Survival of Clostridioides difficile in finished dairy compost under controlled conditions.

AIM: The survival of Clostridioides difficile (previously Clostridium difficile) vegetative cells and endospores was compared at different levels of indigenous microflora using autoclaved and unautoclaved dairy composts with different moisture contents (MCs). METHODS AND RESULTS: Both types of composts adjusted to 20, 30 and 40% MCs were inoculated with a suspension of C. difficile that contained both vegetative cells (c. 5-6 log CFU per gram) and endospores (c. 5·0 CFU per gram), and then stored aerobically inside a humidity-controlled chamber at room temperature 22·5 ± 0·8°C for 1 year. The level of indigenous microflora was very stable during the storage after day 7 in both types of compost. The greatest reductions of C. difficile vegetative cell counts occurred during the first 24 h of storage in autoclaved and unautoclaved composts, which had 4·7 and 5·5 log CFU per gram with 20% MC, 1·8 and 2·1 log CFU per gram with 30% MC, and 2·3 and 1·3 log CFU per gram with 40% MC, respectively. Both MC and the duration of storage have significant (P < 0·05) effects on the survival of vegetative cells for first 120 days of storage. The slow inactivation of C. difficile vegetative cells at higher MCs during aerobic storage was confirmed by exponentially decaying modelling data during the early stage of aerobic exposure. The reduction of endospore counts (<1·0 log CFU per gram) during the storage for both types of compost at all MCs was not significant (P > 0·05) except for the autoclaved compost with 30% MC. CONCLUSION: The highly resistant C. difficile endospores to the unfavourable environmental conditions survived for more than a year while vegetative cells died off exponentially upon the initial aerobic exposure. SIGNIFICANCE AND IMPACT OF THE STUDY: The long-term survival of C. difficile endospores in contaminated compost may transmit the pathogen to fresh produce, animals or water in pre-harvest conditions.

Thermal resistance of Clostridium difficile endospores in dairy compost upon exposure to wet and dry heat treatments.

AIM: Thermal resistance of Clostridium difficile endospores in finished dairy compost was compared at 55 and 65°C under wet and dry heat conditions. METHODS AND RESULTS: A three-strain cocktail of C. difficile endospores was inoculated into dairy compost to a final concentration of c. 5·5 log CFU per gram and the moisture content (MC) of the compost was adjusted to be 20, 30 and 40%. For the dry heat treatment at 55 and 65°C, the compost samples were placed in an environmental chamber, whereas for the wet heat treatment, the inoculated compost samples were placed in a tray submerged in a water bath. The MCs of composts were maintained well throughout the wet heat treatment while the dry heat treatment reduced the MCs of composts to <10% by the end of come-up time. During the come-up time, the log endospore reductions at a selected temperature were not significantly different in compost with three selected MCs, in each heat treatment. During the holding time, endospore counts reduced by <0·5 log CFU per gram at 55 and 65°C of dry heat treatment, whereas 0·7-0·8 and 0·6-3·0 log CFU per gram reductions were observed at 55 and 65°C in wet heat treatment respectively. CONCLUSION: The recommended minimum composting guidelines were not sufficient to reduce C. difficile endospore counts to an undetectable level (five endospores per gram). Increasing the temperature of thermophilic phase to 65°C, and maintaining higher MCs of composting feedstocks have significant (P < 0·05) effects on the endospore inactivation. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study identified factors that significantly affecting the thermal resistance of C. difficile endospores during composting, and the results suggest the current composting guidelines need to be amended in order to reduce the dissemination of C. difficile endospores in agricultural environment.

Changes in fermentation and animal performance during recovery from classical diet-induced milk fat depression using corn with differing rates of starch degradability.

