Single Nucleotide Polymorphism Effects on Lamb Fecal Egg Count Estimated Breeding Values in Progeny-Tested Katahdin Sires.

Estimated breeding values (EBV) for fecal egg counts (FEC) at 42-90 days of age (WFEC) and 91-150 days of age (PFEC) for 84 progeny-tested Katahdin sires were used to identify associations of deregressed EBV with single-nucleotide polymorphisms (SNP) using 388,000 SNP with minor-allele frequencies ≥0.10 on an Illumina high-density ovine array. Associations between markers and FEC EBV were initially quantified by single-SNP linear regression. Effects of linkage disequilibrium (LD) were minimized by assigning SNP to 2,535 consecutive 1-Mb bins and focusing on the effect of the most significant SNP in each bin. Bonferroni correction was used to define bin-based (BB) genome- and chromosome-wide significance. Six bins on chromosome 5 achieved BB genome-wide significance for PFEC EBV, and three of those SNP achieved chromosome-wide significance after Bonferroni correction based on the 14,530 total SNP on chromosome 5. These bins were nested within 12 consecutive bins between 59 and 71 Mb on chromosome 5 that reached BB chromosome-wide significance. The largest SNP effects were at 63, 67, and 70 Mb, with LD among these SNP of r 2 ≤ 0.2. Regional heritability mapping (RHM) was then used to evaluate the ability of different genomic regions to account for additive variance in FEC EBV. Chromosome-level RHM indicated that one 500-SNP window between 65.9 and 69.9 Mb accounted for significant variation in PFEC EBV. Five additional 500-SNP windows between 59.3 and 71.6 Mb reached suggestive (p < 0.10) significance for PFEC EBV. Although previous studies rarely identified markers for parasite resistance on chromosome 5, the IL12B gene at 68.5 Mb codes for the p40 subunit of both interleukins 12 and 23. Other immunoregulatory genes are also located in this region of chromosome 5, providing opportunity for additive or associative effects.

Variants Within Genes EDIL3 and ADGRB3 are Associated With Divergent Fecal Egg Counts in Katahdin Sheep at Weaning.

Gastrointestinal nematodes (GIN) pose a severe threat to sheep production worldwide. Anthelmintic drug resistance coupled with growing concern regarding potential environmental effects of drug use have demonstrated the necessity of implementing other methods of GIN control. The aim of this study was to test for genetic variants associated with resistance or susceptibility to GIN in Katahdin sheep to improve the current understanding of the genetic mechanisms responsible for host response to GIN. Linear regression and case-control genome-wide association studies were conducted with high-density genotype data and cube-root transformed weaning fecal egg counts (tFEC) of 583 Katahdin sheep. The case-control GWAS identified two significant SNPs (P-values 1.49e-08 to 1.01e-08) within introns of the gene adhesion G protein-coupled receptor B3 (ADGRB3) associated with lower fecal egg counts. With linear regression, four significant SNPs (P-values 7.82e-08 to 3.34e-08) were identified within the first intron of the gene EGF-like repeats and discoidin domains 3 (EDIL3). These identified SNPs were in very high linkage disequilibrium (r 2 of 0.996-1), and animals with alternate homozygous genotypes had significantly higher median weaning tFEC phenotypes compared to all other genotypes. Significant SNPs were queried through public databases to identify putative transcription factor binding site (TFBS) and potential lncRNA differences between reference and alternate alleles. Changes in TFBS were predicted at two SNPs, and one significant SNP was found to be within a predicted lncRNA sequence with greater than 90% similarity to a known lncRNA in the bovine genome. The gene EDIL3 has been described in other species for its roles in the inhibition and resolution of inflammation. Potential changes of EDIL3 expression mediated through lncRNA expression and/or transcription factor binding may impact the overall immune response and reduce the ability of Katahdin sheep to control GIN infection. This study lays the foundation for further research of EDIL3 and ADGRB3 towards understanding genetic mechanisms of susceptibility to GIN, and suggests these SNPs may contribute to genetic strategies for improving parasite resistance traits in sheep.

