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.

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.

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.

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.

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.

Egg Hatch Rate and Nymphal Survival of the Bed Bug (Hemiptera: Cimicidae) After Exposure to Insecticide Sprays

Few studies have addressed the efficacy of insecticides used against eggs and first-instar nymphs of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Insect eggs are often resistant to insecticides; therefore, information on which products are effective is important. We evaluated the efficacy of four commonly used insecticide sprays applied directly to bed bug eggs. We also evaluated the efficacy of these insecticides to first-instar nymphs exposed to residuals resulting from directly spraying eggs. Temprid SC (beta-cyfluthrin, imidacloprid) was the most effective insecticide at preventing egg hatch (13% hatch rate) for pyrethroid-resistant, field-strain (Jersey City) bed bugs compared with a control (water [99% hatch rate]), Bedlam (MGK-264, sumithrin [84% hatch rate]), Demand CS (lambda-cyhalothrin [91% hatch rate]), and Phantom SC (chlorfenapyr [95% hatch rate]). Demand CS and Temprid SC were most effective at preventing egg hatch (0%) for an insecticide-susceptible (Harold Harlan) strain, followed by Bedlam (28%). Phantom SC produced a hatch rate similar to the control (97% and 96%, respectively). Harold Harlan-strain nymphs showed 100% survival for the control but 0% survival for Bedlam and Phantom SC. Jersey City-strain nymphs showed 100% survival for the control, 99% survival for Bedlam, 0% survival for Demand CS, 4% survival for Phantom SC, and 38% survival for Temprid SC. Demand CS was less effective at preventing hatch (91% hatch rate) of Jersey City-strain nymphs but was the only product to kill all nymphs (0% survival). One of the least effective products for preventing Jersey City-strain egg hatch (Phantom SC, 95% hatch rate) was the second most effective at killing nymphs, leaving only six of 141 alive. These findings indicate that survival of directly sprayed eggs and residually exposed, first-instar nymphs varies by strain, life stage, and product used.

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.

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.

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.

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.

Comparative morphology of the pyloric armature of adult mosquitoes (Diptera: Culicidae)

The structure of the pyloric armature, hypothesized to aid in blood-meal digestion or parasite resistance, was compared quantitatively among the following 8 species in 5 genera of adult mosquitoes from the southeastern United States: Aedes albopictus, Aedes japonicus, Aedes triseriatus, Anopheles punctipennis, Culex pipiens s.l., Culex restuans, Orthopodomyia signifera, and Toxorhynchites rutilus. Females differed significantly among species in the structure of spines composing the armature, with Aedes spp. forming one general group, Culex spp. another, and An. punctipennis and Or. signifera a third. Relationships of species based on structural characters of the armature were consistent with recent culicid phylogenies. Although pyloric armature has been noted in mosquitoes and other insects, this is the first quantitative investigation of the mosquito pyloric armature.

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.

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.

Activity of selected neonicotinoids and dicrotophos on nontarget arthropods in cotton: implications in insect management

Certain neonicotinoids are used in cotton, Gossypium hirsutum (L.), to control various piercing-sucking pests. We conducted field studies using three neonicotinoids (acetamiprid, thiamethoxam, and imidacloprid) and an organophosphate (dicrotophos) to assess the activity of these insecticides against nontarget arthropods, particularly predators, and to determine the potential economic consequences of such activity. Mortality among populations of the big-eyed bug, Geocoris punctipes (Say), and the red imported fire ant, Solenopsis invicta Buren, was highest after thiamethoxam and dicrotophos treatments. Numbers of arachnids were consistently lower after dicrotophos treatments, whereas none of the neonicotinoids caused appreciable mortality. Total predators in pooled data from five separate studies revealed that numbers, compared with untreated plots, were reduced by -75% in dicrotophos, 55-60% in thiamethoxam, and only 30% in both acetamiprid and imidacloprid plots. Acetamiprid and thiamethoxam exhibited significant mortality against field-deposited eggs of bollworm, Helicoverpa zea (Boddie). Both thiamethoxam and dicrotophos plots exhibited bollworm numbers that were approximately three times higher than treatment thresholds (three per 100 plants), whereas numbers in untreated plots were below threshold levels. In one study on Bt cotton, a significant negative correlation was observed between numbers of predators and bollworm larvae. Results demonstrated that neonicotinoids differ in activity against predaceous arthropods and bollworm eggs and that high predator mortality can result in resurgence of bollworm larvae and additional insecticide costs.

