Effects of Application of Fungicide During the Dormant Period on Phomopsis Cane and Leaf Spot of Grape Disease Intensity and Inoculum Production.

Efficacy of application of the fungicides calcium polysulfide or fixed copper during the dormant period on control of Phomopsis cane and leaf spot of grape (Vitis spp.), caused by Phomopsis viticola, was examined under field conditions during the 2003 and 2004 growing seasons in Ohio. Dormant-period fungicide applications were made either in the fall (after leaf drop and periderm tissue formation on the first-year canes, mid-November), or spring (at bud-swell, mid-April), or both. Disease incidence and severity on leaves and internodes were examined. In addition, effects of dormant-period application on sporulation of P. viticola were determined by examining the number of conidia in rain-splashed water in the spring and formation of mature pycnidia on cane sections in the winter. Fall-and-spring and spring applications of calcium poly-sulfide provided 12 to 88% reduction in disease intensity (incidence or severity), whereas calendar-based protectant mancozeb applications reduced overall disease intensity by 47 to 100%. Fixed-copper applications did not provide a consistent reduction of the disease. Fall applications of dormant-period fungicide provided little or no effect by itself. There was a significantly lower number of conidia observed in collected splashed rain water from vines treated with fall-and-spring applications of calcium polysulfide than in rain water from nonsprayed vines. Fall-and-spring and spring applications of calcium polysulfide provided a significant reduction in the number of mature pycnidia formed on incubated cane sections compared with the nonsprayed control (5 versus 10 pycnidia/cm2), whereas fixed copper did not provide a significant reduction.

Evaluation of a Disease Warning System for Phomopsis Cane and Leaf Spot of Grape: A Field Study.

A field evaluation of a warning system for Phomopsis cane and leaf spot of grape (Vitis spp.), caused by Phomopsis viticola, was conducted in Ohio over 3 years (2002 to 2004) by applying fungicides and fungicide-adjuvant combinations based on predicted infection events. Three different criteria for risk-light, moderate, and high-were evaluated with the warning system. The warning system is based on measured weather conditions (temperature and wetness duration following rain) and a model for risk of leaf and internode infection. Vines were sprayed with fungicides based on either the warning system or a calendar-based 7-day protectant program, from 2.5-cm shoot growth (Eichhorn-Lorenz [E-L] stage 7) to the end of the broom (E-L stage 27). Fungicides were tested with or without an adjuvant (JMS Stylet-Oil or Regulaid). In the controls, the mean percentage of leaves and internodes with infections ranged from 36 to 100%, the number of lesions per leaf ranged from 1 to 28, and percentage of internodes covered by lesions ranged from 1 to 12%. Both the calendar-based protectant treatment (based on use of mancozeb) and the warning system treatment based on spraying in response to light or moderate predicted infection events (especially with mancozeb + Regulaid) resulted in significantly less disease incidence and severity compared with the controls. The mean percent control (relative difference in disease between a treatment and the control) was higher for the protectant schedule (˜55% and ˜80% for incidence and severity, respectively, based on application of mancozeb) than for the warning system (˜36% and ˜60% for incidence and severity, respectively, based on application of mancozeb + Regulaid), but there were two to three times more fungicide applications with the protectant schedule than with the warning system.

Characterization of Hepatitis B and C Among Liver Transplant Recipients With Hepatocellular Carcinoma: An Analysis of the Nationwide Inpatient Sample Database.

