Effects of corn silage inclusion in preweaning calf diets.

The objective of this research was to evaluate the effects of corn silage inclusion in starter feed provided to calves after birth through weaning at 7 wk of age. Thirty-six heifer calves and 9 bull calves were individually housed in hutches. Calves in treatment groups received pasteurized milk with all calf starter, 25% calf starter and 75% corn silage, or all corn silage. Values were recorded daily for feed intake and health, which included fecal, respiratory, and attitude scores; and at wk 2, 4, and 8 for concentrations of serum protein, hematocrit, and serum ß-hydroxybutyrate. Body weight, withers height, and hip height were measured at wk 2, 4, 8, and 52. Nine bull calves (3/treatment) were killed at 8 wk of age for assessment of rumen and intestinal tissue morphology. Feed intake and average daily gain were not different among treatments. Least squares means of rumen papillae lengths were significantly different and decreased as corn silage inclusion increased. Crypt depths and total thickness of epithelium were reduced for the corn silage group. Least squares means of body weight, heart girth, hip height, withers height, serum protein, hematocrit, and ß-hydroxybutyrate concentrations did not differ among treatments. These data indicated that the mixture of corn silage and starter did not affect growth, feed intake, or intestinal morphology but did affect rumen wall morphology. Feeding solely corn silage as starter feed stunted the growth of rumen papillae and tended to impair intestinal morphology, indicating that only calf starter or a mixture of calf starter and corn silage is more appropriate.

Oral probiotic combination of Lactobacillus and Bifidobacterium alters the gastrointestinal microbiota during antibiotic treatment for Clostridium difficile infection.

Perturbations in the gastrointestinal microbiome caused by antibiotics are a major risk factor for Clostridium difficile infection (CDI). Probiotics are often recommended to mitigate CDI symptoms; however, there exists only limited evidence showing probiotic efficacy for CDI. Here, we examined changes to the GI microbiota in a study population where probiotic treatment was associated with significantly reduced duration of CDI diarrhea. Subjects being treated with standard of care antibiotics for a primary episode of CDI were randomized to probiotic treatment or placebo for 4 weeks. Probiotic treatment consisted of a daily multi-strain capsule (Lactobacillus acidophilus NCFM, ATCC 700396; Lactobacillus paracasei Lpc-37, ATCC SD5275; Bifidobacterium lactis Bi-07, ATCC SC5220; Bifidobacterium lactis B1-04, ATCC SD5219) containing 1.7 x 1010 CFUs. Stool was collected and analyzed using 16S rRNA sequencing. Microbiome analysis revealed apparent taxonomic differences between treatments and timepoints. Subjects administered probiotics had reduced Verrucomicrobiaceae at week 8 compared to controls. Bacteroides were significantly reduced between weeks 0 to 4 in probiotic treated subjects. Ruminococcus (family Lachnospiraceae), tended to be more abundant at week 8 than week 4 within the placebo group and at week 8 than week 0 within the probiotic group. Similar to these results, previous studies have associated these taxa with probiotic use and with mitigation of CDI symptoms. Compositional prediction of microbial community function revealed that subjects in the placebo group had microbiomes enriched with the iron complex transport system, while probiotic treated subjects had microbiomes enriched with the antibiotic transport system. Results indicate that probiotic use may impact the microbiome function in the face of a CDI; yet, more sensitive methods with higher resolution are warranted to better elucidate the roles associated with these changes. Continuing studies are needed to better understand probiotic effects on microbiome structure and function and the resulting impacts on CDI.

Contribution of Mid-Season Cover Sprays to Management of Peach Brown Rot at Harvest.

Four protectant fungicides applied as midseason cover sprays were quantitatively assessed for their ability to reduce brown rot caused by Monilinia fructicola during the preharvest fruit ripening periods in the 2012 through 2015 growing seasons. No fungicides were applied during bloom or during the preharvest period. Treatment programs consisted of captan, sulfur, ziram, and thiram applications beginning at early shuck-split stage and ending with the final cover spray at 23 to 26 days before harvest. The incidence of brown rot at harvest was determined by examining 41 to 91 fruit for symptoms of rot on each of four replicate trees for each treatment. The incidence of sporulating blossom blight cankers was assessed during the preharvest period at 8, 15, and 22 days after the final cover spray. An in vivo bioassay was also conducted at 7, 14, and 21 days after the final cover spray to ascertain the level of fungicide residue during the preharvest period. The bioassay uses conidia germination as a quantitative indicator of effective residue. Results of the harvest assessment showed that captan cover sprays significantly reduced brown rot incidence in all years of the study. Furthermore, results of the bioassay demonstrated that fungicide residue was the mechanism by which this control occurred. None of the other fungicide cover spray programs contributed significantly to brown rot control at harvest in any year, and bioassay results showed insufficient residue to inhibit conidial germination. Antisporulant activity against blossom blight cankers was not observed for any fungicide program, indicating that reducing inoculum production from this source was not a mechanism for brown rot control. The captan and sulfur programs provided very good control of peach scab incidence and severity, caused by Fusicladium carpophilum, while the ziram and thiram programs failed to control this disease. These findings demonstrated that captan cover sprays can contribute significantly to control of brown rot at harvest, thereby augmenting the efficacy and consistency of management by preharvest fungicide programs. Furthermore, any reduction of the M. fructicola population by the captan cover sprays should reduce selection pressure against the site-specific fungicides commonly used during the preharvest period, thereby prolonging their useful life for brown rot control.

