A census of the prevalence of vaginal prolapse in sheep flocks in the Borders region of Scotland

A postal census of vaginal prolapse in sheep flocks in the Borders region of Scotland yielded 540 replies from 963 owners (56 per cent). There were 262,250 ewes in 976 flocks and 2573 vaginal prolapses were reported. Analysis of the data revealed that 390 (40 per cent) of the flocks had no vaginal prolapses and in 237 (24.3 per cent) the reported prevalence was between 0.1 per cent and 1.0 per cent. Only 63 (6.5 per cent) of flocks had a greater than 5 per cent prevalence of vaginal prolapses. The greatest number of prolapses occurred in an upland flock of greyface ewes mated with Suffolk tups with 50 cases among 700 ewes (7.1 per cent) and the highest prevalence was in an upland Scottish blackface flock of ewes bred with Suffolk tups with 15.2 per cent (35 cases among 230 ewes). There were marked breed differences; very few hill breeds were affected and most cases occurred in greyface ewes mated with Suffolk tups.     

Nutritional factors associated with vaginal prolapse in ewes

Serum calcium, magnesium and phosphate values of ewes recently affected by vaginal prolapse were compared with unaffected ewes in four flocks. Subclinical hypocalcaemia was demonstrated in some affected and unaffected ewes in three flocks. Magnesium and phosphate values were normal. In two flocks the body condition of ewes recently affected by vaginal prolapse was variable and reflected the variation in condition found in the flock. In a third flock affected ewes had significantly lower body condition scores than unaffected ewes (P less than 0.001). Analysis of the fourth flock was not possible. Oestrogenic mycotoxins were not detected in any of the feed samples taken from these flocks. The following year the management, nutrition and energy, and the protein and calcium status of ewes in 12 flocks of greyface/mule ewes with a history of a regular high (greater than 3 per cent) or low (less than 1 per cent) prevalence of vaginal prolapse were compared. A high prevalence was not associated with any particular feedstuff. A high or intermediate (1 to 3 per cent) prevalence of vaginal prolapse was found in three of the four flocks managed as a single group and these three flocks were fed on an unrestricted basis. Body condition scoring and beta-hydroxybutyrate estimation confirmed that ewes in these flocks were overfed. The prevalence of vaginal prolapse in the flocks was not related to the serum albumin, calcium or urea of the ewes. Therefore subclinical hypocalcaemia was probably a consequence of vaginal prolapse rather than a cause.     

Reservoirs of Staphylococcus aureus in meat sheep and dairy cattle

The objective of the study was to investigate reservoirs and transmission of S. aureus in ewes and lambs in 3 meat sheep flocks. Repeated sampling of milk, teat skin, nasal- and vaginal mucous membranes was performed and samples were analysed for S. aureus. For comparison, samples were also collected from cows and young heifers in 3 dairy cattle herds. Selected isolates were compared by pulsed-field gel electrophoresis (PFGE). S. aureus was detected in 8 (1.5%) of 520 milk samples from ewes and in 38 (6.4%) of 588 milk samples from cows. From body site swabs, S. aureus was found in 394 (32.6%) of 1208 samples from sheep and in 67 (16.0%) of 420 samples from cattle. The proportion of S. aureus-positive nasal swabs from ewes and cows were 56.7% and 13.9%, respectively. From lambs, 58.2% of the nasal swabs were S. aureus-positive. In each flock, one S. aureus pulsotype predominated. Identical S. aureus pulsotypes were found in milk and from body sites. Paired S. aureus isolates from the nasal cavity of (i) ewes and their lambs, (ii) twins and (iii) from repeated swabs of individual ewes were compared by PFGE, and in the majority of cases the two isolates were identical. The results contribute new knowledge indicating frequent transmission of S. aureus between the dam and her lambs and within animals in a flock. In contrast to cattle, S. aureus is frequently present in the nose of sheep which may represent the primary reservoir of S. aureus in sheep flocks.     

Coxiella burnetii shedding and environmental contamination at lambing in two highly naturally-infected dairy sheep flocks after vaccination

Abortion due to Coxiella burnetii was confirmed in the 2007/08 season in two naturally-infected dairy sheep flocks. Proportion of C. burnetii shedders and bacterial loads in vaginal mucus were high among aborted or lambed ewes, as was within-flock seroprevalence. Before the next reproductive season (2008/09) 75% of ewes and 50% of replacement lambs were vaccinated (Coxevac, CEVA Santé Animale) keeping the remaining as untreated controls. Compared with the previous year results when abortion outbreak started, a great reduction in the percentage of abortions, in the number of shedders and in the bacterial burden excreted by the ewes was found in both flocks. However, seroconversion in non-vaccinated yearlings from both flocks and the presence of C. burnetii DNA in bioaerosols taken at sheep premises at lambing indicated that infection was still active. No differences were observed between vaccinated and control groups in terms of proportion of C. burnetii shedders. These results suggest that optimal results of vaccination in heavily infected flocks may not be obtained in a short-term period.     

