Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 89
Filter
1.
J Anim Sci ; 91(4): 1907-19, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23408805

ABSTRACT

The National Beef Quality Audit (NBQA)-2011 benchmarked the current status of and assessed progress being made toward quality and consistency of U.S. cattle, carcasses, and beef products after the completion of the first NBQA in 1991. Unlike previous NBQA, objectives of the 2011 Phase I study were to determine how each beef market sector defined 7 quality categories, estimate willingness-to-pay (WTP) for the same quality categories by market sector, and establish a best-worst (B/W) scaling for the quality categories. Structured face-to-face interviews were conducted and responses were recorded using dynamic routing software over an 11-mo period (February to December 2011) with decision makers in each of the following beef market sectors: Feeders (n = 59), Packers (n = 26), Food Service, Distribution, and Further Processors (n = 48), Retailers (n = 30), and Government and Allied Industries (n = 47). All respondents participated in a structured interview consisting of WTP and B/W questions that were tied to 7 quality categories and then were asked to "define" each of the 7 categories in terms of what the category meant to them, resulting in completely unbiased results. The 7 quality categories were a) how and where the cattle were raised, b) lean, fat, and bone, c) weight and size, d) cattle genetics, e) visual characteristics, f) food safety, and g) eating satisfaction. Overall, "food safety" and "eating satisfaction" were the categories of greatest and second most importance, respectively, to all beef market sectors except for Feeders. Feeders ranked "how and where the cattle were raised" and "weight and size" as the most important and second most important, respectively. Overall, "how and where the cattle were raised" had the greatest odds of being considered a nonnegotiable requirement before the raw material for each sector would be considered for purchase and was statistically more important (P < 0.05) as a requirement for purchase than all other categories except "food safety." When all market sectors were considered, "eating satisfaction" was shown to generate the greatest average WTP percentage premium (11.1%), but that WTP premium value only differed statistically (P < 0.05) from "weight and size" (8.8%). Most notably, when a sector said that "food safety" was a nonnegotiable requirement, no sector was willing to purchase the product at a discounted price if the "food safety" of the product could not be assured.


Subject(s)
Meat-Packing Industry/standards , Meat/standards , Animal Husbandry/economics , Animal Husbandry/standards , Animals , Cattle , Food Quality , Food-Processing Industry/economics , Food-Processing Industry/standards , Marketing/standards , Meat/economics , Meat-Packing Industry/economics , United States
2.
J Anim Sci ; 90(13): 5152-8, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952354

ABSTRACT

The instrument grading assessments for the 2011 National Beef Quality Audit evaluated seasonal trends of beef carcass quality and yield attributes over the course of the year. One week of instrument grading data, HCW, gender, USDA quality grade (QG), and yield grade (YG) factors, were collected every other month (n = 2,427,074 carcasses) over a 13-mo period (November 2010 through November 2011) from 4 beef processing corporations, encompassing 17 federally inspected beef processing facilities, to create a "snapshot" of carcass quality and yield attributes and trends from carcasses representing approximately 8.5% of the U.S. fed steer and heifer population. Mean yield traits were YG (2.86), HCW (371.3 kg), fat thickness (1.19 cm.), and LM area (88.39 cm(2)). The YG distribution was YG 1, 15.7%; YG 2, 41.0%; YG 3, 33.8%; YG 4, 8.5%; and YG 5, 0.9%. Distribution of HCW was <272.2 kg, 1.6%; 272.2 to 453.6 kg, 95.1%; and ≥453.6 kg, 3.3%. Monthly HCW means were November 2010, 381.3 kg; January 2011, 375.9 kg; March 2011, 366.2 kg; May 2011, 357.9 kg; July 2011, 372.54 kg; September 2011, 376.1 kg; and November 2011, 373.5 kg. The mean fat thickness for each month was November 2010, 1.30 cm; January 2011, 1.22 cm; March 2011, 1.17 cm; May 2011, 1.12 cm; July 2011, 1.19 cm; September 2011, 1.22 cm; and November 2011, 1.22 cm. The overall average marbling score was Small(49). The USDA QG distribution was Prime, 2.7%; Top Choice, 22.9%; Commodity Choice, 38.6%; and Select, 31.5%. Interestingly, from November to May, seasonal decreases (P < 0.001) in HCW and fat thicknesses were accompanied by increases (P < 0.001) in marbling. These data present the opportunity to further investigate the entire array of factors that determine the value of beef. Data sets using the online collection of electronic data will likely be more commonly used when evaluating the U.S. fed steer and heifer population in future studies.