INTRODUCTION: Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for most hepatocellular carcinoma (HCC) and subsequent liver transplant cases. Racial/ethnic disparities exist in access to liver transplantation and post-transplantation survival, and we sought to compare and explore potential disparities in HBV and HCV-related liver transplant populations. METHOD: The Nationwide Inpatient Sample database was used (2001 to 2010). RESULTS: In this study, 2269 liver transplant recipients were included: 56% HCV, 6% HBV, and 37% non-HV. HBV and HCV patients were mostly Asian/Pacific Islander (API) and white, respectively. Within HBV transplant recipients, the mean age was youngest in black patients (P = .02); variation of mean age was not seen within HCV patients. Regarding the transplant recipients' income and insurance, most API and white patients were in the highest income quartile, whereas most black and Hispanic patients were in the lowest income group (P < .001). The most common form of payer across all racial/ethnic groupings was private insurance (P < .001). The mean length of hospitalization was longest in Hispanic patients (P = .008); they had a significantly longer stay compared with white patients (P = .02). The liver transplantations were mostly performed in teaching hospitals, located in urban areas in the West region of the United States (P < .001). CONCLUSION: Differences were found in the HBV and HCV-associated liver transplant populations. More work needs to be done to elucidate disparities regarding black and Hispanic liver transplant recipients as they receive transplants at younger mean ages, are in lower income quartiles, and have longer lengths of hospitalization compared with other racial/ethnic groupings.

Clinical and haemodynamic effects of minoxidil in refractory hypertension.

Thirteen patients whose hypertension had been resistant to conventional drug therapy, had minoxidil added to their regimen in doses from 5 to 60 mg/day. All responded with satisfactory reductions of blood pressure to mean values of 149/90mm Hg (supine) and 143/89mm Hg (standing). A significant portion of their previous antihypertensive therapy was either greatly decreased or withdrawn completely. Although fluid retention occurred in most patients as the dose of minoxidil was increased, this could be successfully checked by the use of diuretics. It was considered that in addition to beta-adrenoreceptor blocking drugs to control the reflexly induced cardiac stimulation, sufficiently aggressive diuretic therapy is mandatory to ensure the successful use of this drug. Haemodynamic evaluations in seven patients clearly showed that lowering of blood pressure was the result of decreases in peripheral vascular resistance as significant increases in the cardiac index occurred in all patients.

Effect of Rain Distribution Alteration on Splash Dispersal of Colletotrichum acutatum.

ABSTRACT Splash dispersal of Colletotrichum acutatum conidia from infected strawberry fruit was assessed using a rain simulator to determine the properties of rain (e.g., intensity [millimeters/hour] or drop size distribution) most related to dissemination. Dispersal with a simulated rain corresponding to a natural rain of about 11 mm/h was compared with dispersal of three other simulated rains that had larger and smaller drop sizes, on average, than idealized natural rains. Splash droplets were collected in sheltered petri plates with a selective medium for Colletotrichum, and colonies formed from conidia entrained in the droplets were counted and used as the measure of dispersal. Colonies were mostly confined to a 27-cm radius from the source, and density of colonies decreased exponentially with the distance squared, as indicated by the fit of a diffusion-type model to the data. Splash dispersal was more affected by drop size distribution than rain intensity or other properties of the generated rains. That is, there was a direct positive relationship between total colonies over 61 min of rain for a circular area with a 72-cm radius (Sigma) and the mass (volume) median diameter of impacting drops (D(0)') for four rain-simulation treatments. In a separate study, strawberry fruit were exposed to the same four simulated rains at two distances from a point source and for two rain durations. Although the proportion of infected fruit (y) increased with time and decreased with distance, rain treatment did not significantly affect y, as predicted based on past work with a wide range of intensities of simulated rains.

Calibration and evaluation of an electronic sensor for rainfall kinetic energy.

ABSTRACT A novel sensor for measuring the kinetic energy of impacting raindrops, developed based on a soil-mass erosion sensor, was tested in the laboratory, with a rain simulator, and in the field. Drop impactions on the sensor-consisting of a piezoelectric crystal and associated electronics-produce an electrical charge that equals a fixed amount of energy. Calibration of the sensor was done in the laboratory using water drops of known diameter impacting with known velocity, and thus, with known kinetic energy. The relationship between pulse-count output of the sensor minus the background pulse counts when no drops were impacting (O; per min) and kinetic energy flux density (i.e., power [P; mJ cm(-2) min(-1)]) was found to be described by the formula P; = (0.204 + 0.065 . O)(0.67). The measurement threshold was 0.34 mJ cm(-2) min(-1). Using the sensor, generated rains with intensities of 23 to 48 mm/h were found to have powers of 0.4 to 2.2 mJ cm(-2) min(-1). In 2 years of field testing, 85 individual rain episodes were monitored, with mean intensities ranging from 0.1 to 42 mm/h. These rains had mean powers ranging from 0 to 5 mJ cm(-2) min(-1), and the highest power for a 5-min sampling period was 10 mJ cm(-2) min(-1). Both power and intensity varied greatly over time within rain episodes, and there was considerable variation in power at any given rain intensity, emphasizing the importance of measuring rather than simply predicting power. Although there was no known true power measurements for the generated or natural rains, estimates were realistic based on theoretical calculations, assuming that the gamma distribution represents raindrop sizes. The sensor is important in assessing the risk of rain splash dispersal of plant pathogens.