Compositional and operational impacts on the thermochemical reduction of CO2 to CO by iron oxide/yttria-stabilized zirconia.

Ferrites have potential for use as active materials in solar-thermochemical cycles because of their versatile redox chemistry. Such cycles utilize solar-thermal energy for the production of hydrogen from water and carbon monoxide from carbon dioxide. Although ferrites offer the potential for deep levels of reduction (e.g., stoichiometric conversion of magnetite to wüstite) and correspondingly large per-cycle product yields, in practice reactions are limited to surface regions made smaller by rapid sintering and agglomeration. Combining ferrites with zirconia or yttria-stabilized zirconia (YSZ) greatly improves the cyclability of the ferrites and enables a move away from powder to monolithic systems. We have studied the behavior of iron oxides composited with YSZ using thermogravimetric analysis under operando conditions. Samples in which the iron was fully dissolved within the YSZ matrix showed greater overall extent of thermochemical redox and higher rate of reaction than samples with equal iron loading but in which the iron was only partially dissolved, with the rest existing as agglomerates of iron oxide within the ceramic matrix. Varying the yttria content of the YSZ revealed a maximum thermochemical capacity (yield per cycle) for 6 mol% Y2O3 in YSZ. The first thermochemical redox cycle performed for each sample resulted in a net mass loss that was proportional to the iron oxide loading in the material and was stoichiometrically consistent with complete reduction of Fe2O3 to Fe3O4 and further partial reduction of the Fe3O4 to FeO. Mass gains upon reaction with CO2 were consistent with re-oxidation of the FeO fraction back to Fe3O4. The Fe dissolved in the YSZ matrix, however, is capable of cycling stoichiometrically between Fe3+ and Fe2+. Varying the re-oxidation temperature between 1000 and 1200 °C highlighted the trade-off between re-oxidation rate and equilibrium limitations.

Quebracho tannins aid in the control of Eimeria spp. and gastrointestinal nematodes in lambs and goat kids.

The objective was to examine the effects of supplementary quebracho on control of coccidiosis and gastrointestinal nematodes in lambs and kids. In Exp. 1, naturally infected lambs weaned (87.8 ± 0.4 days of age; day 0) in January (winter) were blocked by sex and randomly assigned (n = 10/treatment) to receive supplement with or without 100 g/lamb of quebracho for 28 days. In Exp. 2, single or twin rearing ewes were randomly assigned into two groups, and naturally infected lambs were fed control (n = 28) or quebracho (100 g/lamb of quebracho tannins in feed; n = 27) between -28 and 21 days (weaning = day 0; 70.8 ± 0.1 days of age). In Exp. 3, weaned doe kids (57.6 ± 2.0 days of age) were randomly assigned to receive alfalfa (Medicago sativa) supplement with (n = 9) or without (n = 8) 50 g/kid quebracho or sericea lespedeza (Lespedeza cuneata) with quebracho (n = 8) for 21 days. Fecal oocyst count (FOC), nematode egg counts (FEC), fecal score, dag score (soiling around rear quarters), and blood packed cell volume (PCV) were determined every 7 days. Data were analyzed as repeated measures using mixed models. In Exp. 1, FOC decreased in quebracho-fed lambs (diet × time, P < 0.001) but FEC was similar between treatments during the feeding period (P = 0.19). Packed cell volume (P = 0.19) and fecal score (P = 0.42) were similar between groups. Quebracho-fed lambs had a greater dag score initially (diet × time, P = 0.02), but were similar by day 42 (P = 0.72). In Exp. 2, FOC remained low (P = 0.02), PCV tended to decrease (P = 0.06), but FEC increased on days 14 and 21 (diet × time; P < 0.001) in quebracho compared with control-fed lambs. Quebracho-fed lambs had lower fecal score (diet × time; P = 0.005) but higher dag score (diet × time; P < 0.001). In Exp. 3, FOC of kids fed quebracho (alfalfa or sericea lespedeza supplement) was lower than control (P < 0.001). Fecal score of kids fed sericea lespedeza compared with alfalfa were lower regardless of quebracho (P = 0.01). There were no differences among treatments for dag, FEC, PCV, or body weight (P> 0.10). Quebracho was effective in reducing FOC but not clinical signs of coccidiosis in both lambs and kids, and may not be highly digestible in lambs as it caused loose stools.