Subject(s)
Cattle/physiology , Meat-Packing Industry/standards , Meat/standards , Adipose Tissue/anatomy & histology , Analysis of Variance , Animals , Body Composition , Cattle/anatomy & histology , Female , Least-Squares Analysis , Male , Meat-Packing Industry/instrumentation , Seasons , United States
3.
J Anim Sci ; 90(13): 5143-51, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952369

ABSTRACT

The 2011 National Beef Quality Audit (NBQA-2011) assessed the current status of quality and consistency of fed steers and heifers. Beef carcasses (n = 9,802), representing approximately 10% of each production lot in 28 beef processing facilities, were selected randomly for the survey. Carcass evaluation for the cooler assessment of this study revealed the following traits and frequencies: sex classes of steer (63.5%), heifer (36.4%), cow (0.1%), and bullock (0.03%); dark cutters (3.2%); blood splash (0.3%); yellow fat (0.1%); calloused rib eye (0.05%); overall maturities of A (92.8%), B (6.0%), and C or greater (1.2%); estimated breed types of native (88.3%), dairy type (9.9%), and Bos indicus (1.8%); and country of origin of United States (97.7%), Mexico (1.8%), and Canada (0.5%). Certified or marketing program frequencies were age and source verified (10.7%), ≤A(40) (10.0%), Certified Angus Beef (9.3%), Top Choice (4.1%), natural (0.6%), and Non-Hormone-Treated Cattle (0.5%); no organic programs were observed. Mean USDA yield grade (YG) traits were USDA YG (2.9), HCW (374.0 kg), adjusted fat thickness (1.3 cm), LM area (88.8 cm2), and KPH (2.3%). Frequencies of USDA YG distributions were YG 1, 12.4%; YG 2, 41.0%; YG 3, 36.3%; YG 4, 8.6%; and YG 5, 1.6%. Mean USDA quality grade (QG) traits were USDA quality grade (Select(93)), marbling score (Small(40)), overall maturity (A(59)), lean maturity (A(54)), and skeletal maturity (A(62)). Frequencies of USDA QG distributions were Prime, 2.1%; Choice, 58.9%; Select, 32.6%; and Standard or less, 6.3%. Marbling score distribution was Slightly Abundant or greater, 2.3%; Moderate, 5.0%; Modest, 17.3%; Small, 39.7%; Slight, 34.6%; and Traces or less, 1.1%. Carcasses with QG of Select or greater and YG 3 or less represented 85.1% of the sample. This is the fifth benchmark study measuring targeted carcass characteristics, and information from this survey will continue to help drive progress in the beef industry. Results will be used in extension and educational programs as teaching tools to inform beef producers and industry professionals of the current state of the U.S. beef industry.


Subject(s)
Body Composition , Cattle/physiology , Marketing , Meat-Packing Industry/standards , Meat/standards , Analysis of Variance , Animals , Cattle/anatomy & histology , Female , Least-Squares Analysis , Male , United States
4.
J Anim Sci ; 90(13): 5135-42, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952370

