Initial Effects of Wildfire on Freshwater Turtle Nesting Habitat

Natural wildfire regimes are important for ecosystem succession but can have negative ecological effects depending on fire characteristics. A portion of a granite rock barrens landscape that extends along the eastern shoreline of Georgian Bay, Lake Huron to eastern Ontario, Canada, burned in 2018 during a wildfire that affected >11,000 ha. This landscape is a biodiversity hotspot providing habitat for many species at risk where freshwater turtles nest in soil deposits in cracks and crevices in the bedrock dominated by moss (Polytrichum spp.) and lichen (Cladonia spp.) cover. To assess the initial effect of wildfire on freshwater turtle nesting habitat, we measured soil depths and estimated moss, lichen, and vascular plant cover at 2 morphology types (crevice, flat) in burned and unburned areas of the landscape. The probability that burned flat plots supported soil was near zero; the burned flat plots had 98% less soil volume compared to unburned flat plots. Although crevices were more resistant to soil loss, burned crevices still had a 15% lower probability of having soil and 35% less soil volume compared to unburned crevice plots. We estimated nest site availability by calculating the number of locations with shallow (5–10 cm), intermediate (10–20 cm), and deep (>20 cm) soils required for a small (5 cm × 5 cm) or medium (10 cm × 10 cm) nest chamber. Overall, the burned open rock barrens had 71–73% fewer sites with suitable soil depth and volume for a nest chamber of either size. Furthermore, burned plots had almost no lichen and moss cover but were dominated by bare soil, forbs, and jack pine (Pinus banksiana) seedlings. Although the loss of tree cover in previously forested areas may increase nest site availability for freshwater turtles in newly open areas, we suggest that organic soil combustion and soil erosion may require restoration activities in the post-fire landscape to support successful nesting of at-risk turtles. © 2020 The Wildlife Society.     

Magnitude of the Freshwater Turtle Exports from the US: Long Term Trends and Early Effects of Newly Implemented Harvest Management Regimes

Unregulated commercial harvest remains a major threat for turtles across the globe. Due to continuing demand from Asian markets, a significant number of turtles are exported from the United States of America (US). Beginning in 2007, several southeastern states in the US implemented restrictions on the commercial harvest of turtles, in order to address the unsustainable take. We have summarized freshwater turtle exports from the US between 2002 and 2012 and demonstrated that the magnitude of turtle exports from the US remained high although the exports decreased throughout the decade. Louisiana and California were the major exporters. The majority of exports were captive bred, and from two genera, Pseudemys and Trachemys. We review the changes over the decade and speculate that the increase in export of wild turtles out of Louisiana after 2007 could be a consequence of strict regulations in surrounding states (e.g., Alabama, Florida). We suggest that if wild turtle protection is a goal for conservation efforts, then these states should work together to develop comprehensive regulation reforms pertaining to the harvest of wild turtles.     

Options for the Production of Selenized Chicken Meat

A 42-day experiment was conducted to compare the effects of various levels of sodium selenite (SS) and Se-enriched yeast (SY) on chicken productivity, carcass traits, and breast Se concentration. Six hundred 1-day-old Cobb 500 broiler chicks were placed on 1 of 6 experimental treatments. The treatments consisted of feeding a diet without Se supplementation (basal diet) or basal diet with 0.6 mg/kg supplemented Se supplied by SS, SY, or a mix of the two (0.45 SS + 0.15 SY; 0.3 SS + 0.3 SY; 0.15 SS + 0.45 SY). Chicks in all Se-supplemented treatments had significantly higher final body weight and eviscerated weight than those on the basal diet (P < 0,05) and no significant differences were observed among selenium source (P < 0.05). Also, chicks in all Se-supplemented treatments had significantly higher Se contents in breast tissue than the control group (P < 0.05). Replacing SS by SY in the broiler diets resulted in increased concentrations of Se in the breast (P < 0.01). Strong correlations were found between breast Se concentrations and the level of SY supplementation of the broiler diet (r = 0.992). The results from this experiment indicate that SY is a superior source of selenium for the production of selenized meat, and can be used, without any detrimental effect on chicken performance, for adding nutritional value to broiler meat and thus safely improving human selenium intake.     