Sustainable Approaches to Parasite Control in Ruminant Livestock.

It is increasingly difficult to manage and control gastrointestinal nematode parasites in pasture-based ruminant livestock operations because of the high prevalence of anthelmintic resistance. Anthelmintics should be combined with alternative forms of control. Sustainable tools include copper oxide wire particles and condensed tannin-rich plants, which target primarily Haemonchus contortus in small ruminants. Nematophagous fungi reduce larvae on pasture and target nematode larvae in feces of most livestock species. In addition, and perhaps most importantly, genetic selection focuses on parasite resistance. Producers should use as many tools as possible to minimize the need for pharmaceutical interventions and optimize animal production.

Genetic parameters for ewe reproductive performance and peri-parturient fecal egg counts and their genetic relationships with lamb body weights and fecal egg counts in Katahdin sheep.

This study estimated genetic parameters for ewe reproductive traits [number of lambs born (NLB) and weaned (NLW) per ewe lambing] and fecal egg counts (FEC) during the peri-parturient rise (PPR) for use in genetic evaluation of Katahdin sheep. Data included NLB and NLW for 23,060 lambings by 9,295 Katahdin ewes, 1,230 PPR at lambing (PPR0) for 750 ewes, 1,070 PPR at approximately 30 d postpartum (PPR30) for 611 ewes, BW at birth, weaning, and (or) post-weaning for 12,869 lambs, and FEC at weaning and (or) post-weaning for 4,676 lambs. Direct additive, permanent environmental, and residual (co)variances were estimated in univariate and bivariate animal models. Fixed effects included effects of ewe management group and ewe age for all traits, and, for PPR, a continuous effect of days between lambing and measurement. Effects of litter size on PPR0 and number of lambs suckled on PPR30 were included in univariate models but excluded from bivariate models for PPR and NLB or NLW. Heritability estimates in univariate models for NLB, NLW, PPR0, and PPR30 were 0.09 ± 0.01, 0.06 ± 0.01, 0.35 ± 0.06, and 0.24 ± 0.07, respectively. Estimates of permanent environmental variance as a proportion of total phenotypic variance were 0.02 ± 0.01 for NLB, 0.03 ± 0.01 for NLW, 0.05 ± 0.06 for PPR0, and 0.13 ± 0.07 for PPR30. Direct additive, phenotypic, permanent environmental, and residual correlations between NLB and NLW were 0.88 ± 0.03, 0.74 ± 0.004, 0.54 ± 0.15, 0.74 ± 0.003, respectively; corresponding correlations between PPR0 and PPR30 were 0.96 ± 0.07, 0.46 ± 0.03, 0.98 ± 0.50, 0.18 ± 0.05, respectively. The additive genetic correlation (rd) between ewe reproductive traits and PPR ranged from 0.12 to 0.18. Estimates of rd between lamb BW and subsequent ewe NLB and NLW ranged from 0.07 to 0.20, and those between PPR and lamb BW ranged from -0.03 to 0.29. The rd between ewe reproductive traits and lamb FEC ranged from 0.27 to 0.40, and those between PPR and lamb FEC ranged from 0.56 to 0.77. Correlations between maternal additive effects on BW and direct additive effects on PPR were low (-0.08 to 0.10), and those between maternal additive effects on BW and direct additive effects on ewe reproductive traits were variable (-0.36 to 0.11). We conclude that FEC in growing lambs and peri-parturient ewes are controlled by similar genes and that modest, but manageable, genetic antagonisms may exist between FEC and ewe productivity.

Evaluation of crude larval protein and recombinant somatic protein 26/23 (rHcp26/23) immunization against Haemonchuscontortus in sheep.

