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Concept: Domestic sheep

167

Sheep scab is an intensively pruritic, exudative and allergic dermatitis of sheep caused by the ectoparasitic mite Psoroptes ovis. The purpose of the present study was to investigate the effect of P. ovis infestation on different components of the ovine epidermal barrier within the first 24 hours post-infestation (hpi). To achieve this, the expression of epidermal differentiation complex (EDC) genes and epidermal barrier proteins, the nature and severity of epidermal pathology and transepidermal water loss (TEWL) were evaluated.By 1 hpi a significant dermal polymorphonuclear infiltrate and a significant increase in TEWL with maximal mean TEWL (598.67 g/m2h) were observed. Epidermal pathology involving intra-epidermal pustulation, loss of epidermal architecture and damage to the basement membrane was seen by 3 hpi. Filaggrin and loricrin protein levels in the stratum corneum declined significantly in the first 24 hpi and qPCR validation confirmed the decrease in expression of the key EDC genes involucrin, filaggrin and loricrin observed by microarray analysis, with 5.8-fold, 4.5-fold and 80-fold decreases, respectively by 24 hpi.The present study has demonstrated that early P. ovis infestation disrupts the ovine epidermal barrier causing significant alterations in the expression of critical barrier components, epidermal pathology, and TEWL. Many of these features have also been documented in human and canine atopic dermatitis suggesting that sheep scab may provide a model for the elucidation of events occurring in the early phases of atopic sensitisation.

Concepts: Protein, Allergy, C-reactive protein, Domestic sheep, Ovis, Sheep, Glossary of sheep husbandry, Sheep husbandry

167

This paper concerns the likely origin of three mutations with large effects on ovulation rate identified in the Belclare and Cambridge sheep breeds; two in the BMP15 gene (FecX(G) and FecX(B)) and the third (FecG(H)) in GDF9. All three mutations segregate in Belclare sheep while one, FecX(B), has not been found in the Cambridge. Both Belclare and Cambridge breeds are relatively recently developed composites that have common ancestry through the use of genetic material from the Finnish Landrace and Lleyn breeds. The development of both composites also involved major contributions from exceptionally prolific ewes screened from flocks in Ireland (Belclare) and Britain (Cambridge) during the 1960s. The objective of the current study was to establish the likely origin of the mutations (FecX(G), FecX(B) and FecG(H)) through analysis of DNA from Finnish Landrace and Lleyn sheep, and Galway and Texel breeds which contributed to the development of the Belclare breed. Ewes with exceptionally high prolificacy (hyper-prolific ewes) in current flocks on Irish farms were identified to simulate the screening of ewes from Irish flocks in the 1960s. DNA was obtained from: prolific ewes in extant flocks of Lleyn sheep (n = 44) on the Lleyn peninsula in Wales; hyper-prolific ewes (n = 41); prolific Galway (n = 41) ewes; Finnish Landrace (n = 124) and Texel (n = 19) ewes. The FecX(G) mutation was identified in Lleyn but not in Finnish Landrace, Galway or Texel sheep; FecX(B) was only found among the hyper-prolific ewes. The FecG(H) mutation was identified in the sample of Lleyn sheep. It was concluded from these findings that the Lleyn breed was the most likely source of the FecX(G) and FecG(H) mutations in Belclare and Cambridge sheep and that the FecX(B) mutation came from the High Fertility line that was developed using prolific ewes selected from commercial flocks in Ireland in the 1960’s and subsequently used in the genesis of the Belclare.

Concepts: DNA, Genetics, Mutation, Evolution, United Kingdom, Breed, Domestic sheep, Sheep breeds

