1,067 research outputs found

    Mild recessive epidermolytic hyperkeratosis associated with a novel keratin 10 donor splice-site mutation in a family of Norfolk terrier dogs

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    Background  Epidermolytic hyperkeratosis in humans is caused by dominant-negative mutations in suprabasal epidermal keratins 1 and 10. However, spontaneous keratin mutations have not been confirmed in a species other than human. Objectives  To describe an autosomal recessive, mild, nonpalmar/plantar epidermolytic ichthyosis segregating in an extended pedigree of Norfolk terrier dogs due to a splice-site mutation in the gene encoding keratin 10 (KRT10). Methods  Dogs were evaluated clinically, and skin samples were examined by light and electron microscopy. Genomic DNA samples and cDNA from skin RNA were sequenced and defined a mutation in KRT10. Consequences of the mutation were evaluated by assessing protein expression with immunohistochemistry and Western blotting and gene expression with real-time RT-PCR (reverse transcriptase-polymerase chain reaction). Results  Adult dogs with the disease had generalized, pigmented hyperkeratosis with epidermal fragility. Light microscopic examination defined epidermolysis with hyperkeratosis; ultrastructural changes included a decrease in tonofilaments and abnormal filament aggregation in upper spinous and granular layer keratinocytes. Affected dogs were homozygous for a single base GT→TT change in the consensus donor splice site of intron 5 in KRT10. Keratin 10 protein was not detected with immunoblotting in affected dogs. Heterozygous dogs were normal based on clinical and histological appearance and keratin 10 protein expression. The mutation caused activation of at least three cryptic or alternative splice sites. Use of the cryptic sites resulted in transcripts containing premature termination codons. One transcript could result in shortening of the proximal portion of the 2B domain before the stutter region. Quantitative real-time PCR indicated a significant decrease in KRT10 mRNA levels in affected dogs compared with wild-type dogs. Conclusions  This disease is the first confirmed spontaneous keratin mutation in a nonhuman species and is the first reported recessive form of epidermolytic hyperkeratosis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74670/1/j.1365-2133.2005.06735.x.pd

    Evaluation of Hay-Type and Grazing Tolerant Alfalfa Hybrids in Season-Long or Complementary Rotational Stocking Systems for Beef Cows

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    Pastures containing hay-type and grazing tolerant alfalfa hybrids were grazed in a season-long or complementary rotational stocking system with Nfertilized smooth bromegrass. The pastures were stocked at a seasonal density of .8 cow-calf pairs per acre for 120 days in 1998 and 141 days in 1999. Pastures were intensively managed by daily stripstocking with the assumptions that 50% of live forage was available and daily live dry matter consumption of each cow-calf pair was 3.5% of the cow’s body weight. First-cutting forage was harvested as hay from 40% of the pasture acres to remove excess forage growth early in the grazing season. Grazing occurred on the remaining 60% of each pasture for the first 44 and 54 days and 100% of each pasture after days 45 and 55 in 1998 and 1999, respectively. Proportions of ‘Amerigraze’ and ‘Affinity’ alfalfa in the live forage dry matter decreased by 70% and 55% in pastures stocked season-long and by 60% and 42% in pastures used for complementary stocking (alfalfa type, p\u3c.05; grazing management, p\u3c.05) in 1998, but decreased by a mean of 72% and was unaffected by hybrid or stocking system in 1999. Cows grazing either alfalfa hybrid by either grazing system had greater weight gains during the breeding and overall grazing seasons and greater increases in body condition score pre-breeding and during the breeding season than the cows that grazed smooth bromegrass for the entire season in 1998. Also, cows grazing either alfalfa hybrid in the season-long system had greater breeding season increases in body condition score than cows grazing alfalfa in the complementary system with smooth bromegrass in 1998. Cows grazing in the season-long alfalfa system had greater prebreeding season weight (p\u3c.10) increases and condition score (p\u3c.05) increases than cows grazing alfalfa in the complementary system in 1999. Daily and seasonal body weight gains of calves were not affected (p\u3e.10) by the presence of alfalfa in 1998 or by alfalfa type and grazing management in 1998 and 1999. Total animal production (cow and calf) in 1998 was greater (p\u3c.10) from the season-long alfalfa pastures compared with the complementary stocked pastures. Total (p\u3c.10) and live (p\u3c.05) forage masses, estimated by monthly clippings, were greater in September of 1998 from the season-long alfalfa pastures than pastures using alfalfa for complementary stocking. Total (p\u3c.10) and live (p\u3c.05) forage masses were greater in August of 1999 from season-long alfalfa pastures than pastures using alfalfa for complementary stocking

