Trypanosomosis and phenotypic features of four indigenous cattle breeds in an Ethiopian field study

We conducted a two-part study in the native home areas of four cattle breeds, Abigar, Gurage, Horro and Sheko, in south-western Ethiopia. The first part of the study investigated livestock keeper knowledge about trypanosomosis and trypanotolerance. For each breed 60 livestock keepers were interviewed, resulting in a total of 240 interviews. The second part of the study focused on biological evidence for trypanotolerance. Blood samples of about 100 head of cattle per breed were collected during peak trypanosomosis challenge period and analyzed for packed cell volume (PCV) and parasitaemia. In addition individual body measurements of the sampled animals were taken and the keepers provided some information regarding their animals. Livestock keeper interviews revealed that trypanosomosis was considered a major problem in all areas (95-100%). Almost all Abigar livestock keepers knew how trypanosomosis is transmitted, whereas only 34-52% of the keepers of the other breeds had that knowledge. Most Sheko keepers (75%) knew of trypanotolerance and claimed to have trypanotolerant animals in their own herds. Among the other three breeds the knowledge of trypanotolerance was much less (8-18%). A majority of the keepers were interested in purchasing trypanotolerant animals. PCV was highest among Horro (26.2) and Sheko (25.1) cattle whereas Abigar had the lowest PCV (20.0). Sheko were least infected by trypanosomes (6%) and had the lowest number of trypanocidal treatments per year (1 treatment/animal and year). Abigar cattle were most infected (23%) followed by Gurage (20%) and Horro (17%). Gurage had by far the highest number of treatments per animal and year (24). There were large differences between the number of cattle perceived by the keepers to be infected, and the number detected from blood sampled, among Abigar, Gurage and Horro. Sheko livestock keepers were better at correctly diagnosing trypanosomosis in their animals. It is concluded that Sheko cattle have higher trypanotolerance attributes of the breeds investigated and a better use of this breed could improve cattle health and household welfare in tsetse-infested areas.     

Identification of mechanisms of natural resistance to African trypanosomiasis in cattle

Natural resistance to African trypanosomiasis in certain Bos taurus cattle in West Africa, called trypanotolerance, may hold solutions for control of this economically crippling disease. Comparison of immune responses between trypanotolerant and trypanosusceptible cattle have shown some differences in antibody response, complement level and cytokine expression, but it is not known whether these differences are the cause of resistance.Two experiments were carried out to assess the contribution of the immune and haemopoietic systems to trypanotolerance. The production of haemopoietic chimaeras from trypanotolerant and susceptible twin calves and comparison of their responses after infection with singleton calves, allowed an assessment of the role of the haemopoietic system in trypanotolerance. An in vivo depletion of CD4 cells in the two breeds allowed an appraisal of the role of T and B lymphocytes in trypanotolerance. The results of the two experiments suggest that natural resistance comprises at least two mechanisms, an innate mechanism that controls parasite growth, and another, involving the haemopoietic system, that is able to limit anaemia. This supports the hypothesis that innate mechanisms in trypanotolerant cattle are more efficient in controlling disease, making them less reliant on antibody responses.     

Blood picture of calves from primiparae kept under large-scale production conditions in the early postnatal period]

Twelve calves of the Red Spotted breed and its crossbreds born by first-calvers, kept in a large-capacity stable of a dairy farm, were subject to the study of the ontogenetic development of the values of the blood picture from birth up to the 10th day of age. The erythrocyte and leucocyte count, the packed cell volume and the relative and absolute number of neutrophils reached the significantly highest levels in calves before drinking the colostrum. The amount of haemoglobin, MCV and MCHC reached the highest values on the first day after birth. The values of the red blood picture decreased in the first week of life and reached the minimum on the tenth day. The leucocyte count decreased during the first to second day after birth, the decrease being due to a drop of the absolute number of neutrophils, and on the tenth day the leucocyte count returned to its initial value. Neutrophils prevailed in the peripheral blood of new-born calves whereas lymphocytes prevailed in the peripheral blood from the fourth day of life on. The amount of cosinophiles in the peripheral blood of the calves was about 0.5% up to the fourth day; on the seventh day it exceeded 1%. The relative number of monocytes was at its minimum level just after birth and showed a significant increase during the second to fourth day.     

