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The use of agricultural by-products might provide an important alternative to improve animal agriculture and to reduce feeding costs. The effects of inclusion in the diet of four levels of delinted cottonseed (0, 80, 160, and 240 g/kg) on intake, digestibility, nitrogen balance, blood parameters, and the ingestive behaviour of confined sheep were studied. Twenty-four mixed-breed rams with an average body weight of 27.6 ± 2.9 kg were used in a completely randomised design with four treatments. The addition of delinted cottonseed (DCS) did not alter (P > 0.05) the intake of dry matter, crude protein, organic matter, neutral detergent fibre, or ether extract in the two forms calculated (g/day and % body weight). The use of different levels of DCS in sheep feed did not influence (P > 0.05) the voluntary water intake. The dietary DCS levels linearly affected (P < 0.05) the digestibility coefficients of the dry matter (DM), organic matter, neutral detergent fibre, ether extract, and non-fibrous carbohydrates. The DCS inclusion levels did not affect the nitrogen balance (P = 0.22), plasma concentrations of urea (P = 0.51), and glucose (P = 0.17).The feeding efficiency and rumination in g DM/h reduced linearly (P < 0.05) with the addition of DCS in the diet. Therefore, the addition of delinted cottonseed affects the intake, digestibility, and ingestive behaviour of confined sheep, and the addition of up to 80 g/kg delinted cottonseed in the diet of confined sheep is recommended.

The objective of this study was to evaluate whether dairy sheep during the transition period are affected by their parity numbers with regard to (1) body weight (BW), body condition score (BCS), and production performance (milk yield and composition) and (2) metabolic, inflammation, and stress biomarkers. For this purpose, 30 Sarda dairy ewes [15 primiparous (PRP) and 15 multiparous (MUP) ewes] were recruited on d 90 of gestation. Each group was homogeneous according to age, BW, and BCS. Sampling was carried out at -60, -30, -7, 0, +30, and +60 d from lambing. The MUP ewes showed a higher BW (46.32 vs. 38.71 kg) and larger litter size (1.45 vs. 1.06 kg) but a lower BCS (2.47 vs. 2.70) than the PRP ewes. Furthermore, the MUP ewes had lower concentrations of glucose (3.49 vs. 4.27 mol/L), cholesterol (1.63 vs. 1.81 mmol/L), free fatty acids (0.47 vs. 0.62 mmol/L), and triglycerides (0.22 vs. 0.25 mmol/L) compared with PRP ewes. With regard to inflammation and oxidative stress parameters, the PRP group had higher haptoglobin (0.48 vs. 0.18 g/L) and paraoxonase (187.90 vs. 152.11 U/L) activity than the MUP group. Overall, the MUP ewes were characterized by greater milk production performance and greater feed intake, resulting in a better energy balance, than the PRP ewes. Interestingly, these findings highlighted a different metabolic and inflammatory response over the transition period between PRP and MUP ewes, with the latter displaying lower concentrations of inflammatory-related biomarkers., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Brachiaria decumbens (signal grass) is a highly productive tropical grass that is widespread in some tropical countries due to its adaptation to a wide range of environments and soil types. However, a limiting factor for the use of this grass is its toxicity from steroidal saponins. Sporadic outbreaks of hepatogenous photosensitization in ruminants grazing on this grass have been reported. Sheep are more susceptible than other animal species and the young are more susceptible than adults. This review article will critically shed light on the B. decumbens profile, its toxic compounds, mechanisms, clinical responses, blood profile alterations, pathological changes, and acute phase responses related to signal grass intoxication. Further research is needed to integrate new findings on B. decumbens intoxication with previous preventive and therapeutic trials to minimize or remove its deleterious toxic effect., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Late-gestation ewes are susceptible to ketonemia resulting from high energy requirement for fetal growth during the last few weeks of pregnancy. High lamb mortality is a possible consequence of effects of ketonemia on both ewes and lambs. Determining risk factors to ketonemia is a fundamental step to identify ewes at risk, in order to avoid losses caused by ketonemia. Serum β-hydroxybutyrate (BHBA) concentrations of 384 late-gestation ewe samples were determined. Physical examinations, including body condition, FAMACHA © and hygiene scoring, were performed. Udders and teeth were also examined. Fecal floatation was performed to detect gastrointestinal helminth eggs of the ewe fecal samples. General feeding management practices and season at sampling were recorded. Litter sizes were retrieved from lambing records. Factors associated with log serum BHBA concentration were determined using a linear mixed model, with flock and lambing groups as random effects. The mean serum BHBA concentration was 545.8 (±453.3) μmol/l. Ewes with a body condition score (BCS) of 2.5-3.5 had significantly lower log BHBA concentrations than ewes with a BCS of ≤2.0, by 19.7% (p = 0.035). Ewes with a BCS of >3.5 had a trend toward higher log BHBA concentrations compared to ewes with a BCS of 2.5-3.5. Ewes with a FAMACHA © score of 3 had significantly higher log BHBA concentrations than ewes with a FAMACHA © score of 1 or 2, by 12.1% (p = 0.049). Ewes in which gastrointestinal helminth eggs were detected had significantly higher log BHBA concentrations than ewes in which helminth eggs were not detected, by 12.3% (p = 0.040). An increased litter size was associated with higher log BHBA concentration (p ≤ 0.003), with the log BHBA concentrations of ewes having twins, triplets, and quadruplets or quintuplets were higher than those of ewes having singleton by 19.2%, 30.4%, and 85.2%, respectively. Season at sampling confounded the association between log BHBA concentration and FAMACHA © score, and therefore was retained in the final model even though it was not statistically significant. Intra-class correlation coefficients at the flock and lambing group levels were 0.14 and 0.32, respectively., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

The study was carried out in Bensa district of Sidama zone, Southern Ethiopia. Agro-ecologically, the study sites were classified into highland and mid-altitude. The objective of the study was to identify sheep farming practices in relation to future production strategies in the study area. A total of 128 households from four kebeles (lower administrative structure) were selected purposively based on sheep population and production potential and accessibility. Data was collected through semi-structured questionnaire, focus group discussions, and key informants. The result showed that most of the household heads were male (92.75%) and mixed crop-livestock system was the dominant production system. Among the livestock species, sheep accounted for the largest proportion across the two agro ecologies and the average sheep flock size/household was 4.6 ± 0.33 and 22 4.3 ± 0.213 in highland and in mid-altitude, respectively. The primary reason of keeping sheep was for cash income and saving across the two agro ecologies. The major feed resources for sheep during the wet and dry seasons were natural pasture and crop residues respectively across the two agro ecologies. Feed shortages, disease, parasite prevalence, and market were the major sheep production constraints in highland while feed shortage, genotype, disease, parasite prevalence, and market in mid-altitude. It can be concluded that for enhancing future production from sheep in the area, emphasis is to be given on feed availability, disease management, breeding policy, and marketing strategies.