Staphylococcal Growth and Enterotoxin Production in Meat

Preliminary attempts were made to explain the association of staphylococcal food poisoning with cooked rather than uncooked meats. The abilities of various meats to support the growth of an enterotoxigenic staphylococcus, and the production of enterotoxin A, were determined. The production of enterotoxin was detected by means of serological procedures. Little or no growth was obtained when the inoculum was mixed with raw ground beef. When the surfaces of raw and cooked meats were inoculated, however, good growth was obtained with the production of enterotoxin.     

武汉近郊集贸市场淡水鱼华枝睾吸虫囊蚴感染情况调查

本实验采用直接压片法和人工消化法,分别对武汉近郊厂埠屯,马房山集贸市场５种常见小型淡水鱼感染华枝睾吸虫囊蚴进行了调查,其总感染率为７３．２％,麦穗鱼感染率最高９０．８％,鲫鱼,中华旁旁皮鱼,银飘鱼,黄幼鱼的感染率分别为１９．４％,１６．７％,９．１％,５．９％;每克鱼肉含囊蚴最高的也是麦穗鱼,经统计学检验,感染率有显著性差异。     

Genome-Wide Association Studies for Growth and Meat Production Traits in Sheep

Background

Growth and meat production traits are significant economic traits in sheep. The aim of the study is to identify candidate genes affecting growth and meat production traits at genome level with high throughput single nucleotide polymorphisms (SNP) genotyping technologies.

Methodology and Results

Using Illumina OvineSNP50 BeadChip, we performed a GWA study in 329 purebred sheep for 11 growth and meat production traits (birth weight, weaning weight, 6-month weight, eye muscle area, fat thickness, pre-weaning gain, post-weaning gain, daily weight gain, height at withers, chest girth, and shin circumference). After quality control, 319 sheep and 48,198 SNPs were analyzed by TASSEL program in a mixed linear model (MLM). 36 significant SNPs were identified for 7 traits, and 10 of them reached genome-wise significance level for post-weaning gain. Gene annotation was implemented with the latest sheep genome Ovis_aries_v3.1 (released October 2012). More than one-third SNPs (14 out of 36) were located within ovine genes, others were located close to ovine genes (878bp-398,165bp apart). The strongest new finding is 5 genes were thought to be the most crucial candidate genes associated with post-weaning gain: s58995.1 was located within the ovine genes MEF2B and RFXANK, OAR3_84073899.1, OAR3_115712045.1 and OAR9_91721507.1 were located within CAMKMT, TRHDE, and RIPK2 respectively. GRM1, POL, MBD5, UBR2, RPL7 and SMC2 were thought to be the important candidate genes affecting post-weaning gain too. Additionally, 25 genes at chromosome-wise significance level were also forecasted to be the promising genes that influencing sheep growth and meat production traits.

Conclusions

The results will contribute to the similar studies and facilitate the potential utilization of genes involved in growth and meat production traits in sheep in future.     

Photothermal Catalytic Gel Featuring Spectral and Thermal Management for Parallel Freshwater and Hydrogen Production

Desalination processes often require large amounts of energy to create clean water, and vice versa for the generation of energy. This interdependence creates a tension between the two essential resources. Current research focuses on one or the other, which exacerbates water‐energy stress, while few tackle both issues jointly. Herein, a low‐carbon technology, H₂O–H₂ co‐generation system that enables concurrent steady freshwater and clean energy output is reported. The water‐energy coupled technology features a spectrally and thermally managed solar harvesting gel for photoredox and photoheating effects. This photothermal catalytic gel exploits interfacial solar heating for heat confinement, and localized plasmonic heating at the catalyst active sites to remarkably improve water and hydrogen production, thus maximizing energy value per area. To this end, a stand‐alone renewable solar desalination system is successfully demonstrated for parallel production of freshwater and hydrogen under natural sunlight. By doing so, the water–energy nexus is transformed into a synergistic bond that offers opportunities to better meet expected demand rather than acting in competition.     