In utero transmission of bovine leukemia virus

In an initial study, 18 calves born to cows persistently infected with bovine leukemia virus (BLV) were tested for infective virus and antibodies at birth, and no infected or seropositive animals were found. Four of these calves were maintained in quarters where infected animals were housed, and 3 of the 4 subsequently became infected. These were probably contact infections acquired during, or at some time after, birth. The remaining 14 calves were kept in isolation pens in a building housing no infected cattle. None of this group was found to be BLV infected during 1 year of observation. In further studies, 15 pregnant cows inoculated with BLV became infected. One abortion, considered to be unrelated to the BLV inoculation, occurred 38 days later. The remaining 14 cows gave birth to 1 dead and 14 live calves. The dead calf and its live twin were seropositive for BLV at birth, indicating that they had been infected in utero. The remaining 13 calves were negative for BLV antibodies at birth and remained so during 1 year of observation.     

Transfer of maternal colostral leukocytes promotes development of the neonatal immune system Part II. Effects on neonatal lymphocytes

It has been established that maternal leukocytes, conditioned by the mammary environment, cross the neonatal gut and circulate in the newborn calf. However, the impact of these cells on the development of neonatal immunity remains to be determined. This study examined the effects of maternal colostral leukocytes on development and maturation of neonatal adaptive immunity by examining the expression of surface markers on neonatal lymphocytes. At birth, neonatal calves were fed whole colostrum, or colostrum that had the maternal cells removed (cell-free colostrum), from their respective dams. Peripheral blood samples were collected at regular intervals over the first 4 weeks of life and lymphocytes were evaluated for surface expression of cellular markers. The results of these studies demonstrated that calves receiving whole colostrum had fewer CD11a positive lymphocytes in circulation during the first 2 weeks of life and this marker was expressed at a lower density than calves receiving cell-free colostrum. In addition, calves receiving whole colostrum also had a higher percentage of lymphocytes expressing the activation markers CD25 and CD26 by 7 days after birth. During the first week of life, lymphocytes from calves receiving whole colostrum had a higher density of MHC class I expression on their surfaces than cells from calves receiving cell-free colostrum. In general, these results indicate that transfer of maternal cells with colostrum allows for more rapid development of lymphocytes and maternal cells appeared to enhance their activation.     

Effect of colostrum intake on diarrhoea incidence in new-born calves

In a survey which lasted one year and included data of 73 dairy cows with their calves, colostrum immunoglobulin G (IgG) of 22 primiparous cows and serum IgG of their calves were lower than the corresponding IgG levels of 51 multiparous cows and their calves. Serum IgG concentration was not correlated with diarrhoea incidence. Although there were no seasonal differences in the IgG concentration of colostrum and calf serum, neonatal diarrhoea incidence was higher in calves which were born in winter than in calves which were born in summer (P < 0.01). Thus the high diarrhoea incidence in winter was not a consequence of an insufficient IgG transfer to the calves. The 60 calves of the second study were fed colostrum on the first day of life. From the second to the tenth day 28 experimental calves received milk and 0.5 l of surplus colostrum of the first and second milking twice a day, whereas 32 control calves received milk only twice a day. Two of the 28 experimental and 11 of the 32 control calves suffered from diarrhoea during the first ten days of life (P < 0.05). These results show that the ingestion of surplus colostrum in addition to milk after the first day of life protects the new-born calf against infectious diarrhoea.     