    Rotational Grazing Demonstration with Beef Cattle on Conservation Reserve Land in Adams County, Iowa, USA

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    The United States Dept. of Agriculture\u27s Conservation Reserve Program (CRP) is a voluntary program available to agricultural producers who will enroll erosive, marginally productive cropland for a 10 to 15 year period. In return, participants are provided annual rental payments and cost-share assistance to establish and maintain long- term, resource-conserving vegetative cover to improve the quality of water, control soil erosion, and enhance wildlife habitat. Since the inception of the CRP, policymakers, conservationists, farmers, and rural residents have been concerned about the likely fate of program land after the contracts expire. Most of the existing research, whether it relies on farm surveys or computer models, suggests that a significant proportion, perhaps more than 50 percent, will move back into row-crop production. Many rural residents in areas in which the CRP has significantly affected agricultural production would prefer to see the land returned to some form of agricultural activity, competitive with intensive row-crop production but with management and technologies that lead to acceptable environmental consequences

    Transgenic Maize Hybrid Crop Residues: Nutritive Value and Their Effects on Performance of Grazing Beef Cows

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    Several maize (Zea mays) hybrids, including three transgenic hybrids containing Bacillus thuringiensis (Bt) enzymes (Bt-maize hybrids), were planted in a field study. Mature, midgestation, beef cows (Bos tarus) strip-grazed post-harvest residues as paddocks over 126 days. Body condition-scores and weights were monitored. Forage yield, weathering losses and forage composition were monitored on grazed and ungrazed areas. Forage selection and intake were estimated. Grain yields, dropped grain, initial crop residue concentrations of dry matter (DM), organic matter (OM) and in vitro digestible organic matter (IVDOM) yields were similar among hybrids. Hybrids varied in infestation of maize borers, initial amounts of residue DM, acid detergent fiber (ADF) and acid detergent lignin (ADL) and IVDOM. Mean rates of change in forage and concentration of IVDOM selected by steers was similar between hybrids. Cows grazing residues required 50% less supplemental hay to retain the same body condition as cows consuming hay in drylot

    Animal and plant responses for steers grazing switchgrass and big bluestem pastures

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    Native warm-season grasses can provide large amounts of high-quality forage during the midsummer months. Maximum potential benefits depend on management of the entire cool-and warm-season grazing system. This study compared two grazing systems for the warm-season pasture component. Fall-born steers grazed pastures of \u27Cave-in-Rock\u27 switchgrass or \u27Roundtree\u27 big bluestem over three years using either continuous or rotational grazing systems. Pasture carrying time for switchgrass and bluestem pastures and steer weight gain were considerably higher for the rotational grazing program than for the continuous grazing regimen

    Winter grazing and pasture erosion

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    Winter precipitation, whether it\u27s rain, sleet, or snow, can lead to pasture erosion. Grazing livestock on frozen soil usually causes minimal pasture damage, but grazing pasture when soil is wet or muddy can lead to soil compaction, erosion, and long-term damage to pasture sod. Producers who manage livestock on pasture should consider the potential of soil erosion from winter grazing, particularly on sloped areas

    Use of mob grazing to improve cattle production, enhance legume establishment and increase carbon sequestration in Iowa pastures

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    Mob grazing is a variation on rotational grazing that has been proposed to have promise as one of the tactics graziers can use to improve cattle performance and environmental quality. This project looked at whether and how mob grazing could benefit livestock and producer management of their pastures and soil resources

    Stocking System Effects on Soil and Forage Characteristics, and Performance of Fall-Calving Cows Grazing Cool-Season Grass Pastures (A Progress Report)