166

The discovery and identification of Ovis aries (sheep) miRNAs will further promote the study of miRNA functions and gene regulatory mechanisms. To explore the microRNAome (miRNAome) of sheep in depth, samples were collected that included eight developmental stages: the longissimus dorsi muscles of Texel fetuses at 70, 85, 100, 120, and 135 days, and the longissimus dorsi muscles of Ujumqin fetuses at 70, 85, 100, 120, and 135 d, and lambs at 0 (birth), 35, and 70 d. These samples covered all of the representative periods of Ovis aries growth and development throughout gestation (about 150 d) and 70 d after birth. Texel and Ujumqin libraries were separately subjected to Solexa deep sequencing; 35,700,772 raw reads were obtained overall. We used ACGT101-miR v4.2 to analyze the sequence data. Following meticulous comparisons with mammalian mature miRNAs, precursor hairpins (pre-miRNAs), and the latest sheep genome, we substantially extended the Ovis aries miRNAome. The list of pre-miRNAs was extended to 2,319, expressing 2,914 mature miRNAs. Among those, 1,879 were genome mapped to unique miRNAs, representing 2,436 genome locations, and 1,754 pre-miRNAs were mapped to chromosomes. Furthermore, the Ovis aries miRNAome was processed using an elaborate bioinformatic analysis that examined multiple end sequence variation in miRNAs, precursors, chromosomal localizations, species-specific expressions, and conservative properties. Taken together, this study provides the most comprehensive and accurate exploration of the sheep miRNAome, and draws conclusions about numerous characteristics of Ovis aries miRNAs, including miRNAs and isomiRs.

Concepts: DNA, Gene, Chromosome, Harshad number, Longissimus, Domestic sheep, Ovis, Mouflon

53

Vitamin D deficiency has been associated with the development of many human diseases, and with poor reproductive performance in laboratory rodents. We currently have no idea how natural selection directly acts on variation in vitamin D metabolism due to a total lack of studies in wild animals. Here, we measured serum 25 hydroxyvitamin D (25(OH)D) concentrations in female Soay sheep that were part of a long-term field study on St Kilda. We found that total 25(OH)D was strongly influenced by age, and that light coloured sheep had higher 25(OH)D3 (but not 25(OH)D2) concentrations than dark sheep. The coat colour polymorphism in Soay sheep is controlled by a single locus, suggesting vitamin D status is heritable in this population. We also observed a very strong relationship between total 25(OH)D concentrations in summer and a ewe’s fecundity the following spring. This resulted in a positive association between total 25(OH)D and the number of lambs produced that survived their first year of life, an important component of female reproductive fitness. Our study provides the first insight into naturally-occurring variation in vitamin D metabolites, and offers the first evidence that vitamin D status is both heritable and under natural selection in the wild.

Concepts: Vitamin D, Cancer, Human, Natural selection, Evolution, Vitamins, Nature, Domestic sheep

28

SUMMARY Ivermectin (IVE), one of the most important anthelmintics, is often used in the treatment of haemonchosis in ruminants. The objective of our work was (1) to find and identify phase I and II metabolites of IVE formed by the Barber’s pole worm (Haemonchus contortus), and (2) to compare IVE metabolites in helminths with IVE biotransformation in sheep (Ovis aries) as host species. Ultrahigh-performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) was used for this purpose. During in vitro incubations, microsomes (from adult worms or from ovine liver) and a primary culture of ovine hepatocytes were incubated with IVE. In the ex vivo study, living H. contortus adults were incubated in the presence of 1 μM IVE for 24 h. The results showed that the H. contortus enzymatic system is not able to metabolize IVE. On the other hand, 7 different phase I as well as 9 phase II IVE metabolites were detected in ovine samples using UHPLC/MS/MS analyses. Most of these metabolites have not been described before. Haemonchus contortus is not able to deactivate IVE through biotransformation; therefore, biotransformation does not contribute to the development of IVE-resistance in the Barber’s pole worm.

Concepts: Metabolism, In vivo, Domestic sheep, Haemonchus contortus, Ovis, Sheep, Mouflon, Barber's pole