Ruminal biohydrogenation in Holstein cows fed soybean fatty acids as amides or calcium salts

Fatty amides of high oleate fats and calcium salts of palm oil were reported to resist biohydrogenation by ruminal microorganisms. This study was conducted to determine whether converting polyunsaturated fat sources to amides and calcium salts had equal ability to resist biohydrogenation. A total mixed ration consisting of forage and concentrate contained (dry basis): 1) 2.45% soybean oil (SBO), 2) 2.75% calcium salt of SBO, 3) 2.75% amide of SBO, or 4) 2.75% of a mixture of the calcium salt and amide (80:20, wt/wt) of SBO. The 4 diets were fed ad libitum to 4 multiparous lactating Holstein cows fitted with ruminal cannulas in a 4 x 4 Latin square with 21-d periods. Omasal samples were taken to measure postruminal fatty acid content and determine the extent of ruminal biohydrogenation. Adding SBO to the diets as either calcium salts or amides increased omasal flow of C18:2 (n-6) from 25 to 39 g/d. Omasal flow of C18:1 increased from 36 to 49 g/d when SBO was fed to cows as calcium salts, but increased to 86 g/d when SBO was fed as amides. Adding the soybean amide to the diet more than doubled the delivery of C18:1 (n-9) to the omasum of lactating cows, but it also increased trans fatty acid production in the rumen accompanied by milk fat depression. In this study, calcium salts and amide derivatives of fatty acids were both effective in enhancing omasal flow of unsaturataed fatty acids in lactating dairy cows. Amides were more effective than calcium salts for increasing the postruminal flow of oleic acid.

Field and laboratory evaluations of transgenic cottons expressing one or two Bacillus thuringiensis var. kurstaki Berliner proteins for management of noctuid (Lepidoptera) pests

Field studies were conducted from 1999 to 2001 to evaluate the efficacy of the transgenic cotton, Gossypium hirsutum (L.), genotype, Bollgard II (Monsanto 15985), which expresses two Bacillus thuringiensis Berliner (Bt) proteins (Cry1Ac + Cry2Ab) that are active against lepidopterous pests. Bollgard II was compared with Bollgard (DP50B), which expresses only one Bt protein (Cry1Ac), and, in all tests, the conventional variety, DP50, was used as a non-Bt control. Larval populations of the bollworm, Helicoverpa zea (Boddie), and the soybean looper, Pseudoplusia includens (Walker), were significantly lower in Bollgard II than in Bollgard and conventional cotton, and the proportion of fruit damaged by H. zea was also lower. Fall armyworm, Spodoptera frugiperda (J. E. Smith), populations were lower in Bollgard II than in Bollgard, although not significantly. Field tests were supplemented with laboratory bioassays in 2001 to compare mortality of S. frugiperda, and beet armyworms, Spodoptera exigua (Hübner), feeding on these genotypes. Mortality of both species was significantly greater on Bollgard II plant material than on either Bollgard or conventional cotton. This study demonstrated that the dual-toxin Bollgard II genotype is highly effective against lepidopterous pests that are not adequately controlled by the current single-toxin Bollgard varieties. If toxin expression in future Bollgard II varieties remains consistent with that of Monsanto 15985, supplemental insecticides will be reduced, and may be eliminated for lepidopterous pests in South Carolina.

Breeding soundness evaluations of 3,648 yearling beef bulls using the 1993 Society for Theriogenology guidelines