ABSTRACT

The National Beef Quality Audit-2011 (NBQA-2011) was conducted to assess targeted characteristics on the harvest floor that affect the quality and value of cattle, carcasses, and byproducts. Survey teams evaluated approximately 18,000 cattle/carcasses between May and November 2011 in 8 beef processing facilities. Cattle identification methods were lot visual tags (85.7%), individual visual tags (50.6%), electronic tags (20.1%), metal-clip tags (15.7%), other (5.3%), none (2.5%), and wattles (0.5%). Hide colors or breed types were black (61.1%), red (12.8%), yellow (8.7%), Holstein (5.5%), brown (5.0%), gray (5.0%), white (1.4%), and brindle (1.0%). Brand frequencies were none (55.2%), 1 (40.4%), 2 (4.4%), and 3 or more (0.04%) brands, and brands were located on the butt (35.2%), side (9.0%), and shoulder (2.5%). Hide locations of mud or manure were no mud/manure (49.2%), legs (36.8%), belly (23.7%), side (14.9%), top-line (11.0%), and tail region (13.7%). There were 76.2% of cattle without horns, and the majority of those with horns (71.6%) were between 0 cm and 12.7 cm in length. Permanent incisor numbers were zero (87.3%), 1 (1.4%), 2 (8.0%), 3 (0.9%), 4 (1.9%), 5 (0.3%), 6 (0.2%), 7 (0.1%), and 8 (0.02%). Most carcasses (77.0%) were not bruised, 18.7% had 1 bruise, 3.4% had 2 bruises, 0.6% had 3 bruises, and 0.3% had more than 3 bruises. Bruise locations were loin (50.1%), rib (21.3%), chuck (13.8%), round (7.3%), and brisket/flank/plate (7.5%). Condemnation item and incidence were whole carcass (none recorded), liver (20.9%), lungs (17.3%), tongue (10.0%), viscera (9.3%), and head (7.2%). Compared with the NBQA-2005, the NBQA-2011 had an increased percentage of black-hided cattle (56.3 vs. 61.1%), more cattle with brands (38.7 vs. 44.8%), and more cattle with some form of identification (93.3 vs. 97.5%). In addition, there was a lesser percentage of carcasses with bruising in 2011 (23.0%) than in 2005 (35.2%), as well as a smaller percentage of carcasses with more than 1 bruise (2005 = 9.4% vs. 2011 = 4.2%). Compared with the 2005 audit, a similar percentage of the cattle were deemed 30 mo of age or older using dentition (2005 = 2.7% vs. 2011 = 3.3%). The information from NBQA-2011 helps the beef industry measure progress against previous NBQA assessments and provides a benchmark for future educational and research activities.


Subject(s)
Body Composition , Cattle/physiology , Meat-Packing Industry/standards , Meat/standards , Analysis of Variance , Animal Identification Systems , Animals , Cattle/anatomy & histology , Female , Least-Squares Analysis , Male , Manure/analysis , Meat Products/standards , United States
5.
Vet Parasitol ; 186(1-2): 124-31, 2012 May 04.
Article in English | MEDLINE | ID: mdl-22226153

ABSTRACT

Australian scientists, in partnership with Asian, African and Pacific nations have longstanding interests in applied research on helminth parasite control. Many technologies and practices have been successfully developed to control the parasite problems of smallholder and emerging farmers. This wide range extends from simple herbal remedies to complex, integrated use of chemicals, feeding and breeding. In many cases widespread adoption has been limited by lack of technical support, poor access to input markets and lack of incentives for poorer farmers to seek out and pay for innovations. A further new approach may be required that encompasses the wider production and market environment. The biological, social and economic context of each 'emerging farming system' is different and the matching of technologies to each system requires sound understanding of farmer needs and requirements. Thus, it is essential that farmers, extension workers, and scientists jointly decide what technologies to try, what results mean and, if successful, how to sustain their use. In one Asian example a range of technologies were considered for pig, large ruminant and goat production and parasite control through a participatory process which was also used to agree on what determines sustainability beyond testing. The criteria use to screen technologies and practices were (a) continued availability of inputs including dewormers, (b) dependence on related innovations (e.g. weaning or fencing) and (c) degree of community organisation required (e.g. control of breeding or communal grazing). On this basis deworming with chemicals, especially for Toxacara infection in cattle and buffalo calves following on from supplementary feeding with forages were the most feasible entry points. Further interventions were dependent on changes to the production system, including the introduction of weaning and controlled breeding. Further, the incentives for these production changes could not exist without improved market access and market signals for improved weight and condition. Examples such as this point to the need for stronger multidisciplinary and participatory approaches to parasite control.


Subject(s)
Animal Husbandry/methods , Cattle Diseases/prevention & control , Cattle Diseases/parasitology , Helminthiasis, Animal/prevention & control , Ruminants/parasitology , Swine Diseases/prevention & control , Animal Feed , Animal Husbandry/trends , Animals , Asia , Australia , Breeding , Cattle , Female , Helminthiasis, Animal/parasitology , Helminths/physiology , Herbivory , Livestock , Male , Swine , Swine Diseases/parasitology , Technology , Vaccination/veterinary
6.
Trop Biomed ; 25(1 Suppl): 1-8, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18414372