Effects of a Cover Crop on Splash Dispersal of Colletotrichum acutatum Conidia.

ABSTRACT A rain simulator, with generated rains of 11 and 30 mm/h, was used to determine the effect of a cover crop or intercrop on the splash dispersal of Colletotrichum acutatum conidia. Dispersal through sudangrass, which can be used as a 'living mulch', was tested at two planting densities (140 or 280 kg/ha) and two heights (5 and 20 cm) and compared with a control consisting of a bare soil. Dispersal of C. acutatum conidia was assessed by counting colonies formed from spore-bearing splash droplets deposited in sheltered petri plates containing a selective medium. Both a cover crop and rain intensity significantly affected splash dispersal as measured by the interpolated total number of colonies (denoted by Sigma) from 0 to 72 cm from the inoculum source and in a time span of 61 min of generated rain (P < 0.001). However, there was no significant interaction of cover crop and intensity (P > 0.90). Dispersal with a 30-mm/h rain was higher than dispersal with a 11-mm/h rain, and presence of a cover crop significantly reduced dispersal compared with bare soil (P < 0.001). Of the treatments with sudangrass, cover crop planting density did not affect dispersal overall, but there was greater spore dispersal with the taller sudangrass at the higher planting density, due in part to the higher rate of water splashing with the tall grass compared with the short grass. Spore deposition in the petri plates could be functionally related to distance and time using a diffusion-type model, and parameter estimates could be used to explain the effects of cover crop on Sigma. Although the relationship between cover crop properties and splash dispersal is complex, results show the potential beneficial effects of the cover crop on disease management.

Comparison of rain effects on splash dispersal of three colletotrichum species infecting strawberry.

ABSTRACT Rain simulation studies were performed to compare splash dispersal of three Colletotrichum species: C. acutatum (C. acutatum-O isolate from Ohio and C. acutatum-M isolate from Mississippi), C. fragariae (isolate from Mississippi), and C. gloeosporioides (isolate from Florida). Conidial dispersal was assessed by counting colonies formed from spore-bearing splash droplets deposited in sheltered petri plates containing a selective medium. Colonies were converted to number of conidia based on germination rates of spores on the media. The interpolated total number of dispersed conidia over a 61 min rain and 72 cm from the point source (Sigma) was calculated. For all species, a rain intensity of 30-mm/h resulted in significantly greater dispersal than an intensity of 11-mm/h. C. fragariae had the lowest amount of spore dispersal, and C. acutatum-O had the highest dispersal. C. acutatum-M and C. gloeosporioides were intermediate in magnitude of conidial splash dispersal. However, differences were directly attributed to differences in spore density per fruit at the source. When Sigma was corrected for source strength (Sigma(r)), the species were very similar, with only C. acutatum-M having a mean Sigma(r) significantly less than the others. Proportions and rates of spore removal (per minute) from source fruits were higher for C. acutatum-O and C. gloeosporioides than for other isolates. Wash-off rates of conidia deposited on healthy fruits were the same for all species. Deposition flux density of spores that had been uniformly sprayed over the entire soil surface of the experimental area was affected by species. A significant difference in means was observed between C. acutatum and C. fragariae-the latter had a somewhat lower flux density. This is the first demonstration that closely related species infecting the same plant species are similar in terms of splash dispersal.

Implant sequence effects in intact male Holstein veal calves: live and slaughter traits.