Our objective was to perform a retrospective analysis of breeding soundness evaluations (BSEs) as classified by the 1993 Society for Theriogenology (SFT) guidelines [Chenoweth et al., Guidelines for using the bull breeding soundness evaluation form, in: Theriogenology Handbook, 1993, pp. B-10]. Data included BSE information obtained from five performance-testing stations in South Carolina (SC1, SC2, SC3) and Tennessee (TN1, TN2) from 1986 through 1999 on 3648 Angus, Brangus, Charolais, Chianina, Gelbvieh, Limousin, Polled Hereford, Santa Gertrudis, Simbrah, and Simmental bulls. Analyses were simplified by classifying all bulls as either satisfactory or unsatisfactory potential breeders. Of the 3648 bulls evaluated, 76.2% were classified as satisfactory potential breeders. Of all bulls evaluated, 4.0% were unsatisfactory due to inadequate spermatozoal motility, 7.0% due to inadequate spermatozoal morphology and 2.6% due to a combination of inadequate motility and morphology. Unsatisfactory classifications due to non-spermatozoal parameters out of all bulls were 10.2%, with 7.1% for inadequate scrotal circumference and 3.1% for physical abnormalities. For satisfactory and unsatisfactory bulls, respectively, means and standard deviations were 35.8 +/- 2.7 and 33.0 +/- 4.1 cm (P < 0.001) for scrotal circumference, 63 +/- 18 and 35 +/- 24% (P < 0.001) for percent motility, and 86 +/- 7 and 63 +/- 21% (P < 0.001) for percent normal morphology.

Weight necessary to change body condition scores in Angus cow

Weights and body condition scores (BCS) were measured and assessed on Angus females (n = 367) over 14 yr (1981 to 1994) to allow calculation of weight adjustments for different BCS. Data were collected at five time periods: prepartum, postpartum, prebreeding, postbreeding, and midgestation. Individual cows with multiple records were included in the analysis as repeated measures to yield 3,912 total observations. Body condition score was assigned on a scale of 1 = emaciated to 9 = obese. Only BCS 2 through 8 were analyzed, as there were zero recorded observations of BCS 1 or 9. The final model included age and the time period by BCS interaction as fixed effects. Year by animal within age interaction and a residual error term were treated as random effects. Animal was included to correct for repeated measures across time periods and years for individual animals. All these effects were significant (P < 0.0001). Weight adjustments for BCS were calculated for each time period. Cow weight and weight adjustments for BCS were not consistent for each time period. Overall weight adjustments to adjust cows to BCS of 5 were (kg +/- SEM) BCS = 2 (68 +/- 12), BCS = 3 (50 +/- 4), BCS = 4 (21 +/- 1), BCS = 5 (0), BCS = 6(-24 +/- 2), BCS = 7(-51 +/- 3), and BCS = 8 (-73 +/- 7).

Atrazine effects on in vitro maturation and in vitro fertilization in the bovine oocyte

The effect of low levels of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on in vitro oocyte maturation, in vitro capacitation of sperm, or in vitro fertilization of bovine oocytes and on the quality of blastocyst formation was studied. Bovine oocytes collected from abattoir ovaries were matured, fertilized, and developed to the blastocyst stage in vitro. Embryos that reached a morula or blastocyst stage were stained with Hoechst 33258 stain to determine the number of blastomeres per embryo. Three bulls whose fertilization rates were proven consistent among straws were used for this study. Atrazine was tested at concentrations of 0.01, 0.1, 1, and 10 microM in either the maturation medium, sperm capacitation medium, or the fertilization medium. Because atrazine was dissolved in ethanol, an ethanol control was used to determine any possible effects of ethanol on the in vitro process. The addition of atrazine to both the maturation and fertilization media did not result in any significant difference in fertilization rates between the controls and the treatments. In the capacitation medium, a significant difference between the controls and the atrazine levels of 0.1, 1, and 10 microM was noted for one bull. Atrazine did not affect the number of blastomeres per embryo. There was not a significant difference (p>0.05) in the number of blastomeres per embryo between the controls and the different levels of atrazine in each medium. This study indicates that low levels of atrazine do not have an effect on in vitro fertilization rates or the number of blastomeres per embryo produced in vitro.