An In Vivo Bioassay for Estimating Fungicide Residues on Peach Fruit.

Recent fungicide efficacy studies indicated that brown rot fruit rot at harvest, caused by Monilinia fructicola, was being controlled by residual activity from protectant fungicides applied during the time between bloom and the preharvest fruit ripening period. To determine the extent of this residue, a simple in vivo bioassay was developed by assaying M. fructicola spore germination directly on sampled fruit. A 1.5-cm section of clear flexible tubing was placed upright on harvested fruit to create a small incubation well. After the tubing-fruit interface was sealed using silicon grease, a suspension of M. fructicola conidia was pipetted into the well. The spores were suspended in a buffer-substrate medium consisting of 0.025 M potassium phosphate, 0.1% sucrose, and 0.1% yeast extract. A rubber stopper with an aeration hole was inserted into the well's top and the fruit was placed in an incubator at 25°C. Results of a time-course study indicated that the optimal conidial incubation time was 6 h. Bioassay sensitivity was evaluated by examining test results from varying concentrations of captan fungicide. Results indicated that captan residue levels as low as one-thousandth the standard field rate could be detected using spore germination as the predictor. Fitting of the logistic decline model to the data created a standard curve to allow quantitative estimation of fungicide residue based on observed level of spore germination. A modified version of the bioassay, which can be used to detect carbohydrate or nutrient sources on the fruit surface, was also demonstrated.

Influence of Trifloxystrobin on Primary Inoculum and Progression of Scab Epidemics on Stone Fruit.

The ability of the QoI fungicide trifloxystrobin to reduce production of conidia by Fusicladium carpophilum on twig lesions was quantitatively assessed over a 3-year period from 2005 through 2007. Four annual treatment programs, consisting of two consecutive trifloxystrobin applications at pink + bloom, bloom + petal fall, and petal fall + shuck-split, plus a single application timing at petal fall, were examined in a 'Redgold' nectarine orchard harboring high levels of overwintering scab lesions. Sporulation potential, the ability of twig lesions to produce conidia under optimum environmental conditions, was subsequently assessed five to six times during each spring and early summer. In each year of the study, all four treatments significantly reduced the area under the sporulation curve or peak sporulation. The petal fall + shuck-split program provided the greatest antisporulant activity, reducing conidia production at peak sporulation by 82 to 92%. Furthermore, examination of results over the 3-year period showed that the programs significantly slowed the annual rate of increase in peak sporulation; however, none of the programs completely halted or caused a decline in the annual rate. Although no fungicide was applied after the treatment programs, results from fruit disease assessments showed that these programs, applied as much as 3 months earlier, significantly reduced disease incidence and, in particular, disease severity. A comparison of four QoI fungicides in 2008 indicated that trifloxystrobin and azoxystrobin provided the most control of fruit scab, while pyraclostrobin + boscalid and fluoxastrobin yielded minimal or no benefit. Results of this study demonstrate that certain QoI fungicides, in particular trifloxystrobin and azoxystrobin, can probably improve the efficacy of current protectant programs used for peach scab control by providing season-long control of F. carpophilum sporulation on twig lesions. Such program enhancement may be critical when orchards have high inoculum levels and/or environmental conditions are very favorable to disease development.

Modeling sporulation of Fusicladium carpophilum on nectarine twig lesions: relative humidity and temperature effects.

The production of conidia by Fusicladium carpophilum on twig lesions was quantitatively modeled as a function of temperature and duration of high relative humidity. During peak sporulation periods in 2007, 2008, and 2009, 1-year-old twigs bearing abundant overwintering lesions were removed from a heavily infected 'Redgold' nectarine orchard, placed in trays at high relative humidity (>95%), and incubated at eight constant temperatures for seven durations, resulting in a factorial design of 56 treatment combinations. Conidia numbers were estimated with a hemacytometer. Results from a six-stage modeling process indicated that, at any given temperature, spore production during high relative humidity periods increased in a monomolecular- to Gompertz-like pattern. The Richards model, with shape parameters of 0.79 to 0.90, was found to provide the best overall fit. When the asymptote and rate parameters were derived as functions of temperature using Gaussian and quadratic models, respectively, the duration of high relative humidity and temperature described 90 to 94% of the variation in conidia production. Predictions of the final models were highly correlated with observed levels of sporulation (r > 0.94; P < 0.0001), indicating an excellent fit to the data. The optimum temperature for sporulation, based on fitting a Gaussian model to the maximum sporulation levels at each temperature, was 17.9 to 20.2°C, with an overall average of 18.8°C. The derived models give a quantitative description of sporulation by F. carpophilum and may have potential use in simulators and forecasting systems.

Effect of QoI Fungicides on Colonization and Sporulation of Monilinia fructicola on Peach Fruit and Blossom Blight Cankers.