Coxiella burnetii shedding and environmental contamination at lambing in two highly naturally-infected dairy sheep flocks after vaccination

Abortion due to Coxiella burnetii was confirmed in the 2007/08 season in two naturally-infected dairy sheep flocks. Proportion of C. burnetii shedders and bacterial loads in vaginal mucus were high among aborted or lambed ewes, as was within-flock seroprevalence. Before the next reproductive season (2008/09) 75% of ewes and 50% of replacement lambs were vaccinated (Coxevac, CEVA Santé Animale) keeping the remaining as untreated controls. Compared with the previous year results when abortion outbreak started, a great reduction in the percentage of abortions, in the number of shedders and in the bacterial burden excreted by the ewes was found in both flocks. However, seroconversion in non-vaccinated yearlings from both flocks and the presence of C. burnetii DNA in bioaerosols taken at sheep premises at lambing indicated that infection was still active. No differences were observed between vaccinated and control groups in terms of proportion of C. burnetii shedders. These results suggest that optimal results of vaccination in heavily infected flocks may not be obtained in a short-term period.     

The characteristics and causes of sheep losses in the Victorian Mallee

SUMMARY The extent and causes of sheep losses in the semi-arid Mallee region of north-western Victoria were assessed by interviewing the owners of 79 randomly selected farms running 241 flocks in 1987/88 and 245 flocks in 1988/89. Mean annual losses were higher in ram flocks (21%) than in ewe flocks (7%), in flocks of non-Merino sheep (rams 24%, ewes 11%, weaners 5%) than in Merino (rams 11%, ewes 6%, wethers 4%, weaners 4%) and in ewe flocks 3 or more years old (10%) than in young ewe flocks (3.5%). In flocks where losses exceeded 5%, the causes most often reported by farmers were blowfly strike (especially in Merino sheep and weaners), ewe losses in autumn close to lambing, and heliotrope (Heliotropium europaeum) poisoning. Heliotrope poisoning was considered by the authors to be the main reason for the higher losses in old ewes than in young ewes and in non-Merino sheep than in Merino sheep. Losses of ewes associated with pregnancy and lambing were considered by the authors to be often predisposed by liver damage caused by heliotrope poisoning, and high losses in non-Merino ram flocks were attributed to both heliotrope poisoning and their ability to escape through boundary fences. Reasons for continuing high losses due to enterotoxaemia are discussed. Losses due to gastro-intestinal parasites, footrot and foot abscess were low.     

Flock-prevalence of border disease virus infection in Basque dairy-sheep estimated by bulk-tank milk analysis

Bulk-tank milk (BTM) samples from 154 sheep flocks were used to estimate BDV prevalence in the Basque Country in Spain using an ELISA and a RT-PCR test. The proportion of antibody-positive flocks was 68% but varied significantly between provinces and was 93% in Araba and 54-55% in Bizkaia and Gipuzkoa. Most ELISA-positive flocks had very low antibody inhibition percentage (AIP) indicating high seroprevalence and recent BDV exposure. However, only 9% flocks were PCR-positive suggesting few infected ewes were being milked at the time of sampling. Phylogenetic analysis of the 5' NCR sequences of BDV from seven infected flocks showed that all except one clustered within the group formed by BDV type C strains from a previous study in the region, whereas the remaining isolate was closest to BDV type A. These results suggest that BDV strains in most Basque flocks have a common origin and differences in prevalence between provinces are associated to recent events affecting BDV spread such as use of communal pastures and sheep trading. The widespread distribution of BDV in the region, advocates for the implementation of BDV control strategies and highlights the potential risk of sheep as a pestivirus reservoir for other species.     

Seroprevalence of Q fever (coxiellosis) in sheep from the Southern Marmara Region, Turkey

Little information is available in Turkey on Q fever, a zoonose caused by Coxiella burnetii and transmitted from domestic ruminants. This study aimed at investigating the seroprevalence in sheep flocks from three provinces (Bursa, Balikesir and Canakkale). Serosurvey was undertaken on 42 flocks, which were categorised by sizes. Sera were collected randomly from specific age groups within the young population. CHEKIT Q-fever ELISA kit was used to identify the infection in sheep. The results showed that 20% (n=151) of sheep were seropositive. A total of 34 flocks (81%) revealed at least one seropositive animal. Higher seroprevalence was observed in Balikesir region. Larger flocks resulted more infected than medium and small flocks. An association was found between seropositivity and age, when the primiparous ewes (1-year old) had higher antibodies rates than newborn sheep (aged less than 10 months) or biparous ewes (2 years old). These results showed that Q fever infection was common and circulating in the studied region, hence encourage efforts to propose measures that could reduce the spread and the zoonotic risk.     