Corynebacterium pseudotuberculosis is an intracellular bacteria and the etiologic agent of caseous lymphadenitis in domestic and wildlife species. We report C. pseudotuberculosis infection in Patagonian huemul ( Hippocamelus bisulcus ) from the Cerro Castillo National Reserve, Region of Aysen, Chile. Subcutaneous abscesses in the abdominal and pectoral regions from two animals were sampled and bacteriologic isolation was performed. In both cases, we isolated a C. pseudotuberculosis strain belonging to the ovine genotype. In addition, one isolate was resistant to ciprofloxacin and streptomycin. We report that H. bisulcus is a susceptible species to this bacterium, which is transmitted by direct or indirect contact with domestic sheep ( Ovis aries ) and which represents a potential conservation threat to populations of H. bisulcus . Additional research and prevention efforts should be addressed.

Chlamydia abortus is an obligate intracellular bacterium that is an important cause of ovine abortion worldwide. There are reports of abortions in cattle, but these are very rare compared to the reported incidence in sheep. The bacterium is transmitted oro-nasally and can establish a sub-clinical infection until pregnancy, when it can invade the placenta and induce an inflammatory cascade leading to placentitis and abortion. Early host-pathogen interactions could explain differential pathogenesis and subsequent disease outcome in ruminant species. In this study, we assessed the ability of sheep and cattle oro-nasal turbinate cells to sense and respond to C. abortus infection. The cells expressed toll like receptor (TLR) 2, TLR4, nucleotide oligomerization domain (NOD) 1 and NOD-like receptor pyrin domain containing 3 (NLRP3) mRNA. In response to C. abortus infection, both ovine and bovine turbinate cells produce CXCL8 mRNA and protein late in the bacterial developmental cycle, but do not produce IL-1β or TNF-α. The UV-inactivated bacteria did not elicit a CXCL8 response, suggesting that intracellular multiplication of the bacteria is important for activating the signalling pathways. The production of innate immune cytokines from cattle and sheep turbinate cells in response to C. abortus infection was found to be largely similar., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Interactions between a host and a bacterial pathogen are mediated by cross-talk between molecules present on, or secreted by, pathogens and host binding-molecules. Identifying proteins involved at this interface would provide substantial insights into this interaction. Although numerous studies have examined in vitro models of infection at the level of transcriptional change and proteomic profiling, there is virtually no information available on naturally occurring host-pathogen interactions in vivo. We employed membrane shaving to identify peptide fragments cleaved from surface-expressed bacterial proteins and also detected proteins originating from the infected host. We optimized this technique for media-cultured Corynebacterium pseudotuberculosis, a sheep pathogen, revealing a set of 247 surface proteins. We then studied a natural host-pathogen interaction by performing membrane shaving on C. pseudotuberculosis harvested directly from naturally infected sheep lymph nodes. Thirty-one bacterial surface proteins were identified, including 13 not identified in culture media, suggesting that a different surface protein repertoire is expressed in this hostile environment. Forty-nine host proteins were identified, including immune mediators and antimicrobial peptides such as cathelicidin. This novel application of proteolytic shaving has documented sets of host and pathogen proteins present at the bacterial surface in an infection of the native host.

The ovine Callipyge mutation causes postnatal muscle hypertrophy localized to the pelvic limbs and torso, as well as body leanness. The mechanism underpinning enhanced muscle mass is unclear, as is the systemic impact of the mutation. Using muscle fibre typing immunohistochemistry, we confirmed muscle specific effects and demonstrated that affected muscles had greater prevalence and hypertrophy of type 2X fast twitch glycolytic fibres and decreased representation of types 1, 2C, 2A and/or 2AX fibres. To investigate potential systemic effects of the mutation, proton NMR spectra of plasma taken from lambs at 8 and 12 weeks of age were measured. Multivariate statistical analysis of plasma metabolite profiles demonstrated effects of development and genotype but not gender. Plasma from Callipyge lambs at 12 weeks of age, but not 8 weeks, was characterized by a metabolic profile consistent with contributions from the affected hypertrophic fast twitch glycolytic muscle fibres. Microarray analysis of the perirenal adipose tissue depot did not reveal a transcriptional effect of the mutation in this tissue. We conclude that there is an indirect systemic effect of the Callipyge mutation in skeletal muscle in the form of changes of blood metabolites, which may contribute to secondary phenotypes such as body leanness.

Background: Helicobacter canis has been associated with hepatobiliary and gastrointestinal disease in dogs, cats, and humans. Infection has not been documented in other species., Materials and Methods: Sheep feces subjected to microaerobic culture. Isolates were characterized by genus-specific PCR, restriction fragment length polymorphism, biochemical profiling, and 16S rRNA sequence analysis., Results: Helicobacter canis was isolated from sheep feces and confirmed by the above methods. These isolates are distinct from other sheep-origin enterohepatic Helicobacter species previously isolated., Conclusions: This study identifies sheep as H. canis reservoirs potentially important in zoonotic or foodborne transmission., (© 2013 John Wiley & Sons Ltd.)