Effects of separate and mixed grazing on trichostrongylosis in first- and second-season grazing calves

This study on natural trichostrongylosis in calves on permanent pasture was designed to evaluate whether susceptible first-season calves would benefit from mixed grazing with second-season calves that were more resistant. The experimental plan allowed a comparison of the effect of mixed grazing with that of separate grazing for each age category. The results showed that the first-season calves already grazing with the older animals at the beginning of the grazing season had lower parasite burdens and less clinical symptoms than first-season calves grazing alone. This effect, experienced in 1987 and characterized by a rather high overwintered parasite population on herbage, could not at this early stage be explained by a parasite "diluting" effect exerted by the older animals, but might perhaps be explained by different grazing behaviour of the two age categories. Later in the summer, the first-season calves continued to benefit from the mixed grazing, most likely because the pasture was less contaminated per unit area due to the very low egg deposition of the older animals. The effect of mixed grazing was most clearly reflected in the differences between worm burdens in tracer calves grazing the respective plots at the end of the season. Apparently, the second-season calves did not suffer parasitologically from grazing together with the younger animals. The paper discusses possible long-term implications with combinations of different age categories of cattle.     

Strategic anthelmintic treatment of young cattle during summer in a Mediterranean-type climatic environment

A worm-control program utilising treatment of young grazing cattle with fenbendazole on two occasions during summer was tested in the Mediterranean-type climatic environment of south-west Western Australia. The grazing system aimed to produce steers by introducing three-month-old weaned calves to pasture in mid-winter until they were sold in early summer. Comparisons were made of the numbers of worm eggs passed on to plots by treated and untreated animals during autumn, the performances of treated and untreated cattle and the performances of calves introduced to the plots in mid-winter. The “tracer” calf technique was used to determine the availability of infective larvae on one untreated and one treated plot for each of the two years of the experiment.Treated animals deposited less Ostertagia spp. eggs on to pasture during autumn than did untreated animals in one of the two years. In both years they deposited less eggs of worm species other than Ostertagia spp. Less intestinal worms were acquired by “tracer” calves grazing treatment plots than those grazing no-treatment plots in both years, but there were no differences in the number of abomasal worms acquired.The reduction in availability of infective larvae of intestinal worms was insufficient to prevent the occurrence of parasitic gastroenteritis in calves introduced to the plots in mid-winter. The fenbendazole treatments did not confer any immediate body-weight advantage on treated animals.On both treatment and no-treatment plots, there were few infective larvae available to grazing cattle during early autumn, there was a rapid attainment of peak availability in winter and then a decline to low availability by mid-spring. In one year, infective larvae of intestinal worms (almost exclusively Cooperia spp.) increased in availability again in late spring and early summer. A high proportion of retarded worms was never a feature of the worm counts of “tracer” calves.It was concluded that the treatments may have been more effective had they been given during autumn.     

Post‐natal changes in MCT1 expression in the forestomach of calves

The monocarboxylate transporter 1 (MCT1) has been demonstrated to be involved in the transfer of short‐chain fatty acids (SCFA) and/or their intraepithelial metabolites from the rumen to the blood. As MCT1 plays a role in SCFA transfer, it is assumed that SCFA are the main substrates influencing its expression. However, there are hints that MCT1 may also be expressed during the early life of the animal when SCFA are not released in the forestomach. To figure out whether MCT1 expression in the forestomach is influenced independently of SCFA during that period, we studied post‐natal MCT1 expression immunohistochemically in the epithelia of omasum, atrium ruminis, saccus dorsalis ruminis, saccus ventralis ruminis and reticulum of calves born preterm and at term. The calves were nourished by colostrum or by milk‐based formula diet. MCT1 could be found in all the forestomach compartments tested, even in preterm calves. The protein was mainly oriented to the luminal side in the immature epithelium 24 h after birth. Orientation to the blood side of the cells developed during the first 4 days after birth. In the rumen epithelia (but not in the other forestomach compartments tested), orientation of MCT1 to the blood side of the cells was paralleled by an increase in the overall expression rate during the first 4 days after birth. As lactate levels were very high directly after birth, a lactate‐dependent substrate induction may have been the underlying mechanism. However, non‐specific changes due to general differential processes might also be the cause. Both early upregulation of MCT1 and high blood lactate levels may provide the epithelia with lactate as energy source.     