Comparison of milk-ELISA and serum-ELISA for the diagnosis of Brucella melitensis infection in sheep

Milk and blood samples from 704 lactating ewes were examined for the diagnosis of Brucella melitensis infection by milk-ELISA, serum-ELISA, RBPT, SAT and culture of milk. Of these ewes, 209 were from brucellosis free sheep flock, 443 from brucellosis infected sheep flock and 52 were from private sheep flocks of which status for brucellosis was not known. All the 209 ewes belonging to uninfected sheep flock were found negative in all the tests and of the remaining 495 ewes 105 were positive in serum-ELISA, 103 in milk-ELISA, 92 in RBPT, 85 in SAT, and B. melitensis biovar-1 was isolated from the milk of 29 ewes. Of the 105 serum-ELISA positive ewes, 99 were positive and 6 were negative in milk-ELISA, whereas of the 103 milk-ELISA positive ewes, 4 were negative in serum-ELISA. All together, 99 ewes were positive and 386 were negative in both the assays while 10 ewes yielded variable results. The specificity of milk-ELISA in brucellosis free flock was 100% and sensitivity and positive predictive value were 96.11% and 94.28%, respectively, in infected flocks. The Brucella antibody levels in milk and serum samples as determined by milk-ELISA and serum-ELISA were correlated significantly. The milk-ELISA for brucellosis appears to be an attractive alternative of serum-ELISA particularly in the lactating ewes.     

Selenium, vitamin E and vitamin A status in dairy sheep reared under different feeding systems in Greece

The main purpose of the study was to investigate whether the feeding system applied has any effect on the status of blood selenium (Se) and vitamins A and E in dairy sheep. In total 200 dairy sheep from 10 flocks were used in the study (20 animals per flock). Group A consisted of 100 sheep (five flocks) reared under the intensive feeding system and group B of 100 sheep (five flocks) reared under the semi-intensive feeding system. The 100 sheep of each group consisted of 25 lambs aged 3-6 months, 25 ewes 1-3 years, 25 ewes more than 3 years and 25 non-lactating ewes in late gestation. Another purpose was to evaluate the potential effect of the age and the reproductive stage of the animals on these parameters. To determine the effect of age, 150 of these animals were divided into three subgroups: 50 lambs, 50 non-pregnant lactating ewes aged 1-3 years and 50 non-pregnant lactating ewes aged more than 3 years. For the evaluation of the effect of the reproductive stage the 50 non-lactating ewes in late gestation and the 100 non-pregnant lactating ewes were used. Blood samplings were performed once, between December and January for non-lactating ewes in late gestation and March to May for lambs and lactating ewes. Whole blood Se and vitamin E and A serum concentrations were determined. The main conclusion is that the feeding system significantly affects Se and serum vitamin A concentration, as they were higher in the intensive one. It was secondly concluded that age affects the serum concentrations of vitamin A.     

The seroprevalence of maedi-visna in Ontario sheep flocks and its relationship to flock demographics and management practices.

The objectives of this study were to describe the serological prevalence of maedi-visna in a sample of Ontario sheep flocks, and to identify management and demographic variables that were associated with seroprevalence for maedi-visna. A sample of 103 sheep flocks in Ontario was randomly selected from those flocks participating in the Red Meat Plan. The owners of these flocks were surveyed regarding management procedures on their farms, and blood samples were taken from a random sample of ewes in each flock. At least one ewe tested serologically positive, based on the agar gel immuno-diffusion test, in 69.9% of the farms. Positive serological reactions occurred in 20.9% of the 3880 sheep tested. Flock demographics and farm management variables were considered in a multiple regression model, and several factors were positively associated with higher maedi-visna seroprevalence rates. These included the average age of the flock, the number of years the owner had been sheep farming, the practice of using foster ewes, the practice of allowing lambs to have contact with other ewes that are lambing, and the average pasture acreage per ewe.     