Modern livestock breeding practices provide new opportunities for producing animals that are adapted to their production environment and are free of disease. Using current knowledge of biology and by seeking 'the desired outcome' animal selection strategies can be designed that deliver more precisely defined results so maximising genetic gain and minimising risk. This review briefly describes the evolution of genetic selection in livestock and considers some of the positive and negative aspects of selection practices over time. The selection of sheep to withstand gastro-intestinal nematode parasitism is used as an example to explain how developments in selection strategy have improved genetic progress for complex traits. Re-evaluation of the understanding of the outcomes of selection for parasite resistance is used here to examine whether a more sophisticated approach is desirable, and to propose a number of additional phenotype measurement strategies that could complement and improve the quality of information used for animal selection. Finally some ideas are presented for creating a situation where a designed, highly defined breeding objective might be used to increase precision and reduce risk. This may become possible via research to adapt or develop tools for more sophisticated phenotypic evaluation, to discover biological processes integral to desired breed changes, and to define desired animal types which match economic and societal expectations., (Copyright © 2013. Published by Elsevier Ltd.)

In a female White Polled Heath a congenital shortening and abnormal bending of the tail was observed. The trunk appeared to be shortened and almost quadratic. However, further findings could not be ascertained in the general clinical, neurological and orthopaedic examination. Maceration of the trunk skeleton showed vertebral fusion in several segments of the vertebral column and a wedge-shaped vertebra of the cervical spine, causing slight scoliosis. In addition, several ribs were fused. Exogenic causes such as drugs or viral infections during pregnancy were unlikely, whereas hereditary could not be ruled out.

Bighorn sheep populations have greatly declined in numbers and distribution since European settlement, primarily because of high susceptibility to infectious diseases transmitted to them from domestic livestock. It has been suggested that low variation at major histocompatibility complex (MHC) genes, the most important genetic aspect of the vertebrate immune system, may result in high susceptibility to infectious disease. Therefore, we examined genetic polymorphism at a MHC gene (Ovca-DRB) in a large sample, both numerically and geographically, of bighorn sheep. Strikingly, there were 21 different alleles that showed extensive nucleotide and amino acid sequence divergence. In other words, low MHC variation does not appear to be the basis of the high disease susceptibility and decline in bighorn sheep. On the other hand, analysis of the pattern of the MHC polymorphism suggested that nonsynonymous substitutions predominated, especially at amino acids in the antigen-binding site. The average overall heterozygosity for the 16 amino acid positions that are part of the antigen binding site is 0.389 whereas that for the 67 amino acid positions not involved with antigen binding is 0.076. These findings imply that the diversity present in this gene is functionally significant and is, or has been, maintained by balancing selection. To examine the evolution of DRB alleles in related species, a phylogenetic analysis including other published ruminant (Bovidae and Cervidae) species, was carried out. An intermixture of sequences from bighorn sheep, domestic sheep, goats, cattle, bison, and musk ox was observed supporting trans-species polymorphism for these species. To reconcile the species and gene trees for the 104 sequences examined, 95 'deep coalescent' events were necessary, illustrating the importance of balancing selection maintaining variation over speciation events.

The effects on liveweight gain and development of immunity were studied in lambs trickle infected for 8 weeks with either a benzimidazole-resistant isolate (Moredun ovine resistant isolate, MORI), a multiple benzimidazole + ivermectin-resistant isolate (Moredun caprine resistant isolate, MCRI) or an unselected susceptible isolate (Moredun ovine susceptible isolate, MOSI) of Teladorsagia circumcincta. Plasma pepsinogen concentrations of infected groups were significantly elevated compared to an uninfected control group (P < 0.001) by day 14. The liveweight gains varied markedly but there were no statistical differences between the infected and uninfected control groups at any point in time during the study. Lambs infected with the MORI had significantly lower faecal consistency scores than the other challenged groups on days 7 and 14 (P < 0.05) but from day 21 onwards, faecal consistencies were similar in all of the groups. There was a notable difference in the pre-patent periods of the different isolates with the MOSI producing positive faecal egg counts (FECs) by day 14 of the study. The FECs remained reasonably low once infections had reached patency and there were no further differences between the groups. Following administration of anthelmintic to remove residual worms from the trickle infection, no differences between the infected groups in terms of worm burden or mucosal mast cell numbers were evident as a consequence of a single challenge infection. The changes in genetic code associated with enhanced resistance against anthelmintics do not appear to have resulted in any fundamental alteration of the pathogenicity and immunogenicity of these three isolates of Teladorsagia.

The Spanish sheep and horse strains of Echinococcus granulosus possess several differential characteristics in their metacestode stage. Cysts from sheep vary widely in size and fertility, but they usually have a thin cyst wall and, when fertile, a whitish hydatid sand formed by brood capsules and protoscoleces. Two types of infections have been observed in horses: one resembling that of sheep, caused by small, non-fertile cysts with a thin wall, and a second type caused by medium to large, always fertile cysts with a thick wall. In this latter case, hydatid sand is always dark brown in color and formed mainly by brood capsules (with almost no free protoscoleces) and abundant calcareous corpuscles. These characteristics of the fertile equine cysts, which were identified in other studies by genetic, biochemical, immunological and physiological criteria as belonging to the horse strain, have not been previously described nor observed in cysts from other host species. It is considered that the horse strain possesses a strong intermediate host specificity.

Ovine footrot is a contagious disease of sheep that occurs in temperature climates. It is caused by the strict anaerobe, Dichelobacter nodosus. Benign and virulent organisms are differentiated according to serotype and protease production. This study was conducted to identify the presence of virulent serotypes of D. nodosus in sheep flocks in Alberta and British Columbia. Dichelobacter nodosus was detected in lame sheep from 11 of 15 (73%) flocks in Alberta and in 4 of 5 (80%) British Columbia flocks. It was recovered from 57 of 107 (53%) lame sheep. In Alberta, 4 distinct serotypes were isolated from the 11 positive flocks while in British Columbia a total of 6 different serotypes were isolated. One British Columbia isolate could not be classified into existing serotypes. Of the 19 field strains tested, all but 3 were defined as virulent based upon the rapid rise in protease activity in vitro which was maintained between 3 and 5 d. The knowledge of the serotype and virulence of the D. nodosus isolated from affected animals can assist in the control and prevention of ovine footrot.