Seven sequences of growth promotant implants were used in special-fed intact male Holstein veal calves (n = 443). Calves received implants 4 d after arrival at the veal barn, 42, and 84. The following implants were used: placebo (0), Z (36 mg zeranol), ET (20 mg estradiol, 200 mg testosterone), EP/2 (10 mg estradiol, 100 mg progesterone), EP (20 mg estradiol, 200 mg progesterone), and EBA (24 mg estradiol, 120 mg trenbolone acetate). The following sequences were compared: 0-0-0 (negative control), 0-ET-ET, Z-ET-ET, 0-EP-EP, Z-EP-EP, 0-EP/2-EBA, and Z-0-EBA. From 0 to 42 d, Z implants increased (P<.05) ADG by 3.4% compared to placebo. However, implant schemes without an initial Z implant (0-ET-ET and 0-EP-EP) had higher (P<.05) mean ADG for the period from d 42 to 84. From 84 d to the end of the experiment, only the 0-EP/2-EBA treatment increased (P<.05) ADG compared to 0-0-0. Over the entire trial 0-ET-ET, 0-EP-EP, Z-EP-EP, and 0-EP/2-EBA implant sequences increased (P<.05) ADG by 3.2, 3.2, 2.4, and 4.7%, respectively, compared to the 0-0-0 sequence. Blood traits measured within 2 wk before slaughter were not affected by implant sequence, except that sequences with EP had higher (P<.05) leukocyte counts than were observed for the other sequences. Testicular weight was less (P<.01) for all of the implant sequences than for the negative control and less (P<.05) for Z-ET-ET than for 0-ET-ET, 0-EP-EP, 0-EP/2-EBA, and Z-0-EBA. The type and frequency of medical treatments did not differ among implant sequences for any of the 42-d phases, or over the entire trial. Generally, the growth promotant implants currently approved for beef cattle resulted in approximately 50% of the increase in growth rate in Holstein intact bull calves, as has been observed in beef-type steers or heifers.

Scrotal measurements in beef bulls: heritability estimates, breed and test station effects.

Heritability estimates for scrotal circumference and testicular tone at weaning (225 d) and yearling (365 d) were determined from records on 565 bulls from a purebred Angus herd; year, station and breed effects were determined from scrotal circumference records on 2,420 bulls at five tests stations. Year, breed and breed X year effects on scrotal circumference, length, width and volume were determined from records on 347 bulls at one station. Heritability estimates (+/- SE) were .60 +/- .17, .28 +/- .18 and .25 +/- .18 for weaning scrotal circumference, right and left tone, and .38 +2- .16, .72 +/- .18 and .52 +/- .17 for yearling scrotal circumference, right and left tone, respectively. With the exception of low negative correlations of 205-d weight and longissimus muscle area with yearling scrotal circumference (-01 and -.02, respectively), correlations of growth and live-estimated carcass traits with weaning or yearling scrotal dimensions were low and positive (0.8 to .35). In the second data set, Simmental and Angus had greater (p less than .01) yearling scrotal circumferences than Charolais or Herefords; means were 35.3, 35.0, 33.7 and 33.5 cm, respectively. Station and station x breed effects were significant (P less than .01), with the latter effect indicating that breeds did not rank similarly in scrotal circumference at different test stations. In the third data set, scrotal circumference and volume were essentially the same as scrotal length and width in ranking breeds. year X breed interactions were nonsignificant for all scrotal traits, indicating that breeds were ranked similar in different years with respect to scrotal dimensions. These results indicate that bulls of different breeds should not be compared to established standards; a more acceptable procedure would be the use of deviations from the respective breed-station-year means.

Mastitis in beef cows and its effects on calf weight gain.