Growth of mashona cattle on range in Zimbabwe. I. Environmental influences on liveweight and weight gain

Data from 1,456 purebred Mashona calves were analysed to determine environmental influences on growth rate and liveweight at birth, weaning (205 days) and 18 months of age. Calves were born between mid-September and mid-December each year. Year of birth was highly significant for all traits (P less than 0.001). Pre-weaning liveweight and weight gain increased as age of dam increased to seven years after which growth tended to decline. Post-weaning compensatory growth was apparent in calves of young dams. Male calves grew faster and were heavier at all stages than female calves (P less than 0.001). Calves from previously non-lactating cows grew more rapidly and were heavier at all ages than those from previously lactating cows. Birth weight increased as calving season advanced and calves born late maintained their growth advantage until 18 months of age. The results indicate that environmental influences experienced in early life persist long after weaning.     

The supply of newborn camel foals (Camelus dromedarius) with immunoglobulin G

A major problem in camel breeding in East Africa is the high mortality rate of young camel calves. The purpose of this research was to examine the quality of camel colostrum and extent of the calves passive immunization by maternal antibodies. In 31 camel birth on a ranch in Kenya, IgG concentrations in the colostrum and in the serum of the calf during the first three days of life were measured. IgG concentration in the serum of the calf reaches a maximum 24 hours after birth. In 39% of the examined calves, this maximum concentration was below 4 g/l. In 61% of the calves, an IgG concentration of more than 4 g/l was reached. No correlation was found between diseased animals and the IgG concentrations in the serum of the calves involved. A minor IgG concentration can be excluded as a reason for calves mortality. The high percentage of insufficient IgG concentration in the serum of the calves therefore must be caused by insufficient intake of colostrum. Future measures in order to decrease calves mortality must therefore try to improve the management of calves, especially the sufficient intake of colostrum.     

Influence of calving season and stocking rate on birth weight and weaning weight of Simmental-sired calves from Brahman-Hereford F1 dams.

Braham-Hereford F1 dams have been used to evaluate the influence of grazing pressure on forage attributes and animal performance at the Texas A&M University Agricultural Research Center at Overton. Data for this study were compiled from 1,909 records of Simmental-sired calves born to Braham-Hereford F1 cows from 1975 to 1990. Birth weight and weaning weight were analyzed independently to estimate the influence of year, season of birth, dam age, weaning age, and sex of calf. The effect of stocking rate as represented by levels of forage availability on weaning weights and subsequent birth weights was measured. Within the fall and winter calving seasons, lactating dams grazing at a high stocking rate produced calves with the lowest subsequent birth weights. Lactating dams assigned to creep-fed treatments had calves with the heaviest subsequent birth weights. Although dams that were less than 3.5 yr of age had calves with the lightest birth weights, there was no apparent decline in birth weight of calves from dams 12 to 17 yr old. Year, sex of calf, age of dam, stocking rate, season of birth, age at weaning, and birth weight were significant factors affecting weaning weight (P less than .01). Fall-born calves grazing cool-season annual pastures were heavier at weaning (267.6 kg) than either winter- (252.0 kg) or spring-born calves (240.9 kg). A stocking rate x season-of-birth interaction was observed for birth weight and weaning weight (P less than .05). Differences in weaning weight from low- vs high-stocked pastures were greater for fall-born calves (61.6 kg) than for winter-born calves (48.7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Nematode control practices and anthelmintic resistance in dairy calves in the south west of England.