The trial was carried out to investigate parasite host specificity and to analyse the dynamics of infection with nematodes parasitizing sheep and cattle raised together or separately in São Paulo state, Brazil, and, also to clarify doubts about the systematics of species of the genus Haemonchus on the basis of cytological and morphological studies. Ten steers and 32 ewes were randomly assigned to three paddocks (P), as follows: P1, 5 steers; P2, 5 steers and 16 ewes; and P3, 16 ewes. The animals remained on these paddocks in continuous grazing throughout the trial (1-yr period). Faecal exams and larvae counting on pasture were performed fortnightly. Once a month two tracer lambs were placed in each paddock, while two tracer calves were also placed, but only in the eighth month of the trial. All these animals were slaughtered for worm identification and counting. At the end of the trial, one steer and one ewe from P2, which showed high faecal egg counts, were also slaughtered for the same purpose. Nematodes identified cytogenetically as H. placei presented spicule hooks longer than those identified as H. contortus. The following distribution of parasites in cattle and sheep was observed: Bunostomum phlebotomum, H. similis, Mammomonogamus laryngeus strongly adapted to cattle, H. placei and Cooperia punctata more adapted to cattle than to sheep, Trichostrongylus axei and C. spatulata apparently more adapted to cattle, T. colubriformis strongly adapted to sheep, H. contortus more adapted to sheep than to cattle and C. curticei apparently more adapted to sheep. Cross-infection was shown to occur involving some species, however, with time the animals apparently eliminate the species that are not well adapted to them. Therefore, grazing management systems using cattle and sheep appear to be promising for worm control in southeastern Brazil.

Oestrosis or infestation of sheep, goats, ibex, argali and sometimes man with Oestrus ovis maggots is a real problem in sheep-farming areas allover the world. Parasitism in sheep may be benign, the majority of cases do not terminate fatally, but death may come within a week after appearance of aggravated symptoms. In man, ophthalmomyiasis (sometimes nasopharyngeal) may be benign to destruction of the eye ball or the entire eye in misdiagnosis. In the present study, examination of 1200 slaughtered sheep heads at Cairo abattoir, showed 104 (8.67%) infested with O. ovis maggots. Sheep were parasitized all the year round with more or less maximum number (12.5%) in September. The sex ratio of parasitized sheep (female to male) was 1:2.71. A total of 556 maggots were recovered allover the year with a peak in March (12.6%). The peak for the first instar larvae recovered was September (17.4%), for the second instar was March (15.7%) and for the third instar was June (11.6%). Older sheep were more infested (12.0%) with oestrosis than smaller ones (6.87%). The whole results were discussed.

Research in the last 20 years has firmly established that it is possible to exploit genetic variation in resistance to the nematode parasites of sheep by selection. Selected sheep are more resistant to infection and commercial application of this research is under way in both Australia and in New Zealand. Not all the consequences of these breeding programs have been established, particularly long-term consequences for productivity and the interaction with other control measures, but the technology is available in the public domain with no commercial restrictions. Faecal worm egg count remains the most effective way of selecting sheep although many alternatives, such as DNA markers, host antibody and parasite antigen assays are being developed for use as selection criteria. Strategic nutritional supplementation is an immediate candidate for inclusion in worm control programs and although nematode vaccines remain elusive, it is likely that some will be field-tested in the next few years. For both of these approaches, nutritional and immunological, it is critical that the response of selected genotypes are assessed under commercial conditions and as components of worm control programs. There is evidence to support the possibility that selected sheep will be more responsive to vaccination while the long-term interaction between the effect of strategic nutritional supplements and resistant genotypes needs to be investigated.

A three month old lamb suffering from locomotory disturbances was submitted to the clinic. It had a tilted head to the left and an atactic gait especially in the hind limbs. When it was forced to stop or to change direction it fell down. General condition and sensorium were apart from a reduced bathyaesthesia normal. By clinical and laboratory examination some possible causes of locomotion disturbances in lambs like copper deficiency, nutritive muscle dystrophy and meningitis could be ruled out. By X-ray examination an asymmetry of the os occipitale and atlas was diagnosed. They were not well distinguishable from each other. The second vertebra showed a rotation with angulation of its longitudinal axis to the left and a dorso-lateral subluxation. By myelography a narrowing of the vertebral canal between first and second vertebra could be shown. Because of the poor prognosis the animal was euthanised. The pathological examination confirmed and completed the X-ray findings.

In 144 clinical healthy and 97 sick sheep pneumotachographic investigations were performed. In 119 sheep the diagnoses "healthy" based on adspection, auscultation and palpatory percussion. In 25 additional healthy and in the sick animals the diagnoses based on clinical, endoscopical, serological, parasitological, and in 82 animals also pathomorphological findings. According to these diagnoses the animals were divided into the following groups: G = healthy, K = catarrhal purulent bronchopneumonia, E = suppurative pneumonia, W = verminous pneumonia, M = Maedi, MKE = Maedi + catarrhal purulent or suppurative pneumonia, MAKE = Maedi + Adenomatosis + catarrhal purulent or suppurative pneumonia, AKE = Adenomatosis + catarrhal purulent or suppurative pneumonia, and FAKE = animals of the AKE group at an earlier date of investigation. In all sheep respiration rate, tidal and minute volumes, forced tidal volume, peak flow and resistance were measured with the portable pneumotachograph Flowscreen. Tidal and minute volumes and flow rates depended at rest as well as after forced ventilation essentially from the respiratory rate and from the body weight of the animals. The average individual coefficients of variation of repeated measurements of healthy animals were between 21% and 36%. Only in tidal volume after forced ventilation (10%) and in the resistance (18%) the individual coefficients of variations were lower. In 57% of the animals with Lung Adenomatosis resistance-values over 0.4 kPa*s/l were measured, but in 94% of the sheep without adenomatosis resistance-values remained under this limit.