28

The objective of this study was to compare some husbandry procedures on the base of physiological stress parameters and evaluate the welfare status in sheep. Forty ewes were used as the study material. Measurements were taken during several routine husbandry procedures such as milking, shearing, weighing, loading and hoof care. Data regarding time spent for each application, as well as heart and respiratory rates were recorded during the applications. Blood samples were taken 15 min before and after each application and malondialdehyde (MDA), glutathione-peroxidase (GSH-Px), cortisol T3 and T4 parameters were measured. In addition, changes in the same parameters between pre- and post-application periods were evaluated. According to the results, machine milking caused less stress than hand milking. No significant difference was seen between shearing methods for hand shearer or clipper; however, both applications caused stress in animals. The results for weighing methods of animals demonstrated significant differences in cortisol, T3 and T4 values in favor of traditional method. Cortisol, T3 and T4 levels were significantly higher in manual loading compared with loading by ramp. Regarding hoof care, all the examined parameters differed in favor of modern method. On the other hand, significant differences were determined between the stress parameters regarding pre- and post-applications. All values differed for hand milking while no significant difference was observed in MDA and T3 values in machine milking group. Parameters in weighing groups changed significantly. For loading process, GSH, cortisol, T3 and T4 values differed in both treatment groups. With regard to hoof care, parameters except T4 in laying group differed significantly. An increase occurred in minute-based measurements of heart and respiratory rates parallel to physiological data. The number of the respiratory rates during the applications differed except for the shearing process. All the parameters displayed significant differences between groups in terms of heart rates. Time spent for each application also differed between groups. Time saved for milking, shearing, weighing, loading and hoof care was 3.23 min, 4.37 min, 1.71 min, 7.85 s and 1.55 min, respectively. These results appear to provide a tangible advantage of using new husbandry methods to the breeders. It was concluded that using new methods in sheep husbandry procedures provided advantages in terms of saving time and reducing labor, as well as improved conditions for welfare of animals. In addition, it facilitated the routine works and flock husbandry.

Concepts: Physiology, Statistical significance, Metabolic syndrome, Stress, Livestock, Subroutine, Domestic sheep, Sheep husbandry

28

A molecular procedure was developed to detect and quantify larvae of different strongylid parasite species recovered from pasture samples. Two lamb flocks (L and S) grazed separate paddocks with different natural larvae challenges (one low [Paddock L] and one high [Paddock S] challenge) on a commercial farm in Western Australia. Pasture samples were collected and analysed for larvae on 9 separate occasions from each paddock. Pregnant Merino ewes were sampled on 3 separate occasions (2 pre-partum and 1 post-partum). Following lambing, 203 female crossbred lambs were identified, from which faecal samples were collected across five separate samplings. Lamb production and faecal attributes were recorded. Genomic DNA was extracted directly from lamb faeces, in addition to the genomic DNA extracts from strongylid larval species recovered from pastures. Faecal worm egg counts (FWECs) were undertaken. Species-specific qPCRs and conventional PCRs (ITS-2 nuclear ribosomal DNA) were used to screen samples for strongylid species (Teladorsagia circumcincta, Trichostrongylus spp., Haemonchus contortus, Chabertia ovina and Oesophagostomum venulosum). Negative correlations (r(2)>0.91) were found between qPCR C(q) values and log-transformed pasture larval counts for Trichostrongylus spp. and T. circumcincta. Moderate levels of agreement between pasture larval counts and qPCR results were observed (67%). A clear difference in pasture larval challenge levels was observed between the two flocks using both qPCR and conventional pasture larval counts. It is difficult to draw conclusions on the production performances of lambs from the two experimental flocks, as no further replicates were able to be conducted following this experiment. Flock L had higher dressing percentages than Flock S (P=0.038), along with significantly higher faecal consistency and breech fleece faecal soiling scores at successive samplings. The molecular procedures utilised in this study have the potential to be beneficial for livestock grazing management strategies and parasite surveillance, however further investigation is necessary before they can become part of routine diagnostics.

Concepts: Pasture, Field, Farm, Livestock, Grazing, Domestic sheep, Haemonchus contortus, LaMB