AIM: The aim of this study was to evaluate the potential possibility of crude larval and recombinant (rHcp26/23) antigens of Haemonchus contortus for immunization to control sheep hemonchosis. MATERIALS AND METHODS: A total of 21 lambs were divided into five groups. Lambs were immunized with larval and recombinant (rHcp26/23) proteins at day 0 and day 14 and after that challenged with 5000 infective larvae of H. contortus on day 42. An unvaccinated positive control group was challenged with L3 in the meantime. An unvaccinated negative control group was not challenged. RESULTS: Fecal egg count reduction taking after challenge for rHcp26/23 and larval antigens was 92.2% and 38.2%, respectively, compared with the positive control group. Vaccine incited protection in rHcp26/23 and larval immunization was reflected in significant (p<0.05) decreases in worm burden; 59.9% and 40.1%, respectively. CONCLUSION: Recombinant rHcp26/23 vaccine induced a partial immune response and had immune-protective effect against sheep hemonchosis.

Tracking the emergence of a new breed using 49,034 SNP in sheep.

Domestic animals are unique in that they have been organised into managed populations called breeds. The strength of genetic divergence between breeds may vary dependent on the age of the breed, the scenario under which it emerged and the strength of reproductive isolation it has from other breeds. In this study, we investigated the Gulf Coast Native breed of sheep to determine if it contains lines of animals that are sufficiently divergent to be considered separate breeds. Allele sharing and principal component analysis (PCA) using nearly 50,000 SNP loci revealed a clear genetic division that corresponded with membership of either the Florida or Louisiana Native lines. Subsequent analysis aimed to determine if the strength of the divergence exceeded that found between recognised breed pairs. Genotypes from 14 breeds sampled from Europe and Asia were used to obtain estimates of pair-wise population divergence measured as F(ST). The divergence separating the Florida and Louisiana Native (F(ST) = 6.2%) was approximately 50% higher than the average divergence separating breeds developed within the same region of Europe (F(ST) = 4.2%). This strongly indicated that the two Gulf Coast Native lines are sufficiently different to be considered separate breeds. PCA using small SNP sets successfully distinguished between the Florida and Louisiana Native animals, suggesting that allele frequency differences have accumulated across the genome. This is consistent with a population history involving geographic separation and genetic drift. Suggestive evidence was detected for divergence at the poll locus on sheep chromosome 10; however drift at neutral markers has been the largest contributor to the genetic separation observed. These results document the emergence of populations that can be considered separate breeds, with practical consequences for bio-conservation priorities, animal registration and the establishment of separate breed societies.

Experiences with integrated concepts for the control of Haemonchus contortus in sheep and goats in the United States.

The generally warm, moist environmental conditions in the southern United States (U.S.) are ideal for survival and growth of the egg and larval stages of Haemonchus contortus and other gastrointestinal nematodes (GIN) of sheep and goats. Consequently, infection with GIN is the greatest threat to economic small ruminant production in this region. With anthelmintic resistance now reaching epidemic proportions in small ruminants in the U.S., non-chemical control alternatives are critically needed. The Southern Consortium for Small Ruminant Parasite Control (SCSRPC) was formed in response to this crisis and over the last decade has successfully validated the use of several novel control technologies, including FAMACHA(©) for the implementation of targeted selective treatments (TST), copper oxide wire particles (COWP), nematode-trapping fungi, and grazing or feeding hay of the high-tannin perennial legume sericea lespedeza [Lespedeza cuneata (Dum.-Cours. G. Don)]. Producer attitudes toward GIN control in the U.S. have been shifting away from exclusive dependence upon anthelmintics toward more sustainable, integrated systems of parasite control. Some novel control technologies have been readily adopted by producers in combination with appropriate diagnostic tools, such as FAMACHA(©). Others techniques are still being developed, and will be available for producer use as they are validated. Although new drugs will likely be available to U.S. goat and sheep producers in the future, these will also be subject to development of anthelmintic resistance. Therefore, the adoption and implementation of sustainable GIN control principles will remain important. With emerging markets for grass-fed or organic livestock, there will continue to be a critical need for research and outreach on development and on-farm application of integrated GIN control systems for small ruminants in the U.S. for the foreseeable future.

Morphological families of self-assembled porphyrin structures and their photosensitization of hydrogen generation.