Diet-induced milk fat depression (MFD) is a multifactorial disorder that can be triggered by a variety of conditions. Feeding high amounts of starch and unsaturated fatty acids has been shown to reduce milk fat yield and composition, as well as alter ruminal biohydrogenation patterns. However, little is known about how starch degradability in the rumen influences recovery from diet-induced MFD and if production of milk fat-inhibiting isomers will persist following an episode of MFD. The objective of this study was to evaluate production performance and ruminal fermentation in cows recovering from MFD when corn with a low or high starch degradability is fed. Six ruminally fistulated Holstein cows were used in a crossover design with 2 periods. During each period, MFD was induced for 10 d by feeding a diet with low fiber, high starch, and high unsaturated fatty acid. The polyunsaturated fatty acid concentration of the diet during the induction phase was modified primarily through inclusion of soybean oil. Following induction, cows were switched to either a high degradable starch recovery diet (HDS) or a low degradable starch recovery diet (LDS) for 18 d. The 7-h starch degradability was 66.5% for LDS and 87.8% for HDS. Milk was collected every 3 d for component and fatty acid analysis. On d 0, 4, 7, 10, 16, 22, and 28 of each period, ruminal pH and rumen fluid were collected every 2 h. Milk fat yield and composition was reduced during MFD induction and progressively increased by day in both HDS and LDS during recovery. Dry matter intake was similar among treatments and increased steadily over time during recovery. Preformed fatty acids were greater for HDS-fed animals, and de novo fatty acid in milk fat was greater for LDS-fed animals. Milk trans-10 C18:1 tended to be greater for HDS, and trans-10,cis-12 conjugated linoleic acid was significantly greater for HDS. cis-9,trans-11 conjugated linoleic acid was not affected by starch degradability during recovery. Total volatile fatty acids, butyrate, and valerate tended to differ or differed with recovery treatment, but ruminal pH and ammonia concentration were unaffected. The HDS diet responded similarly to the LDS diet during recovery with regard to milk fat percentage, but milk and fat yield tended to consistently be lower in HDS. When considering approaches to ameliorate diet-induced MFD, the degradability of the starch within rations should be evaluated. Although animal performance was similar, some trans fatty acid isomers were persistent in the milk through the recovery phase with HDS-fed animals, suggesting that milk fat synthesis might be potentially inhibited and biohydrogenation pathways modified in the rumen following an episode of MFD.

Addition of potassium carbonate to continuous cultures of mixed ruminal bacteria shifts volatile fatty acids and daily production of biohydrogenation intermediates.

A recent study reported a 0.4 percentage unit increase in milk fat of lactating dairy cattle when dietary K was increased from 1.2 to 2% with potassium carbonate. Because milk fat yield has been associated with ruminal production of certain conjugated linoleic acid (CLA) isomers, 2 studies were conducted to determine if increasing potassium carbonate in the rumen would alter patterns of fermentation and biohydrogenation. In experiment 1, 5 dual-flow continuous fermenters were injected just before each feeding with a 10% (wt/wt) stock potassium carbonate solution to provide the equivalent of 1.1 (K1), 2.2 (K2), and 3.3 (K3) % of diet dry matter (DM) as added K. One of the remaining fermenters received no K (K0) and the last fermenter (NaOH) was injected with adequate NaOH stock solution (10%, wt/wt) to match the pH observed for the K3 treatment. For experiment 2, 6 dual-flow continuous fermenters were used to evaluate 6 treatments arranged in a 2 × 3 factorial to examine 2 levels of soybean oil (0 and 3.64% of diet DM) and added K at 0, 1.6, and 3.3% of diet DM. In both experiments, fermenters were fed 55 to 57 g of DM/d of a typical dairy diet consisting of 1:1 forage (10% alfalfa hay and 90% corn silage) to concentrate mix in 2 equal portions at 0800 and 1630 h, and fed the respective diets for 10-d periods. Potassium carbonate addition increased pH in both experiments. Acetate:propionate ratio and pH in experiment 1 increased linearly for K0 to K3. Acetate:propionate ratio was lower for NaOH compared with K3 but the pH was the same. The trans-11 18:1 and cis-9,trans-11 CLA production rates (mg/d) increased linearly from K0 to K3, but K3 and NaOH did not differ. Production of trans-10 18:1 decreased and that of trans-10,cis-12 tended to decrease from K0 to K3, but production of trans-10,cis-12 CLA remained high for NaOH. Addition of K to the cultures in experiment 2 decreased propionate and increased acetate and acetate:propionate ratio for the 0% fat diet but not for the 3.64% fat diet. Addition of K increased stearic acid and cis-9,trans-11 CLA but decreased daily production of trans-10 C18:1 and trans-10,cis-12 CLA. The results indicate that increasing potassium carbonate in the diet shifts both fermentation and biohydrogenation pathways toward higher milk fat percentage in dairy cows, but the effects are only explained in part by elevation of pH.