Hazards Associated with the Consumption of Sea Turtle Meat and Eggs: A Review for Health Care Workers and the General Public

Sea turtle products (e.g., meat, adipose tissue, organs, blood, eggs) are common food items for many communities worldwide, despite national regulations in some countries prohibiting such consumption. However, there may be hazards associated with this consumption due to the presence of bacteria, parasites, biotoxins, and environmental contaminants. Reported health effects of consuming sea turtles infected with zoonotic pathogens include diarrhea, vomiting, and extreme dehydration, which occasionally have resulted in hospitalization and death. Levels of heavy metals and organochlorine compounds measured in sea turtle edible tissues exceed international food safety standards and could result in toxic effects including neurotoxicity, kidney disease, liver cancer, and developmental effects in fetuses and children. The health data presented in this review provide information to health care providers and the public concerning the potential hazards associated with sea turtle consumption. Based on past mortality statistics from turtle poisonings, nursing mothers and children should be particularly discouraged from consuming all sea turtle products. We recommend that individuals choose seafood items lower in the food chain that may have a lower contaminant load. Dissemination of this information via a public health campaign may simultaneously improve public health and enhance sea turtle conservation by reducing human consumption of these threatened and endangered species.     

Biological Control of Sheep Parasites using Duddingtonia flagrans: Trials on Commercial Farms in Sweden

   

Trials were conducted on 3 commercial sheep farms in Sweden to assess the effect of administering spores of the nematode trapping fungus, Duddingtonia flagrans, together with supplementary feed to lactating ewes for the first 6 weeks from turn-out on pastures in spring. Also control groups of ewes, receiving only feed supplement, were established on all 3 farms. Groups were monitored by intensive parasitological investigation. The ewes and their lambs were moved in late June to saved pastures for summer grazing, the lambs receiving an anthelmintic treatment at this time. After approximately 6 weeks on summer pasture the lambs were weaned, treated a second time with anthelmintic, and returned to their original lambing pastures for finishing. Decisions as to when lambs were to be marketed were entirely at the discretion of the farmer co-operators. No difference in lamb performance was found between the two treatments on all three farms. This was attributed to the high levels of nutrition initially of the ewes limiting their post-partum rise in nematode faecal egg counts in spring, which in turn resulted in low levels of nematode infection on pastures throughout the autumn period. Additionally, pastures were of good quality for the lambs during the finishing period, so they grew at optimal rates as far as the farmers were concerned.     

Influence of Food Microorganisms on Staphylococcal Growth and Enterotoxin Production in Meat

Forty-four microorganisms were studied for their influence on staphylococcal growth and enterotoxin production. Inhibition was found to be more common than stimulation. Two types of inhibition were observed: inhibition of staphylococcal growth, and inhibition of enterotoxin formation with no apparent effect on growth. By use of a plate test, 12 of the 44 food microorganisms were found to inhibit staphylococcal growth at 35 C. Of the 12, 3 also inhibited growth at 25 C. No significant differences in inhibition were observed with the 15 strains of enterotoxigenic staphylococci. In meat slurries, inhibition of staphylococcal growth was found to be greater at 25 C than at 35 C. Results on inhibition obtained from the plate test could not be correlated with the effect of the organisms in slurries. Environmental conditions were found to affect markedly the influence of food microorganisms on staphylococci. Of the 44 food microorganisms studied, only Bacillus cereus was observed to stimulate significantly staphylococcal growth and enterotoxin formation. Stimulation was more pronounced with Staphylococcus aureus 196E than with other strains of enterotoxigenic staphylococci. Bacillus megaterium and Brevibacterium linens were inhibited by staphylococci. These organisms were completely inhibited when inoculated in mixed cultures with staphylococci. In pure cultures, good staphylococcal growth was found to be accompanied by enterotoxin production; however, in the presence of food microorganisms, good staphylococcal growth occurred without the formation of detectable levels of enterotoxin A.     