Varying the solution growth conditions of cooperative binary ionic solids composed of anionic and cationic metalloporphyrins produces a series of families of self-assembled structures that efficiently and durably photosensitize the evolution of hydrogen.

Community-associated methicillin-resistant Staphylococcus aureus survival on artificial turf substrates.

OBJECTIVE: Artificial turf has been suggested as a risk factor for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). This is an experimental study looking at survival of CA-MRSA on artificial turf. METHODS: MRSA strain USA-300-0114 was grown as either planktonic cells or biofilms in liquid cultures of beef heart infusion broth overnight at 37 °C. Beakers containing ProGrass (Pittsburgh, PA) turf were inoculated at the dirt interface with either ∼5 × 10 planktonic bacteria or with biofilms. The inoculum included varying nutrient conditions consisting of spent medium, saline, or 5% mucin. The beakers were incubated at 37 °C in ambient air. The main outcome measure was the number of surviving colony-forming units determined by plating on mannitol salt agar. RESULTS: Survival was biphasic with a colony-forming unit drop from ∼5 × 10 to ∼5 × 10 after the first week followed by survival of between 10 and 10 bacteria until termination of the experiment (20-50 d). Survival was dependent on nutrients, and washed cells survived less than 1 d. Mucin could serve as a nutrient source and slightly increased surviving numbers to 10-10 bacteria. Biofilm formation did not influence survival. CONCLUSIONS: CA-MRSA survivability on artificial turf surfaces is dependent on the availability of nutrients. These results suggest that CA-MRSA could survive on artificial turf in significant numbers for 1 wk, and lower numbers for at least 1 month, if supplied with appropriate nutrients. Outdoor environmental conditions may affect these findings.

Templated growth of platinum nanowheels using the inhomogeneous reaction environment of bicelles.

Novel platinum nanowheels were synthesized by the reduction of aqueous platinum complex with ascorbic acid in the presence of disk-like bicelles. The platinum nanowheels possess thickened centers and flared edges that are connected by dendritic platinum nanosheets. This structural complexity can be attributed to the inhomogeneous micro-environment of the templating bicelles consisting of a central bi-layer region and a high curvature rim. The formation mechanism of the nanowheels was investigated by imaging nanostructures at different stages of the reaction. The templating bicelles were also imaged by TEM with the aid of negative staining. The variation of reaction parameters including platinum concentration, temperature, and total concentration of surfactants (CTAB + FC7) led to other types of platinum nanostructures, such as circular dendritic nanosheets with a tunable diameter and rectangular dendritic nanosheets. Interestingly, under irradiation by a TEM electron beam, the dendritic nanosheet portion of the nanowheels transforms into a metastable holey sheet. In addition, the platinum nanowheels have an electrochemical active surface area comparable to that of ETEK platinum black and thus are expected to have potential applications in catalysis.

Evolution of dendritic platinum nanosheets into ripening-resistant holey sheets.

Under electron-beam irradiation, dendritic platinum nanosheets structurally evolve into metastable "holey" nanosheets. Monte Carlo simulations of this structural transformation agree well with electron microscope images detailing the ripening process. The experiments and simulations show that nanoscale holes of a critical size are persistent and give holey sheets their morphological stability and sustained high surface area. Platinum nanostructures composed of these holey nanosheets exhibit improved durability in electrocatalytic reactions due to their remarkable ripening resistance.

Prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States.

OBJECTIVE: To determine prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States. DESIGN: Cross-sectional study. ANIMALS: Sheep and goats from 46 farms in 8 southern states, Puerto Rico, and St Croix in the US Virgin Islands. PROCEDURES: Parasite eggs were isolated from fecal samples, and susceptibility to benzimidazole, imidathiazole, and avermectin-milbemycin anthelmintics was evaluated with a commercial larval development assay. RESULTS: Haemonchus contortus was the most common parasite on 44 of 46 farms; Trichostrongylus colubriformis was the second most commonly identified parasite. Haemonchus contortus from 45 (98%), 25 (54%), 35 (76%), and 11 (24%) farms were resistant to benzimidazole, levamisole, ivermectin, and moxidectin, respectively. Resistance to all 3 classes of anthelmintics was detected on 22 (48%) farms, and resistance to all 3 classes plus moxidectin was detected on 8 farms (17%). CONCLUSIONS AND CLINICAL RELEVANCE: Findings provided strong evidence that anthelmintic resistance is a serious problem on small ruminant farms throughout the southeastern United States. Owing to the frequent movement of animals among regions, the prevalence of resistance in other regions of the United States is likely to also be high. Consequently, testing of parasite eggs for anthelmintic resistance should be a routine part of parasite management on small ruminant farms.