Site of administration and duration of feeding oleamide to cattle on feed intake and ruminal fatty acid concentrations

Two experiments were conducted to determine effects of oleamide on feed intake and ruminal fatty acids when the oleamide was introduced in the feed vs through a ruminal fistula (Exp. 1) or the oleamide was fed for an extended (9-wk) length of time (Exp. 2). In Exp. 1, four nonlactating Holstein cows, each fitted with a ruminal cannula, were fed four diets in a 4 x 4 Latin square design. Each period lasted 2 wk. Diets consisted of 48% corn silage and 52% concentrate on a DM basis. One diet contained no added fat (control) and a second diet contained 4.2% oleic acid. The remaining two diets were designed to expose cows to 4.2% amide (as oleamide) either through the feed (AF) or by administering oleamide into the rumen (AR) each day through the ruminal cannula. The AF diet reduced DMI similarly to results reported previously for lactating dairy cows and sheep. Intake of the oleic acid diet was intermediate between the control and AF diets. Dry matter intake was reduced by AR similarly to the AF diet. The acetate:propionate ratio in samples of ruminal contents was reduced by oleic acid but not by AF or AR. In Exp. 2, 12 steers were divided into three equal groups of two Angus and two Simmental x Angus crosses, and each group was assigned a diet containing either no added fat (control), 4% oleamide, or 4% high-oleic canola oil. All steers had ad libitum access to feed and water. Dry matter intake by steers fed the canola oil diet was not different from that by steers fed the control diet when averaged over the first 3 wk, the last 3 wk, or over the entire 9-wk study. Oleamide reduced DMI 4 kg/d over the first 3 wk of the study. However, DMI of the oleamide diet consistently increased over the 9-wk study, resulting in wk 7 to 9 DMI that was not different from that of steers fed the control diet. These results show that the reduction in feed intake when oleamide is added to cattle rations can be attributed more to physiological responses than to an undesirable unique taste or odor of the oleamide. In finishing beef steers, the decreased intake induced by oleamide was most severe during the first 1 or 2 wk of feeding but gradually lessened over time until it nearly returned to normal by wk 9.

The influence of husbandry schedules on the number of embryos collected from superovulated mice

We undertook this study to assess the effect of urine and fecal contamination in the cages of male mice on embryo production in females placed in these cages for breeding. Each superovulated female was placed with a stud male in a cage that was cleaned at 1, 24, or 168 h prior to breeding. Approximately 41 h after mating, embryos were flushed from the oviducts, and we determined the number of embryos and their developmental stages for each treatment group. The number of two-cell embryos collected did not differ significantly when cages were cleaned 1 or 24 h prior to mating the mice. However, significantly (p < 0.05) fewer embryos were recovered when cages were changed 168 h before the animals were mated.

Outcomes of breeding soundness evaluation of 2898 yearling bulls subjected to different classification systems

This study is a retrospective analysis comparing data on yearling bull breeding soundness evaluation (BSE) subjected to 3 different classification systems: the Society for Theriogenology (SFT) 1983 and 1993 systems, and the Western Canadian Association of Bovine Practitioners (WC) 1993 system. Data were collected at 5 performance bull-test stations located in South Carolina and Tennessee from 1986 through 1996. Yearling bulls (n=2898) that were 10 to 20 mo of age were used in the analysis. To simplify analysis, bulls were determined to be either satisfactory or unsatisfactory potential breeders (including those classified as questionable, deferred or unsatisfactory). Data were analyzed 1) within location where a location was treated as an individual experiment, 2) with breeds and locations collapsed, and 3) within age-group where each age-group was treated as an individual experiment. An ANOVA was performed using GLM procedures of SAS, and this model was used to generate least square means for the proportion of bulls classified as satisfactory and the 5 possible unsatisfactory outcomes due to inadequacies in scrotal circumference, spermatozoal morphology, spermatozoal motility, a combination of inadequate spermatozoal morphology and motility, or physical abnormalities. Inadequate scrotal circumference or physical abnormality did not affect differences for BSE outcomes among systems. Using the SFT93 system, bulls failed at a higher rate due to inadequate spermatozoal morphology (P < 0.05) than when subjected to the SFT83 system. In the WC93 system, a higher percentage of bulls failed due to inadequate spermatozoal motility and to a combination of inadequate spermatozoal morphology and motility than in the other 2 systems (P < 0.05). The proportion of bulls in this data failing under the WC93 system appears to be the result of overestimation.