In Situ Production of Zoospores by Five Species of Phytophthora in Aqueous Environments for Use as Inocula.

The goal of this study was to develop a procedure that could be used to evaluate the potential susceptibility of aquatic plants used in constructed wetlands to species of Phytophthora commonly found in nurseries. V8 agar plugs from actively growing cultures of three or four isolates of Phytophthora cinnamomi, P. citrophthora, P. cryptogea, P. nicotianae, and P. palmivora were used to produce inocula. In a laboratory experiment, plugs were placed in plastic cups and covered with 1.5% nonsterile soil extract solution (SES) for 29 days, and zoospore presence and activity in the solution were monitored at 2- or 3-day intervals with a rhododendron leaf disk baiting bioassay. In a greenhouse experiment, plugs of each species of Phytophthora were placed in plastic pots and covered with either SES or Milli-Q water for 13 days during both summer and winter months, and zoospore presence in the solutions were monitored at 3-day intervals with the baiting bioassay and by filtration. Zoospores were present in solutions throughout the 29-day and 13-day experimental periods but consistency of zoospore release varied by species. In the laboratory experiment, colonization of leaf baits decreased over time for some species and often varied among isolates within a species. In the greenhouse experiment, bait colonization decreased over time in both summer and winter, varied among species of Phytophthora in the winter, and was better in Milli-Q water. Zoospore densities in solutions were greater in the summer than in the winter. Decreased zoospore activities for some species of Phytophthora were associated with prolonged temperatures below 13 or above 30°C in the greenhouse. Zoospores from plugs were released consistently in aqueous solutions for at least 13 days. This procedure can be used to provide in situ inocula for the five species of Phytophthora used in this study so that aquatic plant species can be evaluated for potential susceptibility.

Antioxidant activity of carnosine extracted from various poultry tissues.

The aim of the present research was 1) to extract carnosine from different low economic value poultry tissues and 2) to measure their antioxidant activities using different analytical methods. Low economic value poultry tissues such as the head, liver, lungs, tail, gizzard, brain, and heart were used in this study. Results have indicated that carnosine was present in all the tissue samples investigated. The liver had the highest (102.29 mg/g) and brain the lowest carnosine content (0.95 mg/g; P ≤ 0.05). Except for the brain, all tissue ultrafiltrates and reconstituted dry powders showed TBA reactive species inhibition ranging from 20.87 to 39.57% and 5.66 -14.47%, respectively. Free radical scavenging activity of ultrafiltrate from all tissues samples ranged from 25.11 to 79.38%, whereas this activity was higher (29.76 to 84.05%) in the reconstituted dry powder of all tissue samples. Conclusions include that extraction of bioactive dipeptide carnosine can be exploited from low economic value poultry tissues to increase the economy of the poultry industry.

Use of AgomiR and AntagomiR technologies to alter satellite cell proliferation in vitro, miRNA expression, and muscle fiber hypertrophy in intrauterine growth-restricted lambs.