A postal survey of worming practices on West Country dairy farms was undertaken and farmers were requested to send faecal samples for nematode egg counts. The majority of the farmers who responded had a nematode control policy which was based on a mixture of anthelmintics and pasture rotation. Sixty-five per cent turned out calves on to the same paddock each year and 57 per cent treated their stock with anthelmintics during the second year. Ninety farms submitted samples for analysis but only 16 samples contained sufficient eggs to justify repeat egg counts and only eight of these produced enough eggs for in vitro tests. The small number of positive samples, even into the latter part of the year suggests a heavy use of anthelmintics with relatively clean pasture. One Somerset farm had larvae which developed in high concentrations of ivermectin, and eggs were still being passed after two treatments with ivermectin at the manufacturer's recommended dose seven days apart. Of 100 male nematodes isolated from two of the calves, 88 were Cooperia species and 12 were Nematodirus species. A controlled trial with this isolate in eight Friesian male calves showed a 44 per cent reduction in egg counts at day 7 but no significant reduction in worm burden postmortem. This is the first reported case of ivermectin-resistant Cooperia species in cattle in the United Kingdom.     

Dynamics of Eimeria oocyst excretion in dairy calves in the Province of Buenos Aires (Argentina), during their first 2 months of age

Clinical coccidiosis is associated with high fecal contamination and stress situations, mainly in animals under 1 year of age. Artificially fed dairy calves are one of the categories most prone to suffer from this parasitic disease. The study was carried out in a commercial dairy farm. Feces samples of heifer calves between 2 and 8 weeks old were taken monthly for oocyst counts and Eimeria spp. identification. Of the 862 feces samples analyzed, 48% presented oocysts. When grouping the results of monthly samplings of each age group, it was observed that this percentage increased in the group of calves between 20 and 40 days of life, reaching the peak average of 85% of infection prevalence in the group with between 26 and 30 days of age. The discharge of oocysts observed between 21 and 35 days of age was superior to the rest (p<0.05). This trend appeared every month throughout the whole year. However, during March, April, June, September and November, the curves in the group categories were higher than in the remaining months (p<0.05). Twelve Eimeria species were identified, being E. ellipsoidalis, E. bovis, E. zuernii and E. auburnensis those in highest numbers. E. ellipsoidalis had an important predominance in the opg composition, >75% up to 25 days of life (p<0.05). E. bovis reached peak values in the 26 and 30 days group (p<0.05), remaining without significant variations in the last stage of the artificial milk feeding period (approximately 60 days of life), when the oocyst counts were significantly low. Oocysts of E. auburnensis appeared in great proportion (46%) in the cultures later than the previous species (p<0.05), in calves of the age groups of between 46 and 50 days of age. Oocysts of E. zuernii showed no trend associated with age. The highest prevalence of infection and of oocyst values appeared during the periods with better environmental conditions for sporulation, survival and dispersion of oocysts (spring and autumn), coincident with the highest birth rates and an elevated number of calves in the paddock. Calves developed a process of natural "vaccination" against coccidiosis. This was demonstrated by the decrease in the quantity of animals shedding oocysts and in the number of oocysts eliminated at the end of the artificial milk feeding period.     

Trypanosomiasis by Trypanosoma vivax in cattle in the Brazilian semiarid: Description of an outbreak and lesions in the nervous system

An outbreak of trypanosomiasis by Trypanosoma vivax is reported in the semiarid of Paraíba, Northeastern Brazil from May to August 2002. Sixty-four cows out of 130 were affected; 11 died and the other recovered after treatment with diminazene aceturate. Affected animals had fever, anemia, weight loss, hypoglycemia, increased serum levels of aspartate aminotransferase and, in nine cows, nervous signs. All cows with nervous signs died; six of them recovered after treatment, but the disease relapsed. Six cows aborted and one delivered a calf that died immediately after parturition. Thirty-two out of 100 calves were affected and five died. Nervous signs were not observed in the calves. Gross lesions were thickening of the meninges, enlarged lymph nodes and prominent white pulp of the spleen. The main histological lesion was meningoencephalitis and malacia in the brain of cows with nervous signs. No antibodies against trypanosomes were found in 33 blood samples collected before the outbreak in the affected farm and in 29 samples collected at the same time in two other neighbor farms. Until January 2003, all 89 animals tested had antibodies against T. vivax, suggesting the occurrence of sub clinical infections in cattle without clinical signs. Only two out of 85 serum samples collected on April 2004 were positive for T. vivax antibodies. Data obtained suggested that the semiarid region is non-endemic for trypanosomiasis and that disease occurred due to introduction of the parasite in a susceptible population after an apparent rise in the Tabanus spp. population.     