Interactions of tallow and hay particle size on yield and composition of milk from lactating Holstein cows

An 18-wk lactation study was conducted to determine whether the effects of tallow on the lactation performance of dairy cows were influenced by particle size of hay in the ration. A total mixed ration containing 50% concentrate, 25% corn silage, and 25% alfalfa hay (dry matter basis) was fed to Holstein cows. Four total mixed rations were developed based on differences in the percentage of tallow in the concentrate and particle size of alfalfa hay: 1) 0% tallow, long-cut hay; 2) 0% tallow, short-cut hay; 3) 5% tallow, long-cut hay; and 4) 5% tallow, short-cut hay. Ration had no effect on dry matter intake, body weight gain or change in body condition score. Tallow increased milk and milk protein yields but reduced milk protein concentration. However, the effects of tallow on milk and milk protein yields were the same, regardless of hay length in the ration. A tendency for an interaction of tallow and hay particle size was detected for fat-corrected milk (FCM) because tallow increased FCM more when hay was short. Ration had no effect on volatile fatty acids in ruminal samples collected via a stomach tube. In this study, the effects of tallow on milk yield and composition from Holstein cows were the same, regardless of hay particle size in the ration. The tendency for tallow to increase FCM more when hay was short suggests at least a limited role of forage particle size in the determination of how fat supplements in dairy rations affect lactation performance.

High temperature processing effects on the properties of fowl meat gels

The effects of three moisture levels (0, 10, and 20% added water) and three processing temperatures (115.6, 121.1, and 126.7 C) on texture and collagen solubilization of fowl meat gels were examined. Meat gels were formulated from spent fowl breast meat that were cooked in water (71.1 C internal temperature) prior to heat processing. The water-cooked gels were heat processed at the three temperatures to an F0 value of 6.0 (Z value = 10 C). The addition of 20% water resulted in a reduction of the soluble collagen compared to the 10% water-added treatment. The lowest processing temperature increased the soluble collagen compared to the highest processing temperature. Shear stress and hardness decreased as the amount of added water was increased; and the lowest processing temperature resulted in the lowest hardness values. The increase in soluble collagen parallels the decrease in hardness in the samples processed at the lowest temperature. Because each sample was processed to equivalent F values, the lowest processing temperature had the longest exposure time (26 min at 115.6 C, 12 min at 121.1 C, and 6 min at 126.7 C). The longer exposure to moist heat allowed for greater collagen solubilization and lower hardness values. The 0% added-water treatment had the highest yield from before and after heat processing. However the 10% water-added samples had the greatest overall water retention when each treatment was placed on an equal level of initial water content. Furthermore, the highest processing temperature (shortest processing time) resulted in the greatest yield and moisture retention compared to the other processing temperatures.

Methodology for adjusting scrotal circumference to 365 or 452 days of age and correlations of scrotal circumference with growth traits in beef bulls

A retrospective analysis was conducted on data collected from 1983 through 1991, where weight and hip height were measured at start of test and every 28 d on 604 bulls completing a 224-d forage-based gain test. Scrotal circumference (SC) was measured at start of test, and at either end of test or end of the weigh period after individual bulls reached 365 d of age. Over 3 yr of this study, SC was additionally measured every 28 d. Bulls were representatives of 5 breed groups: Angus, Santa Gertrudis, Simmental, Continental (predominantly Charolais), and Zebu (predominantly Simbrah). Adjusted 365-d SC and adjusted 452-d SC were calculated by regression analysis and from formulas based on SC growth of individuals to 140 and 224 d on test, respectively. Breed group differences were observed for age of dam, birth weight, hip height, weight per day of age, average daily gain and SC at start of test, 140 d, and end of test (224 d). Scrotal circumference was positively correlated with all growth traits. Scrotal circumference was related to breed group, age, weight, hip height, average daily gain, weight per day of age, age by year, and age-by-breed group (P<0.05), as determined by regression analysis. However, omitting weight, hip height, average daily gain, and weight per day of age from the regression model did not significantly affect R2 value. Scrotal circumference growth was linear to 140 d on test; however, SC growth to 224 d on test was curvilinear. The 365-d SC predicted from the formula and from regression analysis differed for Simmental and Zebu by 0.3 and 0.4 cm, respectively (P<0.05). The 452-d SC differed for Santa Gertrudis and Zebu by 0.5 and 0.6 cm, respectively (P<0.05). Formulas based on SC growth of individuals are reasonably accurate predictors of SC at 365 and 452 d of age, when compared with more complex regression analysis. Basing SC adjustments on individual growth appears to account for variables known to affect yearling SC.