Introduction: microRNAs (miRNAs) are small non-coding RNAs that work at the posttranscriptional level to repress gene expression. Several miRNAs are preferentially expressed in skeletal muscle and participate in myogenesis. This research was conducted to alter endogenous miRNA expression in skeletal muscle to promote muscle hypertrophy. Methods: Two experiments were conducted using mimic/agomiR or antagomir technologies to alter miRNA expression and examine changes in myoblast proliferation in vitro (experiment 1) and muscle hypertrophy in vivo (experiment 2). In vitro experiments found that antagomiR-22-3p and mimic-127 increased myoblast proliferation compared to other miRNA treatments or controls. These miRNA treatments, antagomiR-22-3p (ANT22) and agomiR-127 (AGO127), were then used for intramuscular injections in longissimus muscle. Results and discussion: The use of antagomiR or mimic/agomiR treatments down-regulated or up-regulated, respectively, miRNA expression for that miRNA of interest. Expression of predicted target KIF3B mRNA for miR-127 was up-regulated and ACVR2a mRNA was up-regulated for miR-22-3p. ANT22 injection also up-regulated the major regulator of protein synthesis (mTOR). Proteomic analyses identified 11 proteins for AGO127 and 9 proteins for ANT22 that were differentially expressed. Muscle fiber type and cross-sectional area were altered for ANT22 treatments to transition fibers to a more oxidative state. The use of agomiR and antagomir technologies allows us to alter miRNA expression in vitro and in vivo to enhance myoblast proliferation and alter muscle fiber hypertrophy in IUGR lambs during early postnatal growth.

Comparative efficacy of tannin-free grain sorghum varieties for the control of necrotic enteritis caused by Clostridium perfringens in broiler chickens.

A 28-day battery cage study was conducted to test the efficacy of tannin-free grain sorghum varieties fed to Cobb 500 male broiler chickens (n = 512) and challenged with Eimeria maxima (EM) and Clostridium perfringens (CP). Birds were fed 1 of 8 treatments (corn, red/bronze, white/tan, or U.S. No. 2 sorghum) and were grouped by challenge method (challenged with EM/CP or unchallenged). On d 14, birds in the challenge group were orally inoculated with ∼5,000 oocysts of EM, and on d 19, 20, and 21, birds were given a broth culture of CP with ∼108 CFU/mL once daily. On d 21, three birds were scored for the degree/presence of necrotic enteritis (NE) lesions. Birds and feed were group weighed (d 0, 14, 21, and 28) to calculate average feed intake (FI), body weight gain (BWG), and adjusted feed conversion ratio (AdjFCR). Intestinal integrity was assessed through histological analysis of intestinal tissues, and change in transcriptome was determined using mRNA-sequencing on intestinal mucosa. Relative concentrations of secondary metabolites in grain sorghum were determined by LC-MS/MS analysis. Data were analyzed as a 2-way ANOVA with factors of treatment, challenge and their interaction. Regardless of challenge from 14 to 21 d, birds on the corn, white/tan, and U.S. No. 2 treatments were more efficient than those fed red/bronze treatment (P = 0.0026). From 14 to 28 d, BWG was significantly higher for the white/tan treatment (P = 0.024) compared to the red/bronze treatment. At 21 d, a significant interaction was observed for lesion score (P = 0.0001) in which, challenged birds fed red/bronze and white/tan treatments had reduced intestinal lesions compared to U.S. No. 2 and corn treatments. No differences among treatments were observed in jejunum morphology, but differential expression analysis showed an upregulation in defense response to bacteria and biotic stress in the challenged red/bronze treatment compared to the challenged corn. This study demonstrated improved gut health and minimal impact on growth and efficiency of broilers fed select grain sorghum varieties when challenged with EM/CP.

Blood-feeding ecology of mosquitoes in zoos.