Quarter milk samples from 51 purebred (Angus, Polled Hereford, and Simmental) and 69 crossbred (Angus x Simmental x Charolais three-way cross) beef cows were collected aseptically at three times during lactation to determine the prevalence of intramammary infection, milk somatic cell counts (SCC), and effects of infection on calf weight gain. Quarter infection prevalence was 13.1, 14.9, and 27.5% in early, mid, and late lactation; corresponding cow infection prevalence was 25.8, 29.2, and 54.4%. Staphylococcus aureus was isolated from 2.9, 2.7, and 3.2% of quarters in early, mid, and late lactation, respectively. Corynebacterium bovis, generally regarded as a minor pathogen, was isolated from 4.0, 7.6, and 18.2% of quarters at the three respective times. Geometric SCC means (10(3) cells/ml) were 1,522, 344, and 509 for S. aureus-infected quarters; 344, 899, and 221 for Staphylococcus hyicus-infected quarters; 65, 36, and 86 for C. bovis-infected quarters; and 20, 17, and 18 for uninfected quarters in early, mid, and late lactation, respectively. Adjusted 205-d weight gain for calves with S. aureus-infected dams was 9.6 kg less (P less than .05) than for calves with uninfected dams. Adjusted 205-d weight gain for calves with dams infected with any mastitis pathogen did not differ significantly from that of calves with uninfected dams. At weaning half of the infected cows and half of the uninfected cows were given an intramammary infusion product containing 300 mg of cephapirin benzathine in each quarter; the remaining cows were untreated controls. Quarter samples were collected aseptically from all cows 14 to 28 d after subsequent calving. Quarter prevalence of infection after calving was lower (P less than .05) in treated (8.2%) than in control (22.4%) cows. Significantly more infections present at weaning were eliminated in treated than in control cows, but the new infection rate during the dry period and early lactation did not differ between the two groups.

Effects of individual housing design and size on special-fed Holstein veal calf growth performance, hematology, and carcass characteristics.

The objective was to evaluate the effects of individual housing design (stalls vs pens) with widths of 56, 66, and 76 cm (2 x 3 factorial treatment arrangement) on growth, hematology, cleanliness, ambulation, abomasal hairball, and carcass measurements. Three groups of 36 Holstein bull calves (n = 108) were randomly allotted within group to treatments. There were no effects (P > .05) of housing design, width, or two-way interactions for BW, ADG, carcass weight, or dressing percentage. Blood samples were collected at approximately 33-d intervals. Mean values for hemoglobin, hematocrit, white blood cell count (WBC), and red blood cell count (RBC) were not different among treatments (P > .05), with the exception of d 28 hemoglobin, which was greater in the calves housed in 66-cm vs 76-cm stall. There were differences (P < .05) due to design and design x width effects for hind-quarter cleanliness; manure accumulation tended to be greater in pens vs stalls as width increased. There were increases (P < .05) in left front knee swelling scores as stall or pen size decreased; no important differences were observed in ambulatory ability among treatment groups. There were design effects (P < .05) for excitability scores, with calves in stalls being more excitable. There were no important treatment effects (P > .05) for liver, spleen, and lung condition, number of abomasal hairballs, or 0- and 24-h after slaughter flank or brisket color. These results indicate that housing designs and widths did not affect veal calf growth performance, WBC, RBC, hemoglobin, hematocrit, ambulation, or muscle color.

Effects of individual housing design and size on behavior and stress indicators of special-fed Holstein veal calves.

The objectives of this study were to determine effects of housing design (calves tethered in open stalls vs untethered in individual pens) and widths of 56, 66, and 76 cm (2 x 3 factorial arrangement of treatments) on indicators of stress and behavior in special-fed veal calves. Three production cycles (groups) were used, each with 36 Holstein bull calves. Calves (n = 108) were randomly allotted to treatments upon arrival at the facility. Blood samples were collected four times (wk 4, 9, 13, and 18) during the 18-wk production cycle. Blood serum values for cortisol and alpha1-acid glycoprotein (AGP) exhibited few treatment differences. Blood leukocyte differential counts at 4 and 18 wk (segmented neutrophils [N], banded neutrophils, lymphocytes [L], basophils, and the N:L ratio) were not different (P > .05) among housing designs or widths. However, there were differences (P < .05) in monocytes and eosinophils during the 28-d period after arrival; calves in stalls 76 cm wide had the greatest percentage of both leukocytes, and calves in the 66-cm stalls had the lowest monocyte percentage. Calves were recorded on videotape during wk 4, 13.5, and 18 to determine frequencies and durations of postures and behaviors (e.g., lying, standing, chewing, tongue playing, grooming, and investigative activities). There were no consistent differences (P > .05) in postures or behaviors among calves in different housing designs or widths. Calves spent approximately 71 and 31% in lying and standing positions, with no preference for the right or left side while recumbent. There was a tendency for calves in wider stalls or pens at wk 9 and 18 to exhibit more self-grooming activities. Tongue playing and investigative and chewing activities were exhibited in all treatments, but no differences (P > .05) were observed. However, calves housed in the 56-cm pens displayed difficulty in changing from lying to a standing position and were unable to extend one or more legs while recumbent. Even though there were few differences in behavioral, physiological, growth, or anatomical traits in this study, further increases in age and(or) weight of finished calves will require a reassessment of the appropriateness of individual veal calf housing design and dimensions.