Mapping dominant markers using F2 matings

The development of efficient methods for amplifying random DNA sequences by the polymerase chain reaction has created the basis for mapping virtually unlimited numbers of mixed-phase dominant DNA markers in one population. Although dominant markers can be efficiently mapped using many different kinds of matings, recombination frequencies and locus orders are often mis-estimated from repulsion F2 matings. The major problem with these matings, apart from excessive sampling errors of recombination frequency (θ) estimates, is the bias of the maximum-likelihood estimator (MLE) of θ (θ ML). [Formula: see text] when the observed frequency of double-recessive phenotypes is 0 and the observed frequency of double-dominant phenotypes is less than 2/3 - the bias for those samples is - θ. We used simulation to estimate the mean bias of θ ML. Mean bias is a function of n and θ and decreases as n increases. Valid maps of dominant markers can be built by using sub-sets of markers linked in coupling, thereby creating male and feamle coupling maps, as long as the maps are fairly dense (about 5 cM) - the sampling errors of θ increase as θ increases for coupling linkages and are equal to those for backcross matings when θ=0. The use of F2 matings for mapping dominant markers is not necessarily proscribed because they yield twice as many useful markers as a backcross population, albeit in two maps, for the same number of DNA extractions and PCR assays; however, dominant markers can be more effeciently exploited by using doubled-haploid, recombinant-inbred, or other inbred populations.

Facilitators and Inhibitors of Practice: A Faculty Perspective

Nurse educators are being encouraged to integrate the role of faculty practice into the role expectations of the educational institution. Schools of nursing are faced with the challenge of facilitating faculty who wish to adopt the practice role. There are limited studies documenting factors that facilitate or inhibit faculty who engage in practice. This article presents the findings of a Delphi procedure used to collect the consensus of practicing faculty concerning organizational and personal facilitators and inhibitors of faculty practice. In this study, 299 faculty representing 170 schools of nursing completed all three rounds of the Delphi. The findings present the top five factors identified by practicing faculty as personal and organizational facilitators and inhibitors of their practice.

Effects of metestrous administration of a norgestomet implant and injection of norgestomet and estradiol valerate on luteinizing hormone release and development and function of corpora lutea in suckled beef cows

Sixteen suckled beef cows were used to determine effects of Syncro-Mate-B (SMB) on the development and function of corpora lutea (CL) and LH release. Twelve cows were treated 2 d after estrus with the standard SMB treatment regimen, a 6-mg Norgestomet ear implant (in situ 9 d) and a 2-mL i.m. injection of 3 mg of Norgestomet and 5 mg of estradiol valerate at time of implant insertion. Four cows served as untreated controls. In cows treated with SMB with subsequently nonfunctional CL (n = 5), mean concentrations of progesterone (P4) were lower on d 9, 12 (implant removal), and 14 of the treated cycle than in control cows or in those cows treated with SMB that developed functional CL (P < .01). In cows treated with SMB that developed functional CL (n = 7), mean concentrations of P4 were lower only on d 12 of the treated cycle than those in control cows (P < .01). In cows treated with SMB with subsequently nonfunctional CL, CL were smaller from d 9 through 14 of the treated cycle than in control cows or in those cows treated with SMB that developed functional CL (P < .01). In cows treated with SMB that developed functional CL, CL were smaller on d 9 and 11 of the treated cycle than in control cows (P < .01). Regardless of subsequent CL function, mean concentrations of LH and numbers of LH pulses were lower in cows treated with SMB than in control cows on d 3 and 4 of the treated cycle (P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Schools with nursing centers: a 5-year follow-up study

The article reviews the growing body of literature that examines academic nursing centers in the aggregate including the first such study conducted by the primary author 5 years earlier. A follow-up study to this original work was conducted to determine current demographics and faculty practice policies of schools or colleges of nursing that operate nursing centers and to compare these findings with those of schools without nursing centers. A survey was sent to the deans or directors of the 462 National League of Nursing (NLN)-accredited baccalaureate nursing programs. Although there were 362 respondents to the survey (78 per cent), only 41 indicated they had a nursing center. Schools with nursing centers were significantly more likely to be in public institutions (P = .05), and offer master's degrees (P = .01). They also were significantly larger (P = .01), with a mean of 34 full time-equivalent (FTE) faculty members. Then the administrative policies of schools with nursing centers (N = 41) were compared with those of schools without centers but with practicing faculty (N = 187). Requiring practice was not a common policy in either group. While about one-third of both groups had practice plans, the majority were described as informal. More schools with nursing centers had other formalized practice arrangements than did schools without centers (P = .01). Faculty practice was more likely to be a criterion for promotion (P = .05) but not for tenure in schools with nursing centers. An inverse relationship (P = .05) was found between the amount of practice revenue generated and the presence of a nursing center.(ABSTRACT TRUNCATED AT 250 WORDS)