To determine if the unique host assemblages in zoos influence blood-feeding by mosquitoes (Diptera: Culicidae), a sampling programme was conducted in Greenville and Riverbanks Zoos, South Carolina, U.S.A., from April 2009 to October 2010. A total of 4355 female mosquitoes of 14 species were collected, of which 106 individuals of nine species were blood-fed. The most common taxa were Aedes albopictus (Skuse), Aedes triseriatus (Say), Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Culex pipiens complex (L.) and Culex restuans (Theobald). Molecular analyses (cytochrome b) of bloodmeals revealed that mosquitoes fed on captive animals, humans and wildlife, and took mixed bloodmeals. Host species included one amphibian, 16 birds, 10 mammals (including humans) and two reptiles. Minimum dispersal distances after feeding on captive hosts ranged from 15.5 m to 327.0 m. Mosquito-host associations generally conformed to previous accounts, indicating that mosquito behaviour inside zoos reflects that outside zoos. However, novel variation in host use, including new, exotic host records, warrants further investigation. Zoos, thus, can be used as experiment environments in which to study mosquito behaviour, and the findings extrapolated to non-zoo areas, while providing medical and veterinary benefits to zoo animals, employees and patrons.

miRNA transcriptome and myofiber characteristics of lamb skeletal muscle during hypertrophic growth1.

Postnatal muscle growth is achieved through hypertrophy of the muscle fibers and is impacted by the activity of satellite cells, the quiescent muscle stem cell. Several miRNAs are preferentially expressed in skeletal muscle and could provide a mechanism for increasing muscle hypertrophy through satellite cell proliferation and/or differentiation. The objectives of this study were to: 1) Characterize the miRNA transcriptome of the longissimus thoracis et lumborum muscle at several developmental timepoints [gestational d 85 (PN1), 110 (PN2), 133 (PN3), postnatal d 42 (PW1), 65 (PW2), 243 (MAT)] during muscle hypertrophy in lambs, and 2) examine miR-29a, identified in sequencing to be differentially regulated across development, loss of function on satellite cell proliferation and differentiation. Muscle fiber characteristics showed drastic increases (p < 0.0001) in fiber size and alterations in muscle fiber type occur during pre and postnatal development. miRNA sequencing comparisons were performed in developmental order (PN1 vs. PN2, PN2 vs. PN3, PN3 vs. PW1, PW1 vs. PW2, PW2 vs. MAT). There were 184 differentially expressed (P adj < 0.05) miRNA, 142 unique miRNA, from all 5 comparisons made. The transitional stage (PN3 vs. PW1) had the largest number (115) of differentially expressed miRNA. Inhibition of miR-29a in satellite cell culture increased (p < 0.05) cell proliferation and differentiation capacity. Characterization of the miRNA transcriptome provides valuable insights into the miRNA involved in muscle fiber hypertrophy and the potential importance of the transitional period.

Apparent metabolizable energy, growth performance and carcass traits of Japanese quail fed select modern grain sorghum varieties.

OBJECTIVE: This study was performed to determine the apparent metabolizable energy (AMEn) content of tannin-free red/bronze, white/tan and U.S. No. 2 varieties of grain sorghum for feeding Japanese quail and validate their nutrient profile by evaluating effects on performance and carcass traits with full-substitution of corn. METHODS: Experiment 1 determined the AMEn content of red/bronze, white/tan, and U.S. No. 2 grain sorghum varieties fed to mixed-sex Japanese quail (Coturnix japonica) (n = 314) at 3 and 6-weeks of age. Analyses were based on a 2×4 factorial treatment design with age and grain types defining the treatments, and a randomized complete block experiment design with cage and trials defining the block. AMEn values were validated by evaluating the performance and carcass traits of Japanese quail (n = 644) from 1 to 40 days of age in Experiment 2 with birds were fed 1 of 4 complete diets. Statistical analyses were conducted on performance data and select individual carcass trait measurements. RESULTS: Determined AMEn values at 3-weeks of age were 3,524±122.03 (red/bronze), 3,252±122.03 (white/tan), and 3,039±123.44 (U.S. No. 2) kcal/kg. At 6-weeks of age, determined AMEn were 3,373±297.35 (red/bronze), 3,279±297.35 (white/tan), and 2,966±298.64 (U.S. No. 2) kcal/kg. Carcass traits showed live body weight (p = 0.0409) and hot carcass weight (p = 0.0234) were greatest in U.S. No. 2; however, carcass yield (p<0.0001) was lowest. No significant differences were observed among treatments for feed intake, feed conversion ratio, breast weight and breast yield (p>0.05). CONCLUSION: These studies demonstrated that tannin-free grain sorghum varieties may be a potential alternative to corn in quail diets while maintaining growth performance and carcass parameters.