Three studies were conducted to examine the curative activity of azoxystrobin, trifloxystrobin, and pyraclostrobin + boscalid against Monilinia fructicola, causal agent of brown rot on peach. In the first study, 'Autumnglo' peach trees were treated with each of the three fungicides both before and after fruit inoculation. In the second study, the effects of fungicide active ingredient, rate/volume, and inoculation timing were examined on inoculated 'Suncrest' peach fruit. Results of these studies showed that sporulating area, on average across all treatments, was reduced by 15.9, 42.4, and 0.4% for azoxystrobin, trifloxystrobin, and pyraclostrobin + boscalid, respectively. In any single treatment, trifloxystrobin provided the greatest benefit with two consecutive sprays, reducing sporulating area by 53 to 60%. In contrast to sporulation activity, the three fungicides exhibited less of an inhibitory effect on fruit colonization. When applied at maximum labeled rates in the various treatments, azoxystrobin, trifloxystrobin, and pyraclostrobin + boscalid reduced colony growth, on average, by 12.3, 7.5, and 7.4%, respectively. Because the pathogen was inoculated into the mesocarp, this low level of activity against colonization may be due to a lack of deeper systemic movement of the fungicides into fruit tissue. In the final study, the three fungicides were examined for their antisporulant activity on blossom blight twig cankers. Unlike results observed on fruit, significant reductions in spore production on cankers were observed for all three fungicides. Azoxystrobin, trifloxystrobin, and pyraclostrobin + boscalid provided 56, 71, and 53% reductions, respectively, in the number of conidia produced per unit canker length. Overall results of these studies indicated that quinone outside inhibitor fungicides, in addition to their known protectant activity, also possess varying levels of curative activity against M. fructicola. In particular, trifloxystrobin demonstrated good antisporulant activity on both fruit infections and cankers.

Phytotoxicity of Copper-Based Bactericides to Peach and Nectarine.

Organometallic copper, consisting of a mixture of copper abietate, copper linoleate, and copper oleate (CuALO), is important for postbloom management of bacterial spot in New Jersey peach and nectarine orchards. Rotation of CuALO with oxytetracycline reduces cost and helps prevent (or delay) resistant organisms. However, because copper is also phytotoxic, higher rates and inorganic coppers have not been utilized. A study was conducted on 'Encore' peach and 'Redgold' nectarine to determine the quantitative relationship between copper concentration (metallic equivalent) and phytotoxicity. Different rates of CuALO and copper hydroxide (CuOH) were applied seven times postbloom. Foliar injury and defoliation increased with number of applications and copper concentration. Maximum 'Encore' defoliation was 10 to 17%, while 'Redgold' sustained 30 to 35% leaf loss. CuOH caused similar or less leaf injury and defoliation than CuALO. No injury was observed on fruit, even at three times the labeled metallic copper rate of CuALO. Fruit size and soluble solids were not influenced by copper. Estimates of foliar density and tree volume indicated that sufficient photosynthetic capacity existed to allow acceptable leaf damage and loss from copper applications. These results showed that inorganic coppers may be viable alternatives to organometallic copper for postbloom bacterial spot control; nectarine may be more sensitive to copper injury than peach; and higher rates of metallic copper, above the current commercial rate, can be applied to peach. In the latter case, greater amounts of copper may provide longer residual activity and improved bacterial spot control on highly susceptible cultivars.

Concussion in contact sports: reliable change indices of impairment and recovery.

This paper reports a follow-up study to an article on the sensitivity of three tests of speed of information processing to impairment after concussion (Hinton-Bayre, Geffen, & McFarland, 1997). Group analyses showed that practice effects can obscure the effects of concussion on information processing, thereby making the assessment of functional impairment and recovery after injury unreliable. A Reliable Change Index (RCI) was used to assess individual variations following concussion. It was found that 16 of the 20 concussed professional rugby league players were impaired 1-3 days following injury. It was also demonstrated that 7 players still displayed cognitive deficits at 1-2 weeks, before returning to preseason levels at 3-5 weeks. The RCI permits comparisons between different tests, players, and repeated assessments, thereby providing a quantitative basis for decisions regarding return to play.

The lateralized effects of concurrent cognitive activity on a unimanual skill.

Laterality studies have long been plagued by: (1) poor psychological methodology; (2) lack of specification of treatment parameters' and (3) exclusive use of left-hemisphere dependent measures. It was suspected that a recent study by Kinsbourne and Cook (1971) suffered from these faults. The present experimental findings confirm these original suspicions. Both spatial and verbal cognitive tasks were employed and comparisons made with performance during two control conditions. One was a mixed spatial-verbal activity, the other control required S to merely look at a blank card. While left-hand performance was enhanced under the verbal concurrent activities, when compared with performance under control (spatial-verbal) conditions, no other significant enhancement of performance occurred with any other concurrent activity condition. With the "No Activity Specified" control some support for the Kinsbourne study was found. However, the major finding, or implication, of this study was in demonstrating that the methodological problems outlined above cannot be ignored if worthwhile laterality studies are to be performed.