Nuclear transfer procedures were used to determine the in vivo developmental potential of an ovine embryonic cell line isolated from the inner cell mass of a Day 8 blastocyst-stage embryo. This cell line possessed a differentiated epithelial-like cell morphology. In this study, a comparison was made between in vivo- and in vitro-derived oocytes used as recipient cytoplasts in the nuclear transfer procedure. Cultured cells were induced to quiesce and enter presumptive G0 before being used as donor karyoplasts between passages 8 and 16 of culture. After cell fusion, reconstructed embryos were cultured for 6 days in vitro in embryo culture medium. Blastocyst-stage embryos were subsequently transferred to synchronized recipient ewes (n = 37), and development was allowed to proceed to term. There was a significant effect of source of recipient cytoplast, with development being consistently greater with in vivo compared to in vitro cytoplasts in terms of, respectively, blastocysts produced (24.2 +/- 3.8% vs. 17.1 +/- 2.3%; p = 0.1), Day 35 pregnancy rate (40.0% vs. 9.1 %; p < 0.05), and Day 35 embryo survival (19.4% vs. 4.5%; p < 0.05). A high proportion of fetuses died during late gestation (5 of 8). The major abnormalities were associated with the urogenital tract. However, three lambs were delivered alive following cesarean section on Day 147. One lamb, derived from an in vitro-matured oocyte, died after 10 min, while the remaining two from in vivo-ovulated oocytes are apparently normal and healthy. DNA microsatellite markers conclusively show that the three lambs are genetically identical and were derived from the embryonic cell line. In conclusion, some cells from this blastocyst-derived embryonic cell line are totipotent by nuclear transfer and can produce viable offspring.

The aim of this study was to compare different bacteriological aspects of the respiratory systems of healthy (H) versus unhealthy (UH) animals with respiratory signs. The prevalence of different bacterial species was determined in the upper and lower respiratory tract of H and UH Najdi sheep, Somali sheep and Holstein calves. The characteristics of Pasteurella spp. isolates, and the biotype of Pasteurella haemolytica were identified in H and UH animals, Eighteen out of 28 (64.3%) of the identified bacterial species in the upper respiratory tract were more prevalent in the nasal cavities of UH Najdi and Somali sheep and Holstein calves with respiratory signs than in apparently healthy animals; four of the most prevalent bacteria in the upper respiratory system of UH sheep were Moraxella spp., Pseudomonas pseudomallei, Erysipelothrix spp., Pasteurella multocida, while three of the most prevalent bacteria in UH calves were Pasteurella haemolytica, Actinomyces spp., and Pseudomonas aeruginosa. The prevalence of six different bacterial species was greater in the lungs of UH animals, namely Actinomyces pyogenes, Erysipelothrix spp., P. haemolytica, Pasteurella ureae, Staphylococcus aureus, and Staphylococcus epidermidis, which could be risk factors in the complexity of the prevalent respiratory diseases of the animals surveyed. Of the biochemical, cytological and colonial characteristics studied in the identified P. haemolytica and P. multocida, two characters were significantly different (p < 0.05) in organisms isolated from UH as compared to those from H animals. These were the higher loss of haemolytic power by the strains of P. haemolytica and the decreased fermentation of trehalose by all the strains of P. multocida recovered from healthy animals. The only biotype of P. haemolytica isolated from H animals was biotype A, while both biotypes A (88.0% of the isolates) and T (12.0% of the isolates) were recovered from UH animals.

Samples of dipteran larvae were collected from live sheep throughout Scotland, reared in the laboratory, and identified once adult flies emerged. Lucilia sericata was found in 77% of samples, and other species in 49%. The most common alternative species were L.caesar, which occurred in 31% of samples, and Protophormia terraenovae, which occurred in 18%. Three other calliphorid species, Calliphora vomitoria, C.vicina and L.illustris, and the muscid Muscina pabulorum were also found. The proportion of samples containing alternative species was significantly lower in eastern Scotland than in western Scotland. Significantly higher proportions of samples containing alternative species were collected at altitudes of 200m and above; from sheep of hill breeds; from rough grazing conditions and moorland; in the absence of trees; and in the presence of bracken.

The distribution of Chabertia (Ch.) ovina, Oesophagostomum (O.) venulosum and Trichuris spp. within the large intestine of naturally infected sheep in the dependence of worm counts and the presence of nematodes of other species or genera was evaluated. The large intestine was divided into 4 sections. More than 75% of Ch. ovina were found within the disk-like section of the colon independently from worm count and presence of nematodes of other species. O. venulosum and Trichuris spp. preferred the caecum and the first section of the colon up to the beginning of the disk-like section. In both, the share of worms recovered from the first section of the colon did increase with higher worm counts. The simultaneous presence of O. venulosum and Trichuris spp. had a significantly negative influence on the share of Trichuris spp. isolated from the caecum.

A review is given on the significance, availability, metabolism and application of vitamin E and selenium in sheep. Vitamin E deficiency commonly occurs in spring. Selenium deficiency occurs in certain areas where the selenium content of plants is low. A further factor is the low availability of selenium as a consequence of reduction reactions in the forestomachs. When the supply of vitamin E and selenium is suboptimal, activity of the immune system and growth are impaired.

The relationship between the faecal egg count and the worm burden of the gastrointestinal tract of sheep was examined. Close relationships were found in strongyles, Trichostrongylidae (other than Nematodirus spp.), Nematodirus spp., Strongyloides papillosus, Chabertiidae and Trichuris spp.. Due to high percentage of false negative diagnosis from faecal examination, this relationship was in Nematodirus spp. and Trichuris spp. not as close as in the other nematodes. However, the results support the high diagnostic value of quantitative faecal examinations in sheep.

Fleece rot is an exudative bacterial dermatitis in sheep associated with and initiated by prolonged wetting of the skin. It is the major predisposing disease for flystrike (cutaneous myasis). Based on limited data in the literature, P. aeruginosa is considered to be the main causative organism of fleece rot. This study investigated the occurrence of P. aeruginosa in fleece washings from sheep affected and unaffected with fleece rot under field conditions. Three field surveys of a total of 1568 sheep showed that 646 (41%) were affected with fleece rot and of these 646 sheep. P. aeruginosa could not be detected in 554 (86%). This suggests that other fleece bacteria play a significant role in fleece rot. However, the surveys consistently showed that the presence of P. aeruginosa was associated with increased severity of fleece rot and subsequent flystrike. Although it might only contribute in part to the disease complex, the importance of P. aeruginosa can not be underestimated and warrants consideration for inclusion in future fleece rot vaccines.