Using nestling feathers to assess spatial and temporal concentrations of mercury in bald eagles at Voyageurs National Park, Minnesota, USA.

Bald eagles (Haliaeetus leucocephalus) have been utilized as a biosentinel of aquatic ecosystem health in the Great Lakes Region since the early 1960s. Bald eagle populations have been monitored at Voyageurs National Park (VNP), Minnesota, since 1973. For the past 20 years, researchers have collected feathers from nestling bald eagles to assess their dietary exposure to mercury (Hg) on Rainy, Kabetogama, and Namakan lakes in VNP. Mercury is an environmental pollutant with both natural and anthropogenic sources, and negatively affects many species of wildlife. In a previous study, geometric mean concentrations of Hg in feathers of nestling bald eagles were greater at VNP (20 mg/kg Dry Weight (DW)) than in nestling feathers from other Great Lakes subpopulations (~7 mg/kg DW), for the period 1985-1989. Current geometric mean concentrations have declined by 77.4% since 1989 at VNP. While all samples from 1985 to 1989 had detectable concentrations of Hg, 10% of current samples had concentrations below the reportable detection limit (0.001 mg/kg DW, n = 180). The major lakes at VNP are impounded, and Hg concentrations also declined greatly after the lake level stabilization order by the International Joint Commission was implemented in 1999. Mercury concentrations in feathers of nestling bald eagles from 1989 to 2010 ranged from ND (<0.001) to 34.97 mg/kg DW. The highest single concentration in a nestling was from Namakan Lake in 2010. The five-year geometric means for Rainy, Kabetogama, and Namakan lakes for 2006-2010 were 6.08, 1.07, and 5.56 mg/kg DW (n = 28, n = 32, n = 27) respectively. Although Hg concentrations in feathers of nestlings greatly declined after the change in water level management in 1999 and are lower than 1989 concentrations, recent samples suggest a gradual increase. Continued monitoring of nestling feather concentrations will be essential to assess this increase, to determine the source of Hg, to determine if there are changes to methylation potential, and to evaluate and optimize water level management.

Effects of Fuel Reduction Treatments on Incidence of Phytophthora Species in Soil of a Southern Appalachian Mountain Forest.

The National Fire and Fire Surrogate Study was initiated to study the effects of fuel reduction treatments on forest ecosystems. Four fuel reduction treatments were applied to three sites in a southern Appalachian Mountain forest in western North Carolina: prescribed burning, mechanical fuel reduction, mechanical fuel reduction followed by prescribed burning, and a nontreated control. To determine the effects of fuel reduction treatments on Phytophthora spp. in soil, incidences were assessed once before and twice after fuel reduction treatments were applied. Also, the efficiency of the baiting bioassay used to detect species of Phytophthora was evaluated, and the potential virulence of isolates of Phytophthora spp. collected from forest soils was determined. Phytophthora cinnamomi and P. heveae were the only two species recovered from the study site. Incidences of these species were not significantly affected by fuel reduction treatments, but incidence of P. cinnamomi increased over time. In the baiting bioassay, camellia leaf disks were better than hemlock needles as baits. P. cinnamomi was detected best in fresh soil, whereas P. heveae was detected best when soil was air-dried and remoistened prior to baiting. Isolates of P. heveae were weakly virulent and, therefore, potentially pathogenic-causing lesions only on wounded mountain laurel and rhododendron leaves; however, isolates of P. cinnamomi were virulent and caused root rot and mortality on mountain laurel and white pine plants.