Factors affecting the reproductive performance of Awassi sheep flocks in north-east of Jordan: An epidemiological study

A prospective cohort study was conducted using 32 randomly selected Awassi sheep flocks to identify factors hypothesized to be associated with the occurrence of pregnancy, twinning and fetal loss between August 2005 and May 2006 in the region of Al-Safawi (northeast of Jordan). Vitamins A and E and selenium concentrations were determined on 448 blood samples. Using the forward selection procedure of the logistic regression module, models with statistically significant risk factors (P?<?0.05) were constructed for three outcomes; pregnancy, twinning and fetal loss. Serum vitamin A concentration levels were associated with pregnancy (OR?=?2.26, 2.48), twinning (OR?=?6.49, 17.74) and fetal loss (OR?=?0.13, 0.19). Primiparous ewes were 48% less likely to become pregnant than fourth or higher parity ewes. The likelihood of twinning increased significantly in ewes up to the third parity. Ewes that were fed 700-900 g barley, 250-300 g wheat-bran per head per day and grazed on vegetables residues were 4.15 times more likely to have twins than ewes that were fed 600 g barley and 200 g wheat-bran per head per day. Fetal loss in first and second parity ewes was about 3 times more likely than that in third or higher-parity ewes. Ewes pregnant with twins were about 14 times more likely to have fetal loss than ewes carrying single fetus. Pregnant ewes of the stationary flocks were 37% less likely to have fetal loss than ewes of the semi-nomadic flocks. These results demonstrate that stationary Awassi sheep flocks had higher pregnancy and twinning rates and less pregnancy loss. Supplementation of vitamin A, providing sufficient quantity of dry feed and increasing ram: ewe ratio for primiparous ewes of semi-nomadic flocks is essential to improve Awassi sheep reproductive performance.     

The relationship between nasal myiasis and the prevalence of enzootic nasal tumours and the effects of treatment of Oestrus ovis and milk production in dairy ewes of Roquefort cheese area

Infection by Oestrus ovis is common in Lacaune dairy ewes of Roquefort cheese area (Aveyron, France). It is believed by local breeders that there is a close relationship between nasal myiasis and the incidence of enzootic nasal tumour. In order to check these anecdotal reports, a serological survey was done on 658 breeding ewes before turn-out and 897 breeding and primiparous (hoggets) ewes at the end of the grazing season. By the time of sampling, it was clear whether the sheep were infected at the end of the winter or had been re-infected over summer.In April and September, 40.7 and 26.3%, respectively, were free of O. ovis infection, indicating that the autumn treatment was not completely effective and that O. ovis adult flies were circulating during the summer in many flocks. There were no differences in the incidence of adenocarcinoma between the groups indicating that there is no relationship between O. ovis infection and the presence of the cancer.Differences in milk production between the three groups were not statistically significant (Anova test P>0.05). In flocks where 1-5% of the ewes were infected or in non-infected flocks, ewes produced 3.6 and 8.56%, respectively, more milk than ewes from flocks where more than 5% of animals were infected. For primiparous ewes, the differences were of 8.5 and 12.24%.     

Control of sheep blowfly strike using fly-traps

The use of fly-traps for the control of sheep blowfly strike was examined on 12 commercial sheep farms in south west England in 2003. Two flocks acted as controls, with no prophylactic blowfly strike control. Four flocks of lambs and three flocks of ewes were protected only by blowfly traps, seven of the flocks of ewes and six flocks of lambs were protected by blowfly traps but also had proprietary insecticides applied to them at some stage. There was no difference in the abundance of L. sericata at the various sites. The highest incidence of strike was seen in the two control flocks where 10.9 and 5.8% of the ewes and 10.1 and 9.2% of the lambs were struck. Strike incidence in the flocks that used trapping only and flocks that used trapping plus a chemical preventive was on average five times lower than in the control flocks, but the percentages struck on the sites in the trapping only and trapping plus insecticide groups were not significantly different from each other. The results of this study show that traps can make an effective contribution to blowfly strike control on individual farms.     

Comparison of three enzyme-linked immunosorbent assays for serologic diagnosis of contagious agalactia in sheep.