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    The effects of stocking densities of fall-calving Angus cattle grazing cool-season pastures on cow and calf performance; forage mass, quality, and botanical composition; soil carbon content and compaction; and grazing selectivity of cattle were evaluated. Two blocks of three 10-acre cool-season pastures, divided into 1-acre paddocks, were grazed by 10 fall-calving Angus cows by one of three stocking systems: rotational stocking (RS, low stocking density), strip stocking (SS, moderate stocking density), and mob stocking (MS, high stocking density). Pastures were grazed from mid-May through late September in 2010 (yr 1) and 2011 (yr 2). Cattle received a daily live forage dry matter (DM) allowance of 4.0 and 3.2% of cow body weight (BW) in yr 1 and 2, respectively. Cattle in RS pastures were moved to new paddocks after initial forage sward height, measured with a falling plate meter (8.8 lb/yd2), was reduced by 50% by measurement (yr 1), and after the estimated intake at 3.2% of cow BW/day (yr 2). Cattle in SS and MS pastures received strips containing 100 and 25% of the daily forage allowance one and four times per day, respectively. Cow BCS did not differ between treatments in any month of either year. Cow BW was greater in MS than RS and SS pastures in June of yr 2 and greater in RS than MS pastures in August of yr 2, but did not differ in any other months of either year. Birth weight and average daily gain (ADG) of live calves at the end of the trial did not differ between treatments in either year; however, there were fewer calves per cow in MS pastures at the termination of the trial in yr 2. Forage sward height did not differ between treatments in any month of either year. Rotational stocking decreased forage disappearance in yr 2 compared to strip or mob stocking. Forage disappearance was lower in RS than SS and MS pastures in May and June of both years and was greater in RS than SS pastures in September of yr 1, but did not differ in any other months. Forage botanical composition prior to grazing each year did not differ between years, but dead forage as a percent of total forage DM was lower in RS than SS and MS pastures in yr 2. Soil bulk density from 0-3 inches in yr 1, water infiltration rate into the soil in either year, and penetration resistance at depths of 0 and 3 inches in yr 2, did not differ between treatments in any month. Soil penetration resistance at 6 inches was greater in SS than RS and MS pastures in May, and was greater in MS than SS pastures in August. Grazing selectivity did not differ between treatments in yr 1. Results suggest that, at constant forage allocation, mob stocking does not affect cow or live calf performance, but may reduce the proportion of surviving calves. Mob stocking also does not affect forage mass, botanical composition, or soil compaction measures within the first two years of implementation

    Intensive Rotational Grazing of Steers on Highly Erodible Land at the Adams County CRP Project

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    Grazing yearling steers is one way to utilize the forages required for participation in the Conservation Reserve Program (CRP) after CRP contracts expire. In 1995, a stocker-steer intensive-rotational grazing study was conducted at the CRP Research and Demonstration Project near Corning, Iowa. A similar study was carried out in 1994. Seventy-five yearling crossbred steers grazed a 65- acre pasture that had been divided into 27 paddocks using electric fencing from May 4, 1995 to September 14, 1995. During this period, the 65-acre pasture system produced 9,975 animal-days of grazing and 11,403 pounds of gain. On a per-acre basis, this translates to 153.5 animal-days of grazing and 175.4 pounds of gain. The stocking rate was constant for the entire 133- day grazing season at 1.15 steers per acre. On May 4, 1995, the beginning of the grazing season, the average weight of the steers was 495.7 pounds. By the end of the grazing trial on September 14, 1995, the average weight of the steers had increased to 647.7 pounds. The average gain per steer during the 133-day grazing period was 152 pounds, and the average daily gain per steer was 1.14 pounds. The average bodyweight of the steers during the entire grazing season was 571.7 pounds

    Association between community garden participation and fruit and vegetable consumption in rural Missouri

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    BACKGROUND: Fruit and vegetable consumption reduces chronic disease risk, yet the majority of Americans consume fewer than recommended. Inadequate access to fruits and vegetables is increasingly recognized as a significant contributor to low consumption of healthy foods. Emerging evidence shows the effectiveness of community gardens in increasing access to, and consumption of, fruits and vegetables. METHODS: Two complementary studies explored the association of community garden participation and fruit and vegetable consumption in rural communities in Missouri. The first was with a convenience sample of participants in a rural community garden intervention who completed self-administered surveys. The second was a population-based survey conducted with a random sample of 1,000 residents in the intervention catchment area. RESULTS: Participation in a community garden was associated with higher fruit and vegetable consumption. The first study found that individuals who worked in a community garden at least once a week were more likely to report eating fruits and vegetables because of their community garden work (X(2) (125) = 7.78, p = .0088). Population-based survey results show that 5% of rural residents reported participating in a community garden. Those who reported community garden participation were more likely to report eating fruits 2 or more times per day and vegetables 3 or more times per day than those who did not report community garden participation, even after adjusting for covariates (Odds Ratio [OR] = 2.76, 95% Confidence Interval [CI] = 1.35 to 5.65). CONCLUSION: These complementary studies provide evidence that community gardens are a promising strategy for promoting fruit and vegetable consumption in rural communities
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