Effect of stress on carnosine levels in brain, breast, and thigh of broilers.

The objective of the present study was to compare carnosine levels in tissues of broilers under stress conditions with those of broilers under nonstress conditions. Blood heterophil:lymphocyte ratio and corticosterone levels were measured as indicators of the level of stress. Corticosterone levels of stressed broilers (24,358.67 pg/mL) were 10-fold higher (P = 0.002) than those of nonstressed broilers (2,275.46 pg/mL). However, no difference (P = 0.29) was found in heterophil:lymphocyte ratio of nonstressed (0.29) and stressed (0.31) birds. Carnosine content in breast of stressed birds (17.39 mg/g) was 10 times higher (P = 0.005) than that of nonstressed birds (1.85 mg/g). Carnosine content in thigh of stressed birds (21.25 mg/g) was approximately 2-fold higher (P = 0.001) than that of nonstressed birds (11.10 mg/g). Carnosine content in brain of stressed birds did not differ (P = 0.82) from that of nonstressed birds. Based on the present study, muscle carnosine recovery levels increase during short-term stress, whereas levels in the brain are not affected.

Genetics of species differences in sailfin and shortfin mollies.

Premating reproductive isolation is a strong barrier to hybridization in natural populations, but little is known about the genetic mechanisms that allow changes in mating signals to develop and whether different components of a mating signal can evolve in concert when sexual selection favors phenotypic associations between them. In this study, we report results suggesting that changes in a behavioural trait (courtship display) and multiple phenotypically associated morphological traits (dorsal fin characters and length of the gonopodium) have contributed to divergence in mating signals used by sailfin mollies. Through the use of reciprocal F1 and backcross hybrids, we show that morphological traits important in separating sailfin from shortfin molly species have a genetic basis and are inherited in an autosomal, additive manner. We also report significant associations between the size of certain morphological traits (length of the dorsal fin and length of the gonopodium) and the tendency of males to perform courtship displays or gonopodial thrusts. In particular, higher courtship display rates were associated with increased dorsal fin length but decreased gonopodium length, characteristics most similar to sailfin species. Such phenotypic associations between different components of a mating signal suggest that selective forces can act in concert on multiple aspects of the signal, hence, promoting divergence and speciation in sailfin mollies.

Bovine dopamine type-2 receptor SNP has no effect on growth, semen characteristics and prolactin concentrations in beef bulls treated with a dopamine agonist.

A dopamine type-2 receptor (DRD2) SNP, previously found to be correlated with serum prolactin (PRL) concentrations in cattle, was evaluated for impact on growth traits, serum prolactin concentration, and semen quality. Over a four-year period, yearling beef bulls were allowed diets containing or lacking ergot alkaloids (EA). Every 21 or 28 d semen was collected for semen motility and morphology assessment and blood samples were collected to measure serum PRL concentrations. In addition, body condition score and scrotal circumference were evaluated. Serum PRL concentrations were assessed using a radioimmunoassay. In the first year, all bulls were sacrificed at the end of a 126-day study. Testicles and epididymis were collected at the end of the study or 60 days after removal from treatment. Immunohistochemistry was performed on testis, epididymis, and sperm cells, incubated with or without a primary antibody for DRD2 and counterstained with DAPI. Isolation of DNA was performed on sperm pellets using DNAzol (Thermo Fisher Scientific, Waltham, MA, USA) methods. Polymerase chain reaction was performed to amplify the region of the DRD2 gene containing the SNP of interest. The products were subjected to restriction fragment length polymorphism analysis. Further, all samples were subjected to genotyping using a custom Taqman genotyping assay (Applied Biosystems, Foster city, CA, USA). The presence of DRD2 was detected in the testis, epididymis, and sperm cells. The DRD2 genotype was not associated with semen quality, serum PRL, or growth traits. Consumption of EA resulted in lesser PRL serum concentrations but had no effect on values for other variable examined.