ABSTRACT

Practical helminth control in smallholder systems needs to match technical options with local knowledge, locally available animal and feed resources and the needs of both producers and consumers. Despite extensive research over many decades the uptake of new technology in these systems has been slow and limited to few farmers with access to good technical support. Investment by small holders is constrained by lack of regular market signals for livestock and livestock products. Examples of effective helminth control in cattle, buffalo, sheep, goat and pig systems show that effective control is possible using local resources and knowledge. Livestock systems in Asia are changing rapidly through industrialisation of production and consolidation of supply chains and retail markets, but smallholder systems, which are resilient and multipurpose, will remain important in rural areas and in peri-urban environments. They also provide a significant pathway for the poor to build assets and generate income. Helminth control in these systems will always vary greatly between farmers and systems and will need to be relatively simple and tailored to locally available resources. The public sector will continue to provide advice on appropriate genetics, to regulate drug importation, use and quality, and ensure novel helminth control options are investigated for local application and promotion to livestock producers. The private sector has the complementary role to develop clear market signals for livestock and livestock products, and make anthelmintics available in appropriate packages. Improved helminth control has the potential to increase the profitability and sustainability of all components of the livestock sector.


Subject(s)
Animal Husbandry/methods , Communicable Disease Control/methods , Communicable Disease Control/organization & administration , Helminthiasis, Animal/drug therapy , Helminthiasis, Animal/prevention & control , Animals , Animals, Domestic , Asia
7.
Vet Parasitol ; 120(1-2): 107-21, 2004 Feb 26.
Article in English | MEDLINE | ID: mdl-15019148

ABSTRACT

The negative effects of nematodes in small ruminants can be reduced by use of dewormers but their effectiveness is increasingly limited by the emergence of anthelmintic resistance. The efficacy of benzimidazole (BZ) anthelmintics in the Philippines was estimated by an in vitro larval development assay using worm eggs recovered from faeces collected from goats and sheep. Two hundred and eighteen farms were selected to represent areas of the country with high goat and sheep populations and the full range of farm sizes, from smallholders with just a few animals to commercial and institutional farms with several hundred. Initial surveys of worm control advisers indicated that BZs have been in continuous widespread use for up to 20 years with little use of other chemical groups. A larval development assay (LDA: DrenchRite) was modified for use with BZs alone to allow up to five samples to be analysed on a single microtitre plate. The assay was validated by comparison with the faecal egg count reduction test (FECRT). The dominant nematode genera were Haemonchus and Trichostrongylus with small numbers of Oesophagostomum. The range of BZ efficacy estimated from the LDA results was 0-100% and the distribution of efficacy levels was continuous, with mean efficacy of 82 and 64% for goats and sheep, respectively. There were significant associations between efficacy and parameters measured to characterize the sampled farms: size of animal management group, FEC of sample, recent importation of stock and no access to common grazing were all correlated with decreased efficacy. Likewise, low efficacy was associated with reported frequency and number of years that BZ drenches had been used. The LDA was found to be highly suited to estimate efficacy in nematode populations from small farms where performance of a FECRT for even one chemical would be impractical. Using a larval development assay, we have demonstrated a wide efficacy range for BZs against nematodes from all sizes of goat and sheep farms in the tropics.


Subject(s)
Anthelmintics/therapeutic use , Benzimidazoles/therapeutic use , Goat Diseases/parasitology , Sheep Diseases/parasitology , Strongyloidea/growth & development , Strongyloidiasis/drug therapy , Strongyloidiasis/veterinary , Animal Husbandry , Animals , Drug Resistance , Feces/parasitology , Goat Diseases/drug therapy , Goats , Philippines , Sheep , Sheep Diseases/drug therapy , Strongyloidiasis/parasitology , Surveys and Questionnaires
8.
Vet Parasitol ; 112(3): 211-25, 2003 Mar 10.
Article in English | MEDLINE | ID: mdl-12591197

ABSTRACT

The effectiveness of protein supplementation and genetic selection to enhance the resistance of periparturient Merino ewes to infection from gastrointestinal parasites was tested in a replicated grazing experiment. One hundred and twenty ewes from lines selected for increased resistance (R) to Haemonchus contortus or at random (C) were subjected to one of the three supplement groups that provided 0 or 250 g per day cottonseed meal for 5 weeks prior to, or for 6 weeks after the start of lambing. Faecal egg counts (FEC) of R ewes were consistently lower than those of C ewes but both groups exhibited a periparturient rise in FEC. Supplementation during the pre-partum period reduced FEC and increased ewe body weight gain. The benefits of pre-partum supplementation in reducing FEC continued to be apparent up to 10 weeks after supplementation ceased. There was a strong suggestion that the benefits to parasite resistance from protein supplementation were greatest in C ewes. Wool growth rates (15%) and birth weights (5%) were greater for C ewes but differences between the lines for lamb body weight had disappeared by day 97. The greatest benefit to resistance from protein supplementation was observed when ewes were experiencing a loss of maternal body weight. Conversely, no benefits to resistance were observed when ewes had moderate (78-107 g per day) rates of maternal weight gain. These results suggest that increased resistance as a result of protein supplementation is dependent on the prevailing supply and demand for scarce nutrients such as metabolisable protein (MP). Both genetic selection and protein nutrition are effective strategies to enhance host resistance to nematode infection during the periparturient period.