Implant sequence effects in intact male Holstein veal calves: carcass characteristics.

Seven sequences of growth promotant implants were used in intact male Holstein veal calves (n = 443). Implants were administered on d 0 (within 4 d after arrival at the veal barn), 42, and 84. The implants used were placebo (0), Z (36 mg zeranol), ET (20 mg estradiol, 200 mg testosterone), EP/2 (10 mg estradiol, 100 mg progesterone), EP (20 mg estradiol, 200 mg progesterone), and EBA (24 mg estradiol, 120 mg trenbolone acetate). The following sequences were compared: 0-0-0 (negative control), 0-ET-ET, Z-ET-ET, 0-EP-EP, Z-EP-EP, 0-EP/2-EBA, and Z-0-EBA. Sequences 0-EP-EP, Z-EP-EP, and 0-EP/2-EBA increased (P<.05) carcass weight from 3.3 to 3.9% compared to nonimplanted controls. There were no differences (P>.05) in percentage of carcass weight accounted for by the fore vs. rear halves of carcasses, suggesting there was no difference in the distribution of weight. Although there were differences in longissimus area, the results were not consistent, except that there was a trend for longissimus area to be increased by the use of estrogenic-androgenic implants (ET and EBA). There were no differences among implant sequences for carcass conformation, fat cover, muscle texture, marbling/ feathering, muscle color, or muscle chemical composition. Of four implant sequences (0-0-0, 0-ET-ET, 0-EP-EP, and 0-EP/2-EBA) tested for differences in Warner-Bratzler shear force tenderness, the latter two sequences averaged higher (P<.05) for shear force than did the negative control. These results suggest that aggressive implant strategies in young, intact Holstein bull calves (raised as veal) have minimal effects on carcass characteristics.

Subjective and objective evaluation of veal lean color.

Because veal lean color continues to be a primary factor that determines veal carcass value and is typically assessed by subjective means, it is important to explore objective methods for color assessment. Objective and subjective evaluations of veal flank and breast lean color were compared as predictors of longissimus lean color at 24 h postmortem. One hundred fifty special-fed Holstein veal calves were Kosher-slaughtered with blood samples collected upon exsanguination and analyzed for hematocrit and hemoglobin content. Lean color was evaluated in the flank and breast at 0, 6, 12, and 24 h postmortem. Color of the longissimus was evaluated at 6 h, when possible, and at 24 h. A panel of three trained individuals used a 5-point color standard developed in the Netherlands to visually evaluate lean color. A Minolta Chromameter CR-300 was used to obtain L*, a*, and b* values. A plant employee assigned packer grades at slaughter. Temperature and pH were also measured at each time period. Hemoglobin was more highly correlated than hematocrit with colorimeter values. Hemoglobin levels correlated well with a* values of the flank at 0 h postmortem (r = 0.52) although the correlation declined at 24 h (r = 0.30). The correlation between packer grades and 24-h visual loin color was r = 0.41. Visual loin color at 24 h postmortem was selected as the predicted variable for regression analysis. Temperature and pH did not contribute significantly to any prediction equations. The equation using breast L*, a*, and b* values at 24 h postmortem to predict 24-h loin color gave a higher prediction coefficient (R2 = 0.44) than the corresponding equation using 0-h breast values (R2 = 0.28). Objective measurement of lean color may be useful in veal carcass grading because it is more precise than subjective methods and would allow for uniformity among processing plants.