Nursing faculty practice: an organizational perspective

After reviewing the faculty practice literature of the 1980s and finding philosophical support for practice but also growing concerns about faculty role overload, the authors report a study to identify organizational factors that influence the role expectations of faculty members about practice. A survey was sent to the deans or directors of all National League for Nursing--accredited baccalaureate nursing programs (n = 462). Of the 356 respondents (78 per cent), 224 (63.3 per cent) reported that their school had practicing faculty, but only 20 schools (8.8 per cent) required practice. Written faculty practice plans were reported by 23 schools (10.2 per cent), and nursing centers by 41 schools. Thirty-six respondents (16 per cent) reported that practicing faculty generated revenue for the school. Practice was required for promotion in 15.8 per cent and for tenure in 15.3 per cent of all schools surveyed. The study showed significant direct relationships between master's and doctoral programs and practicing faculty, but there was an inverse relationship between the presence of a health science center and schools with practicing faculty. Organizational factors relating to both the number and per cent of faculty who practiced included requiring practice, having a practice plan, and having practice as a criterion for promotion and for tenure. Revenue generation and presence of formalized practice arrangements were related to the number of faculty who practiced but not the per cent of the total faculty who practiced. The study's findings have implications for nursing education in designing organizational structures and rewards that support faculty practice.

Identification and content of insulin-like growth factors in porcine oviductal fluid

Oviductal fluid (OvF) was collected from gilts by indwelling catheters during the estrous cycle and analyzed for content of insulin-like growth factors (IGF-I, IGF-II). Group 1, composed of 9 gilts in a summer environment near a boar, yielded mean daily fluid volumes of 1.18 +/- 0.16 ml during estrus and 0.69 +/- 0.03 ml post-estrus. Group 2, composed of 7 gilts in a moderate-temperature, light-regulated room, yielded 1.20 +/- 0.18 ml during estrus and then OvF flow essentially stopped. Serum samples were also collected 2 times daily during the cycle and analyzed along with the OvF for IGF-I and IGF-II. Serum was also analyzed for estradiol-17 beta (E2). For group 1, OvF content (concentration x fluid volume) of IGF-I and IGF-II was greater (p less than 0.05) at estrus than pre- and post-estrus. Daily mean content values (ng/day) for IGF-I and IGF-II during peri-estrus were 30.9 +/- 6.3 and 62.2 +/- 12.3, respectively. During nonestrus, values were 6.8 +/- 6.3 and 11.7 +/- 12.3, respectively. For group 2, OvF content of IGF-I and IGF-II during estrus was similar to that of group 1. Whereas IGF content differed between estrus and nonestrus periods, IGF concentrations were similar (p greater than 0.05), a finding that results from the difference in OvF produced. Compared with OvF concentrations of IGF for a given pig, blood plasma concentrations of IGF-I and IGF-II were 2- to 5-fold higher in the plasma sample collected the same day.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum hormone and metabolite concentrations in fasted young bulls and steers