Serologic diagnosis of ovine contagious agalactia (Mycoplasma agalactiae) with the enzyme-linked immunosorbent assay (ELISA) developed by Agence Fran?aise de Sécurité Sanitaire des Aliments (AFSSA) may produce a few false-positive (FP) and false-negative (FN) results. When the prevalence of disease is low, these erroneous results may generate problems for eradication schemes. To prevent this, 2 commercial ELISAs were compared with the AFSSA ELISA. Flocks of known status were selected and classified into 4 categories: true positive (TP), FP, true negative (TN), and FN; 20 sheep per flock were submitted for blood sampling. A flock was considered positive when at least 1 out of 20 sera was positive or 2 sera were doubtful. In the flock, the diagnostic sensitivity of the 3 kits was very good (100%), and the diagnostic specificity showed an improvement from 46% (AFSSA test) to 88% and 92% (commercial tests). Considering individual animals, very few positive ewes were detected within TN or FP flocks; the proportion of positive ewes varied greatly from one kit to another (48% to 82%) within TP flocks. The kinetics of antibody response in sheep experimentally infected with various field strains of M. agalactiae were quite similar with all 3 ELISAs. The agreement between the 3 tests, assessed using the kappa value, varied from moderate to good (respective values of 0.56, 0.61, and 0.86). The 2 commercial ELISAs showed better performances, probably because of a superior analytical sensitivity, and are a good alternative for the serodiagnosis of contagious agalactia in sheep.     

Field studies on enzootic abortion of ewes in south east Scotland

Statistical data were collected from 20 sheep flocks in which enzootic abortion of ewes (EAE) was diagnosed by examination of fetal material and maternal blood samples. The abortion rate in the 10,645 ewes in these flocks was 7.6 per cent. Thirteen of the flocks were fully vaccinated against EAE but the abortion rate in these was still in the order of 6.5 per cent. EAE was the major cause of the problem as ascertained from the laboratory examination of samples from a wide range of cases of abortion. There is therefore evidence that, in some flocks in south east Scotland, the efficacy of the vaccine against EAE is unsatisfactory. The reasons for this are discussed.     

Serologic survey of prevalence of ovine progressive pneumonia in Idaho range sheep.

Blood samples from 2,310 mature sheep in 3 Idaho range flocks were examined by agar gel immunodiffusion to determine the prevalence of ovine progressive pneumonia. The prevalence ranged from 58% for all ages combined in one flock to 90% of cull ewes in another flock. Age-specific prevalence rates increased from 16% in yearlings to 83% in ewes greater than or equal to 7 years old. Rambouillet sheep had a significantly (P less than 0.01) lower prevalence than sheep of 5 other breeds, whereas one-half Finnsheep crosses had a significantly (P less than 0.01) higher prevalence than sheep of other breeds. Within breed and age, there was no significant difference in reproductive performance between seropositive and seronegative ewes.     

A survey of antibodies to pestivirus in sheep in the Republic of Ireland

: Sera from 1,448 adult ewes in 91 flocks, representing all 26 counties in the Republic of Ireland, were examined for pestivirus antibodies using a commercially available ELISA which detected IgG1 antibody to border disease virus. Eighty-one sheep (5.6%) in 42 flocks (46.0%) were antibody-positive. Within infected flocks, the mean seroprevalence level was 11.4% with a range of 6.3% to 30.0%. The highest antibody prevalence was detected in sheep from central lowland counties of Ireland. Comparative neutralisation testing of 42 ELISA-positive sera detected geometric mean antibody titres of 136 to the NADL strain of bovine viral diarrhoea virus (BVDV), 92 to the Moredun strain of border disease virus and 21 to the 137/4 strain of border disease virus. These results suggest that BVDV may be the major ruminant pestivirus infecting sheep in Ireland. Although there are high numbers of infected flocks, many sheep within such flocks remain antibody-negative and are at risk of giving birth to lambs with congenital border disease.     

Reproductive performance of Finnish Landrace and Suffolk sheep maintained indoors year-round

The reproductive performance (fertility and prolificacy) of Finnish Landrace (Finn) and Suffolk sheep on an accelerated breeding program was evaluated. Both breeds were contained in each of two separate flocks housed indoors year-round on expanded metal floors in windowless buildings. The two flocks were bred alternately at 4-mo intervals in January, May and September. The sheep were exposed to either an abrupt (ALR) or constant (CLR) lighting regimen. Data from nine breedings during a 4-yr period were considered. Fertility was significantly higher for ewes in the ALR lighting regimen. Fertility was lower for ewes bred in September. For ewes that had lambed from breeding 8 mo earlier, fertility was higher for Finn ewes than for Suffolk ewes; however, similar fertility levels were observed in both breeds if the ewes had not lambed following the previous breeding. Higher prolificacy was observed in the Finn ewes than in the Suffolk ewes, but the differences in prolificacy varied with the month of breeding. The probability of a ewe having more than one lamb was significantly higher for Finn ewes than for Suffolk ewes in both January and May breedings, but was similar in September breedings. Incorporating the Finnish Landrace breed into an accelerated breeding program for sheep maintained indoors year-round is a practical way to increase the number of lambs born. Controlling daylength and dividing the flock into smaller flocks are also practical procedures to increase lamb production.