Benthic Bacterial Production and Protozoan Predation in a Silty Freshwater Environment

The interrelation of heterotrophic bacteria with bacterivorous protists has been widely studied in pelagic environments, but data on benthic habitats, especially in freshwater systems, are still scarce. We present a seasonal study focusing on bacterivory by heterotrophic nanoflagellates (HNF) and ciliates in the silty sediment of a temperate macrophyte-dominated oxbow lake. From January 2001 to February 2002 we monitored the standing stock of bacteria and protozoa, bacterial secondary production (BSP, ³H-thymidine, and ¹⁴C-leucine incorporation), and grazing rates of HNF and ciliates on bacteria (FLB uptake) in the oxic sediment of the investigated system. BSP ranged from 470 to 4050 µg C L^–1 wet sediment h^–1. The bacterial compartment turned out to be highly dynamic, indicated by population doubling times (0.6–10.0 d), which were comparable to those in the water column of the investigated system. Yet, the control mechanisms acting upon the bacterial population led to a relative constancy of bacterial standing stock during a year. Ingestion rates of protozoan grazers were 0–20.0 bacteria HNF^–1 h^–1 and 0–97.6 bacteria ciliate^–1 h^–1. HNF and ciliates together cropped 0–14 (mean 4)% of BSP, indicating that they did not significantly contribute to benthic bacterial mortality during any period of the year. The low impact of protozoan grazing was due to the low numbers of HNF and ciliates in relation to bacteria (1.8–3.5 × 10⁴ bacteria HNF^–1, 0.9–3.1 × 10⁶ bacteria ciliate^–1). Thus, grazing by HNF and ciliates could be ruled out as a parameter regulating bacterial standing stock or production in the sediment of the investigated system, but the factors responsible for the limitation of benthic protistan densities and the fate of benthic BSP remained unclear.     

Effects of Methane Metabolism on Nitrification and Nitrous Oxide Production in Polluted Freshwater Sediment

We report the effect of CH₄ and of CH₄ oxidation on nitrification in freshwater sediment from Hamilton Harbour, Ontario, Canada, a highly polluted ecosystem. Aerobic slurry experiments showed a high potential for aerobic N₂O production in some sites. It was suppressed by C₂H₂, correlated to NO₃^- production, and stimulated by NH₄⁺ concentration, supporting the hypothesis of a nitrification-dependent source for this N₂O production. Diluted sediment slurries supplemented with CH₄ (1 to 24 μM) showed earlier and enhanced nitrification and N₂O production compared with unsupplemented slurries (≤1 μM CH₄). This suggests that nitrification by methanotrophs may be significant in freshwater sediment under certain conditions. Suppression of nitrification was observed at CH₄ concentrations of 84 μM and greater, possibly through competition for O₂ between methanotrophs and NH₄⁺ -oxidizing bacteria and/or competition for mineral N between these two groups of organisms. In Hamilton Harbour sediment, the very high CH₄ concentrations (1.02 to 6.83 mM) which exist would probably suppress nitrification and favor NH₄⁺ accumulation in the pore water. Indeed, NH₄⁺ concentrations in Hamilton Harbour sediment are higher than those found in other lakes. We conclude that the impact of CH₄ metabolism on N cycling processes in freshwater ecosystems should be given more attention.     

Occurrence of Eimeria Species Parasites on Small-Scale Commercial Chicken Farms in Africa and Indication of Economic Profitability

Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.     

Absence of VanA- and VanB-Containing Enterococci in Poultry Raised on Nonintensive Production Farms in Brazil

We examined cloacal samples from poultry raised on nonintensive production farms in Brazil for the presence of vancomycin-resistant enterococci. No VanA- or VanB-containing enterococci were identified in a total of 200 cloacal swabs. The most prevalent species were Enterococcus gallinarum (vanC1; 13.0%) and E. casseliflavus (vanC2/3; 5.5%).     