The effect of dietary energy restriction on serum insulin, insulin-like growth factor I (IGF-I), growth hormone, (GH), cortisol, plasma urea nitrogen (PUN) and nonesterified fatty acid (NEFA) concentrations was examined. Angus bulls and steers (10 mo) were allotted to two groups of 12 animals and assigned a treatment order. In a switchback design, animals in order 1 were fed a high grain diet, then fasted, while order 2 animals were fasted, and then fed. Animals were allowed 60 hr to acclimate between treatments. Serum and plasma were obtained at 20 min intervals and 60 min, respectively, for 6 hr after feeding and for the last 6 hr of a 30 hr fast. Serum was assayed for insulin, IGF-I, GH, and cortisol (total and free). Plasma was assayed for PUN and NEFA. Mean insulin (ng/ml) differed between fed (.95 +/- .08) and fasted (.26 +/- .08) animals (P less than 01). Both mean total and free cortisol (ng/ml) were lower in fed (11.48 +/- .99) (1.06 +/- .12) than in fasted (17.10 +/- .93) (1.62 +/- .12) animals, respectively (P less than .01). Animals in order 1 differed in mean IGF-I (ng/ml) between fed (199.0 +/- 8.0) and fasted (116.5 +/- 7.2) treatments (P less than .01). Mean IGF-I for animals in order 2 was 146.7 +/- 7.2 in fed and 213.9 +/- 7.2 in fasted animals (P less than .01). Mean GH did not differ between treatments. Mean PUN and NEFA were higher in fasted than in fed animals (P less than .01). Except for % free cortisol (P less than .05), the hormones did not differ between bulls and steers.(ABSTRACT TRUNCATED AT 250 WORDS)

Research note: relationship of comb color to liver appearance and fat content in Single Comb White Leghorn laying hens

A flock of commercial Single Comb White Leghorn laying hens, diagnosed as having fatty Liver Hemorrhagic Syndrome (FLHS), was surveyed to ascertain the relationship between comb color and selected FLHS characteristics. Twenty-eight hens with and without pale combs were selected from 14 cages for paired comparisons. Hens with pale combs had a higher (P less than or equal to .05) liver score and relative liver weight than hens with normal combs. Differences were not detected in BW, comb weight, relative comb weight, liver fat and plasma estrogen concentration. In flocks diagnosed with FLHS, comb appearance is associated with a higher incidence of FLHS.

Association of body weight and feed separation to pen (cage) location for single comb White Leghorn pullets fed with a drag chain-type feeder

A field study was conducted to determine the relationship of pen (cage) location (PL) along a drag chain-type feeder to BW and feed nutrients (FN) for commercial Single Comb White Leghorn pullets. At 12 and 17 wk of age, feed samples were collected and BW was measured individually for 1 pen (cage) at approximate 30-m intervals from 0 to 213 m. Replication was two lines per house, two houses per farm, and three farms at two ages. Feed was analyzed for CP, fat, P, K, Ca, Mg, Zn, Cu, Na, and moisture. Means for BW and FN were regressed on PL using a general linear model. Body weight increased (P less than or equal to .05) as PL increased from 0 to 213.36 m along the feed line. For the nutrients CP, K, Mg, Na, and moisture, there was no PL effect. For the nutrients fat, Zn, and Mn, there was a significant PL and week effect with a significant PL by week interaction. For the nutrients P, Ca, and Cu, there was a significant PL and week effect but no significant PL by week interaction. Body weight was correlated negatively with Zn and positively with K and Mn for 12 wk of age only. Feed separation along a drag chain-type feed line did occur. However, the relationship of feed separation to changes in BW was not fully ascertained in the present study.

Comparison of methods for predicting yearling scrotal circumference and correlations of scrotal circumference to growth traits in beef bulls

From 1981 through 1986, BW, hip height, and scrotal circumference (SC) measurements were obtained on 329 bulls at the start of a 140-d gain test (SOT) and every 28 d to the end of test (EOT). Age, overall ADG, weight per day of age, ADG by period, and SC growth (cm/d) were calculated. Data were analyzed in two data sets because age of dam (AOD) and birth weights were unavailable between 1981 and 1983. Correlations of SC to other traits measured and probabilities for bulls attaining 30 or 32 cm SC by 365 d of age were calculated. Two adjusted 365-d SC (365-d SC) were calculated for each individual from regression analysis and from the following formula: 365-d SC = [(SCEOT-SCSOT)/140 d] x [365-ageSOT] + SCSOT. Except for ADG in Data Set 2, breed group differences (P less than .05) were observed for correlations of SC to all growth traits, age, and AOD. To attain 30 cm SC by 365 d of age with nearly 100% probability, Angus, Simmental and Zebu-derived bulls needed a 23-cm SCSOT, whereas continental (other than Simmental) and Polled Hereford bulls required a 26-cm SCSOT. Overall, 365-d SC means calculated by regression analysis or formula method did not differ (P greater than .10) for either data set.