Subject(s)
Breeding , Dietary Supplements , Nematode Infections/genetics , Nematode Infections/veterinary , Nutritional Physiological Phenomena , Sheep Diseases/genetics , Sheep Diseases/parasitology , Sheep, Domestic/genetics , Sheep, Domestic/parasitology , Aging , Animal Feed , Animals , Birth Weight , Body Weight/drug effects , Dietary Proteins/pharmacology , Feces/parasitology , Female , Genetic Predisposition to Disease , Growth , Nematoda/physiology , Nematode Infections/immunology , Nematode Infections/prevention & control , Parasite Egg Count/veterinary , Sheep Diseases/immunology , Sheep Diseases/prevention & control , Sheep, Domestic/immunology
9.
Int J Parasitol ; 29(3): 451-8, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10333329

ABSTRACT

The mammary glands of 103 pasture-reared non-lactating, non-pregnant Merino ewes were infused via the teat canal with antigens prepared from the nematode Haemonchus contortus, and the inflammatory response to infusion assessed by washing the gland of its contents after 24 h and 14 days. The ewes were of two genotypes: one with proven high levels of resistance to infection with the nematode H. contortus, the other random-bred animals with relative susceptibility to infection. On day 0 of a H. contortus infection, one gland of the subgroups of both genotypes was infused with the antigen preparation. At the same time, the other gland of the random-bred ewes was infused with sterile physiological saline. A third group of infected random-bred ewes was infused with only sterile physiological saline. Similar infusions were performed on other subgroups on days 12, 21 and 35 of infection, which was then terminated with anthelmintic. A fourth group of uninfected random-bred control ewes was given both infusions 35 days after the other groups were infected. Sheep of the resistant genotype had lower worm egg counts and smaller reductions in blood packed cell volumes from day 21 of infection. Infusion of antigen had no effect on the course of infection and no effect on the response of the other gland, which had been infused with saline alone. The dominant leukocyte response from the antigen-infused gland was eosinophilia. On all days of infusion, and after both 24 h and 14 days, eosinophil counts from the resistant genotype were higher than those from their random-bred counterparts. The sheep mammary gland provides a source of eosinophils whose number is related to host genotype and stage of infection and may provide a model for the investigation of cellular responses in mucosal immunity to nematode infections.


Subject(s)
Haemonchiasis/veterinary , Haemonchus/immunology , Inflammation/veterinary , Mammary Glands, Animal/immunology , Sheep Diseases/immunology , Animals , Antigens, Helminth/immunology , Disease Susceptibility , Eosinophils/immunology , Female , Haemonchiasis/immunology , Immunity, Innate , Inflammation/immunology , Mammary Glands, Animal/parasitology , Parasite Egg Count/veterinary , Sheep
10.
Int J Parasitol ; 29(3): 479-88, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10333332

ABSTRACT

Weaner sheep that had been hand-fed on diets containing increasing concentrations of protein for a 9-week period (when uninfected, or infected with Haemonchus contortus) were studied during the next 69 weeks when put on to pasture as a single, unsupplemented flock. During the 9-week period, groups of 12 sheep (six infected, six uninfected) were offered one of five iso-energetic (9.0 MJ kg(-1)) diets containing 10, 13, 16, 19 or 22% crude protein. All sheep were treated with anthelmintic at the end of the 9 weeks and then put out to pasture for 69 weeks, where they were all subject to the same environmental variables including nematode larval challenge. During the grazing period, animals that had previously received the higher protein diets consistently had higher live-weight gain and wool production, higher antibody responses to both H. contortus and Trichostrongylus colubriformis antigenic challenge in vitro, and lower faecal nematode egg counts than did the lambs previously offered the lower protein diets. Faecal egg counts of the grazing sheep that had been artificially infected with H. contortus while being hand-fed were similar to those of the uninfected sheep and there was no interaction between previous infection and dietary protein concentration. We conclude that short periods of enhanced post-weaning nutrition can have long-term and perhaps life-long effects on production.