Presence of Mycobacterium avium subsp. paratuberculosis in Environmental Samples Collected on Commercial Dutch Dairy Farms

Mycobacterium avium subsp. paratuberculosis, the causative agent of Johne''s disease in cattle, was identified in settled-dust samples of Dutch commercial dairy farms, both in the dairy barn and in the young stock housing. Bioaerosols may play a role in within-farm M. avium subsp. paratuberculosis transmission.Paratuberculosis is an infectious enteric disease caused by Mycobacterium avium subsp. paratuberculosis leading to economic losses in dairy cattle globally (2, 10). The main transmission route is the fecal/oral route from infectious adult cattle to susceptible calves (12).Preventive calf management was a key point in model studies (7), but 20-year implementation did not lead to farm-level eradication, suggesting uncontrolled routes of transmission (1, 7).Environmental samples were used to classify commercial dairy herds (3, 9, 11), based on long-term survival of M. avium subsp. paratuberculosis in the environment (16). Recently, bioaerosols containing viable M. avium subsp. paratuberculosis were identified in an experimental setting with 100% M. avium subsp. paratuberculosis prevalence (6) and may thus be a mode of transmission. Dust containing M. avium subsp. paratuberculosis might be ingested or inhaled by calves (4). Experimental M. avium subsp. paratuberculosis challenge studies in sheep successfully used inhalation (8). These transmission routes could hamper current control programs. Our objective was to study whether M. avium subsp. paratuberculosis could be detected in bioaerosols on commercial Dutch dairy farms.Dairy herds in three Dutch veterinary practices were sampled in 2009. All farms participated in a Dutch M. avium subsp. paratuberculosis monitoring program in 2008, either the Dutch Paratuberculosis Program (PPN; n = 2) or the Dutch Bulk Milk Quality Assurance Program (BMQAP; n = 22) (15). Both PPN herds were certified M. avium subsp. paratuberculosis-free. Herds corresponding to the BMQAP had at least one positive animal identified by enzyme-linked immunosorbent assay (ELISA) (Pourquier ELISA; Institut Pourquier, France). Farms were grouped into three M. avium subsp. paratuberculosis test prevalence levels (control, zero positive animals; group A, one positive animal; group B, two or more positive animals; Table ​Table11).

TABLE 1.

Overview of the results of the questionnaire about relevant M. avium subsp. paratuberculosis management practices^a

Production and Consumption of Biotin by the Intestinal Microflora of Cultured Freshwater Fishes

Effects of twelve flavonoids and five catechins as well as gallic acid on two kinds of glutathione-related enzymes were investigated. Glutathione 5-transferase (EC 2.5.1.18) activity was measured by S-2,4-dinitrophenyl glutathione formation from 1-chloro-2,4-dinitrobenzene and reduced glutathione. Glutathione reductase (EC 1.6.4.2) activity was followed by NADPH dehydrogenation. Fisetin and myricetin were potent inhibitors of glutathione S-transferase, while kaempferol, quercetin, baicalein, and quercitrin were medium inhibitors. Epicatechin gallate and epigallocatechin gallate also showed medium inhibition. Kinetic analyses indicated that fisetin was a mixed type inhibitor of glutathione S-transferase with respect to both substrates, while myricetin was a competitive inhibitor of the same enzyme with both substrates. Fisetin and myricetin were noncompetive inhibitors of glutathione reductase with both NADPH and oxidized glutathione. The inhibition patterns of GT and GR as well as the results of kinetic analyses indicated a possibility that inhibitory flavonoids might have some influence on the glutathione recognition sites of the two enzymes.     

Entomopathogenic Nematodes for Control of Insect Pests Above and Below Ground with Comments on Commercial Production

Entomopathogenic nematodes (EPNs) have been utilized in classical, conservation, and augmentative biological control programs. The vast majority of applied research has focused on their potential as inundatively applied augmentative biological control agents. Extensive research over the past three decades has demonstrated both their successes and failures for control of insect pests of crops, ornamental plants, trees and lawn and turf. In this paper we present highlights of their development for control of insect pests above and below ground. The target insects include those from foliar, soil surface, cryptic and subterranean habitats. Advances in mass-production and formulation technology of EPNs, the discovery of numerous efficacious isolates/strains, and the desirability of reducing pesticide usage have resulted in a surge of commercial use and development of EPNs. Commercially produced EPNs are currently in use for control of scarab larvae in lawns and turf, fungus gnats in mushroom production, invasive mole crickets in lawn and turf, black vine weevil in nursery plants, and Diaprepes root weevil in citrus in addition to other pest insects. However, demonstrated successful control of several other insects, often has not lead to capture of a significant share of the pesticide market for these pests.