The genetic basis of the high resistance of Indonesian Thin Tail (ITT) sheep against Fasciola gigantica has been studied by measuring the resistance levels of ITT sheep, St. Croix sheep and their F2 and F3 crossbreds. All of the sheep were bred and reared in the same environment. Approximately half of the F2 and F3 crossbreds were as resistant as the ITT parental breed, one-quarter had the low resistance of the St. Croix parental breed and the rest had an intermediate level of resistance. It is concluded that the high resistance is determined by a major gene with incomplete dominance. The prevalence of the gene in the ITT sheep population is estimated to be about 90%. The resistance may be innate or acquired; but, regardless of the mechanism, it could be used to control fasciolosis caused by F. gigantica by breed substitution or by crossbreeding with other breeds of sheep.

Faecal strongyle egg counts were monitored in peri-parturient ewes and dry ewes grazing in a rubber plantation in North Sumatra, Indonesia. A significant rise in faecal egg counts was observed during the post-parturient period. Haemonchus contortus was the dominant species in the faecal cultures of the lactating ewes. The intensity of the peri-parturient rise was affected by the genotype of the sheep, which were the local Sumatra and its F1 crosses with St. Croix, Barbados Blackbelly and Java Fat-tail. The peri-parturient rise in egg counts was highest in Sumatra and lowest in the Barbados Blackbelly x Sumatra cross. A significant effect of litter size on the peri-parturient rise was also demonstrated. These findings are discussed in relation to the epidemiology and control of gastrointestinal nematodes in the humid tropics.

This study examined whether infective larvae (L3) of Trichostrongylus colubriformis could establish throughout the small intestine and were not restricted to the anterior duodenum in susceptible and resistant sheep. The location of worms was similar in susceptible animals given doses of T. colubriformis between 10,000 and 80,00 T. colubriformis larvae, with 90% of worms located in the proximal 3 m of the small intestine. Those worms recovered from resistant sheep were also found in the first 9 m of the intestine. However, worms recovered from immune sheep were significantly (P = 0.0074) relocated posteriorly from the first 3 m into the next 6 m of the intestine. By the surgical introduction of worms, it was found that T. colubriformis could establish at any site in the small intestine and to some extent in the caecum. Immunity was generated principally in the site of predilection in the anterior 3 m of the small intestine and effectively expelled challenges given at distal sites and caecum, indicating dissemination of immunity throughout the gastrointestinal tract. Moreover, the rejection episode had removed worms from the entire small intestine within 2 h of introduction through the pylorus.

Fifty-five rams aged about 18-24 months weighing 30-42 kg were used in this study. Ten rams of each of four genotypes, S (Sumatra), H1 (50% Sumatra-50% Virgin Island), B1 (50% Sumatra-50% Barbados Blackbelly), E1 (50% Sumatra-50% Java Fat-tail), were infected orally with a newly isolated strain of Haemonchus contortus. Each animal received 2000 infective larvae 3 times week-1 for 3 weeks, with a total of 18,000 larvae. Fifteen rams belonging to Sumatra and its crosses with Virgin Island were used as uninfected controls. Peak egg counts were observed on Day 35 for genotype B1 and on Day 42 for genotype H1 and S. In genotype E1 a slow but consistent increase in EPG continued until Day 49 when the experiments terminated. Overall faecal egg counts at all sampling dates were not statistically different between genotypes (P > 0.05). There was a large variation in the EPG of individual rams within a genotype. The overall average EPG (geometric means) of individual rams within a genotype ranged from 3 to 1028 for B1, 4 to 261 for E1, 7 to 3119 for H1 and 9 to 506 for S. The analysis of packed cell volume (PCV) for four genotypes and controls from all sampling times showed significant differences (P < 0.05). The overall mean PCV was highest in S (31.1) and lowest in H1 (28.4). The ranking of four genotypes for PCV was S > E1 > B1 > H1. The decrease of PCV during the course of infection was highly significant for all genotypes of infected rams (B1, E1, H1, S) (P < 0.01). PCV of the control group did not exhibit much change during the course of the experimental period. Weight gain of infected rams was lower than those of uninfected controls (P < 0.5) but there was no significant difference between the four genotypes of infected rams. Individual variation within genotype in susceptibility to infections was generally more important than between genotype differences. Two major conclusions of the present study are: (1) The imported breeds with higher body weight, namely the Barbados Blackbelly and Virgin Island, may be used in cross breeding to increase the body size of local Sumatra sheep. (2) Based on the faecal egg counts it is possible to identify the animals for use in selective breeding programmes for higher resistance to H. contortus.

This survey was conducted in the southern Brazilian state of Rio Grande do Sul and involved 182 farms located in 26 counties. In addition to the three major broad-spectrum anthelmintic groups (viz. benzimidazole, levamisole and ivermectin) the combination benzimidazole and levamisole and the H. contortus specific anthelmintic, closantel, were tested by the faecal egg count reduction method for the prevalence of anthelmintic resistance. Resistance was found to be 90%, 84%, 13%, 73% and 20%, respectively. This is a crisis situation. Immediate, drastic action needs to be implemented, otherwise the sheep industry in this region (approx. 10 million head) will soon face a lack of any effective anthelmintics with the inevitable consequences of major restructuring or abandonment.

This survey to detect anthelmintic resistance in nematode parasites of sheep was conducted on 11 farms in the Occidental and 26 farms in the Oriental Regions of Paraguay using the faecal egg count reduction test (FECRT). The anthelmintic groups tested were the benzimidazoles, levamisole and avermectins (both oral and injectable). Overall the levels of resistance were 73%, 68%, 73% and 47%, respectively. Levels of resistance were similar for all three important nematode genera, viz. Haemonchus contortus, Ostertagia and Trichostrongylus. This survey clearly indicates that a large, and ever increasing, proportion of sheep farmers are rapidly approaching the time when they will have exhausted all chemotherapeutic options to control parasites. Unless they face having to abandon their sheep farming operations, radical changes will need to be implemented with urgency.