Diagnosis of copper deficiency and effects of supplementation in beef cows.

The effects of feeding supplementary dietary copper to a herd of 400 beef cows, were studied over a two year period. In the first year of the trial, the calves showed clinical signs of copper deficiency. There was improved growth following subcutaneous injection of copper ethylenediamine tetraacetate, and the treated calves had a 2.8% increase in adjusted weaning weights. In the second year of the trial pregnant cows were fed a basal ration of bromegrass silage, barley and minerals over the winter feeding period. The feed was supplemented with copper so that half received 5.5 mg/kg of copper on a dry matter basis and half 40 mg/kg. Calving occurred in the spring and half the calves were treated with injectable copper at birth and again at 12 weeks of age. There was no evidence of copper deficiency in the calves and there was no effect of high level copper supplementation on calf birth weight, or neutrophil candidacidal activity. Susceptibility to diarrhea varied in a complex fashion; morbidity was lowest in calves born to dams fed supplementary copper and highest in calves born to supplemented dams and injected with copper at birth. The cows and calves grazed the same copper deficient pasture over the summer. The average daily gain for calves born to supplemented cows was 0.999 +/- 0.010 kg/day (x +/- SEM) which was significantly greater than the 0.972 +/- 0.009 kg/day for calves from nonsupplemented dams (p = 0.044). The benefit of copper supplementation on 200 day weaning weight was estimated at 4.8 kg. Evidence of copper deficiency was seen when a herd test showed mean serum levels below 9 mumol/L and liver values below 0.09 mmol/kg wet matter.     

Gastro-intestinal parasitism of cattle in native pasture grazing system in Guadeloupe (French West Indies).

Gastro-intestinal parasitism of creole cows and calves, Limousin x creole cross calves and Brahman x creole cross calves was recorded during seasons of calving in a native grazing system in Guadeloupe, a wet tropical area. Calvings were pooled during the dry season for two herds and during the rainy season for two other herds. For each calving season, calves of one herd were drenched monthly with anthelmintic. A marked periparturient rise in egg excretion was observed in cows. Coccidial infection was always present in calves, but no clinical signs were observed. The main parasites during the first 2 months of life were Strongyloides papillosus and Toxocara vitulorum. Then, Haemonchus placei, Trichostrongylus spp. and Cooperia spp. were the dominant species encountered. Brahman cross calves were the most heavily infested animals. There was no clear relationship between third stage larvae (L3) population size on pasture and worm burdens in calves, except during the second month of life. Despite medium levels of infestation, parasitism inhibited the growth of creole calves: -10.5 kg of bodyweight at weaning (-59 g day-1 of daily bodyweight gain from birth to weaning). The pathological effects of subclinical parasitism were confirmed by a lower packed cell volume and albuminaemia in parasitized calves than in treated calves.     

Ichthyosis in two Chianina calves

The occurrence of ichthyosis in two Italian Chianina calves is described for the first time. Both animals, affected by ichthyosis fetalis and ichthyosis congenita, respectively, showed diffuse cutaneous thickening which had been present since birth. The first patient was a three-month-old female calf; inelastic leather cuirass-like skin associated with generalized hypotrichosis and local alopecia, delay of the physiologic change of coat colour, stiff movement and growth retardation were the most prominent clinical characteristics. The patient was kept under observation for almost one year. The second case occurred in a 18-day-old female calf which was referred to our clinic after it had already died; the presence of irregular hyperkeratotic plates separated by deep fissures over the entire cutaneous surface and the slight eversion of the mucocutaneous junction (eclabium and ectropion) were the most characteristic alterations. In both cases, the major histopathological feature was a diffuse lamellar orthokeratotic hyperkeratosis. An underlying genetic defect was strongly suspected on the basis of a common ancestor for the two sires of the affected calves and of the current scientific knowledge.     