Synthesis of platinum nanowheels using a bicellar template.

Disk-like surfactant bicelles provide a unique meso-structured reaction environment for templating the wet-chemical reduction of platinum(II) salt by ascorbic acid to produce platinum nanowheels. The Pt wheels are 496 +/-55 nm in diameter and possess thickened centers and radial dendritic nanosheets (about 2-nm in thickness) culminating in flared dendritic rims. The structural features of the platinum wheels arise from confined growth of platinum within the bilayer that is also limited at edges of the bicelles. The size of CTAB/FC7 bicelles is observed to evolve with the addition of Pt(II) complex and ascorbic acid. Synthetic control is demonstrated by varying the reaction parameters including metal salt concentration, temperature, and total surfactant concentration. This study opens up opportunities for the use of other inhomogeneous soft templates for synthesizing metals, metal alloys, and possibly semiconductors with complex nanostructures.

Development and survival of Haemonchus contortus infective larvae derived from sheep faeces under sub-tropical conditions in the Potohar region of Pakistan.

Assessment on the development and survival of Haemonchus contortus larvae was made to evaluate the influence of microclimatic variables viz., relative humidity (%), temperature (degreesC), rainfall (mm) and intensity of sunlight (hrs). Pasture plots in a subtropical area, Pakistan were contaminated with H. contortus eggs at the start of every month. The plots were sampled on fortnightly basis after contamination for three consecutive months. The overall pattern indicated the most favorable conditions for survival, development and translation to herbage was during the wet season from July to October and the least favorable was during the dry season from April to June. Peak infective larvae (L3) recovery was during the 15-45 day interval for each plot and the lowest number was during the 75-90 day interval. Herbage was collected in the morning, afternoon and evening and greatest recovery of L3 was in the morning time and least in the afternoon. The number of L3 on pasture was directly related to the pattern of rainfall and relative humidity with a significant (P<0.05) positive correlation and temperature and intensity of sunshine were negatively correlated (P<0.05). The results suggest that pastures can remain infective for up to 2 months and become relatively clean by 90 days after contamination. Thus, long pasture rest periods, especially during the high risk wet season, may be a helpful strategy to reduce the infection levels.

Monodisperse porphyrin nanospheres synthesized by coordination polymerization.

Monodisperse nanospheres are formed by coordination polymerization tetrakis(4-pyridyl)porphyrin-metal complexes with chloroplatinic acid in aqueous solution. The porphyrin nanospheres and their platinized nanocomposites have potential applications in catalysis and solar energy conversion systems.

Synthesis of platinum nanowire networks using a soft template.

Platinum nanowire networks have been synthesized by chemical reduction of a platinum complex using sodium borohydride in the presence of a soft template formed by cetyltrimethylammonium bromide in a two-phase water-chloroform system. The interconnected polycrystalline nanowires possess the highest surface area (53 +/- 1 m2/g) and electroactive surface area (32.4 +/- 3.6 m2/g) reported for unsupported platinum nanomaterials; the high surface area results from the small average diameter of the nanowires (2.2 nm) and the 2-10 nm pores determined by nitrogen adsorption measurements. Synthetic control over the network was achieved simply by varying the stirring rate and reagent concentrations, in some cases leading to other types of nanostructures including wormlike platinum nanoparticles. Similarly, substitution of a palladium complex for platinum gives palladium nanowire networks. A mechanism of formation of the metal nanowire networks is proposed based on confined metal growth within a soft template consisting of a network of swollen inverse wormlike micelles.