South America has a large population of small ruminants. Currents estimates are approximately 100 million sheep and 23 million goats. A large percentage of these flocks are raised in the humid tropics/sub-tropics. Nematode parasitism is singly the most important disease of these animals and typically farmers resort to frequent anthelmintic treatment in attempts to control this problem. Because of this reliance on drugs, price consideration is an important determinant in a farmer's choice of anthelmintic. In some circumstances, this has led to unethical practices of drug adulteration and substitution, or the offering to farmers of cheap, sub-standard generic products. The prevalence of anthelmintic resistance has not been investigated in any widespread sense in South America, although some of the first reports of resistance were made in southern Brazil almost 30 years ago. The following series of papers outline surveys conducted in the humid topics/sub-tropics of southern Latin America to assess the significance of resistance to the broad-spectrum anthelmintic groups in nematode parasites of sheep flocks.

This survey was conducted on 252 farms randomly distributed over all the sheep raising areas in Uruguay. The study involved farms with more than 600 sheep, which represented 80% of the total sheep population of the country. Three anthelmintic groups were assessed, namely, benzimidazoles, levamisole and avermectins. Overall, the results showed 80% of sheep flocks had benzimidazole resistance, 71% had resistance to levamisole, and 1.2% of flocks showed resistance to avermectins. Approximately 28% of farms had resistance to one anthelmintic group, 64% to two anthelmintic groups, and 1% resistance to all three groups. Only 7.5% of farms had no detectable levels of anthelmintic resistance. More than 80% of farms had Trichostrongylus populations resistant to both benzimidazoles and levamisole. Resistance was recorded in all three anthelmintic groups for Haemonchus and resistance also occurred to benzimidazoles and levamisole in Ostertagia.

Sixty-five sheep farms in the northern provinces of Buenos Aires, Entre Rios, Corrientes, Cordoba and Sante Fe were used in this survey on anthelmintic resistance. Anthelmintic groups tested were the benzimidazoles, levamisole, the combination levamisole + benzimidazole product and the avermectins. The overall level of resistance was 46% of properties, with resistance to the individual drug groups being 40%, 22%, 11% and 6%, respectively. On a large proportion of farms the resistance recorded was to two, or more, anthelmintic groups. Haemonchus contortus, Ostertagia spp. and Trichostrongylus spp. were the most abundant parasite species recorded. Resistance was greatest in the province of Corrientes where the frequency of treatment is generally high due to the endemic nature of H. contortus. Management practices were also important with resistance greatest on farms where frequent drenching is carried out and on farms carrying only sheep.

Growing lambs (mean liveweight 22.4 kg) were used to test for the effects of long-term subclinical infection with Trichostrongylus colubriformis (2500 larvae per day) on the voluntary food intake (VFI), diet selection and performance of sheep given a choice between two foods of different protein content (low versus high). Sheep were either uninfected controls or parasitised for 27 weeks (Group 27P). Additional sheep were infected for either 9 or 18 weeks (before and after the development of complete resistance to parasites, as assessed by faecal egg counts) and then treated with anthelmintic to remove the parasites (Groups 9P and 18P). Group 18P remained uninfected after anthelmintic treatment whereas Group 9P was infected again for the last 9 weeks after a 9 week worm-free period. The VFI declined or remained static from Week 5 up to Week 11/12 of continuous infection, for the 27P and 18P groups. For 9P sheep, VFI recovered within a few days after the anthelmintic administration and was unaffected during re-infection over the last 9 weeks of the experiment. Diet selection changed in such a pattern that the proportion of the high protein food (prop H) in the selected diet started to increase from Week 6 of the infection. The prop H selected remained higher over the interval 10-18 weeks of the continuous infection for 27P and 18P groups than the uninfected controls. There were no significant differences in diet selection among any of the groups beyond Week 18 of the experiment. The infection caused a growth check from Week 7 to approximately Week 12/14 of dosing; these was no evidence of compensatory growth following the development of resistance or recovery. The results are consistent with the view that sheep given a choice between two appropriate foods will modify their diet selection in order to moderate the adverse effects of subclinical nematode infection. The performance and diet selection of all sheep beyond Week 18 of infection suggest that no obvious nutritional penalties are incurred with the continuation of the infection once the animals have become resistant to parasites.

Age-related changes in hepatic drug metabolizing activities of Lacaune ewes were determined in foetal, neonatal, growing, pregnant and adult animals. The ontogenic evolution of cytochrome P450 was compared to those of microsomal monooxygenases and some microsomal and cytosolic transferases. The involvement of two purified izoenzymes P4502B and P4503A was determined in the N-demethylation of various substrates and the hydroxylations of progesterone. An experimental fascioliasis, provoked by the oral administration of 150 metacercariae of Fasciola hepatica to sheep, was proposed as a pathological model. Its effect was measured on the pharmacokinetics of various hepatic tracers and veterinary drugs. The mean residence times of antipyrine, pentobarbital, albendazole and mebendazole were increased in infected lambs with consequences on the urinary excretion of 4-hydroxyantipyrine, prolongation of pentobarbital-induced sleeping time, elimination of albendazole sulfone and reduced mebendazole. The characteristic decrease in liver cytochrome P450 could be responsible for most of the pharmacokinetic and pharmacodynamic changes observed in fluke-infected ruminants.

Effects of protein supplementation and of nematode control on production responses in young grazing sheep and on nematode population dynamics were assessed. Young Merino wether sheep (n = 270) were allocated to one of three supplementation (Su) treatments and one of three regimes of nematode control (drench, Dr) in a factorial design. Each of the nine treatments was replicated three times in a randomised complete block. Animals received no supplement (Su0) or were given supplements at a level equivalent to 200 g day-1, fed three times a week. The supplements contained 25% lucerne meal with either 75% sunflower meal (Su1) or 75% formaldehyde-treated sunflower meal (Su2). Nematode control regimes were: not drenched unless survival of individual animals was threatened (Dr0); drenched according to a strategic drenching programme (Dr1); treatment with a controlled-release albendazole capsule (Dr2). Infections with Haemonchus contortus were suppressed by use of closantel. Due to drought conditions and lack of pasture growth, lucerne hay was fed to all sheep from Week 14 onwards (350 g per head per day, fed twice a week). Supplementation reduced the need for 'survival drenching' in Dr0 sheep considerably. Live-weight gain was increased significantly by supplementation with Su1 or Su2 during the 36-week experiment. Undrenched animals given Su1 or Su2 tended to grow faster than unsupplemented animals in the Dr1 and Dr2 groups. Greasy wool production and fibre diameter were increased by supplementation and anthelmintic treatment. Faecal worm egg counts (FEC) in undrenched sheep were significantly lower for Su1 and Su2 sheep than for Su0 sheep. There were no effects of supplementation on FEC in Dr1 or Dr2 sheep. Worm burden was generally unaffected by supplementation, while the drenching treatments Dr1 and Dr2 reduced worm burden at Week 16 and to a lesser extent at Week 27. Trichostrongylus colubriformis was the predominant nematode species, with smaller numbers of Nematodirus spp., Trichostrongylus vitrinus, Trichostrongylus axei and Ostertagia circumcincta also present. It was concluded that supplementary feeding with protein meal substantially reduced production losses attributable to nematode infections in young grazing sheep. This appears to be due to an enhanced resilience of the host, rather than any major changes in development of protective immunity.