Effects of grazing tall fescue containing ergot alkaloids on bull sperm cryopreservation.

There are many positive agronomic traits that make tall fescue a desirable forage, however, reduced fertility rates are reported for beef cattle grazing pasture containing the ergot alkaloid-producing endophyte, Epichloë coenophiala. The objective of this study was to assess the influence of consuming tall fescue containing ergot alkaloids on sperm physiology, as measured by survival of sperm following cryopreservation. Yearling Angus bulls (n=25), having passed a breeding soundness exam (BSE), were assigned to one of two treatments accounting for body weight (BW) and body condition score (BCS). Bulls were allotted to one of two treatments on day (d) 0, grazing toxic Kentucky 31 (KY31) or a novel endophyte-containing cultivar, Texoma Max Q II (NE; AR584 Ag Research) that does not produce ergot alkaloids, for 112 days. On d 112, all bulls were placed on NE pasture to the end of test (d 168) to evaluate recovery from grazing KY31. Blood, urine, and semen samples were collected every 28 days. Semen collected on d 28, 84, 112, 140, and 168 was extended, frozen, thawed 48h later, and subjected to analyses. There were significant treatment by day interactions for serum prolactin (PRL) concentrations, verifying the effectiveness of treatment (P<0.05). Serum PRL concentrations were less in the bulls pastured on KY31 compared to NE on d 28, 84, and 112. Urinary alkaloid concentrations were affected by treatment by day interactions, confirming ergot alkaloids were present in animal systems (P<0.05). Bulls in the NE treatment group had lesser urinary alkaloid concentrations than those pastured on KY31 on d 28, 84, and 112. Post-thaw sperm analyses revealed that the percentage of progressively motile sperm was less in bulls pastured on KY31 when compared to NE (P<0.05). There were treatment by day interactions for sperm concentration, percent motile sperm, percent motile sperm concentration, and percent progressively motile sperm concentration post-thawing (P<0.05). The KY31 treatment group had a lesser sperm 1) concentration than the NE group on d 84; 2) percent motility on d 28, 84, and 168; 3) motile concentration on d 28, 84, and 168; and 4) progressively motile concentration on d 28 and 84. Sperm motility was affected post-thawing for at least 56 d following removal from the KY31 pasture.

The effect of cell passage number on osteogenic and adipogenic characteristics of D1 cells.

Cell line passage number is an important consideration when designing an experiment. At higher passages, it is generally understood that cell health begins to decline and, when this occurs, the result can be variable data. However, there are no specific guidelines regarding optimal passage range, and this information is dependent on cell type. To explore these variabilities, low passage D1 cells were thawed (passage 3) and passaged serially until a much higher number (passage 34). Samples were taken every five passages and analyzed for alkaline phosphatase and triglyceride; also, the gene expression of both adipogenic and osteogenic markers was tested. The results indicate that the growth rate of these cells did slow down after passage 30. However, expression of the osteogenic characteristics seemed to cycle, with the highest levels seen at passage 4 and 24. The adipocyte expression levels remained the same throughout the study.

Peach skin powder inhibits oxidation in cooked turkey meat.

The objective of this study was to measure the antioxidant activity of peach skin and test the antioxidant effect of peach skin powder on cooked ground turkey meat during 12 d of refrigerated storage. Antioxidant activity of 3 cultivars of peaches grown in South Carolina was first evaluated by 3 antioxidant assays. The peach variety O'Henry showed the greatest antioxidant effect and therefore was used for further study. Two levels of peach skin powder (0.5%, 1%) and 0.01% butylated hydroxylanisole (BHA) were applied to ground turkey meat. Oxidation of cooked turkey meat was measured by detection of hexanal using gas chromatography-mass spectrometry. Results indicated that all levels of peach skin powder used in this study had an antioxidant effect on ground turkey with a greater effect at the higher concentration. O'Henry peach skin powder was as effective as BHA in preventing oxidation at the levels tested.