Effects of different doses of zeranol on growth, hemoglobin, and carcass traits in veal calves.

Effects of different doses of zeranol on ADG, hemoglobin (Hb), feed efficiency (FE), and carcass traits were evaluated in special-fed veal calves in two trials. On d 0, calves were implanted subcutaneously in the middle third of the ear with either 0 (control, placebo pellet), 12, 24, 36, or 48 mg of zeranol. Trial 1 was conducted from February through May 1990 with 120 Holstein bull calves (17 to 21 d of age on d 0) and Trial 2 was conducted from May through August 1991 with 100 Holstein bull calves (24 to 28 d of age d 0). Calves were fed on an individual calf basis. Calves in Trial 1 that were implanted with 48 mg of zeranol had improved FE (P < .05) and ADG (P < .05) during Period 1 (0 to 43 d). No significant differences in ADG or FE were observed among treatments in Trial 2. Hemoglobin levels at slaughter averaged 7.88 +/- .096 and 8.19 +/- .149 g/dL over all treatments for Trials 1 and 2, respectively. The only postslaughter trait affected by zeranol dose was testicular weight. In both trials, testicular weight at slaughter decreased (P < .05) with increasing doses of zeranol. Dressing percentage tended to be higher for 48-mg implants than for controls but the difference was not significant. There were no significant zeranol dose effects on longissimus muscle area, flank color, carcass conformation, or percentage of fore- vs hind-quarter weight. These results indicated that higher doses of zeranol improved ADG and FE during the first 6 wk after the trial period (to 8 wk of age), decreased testicular weight, and increased hide-on carcass dressing percentage for calves implanted with 48 mg of zeranol compared with those that received 0 mg of zeranol.

Evaluation of a Disease Warning System for Downy Mildew of Grapes.

An electronic warning system for grape downy mildew- based on models for the infection of leaves of Vitis lambrusca, production of sporangia by Plasmopara viticola in lesions, and sporangial survival-was tested over 7 years in Ohio. Grapevines were sprayed with metalaxyl plus mancozeb (Ridomil MZ58) when the warning system indicated that environmental conditions were favorable for sporulation and subsequent infection. Over the 7 years, plots were sprayed from one to four times according to the warning system, and from four to 10 times according to the standard calendar-based schedule (depending on the date of the initiation of the experiment). The warning system resulted in yearly reductions of one to six sprays (with median of three sprays). Disease incidence (i.e., proportion of leaves with symptoms) in unsprayed plots at the end of the season ranged from 0 to 86%, with a median of 68%. Incidence generally was very similar for the warning-system and standard-schedule treatments (median of 7% of the leaves with symptoms), and both of these incidence values were significantly lower (P < 0.05) than that found for the unsprayed control, based on a generalized-linear-model analysis. Simplifications of the disease warning system, where sprays were applied based only on the infection or sporulation components of the system, were also effective in controlling the disease, although more fungicide applications sometimes were applied. Effective control of downy mildew, therefore, can be achieved with the use of the warning system with fewer sprays than a with a standard schedule.

Effects of Temperature on Sporulation and Latent Period of Colletotrichum Spp. Infecting Strawberry Fruit.