Alterations of growth hormone, cortisol, luteinizing hormone, and insulin concentrations in early-postnatal calves affected with diarrhea

The aim of the study was to investigate the influence of diarrheic infections during the early postnatal phase of calves on the concentrations of hormones controlling reproduction and metabolism. Blood samples were collected from 20 male and female calves via jugular vein catheters every 15 min for 6 hr at Days 3, 9, and 21 of life. The animals were classified into three groups. Group 1 (controls): healthy calves (n = 9). Group 2: calves affected with diarrhea at Day 9 (n = 7). Group 3: calves with diarrhea at Days 3 and 9 (n = 4). Infections occurred spontaneously and were mainly due to E. coli infections. All affected calves had recovered at Day 21. Mean GH concentrations in the calves in Groups 2 and 3 compared to control calves had increased by Day 3 (P<0.01; P<0.001). Cortisol levels of calves in all groups were highest at Day 3 and decreased thereafter (P<0.001). Cortisol concentrations were lower at Day 3 in animals in Groups 2 (P<0.001) and 3 (P<0.05) than in controls. Pulsatile LH release was detectable at Days 9 and 21 only in healthy calves. Insulin increased at Day 9 during diarrhea. The results indicate that cortisol concentrations decreased whereas GH concentrations were increased before diarrhea was observed. The onset of pulsatile LH release was delayed in diarrheic calves. It is concluded that diarrhea exerts effects upon the release of reproductive and metabolic hormones in early postnatal calves.     

Neurological disorders, virus persistence and hypomyelination in calves due to intra-uterine infections with bovine virus diarrhoea virus

The clinical and pathological findings after a natural intra-uterine infection with BVD-virus in a Friesian dairy herd are described. The virological and serological aspects will be discussed in a separate paper (30). In a period of 4 years, 11 calves were born with the following nervous symptoms: more or less serious incoordination, tremor, oscillating nystagmus, and a negative blinking reflex. The pupillary and sucking reflexes were normal. No ocular defects, such as lenticular opacity or retinal atrophy were observed. The first calf was born in 1979. Within 6 months the symptoms disappeared. After a normal conception and pregnancy this animal gave birth to 2 clinically normal calves in 1981 and 1982. The second calf died at the age of 2 months, due to an ulcerating enteritis. In 1980, again 8 calves with the same nervous symptoms were born within a period of 3 months. Two calves died at the age of 3 days and 5 weeks respectively; 2 calves were sold when 10 days and 3 weeks old; one calf did not improve and was necropsied at the age of 17 days. The remaining 3 calves showed only a slight hypermetria when examined after 6 months. At that time nystagmus was only visible with ophthalmoscopy. Two calves were slaughtered when 10 months old. The last one, a bull, proved to be sterile and was necropsied at the age of 1 1/2 year. A calf, born in 1981, recovered within a week and was necropsied at the age of 15 days. The last calf, born in 1982, did not improve at all and was necropsied at the age of 14 days. During these 4 years none of the other animals in the herd showed any symptoms due to an acute or chronic BVD-virus infection. At post mortem examination of 6 animals no macroscopically visible malformations were found. Hypomyelination and abnormal glial cells were evident in 5 cases, especially in the two youngest calves which did not show any improvement. One of them had had an obvious thymic hypoplasia. The calf which recovered within a week showed only very slight changes. In one of the calves slaughtered at 10 months, inflammatory lesions were found in the brain. The diagnosis was confirmed by virological investigations. Clinically as well as pathologically there was a close resemblance to Border disease in lambs and congenital tremor in piglets after prenatal exposure to Hog cholera virus.