Subject(s)
Dietary Proteins/administration & dosage , Haemonchiasis/veterinary , Sheep Diseases/immunology , Sheep/physiology , Trichostrongylosis/veterinary , Animals , Antibodies, Helminth/blood , Feces/parasitology , Haemonchiasis/immunology , Haemonchiasis/parasitology , Haemonchus/immunology , Immunity, Innate , Parasite Egg Count/veterinary , Time Factors , Trichostrongylosis/immunology , Trichostrongylosis/parasitology , Trichostrongylus/immunology , Weight Gain/physiology , Wool/growth & development
11.
Int J Parasitol ; 29(1): 193-8, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10048832

ABSTRACT

The development of anthelmintic resistance in gastrointestinal parasites of sheep and goats has meant that there is an urgent need for non-chemical control of these parasites. In order to investigate a potential alternative method of control, a workshop on irradiated larval vaccines (ILV) was held in conjunction with the Second International Conference on Novel Approaches to the Control of Helminth Parasites of Livestock. The objectives of the workshop were to: (1) Review knowledge of irradiated helminth vaccines through the presentation of invited and contributed papers. (2) Identify opportunities for an ILV and in which host/parasite/production systems. (3) Determine what are the gaps in knowledge required to produce and apply an ILV. The workshop concluded that ILVs could be useful as research tools in the further definition of immune responses to parasites and in stimulating the immune response in young sheep and goats to facilitate the estimating of heritability of faecal egg counts. Although the workshop identified some problems associated with a live attenuated vaccine, an ILV could be a useful control measure in the production systems identified by the workshop. Before an ILV could be used on farms, additional research is required into the period of protection afforded by an ILV especially under field conditions. The efficacy of an ILV could be improved by interaction between host genotype and nutritional status and is deserving of further investigation.


Subject(s)
Goat Diseases/prevention & control , Sheep Diseases/prevention & control , Trichostrongyloidea/immunology , Trichostrongyloidiasis/veterinary , Vaccines, Attenuated , Animals , Goats , Larva/immunology , Larva/radiation effects , Sheep , Trichostrongyloidea/growth & development , Trichostrongyloidiasis/prevention & control
12.
Int J Parasitol ; 28(8): 1269-78, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9762574

ABSTRACT

A study was made of the benefits of protein supplementation for parasitised and non-parasitised lambs. Sixty, 5-month-old crossbred wether lambs were placed in individual pens indoors for 9 weeks. Half of the animals were experimentally dosed with 1500 Haemonchus contortus larvae per head per week and were fed ad libitum and the other half were worm-free, pair-fed controls. Diets were formulated to be iso-energetic (9.0 MJ of calculated metabolisable energy per kg dry matter) with five levels of protein (10, 13, 16, 19 and 22% crude protein). These diets were based on oaten chaff, with barley, cotton-seed meal, urea and mineral mix (except for the 22% crude protein diet which did not contain barley). Dietary crude protein content increased live-weight gain, feed intake, rumen fluid ammonia-N, packed cell volume, eosinophil counts and antibody responses to H. contortus L3 antigen and decreased faecal worm egg counts significantly. Infection did not significantly affect packed cell volume of animals on diets with 16, 19 and 22% crude protein content. We conclude that extra dietary protein can prevent the adverse effects of H. contortus infection on animal production.


Subject(s)
Animal Feed , Dietary Fiber/administration & dosage , Dietary Proteins/administration & dosage , Sheep/growth & development , Ammonia/metabolism , Animals , Antibodies, Helminth/blood , Antibody Specificity , Body Weight , Haemonchiasis/blood , Haemonchiasis/veterinary , Haemonchus , Parasite Egg Count , Sheep Diseases/blood , Time Factors
13.
Rev Sci Tech ; 17(1): 315-28, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9638820

ABSTRACT

Breeding for disease resistance in Merino sheep in Australia has attracted considerable research and development attention. Increased labour costs, the reduced efficacy of common anthelmintics and insecticides, consumer demand for products which are free of chemicals and the poor prognosis of alternative long-term control strategies are all forcing sheep breeders to contemplate the best animal health options available, including selective breeding for resistance. The three major diseases which affect sheep production include gastrointestinal nematode parasites, flystrike (cutaneous myiasis) and footrot. Genetic improvement has been shown to be feasible in all these diseases, possibly with little adverse effect on genetic progress in other production traits. Programmes for resistance to internal parasites to be included in practical breeding programmes are now in progress. This paper deals with the incentives for focusing on the three major diseases in Merino sheep, the potential sources of genetic variation, and the means to exploit these sources of variation. The authors also highlight gains and benefits achieved in experimental selection flocks, and the difficulties and options available for commercial breeders.