Effects of temperature on sporulation of Colletotrichum acutatum, C. gloeosporioides, and C. fragariae, causes of anthracnose of strawberry, were determined in controlled-environment studies. Detached immature fruit were inoculated with a conidial suspension and incubated up to 36 days at constant temperatures of 5, 10, 15, 20, 25, 30, and 35°C. Latent period (time to first sporulation) depended on temperature and ranged from 2 to 3 days at 25°C to 6 to 17 days at 5°C. C. acutatum had a shorter latent period than the other species at 5 and 10°C; at higher temperatures, latent periods of the species were very similar. During the first 4 days of sporulation, there was an optimum-type relationship between the logarithm of conidia per fruit [log(Y)] and temperature, with maximum observed sporulation (generally 106 to 107 conidia per fruit) from 15 to 30°C. Sporulation increased over time at temperatures of 15°C and above. The greatest difference among the species was at 5 and 10°C, where tested C. acutatum isolates produced from 10 to 100 more conidia per fruit than the other species. Polynomial regression equations were used successfully to represent log(Y) as a function of temperature and incubation time. The rate of increase in sporulation over time was a function of temperature, with a predicted optimum of 22 to 26°C. Equations were validated by predicting sporulation of the three species infecting fruit attached to plants growing in controlled-environment chambers. Although the predictions tended to be slightly larger than observed, mean error [100(observed - predicted)/ observed] was only -0.7% (95% confidence interval: -2.4 to 1.0%).

Histologic evaluation of the effects of diethylstilbesterol and zeranol on certain lamb tissues.

Forty-eight lambs with equal numbers of rams, ewes, and wethers were used in a growth and metabolism trial. Within each sex, equal numbers were used as controls, and implanted with zeranol or deithylstillbestrol (DES) or both. The lambs were slaughtered 44 days after implanting and the effects of the different implants (or in combination) on certain endocrine glands, urogenital tracts, and other selected tissues were determined. All animals given implants had adrenal cortical hyperplasia. Thyroid gland activity was depressed by DES implants in wethers, and by the combination of zeranol and DES in wethers and rams. Changes in the urogenital tracts of DES-implanted lambs, including the urethra, seminal vesicle, epididymis, testis, and uterus, were similar to those observed following treatment with exogenous estrogens. The results of this evaluation confirm that DES has higher estrogenic activity than zeranol. When these two compounds were used in combination, their estrogenic effects were additive.

Pathologie changes in endocrine glands and certain other tissues of lambs implanted with the synthetic growth promotant zeranol.

As doses of zeranol implants (0 (control), 12, 24, 48, and 96 mg) were increased, there were increased reaction and activity in target organs (such as urogenital tract and mammary, adrenal, hypophyseal, and thyroid glands) of castrated male sheep (wethers). Hyperplasia and transitional and squamous transformation in the prostate were mild (1+) in the wethers given 12- and 24-mg doses, moderate to marked (2.5+) in the wethers given 48-mg doses, and severe (4+) in the wethers given 96-mg doses. Papillary proliferation and fibrosis increased correspondingly in the seminal vesicle. Changes in the distal penile urethra increased from papillary hyperplasia in the wethers given a 24-mg dose to 100% squamous transformation in the wethers given a 96-mg dose. Mammary gland development was noticeable in the wethers given a 24-mg dose and increased thereafter to progressive alveolar growth and secretory activity in the wethers given 48- and 96-mg doses. Along with a progressive increase of adrenal gland weight and adrenal gland/thyroid gland ratios over the controls, the principals had hypertrophy and hyperplasia of the adrenal cortex. Mean adrenal cortex widths for control wethers and wethers given 24-, 48-, and 96-mg doses were 2,089, 2,140 (adjusted value, 2,194), 2,416, and 2,425 mum, respectively. Mean adrenal gland weights for control wethers and wethers given 12-, 24-, 48-, and 96-mg doses were 2.50, 2.61, 2.53, 2.70, and 2.78 g. respectively. Hyperplasia (nodule formation) plus exhaustive and pyknotic changes of the adrenal cortex increased similarly with increasing zeranol dose. After the thyroid gland weights decreased (2.19, 2.04, 2.00, and 1.72 g, respectively, for control wethers and wethers given 12-, 48-, and 96-mg doses), secretory activity of thyroid epithelial cells decreased. In the glandular portion of the hypophysis, secretory activity and proliferation of eosinophilic cells increased with the larger zeranol doses (48 and 96 mg). There was a corresponding decrease in the number of basophils. These changes are consistent with increased somatotropin and adrenocorticotropin secretion and decreased thyrotropin secretion. Muscle and ligament structures appeared looser and widened in the wethers given the 96-mg dose, and fat cell formation was increased in the muscles along ligament muscle junctions.