The concentration of hemoglobin, hematocrit, number of erythrocytes and content of iron in the bloodserum of 35 sheep or lambs from five herds in which Eperythrozoon ovis was demonstrated in summer 1994 in bloodsmears by staining with acridinorange are compared with the findings in 70 animals of the same farms which did not suffer from eperythrozoonosis or which were already treated. Sick animals showed significantly lower levels than clinically healthy sheep except for iron. Eperythrozoonosis is characterised by anaemia, poor weight gains or weight reduction. The mortality in lambs reaches up to 28%. Oxytetracyclin was injected subcutaneously for therapy in a single dose of 20 mg/kg bodyweight. Two weeks after treatment the lambs had less clinical symptoms, the ewes needed up to four weeks. Also eggs of trichostronglylids, coccidia, and once of tapeworms were demonstrated and specifically treated. The transmission of the disease and the economic impact are discussed.

The gynaecological laparoscopy is basical for the correct diagnosis of the ovaries and the uterus in sheep. Physiological (follicles, corpora lutea) and pathological findings (follicle cysts) are described and illustrated. Further, application techniques of the laparoscopic intrauterine insemination as well as of the embryo recovery and embryo transfer in embryo transfer programs are explained.

Autopsy of Soay Sheep on St. Kilda revealed the presence of cysticerci of Taenia hydatigena despite the absence of the definitive host on the island. Both the intensity of infection and the prevalence increased with age implying that the sheep did not acquire immunity to reinfection or superinfection. The sheep on average ingested approximately 2.4 eggs per annum. This is far below that expected if an infected dog had visited the island even on a single occasion. The data provide evidence that taeniid eggs are being transported against the prevailing wind by wildlife from at least the nearest inhabited land mass to St Kilda some 60 km distant.

Fifteen weaned crossbred (Suffolk x Louisiana Native) lambs were treated with albendazole (10 mg kg-1) to remove existing nematode infections. They were inoculated with Haemonchus contortus infective larvae from a residual population surviving treatment with the oral formulation of ivermectin (0.2 mg kg-1). One group of five lambs remained untreated, another group of five was treated with the injectable formulation of ivermectin (0.2 mg kg-1), and a third group of five was treated with the oral formulation of ivermectin (0.2 mg kg-1). Subsequent to the treatments, there was essentially no difference in mean fecal egg count or mean number of H. contortus recovered at necropsy between the three groups.

Transmission of Leptospira interrogans serovar hardjo subtype hardjobovis from naturally infected sheep to uninfected sheep and calves was studied. A microscopic agglutination test and ELISA were used to determine specific antibody responses in serum. Polymerase chain reaction was used to detect bacterial shedding in urine. Six sheep were derived from a dairy farm where cows were infected with L hardjobovis. Three of these sheep were seropositive for L hardjobovis, and 1 also shed leptospires in the urine. The other 2 sheep shed leptospires in the urine 7 days after the first observation date. The 6 sheep were placed on an isolated pasture together with a second group of 6 noninfected sheep. During the observation period of 140 days, 1 sheep of the second group became infected with L hardjobovis. On 5 consecutive days, a urine mixture from the 4 infected sheep was sprayed on the heads of 4 noninfected calves. Within 56 days, all calves that had been sprayed with urine shed L hardjobovis in the urine and became seropositive for L hardjobovis.

Bacteroides nodosus isolates from 62 sources in the United States were obtained from sheep with infectious foot diseases. Serotypic analysis of these isolates revealed 21 serotypes (designated I-XXI). These serotypes were compared with British and Australian/New Zealand B nodosus strains by use of reciprocal tube agglutination tests. These tests, as well as the cross-matching tube agglutination tests of the US serotypes, resulted in arranging the US serotypes into 11 serogroups, and comparing these serogroups with their Australian/New Zealand serogroup and British serotype counterparts. Three US serogroups and 1 additional British serotype had little or no relationship to any of the Australian/New Zealand serogroups A-H (the vaccine strains). One or more of these unrelated serogroups were found in 29% of the sources studied. The most frequently found US serotype was serotype XV at 29%. The most frequently found US serogroups were the serogroups analogous to serogroup B (43.5%) and serogroup H (37%); the other serogroups were found in 22.6% or less of the sources studied. Evaluation of 3 sources revealed that multiple serotypes in a single flock are common, multiple serotypes from a single lesion are possible, B nodosus isolates obtained from goats (unlike those from cattle) appear identical to the isolates obtained from sheep, and disease can appear in vaccinated animals, even in a flock that appears to be harboring only a single serogroup-B serotype (the serogroup for which there are 3 strains in the current vaccine).

Several parameters of immune competence were measured in lambs with genetic resistance to Haemonchus contortus and in lambs with average susceptibility to H contortus (random-bred). Increase in skinfold thickness following intradermal injection was greater in resistant lambs for concanavalin A and to a lesser extent for phytohaemagglutinin. Both mitogens induced infiltration of superficial and deep dermis by eosinophils, CD4+, CD8+ and T19+ lymphocytes, though the responses did not differ between groups. Primary but not secondary antibody responses to the T cell-dependent antigen, ovalbumin was greater in resistant lambs. In contrast, antibody responses to the T cell-independent antigen, Brucella abortus lipopolysaccharide, did not differ between groups. Taken together the data suggest that enhanced T lymphocyte function may contribute to the greater resistance to H contortus of genetically resistant lambs.