27

Twelve Dorper × Pelibuey wether lambs (26.8 ± 1.6 kg initial BW, 5 mo of age) were used to evaluate effects of zilpaterol hydrochloride (ZH) on feedlot performance, and effects of ZH and ZH supplementation period (15 and 30 d) on nutrient intake and digestibility. Lambs were blocked by initial BW, and assigned randomly within BW blocks to 1 of 2 treatments: 1) control (no ZH); and 2) supplemented with ZH (10 mg ZH/wether lamb daily). Measurements of intake and digestibility were performed on d 9 to15 and 24 to 30. Feedlot performance data were analyzed as a randomized complete block design, and nutrient intake and digestibility data were analyzed as a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Final BW, ADG, total BW gain, and G:F were greater (P ≤ 0.04) for ZH than for control lambs. No treatment × feeding duration interaction for nutrient intake and apparent total tract digestibility were observed (P > 0.05). Intake of DM, OM, CP, and gross energy were lower (P ≤ 0.03) for ZH than for control. Lambs fed for 30 d had greater (P ≤ 0.04) NDF and gross energy intake compared with those fed for 15 d. Total tract digestibility of DM, OM, CP, EE, and ADF (P ≤ 0.03) was lower for ZH than control. Furthermore, calculated DE, ME, and TDN intake decreased (P < 0.01) with ZH supplementation. Also, DM, CP, and EE digestibility were greater (P < 0.01) for 30 d than for 15 d. Additionally, greater (P ≤ 0.01) DE, ME, and TDN intake was observed for 30 d compared with 15 d. In conclusion, ZH supplementation of wether lambs consuming feedlot diets resulted in improved feedlot performance and reduced the intake and digestibility of some nutrients.

Concepts: Nutrition, Nutrient, Trigraph, Gh, Block, Domestic sheep, Blocking, Block design

27

SUMMARY A cross-sectional serological survey was conducted during January to August 2001 to determine the seroprevalence of Leptospira serovars in five species of livestock in Thailand and to identify associations between seropositivity and sex, age, species and geographical locations. Sera from 14188 livestock (9288 cattle, 1376 buffaloes, 1898 pigs, 1110 sheep, 516 goats) from 36 provinces were tested for antibodies against 24 Leptospira serovars with the microscopic agglutination test (MAT) for which the criterion for a positive result was set at a titre of ⩾1:50. A total of 1635 [11·5%, 95% confidence interval (CI) 11·0-12·0] animals were seropositive and the highest prevalence (30·4%, 95% CI 28·2-32·5) of evidence of infection was recorded in the northeast region followed by the central region (22·2%, 95% CI 20-24·6). Seroprevalences recorded for cattle, buffaloes, pigs, sheep and goats were 9·9% (95% CI 9·3-10·5), 30·5% (95% CI 28·1-32·9), 10·8% (95% CI 9·5-12·3), 4·7% (95% CI 3·6-6·1) and 7·9% (95% CI 5·8-10·5), respectively. Buffaloes were 3·1 (95% CI 2·8-3·4) times more likely than cattle to be seropositive. The most commonly detected antibodies were against L. interrogans serovars Ranarum, Sejroe, and Mini in cattle, Mini, Sejroe, and Bratislava in buffaloes, Ranarum, Pomona, and Bratislava in pigs and Mini, Shermani, and Ranarum in sheep and goats. Seroprevalences in cattle and buffaloes trended upwards with increasing age and there was no difference in the risk of seropositivity between males and females.

Concepts: Milk, Sex, Mammal, Serology, Livestock, Leptospira, Goat, Domestic sheep

25

Sheep raising in the state of Guerrero, México, is a primary activity that is worth about US$3,251,931 annually. The objective of the present study was to evaluate the chemical composition, degradability, nutrient intake, and animal performance of Pelibuey lambs fed on different combinations of maize-soybean silages. Twenty-one combinations of maize silage (MS) and soybean silage (SS) were evaluated at day 45 post-ensiling; in each combination, MS was replaced by 5 % of SS. The 21 combinations were analysed for crude protein (CP) and chemical composition. In order to obtain a statistical criterion of potential treatments for the animal feeding test, a cluster analysis was performed based on the CP contents of all combinations at day 45 post-ensiling. From cluster analysis, four treatments were selected T1 = 100-0 % (MS/SS), T8 = 65-35 %, T12 = 45-55 %, and T16 = 25-75 %. Results indicated that cluster analysis was useful for identifying the potential treatments for animal feeding based on the crude protein content. The dry matter (DM), organic matter (OM), and acid detergent lignin (ADL) contents did not declined significantly (P > 0.05) during the fermentation of silages but CP content decreased from day 0 to 45 post-ensiling. The treatment with the highest estimated microbial crude protein synthesis was T8 and it showed the highest metabolizable energy intake, high feed efficiency with a forage-concentrate ratio of 84:16.

Concepts: Protein, Cluster analysis, Bioinformatics, Metabolism, Nutrition, Energy, Nitrogen, Domestic sheep