic gonadotrophin (hCG) administration 5 days after breeding did not significantly alter reproductive performance in dairy nulliparous goats and that plasma P4 differed between Saanen and Alpine goats.     

Paratuberculosis: eradication, control and diagnostic methods

At the beginning of the twentieth century, the dairy industry and cattle breeding organisations initiated a programme to control infectious diseases by means of a complex system of rewards and penalties. The history of programmes to control paratuberculosis in sheep, goats, and cattle in various countries is described. The vaccination of young animals (especially goats and sheep) seems to be an effective measure in the prevention of clinical paratuberculosis, although changes in management and hygiene practices are also important. A control programme for infectious cattle diseases has a number of phases (a life cycle) and different components. Two components are essential for success, namely, open and regular communication with farmers, veterinary practitioners, and other people involved, and a good registration and identification system for cattle, herds, and veterinary practitioners. The principles and different levels of control of paratuberculosis are discussed. The Dutch paratuberculosis programme is divided in two parts: an intensive programme based on test and cull and an extensive programme based on education. The intensive programme has ten herd status levels: 5 to 10 for non?suspect herds and 1 to 4 for infected herds or herds of unknown status. The higher the status, the greater the chance that a herd is free of paratuberculosis. An outline is given of the Dutch paratuberculosis programme. Diagnostic methods are summarised. Future developments regarding vaccination and control or acceptance of paratuberculosis are discussed.