Subject(s)
Breeding , Immunity, Innate/genetics , Sheep/genetics , Animals , Australia , Foot Rot/genetics , Foot Rot/immunology , Genetic Variation , Intestinal Diseases, Parasitic/genetics , Intestinal Diseases, Parasitic/immunology , Intestinal Diseases, Parasitic/veterinary , Myiasis/genetics , Myiasis/immunology , Myiasis/veterinary , Nematode Infections/genetics , Nematode Infections/immunology , Nematode Infections/veterinary , Selection, Genetic , Sheep/immunology
14.
J Histochem Cytochem ; 45(11): 1461-7, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9358848

ABSTRACT

We have used high-resolution field emission scanning electron microscopy with backscatter electron imaging to detect immunogold-labeled C5a and interleukin-8 (IL-8) receptors on human blood neutrophils. The receptors were labeled with receptor-specific antibodies in combination with secondary antibody conjugated to immunogold. When neutrophils were isolated in a "nonactivated" state, both of these receptor populations were expressed primarily in clusters on nonprojecting domains of the cell membrane. When these cells were double labeled for C5a and IL-8 receptors, intermixing of these receptor species in a common cluster was not found. When neutrophils were isolated in an "activated" state, by mixing the blood with N-formylmethionyl-leucyl-phenylalanine, the cells were seen to be elongated and ruffled at their anterior pole, but the C5a receptors did not disperse or redistribute on the surface of the peptide-activated cells. Analysis of the distribution of human C5a receptors expressed by transfected mouse L-cell fibroblasts showed the C5a receptors to be clustered, but expressed on nonprojecting and projecting domains of the cell surface. These observations provide new information on the topographical expression of leukocyte receptors involved in directing cell migration.


Subject(s)
Antigens, CD/analysis , Neutrophils/chemistry , Receptors, Complement/analysis , Receptors, Interleukin/analysis , Animals , Antigens, CD/genetics , Female , Fibroblasts/chemistry , Humans , Male , Mice , Microscopy, Electron, Scanning , Microscopy, Immunoelectron , Neutrophil Activation/immunology , Neutrophils/ultrastructure , Receptor, Anaphylatoxin C5a , Receptors, Complement/genetics , Receptors, Interleukin-8A , Transfection
15.
Antisense Nucleic Acid Drug Dev ; 7(3): 133-40, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9212903

ABSTRACT

Animal studies of therapeutic oligonucleotides require measurement of circulating levels of oligonucleotides by multistep, time-consuming methods. In contrast, addition of a single-stranded DNA binding fluorophore, OliGreen, to oligonucleotides in plasma samples allowed rapid quantitation. Dose-response curves were measured for five different oligonucleotide analogs added to plasma or serum. Phosphorothioate or 3'-amino phosphodiester oligodeoxynucleotides in calf serum reliably exhibited linear, dose-dependent fluorescence at 15-500 nM. The assay was equally sensitive in human and mouse plasma, with a heterogeneous variety of sequences. Oligonucleotides shorter than 10 nucleotides yielded substantially reduced fluorescence. In contrast, 2'-O-methyl oligoribonucleotides, DNA methylphosphonates, and peptide nucleic acids demonstrated little or no fluorescence with OliGreen. Following intravenous injection of a phosphorothioate pentadecamer into mice, fluorescence measurements of plasma phosphorothioate levels displayed a dose-dependent, biexponential decline over a 90 min period. Chronic infusion at 2.5 nmol/hour into mice yielded plasma oligonucleotide values equivalent to 0.1 microM, a value reflecting the contributions of intact and partially degraded strands. Tumor-bearing mouse plasma evidenced high fluorescence values in the absence of oligonucleotide administration, presumably because of elevated intrinsic plasma DNA fragments. Although limited in its ability to differentiate intact from partially degraded strands, OliGreen fluorescence provides a simple, rapid, and sensitive method for measuring circulating levels of phosphorothioate or phosphodiester oligonucleotides in healthy animals or humans.


Subject(s)
DNA, Single-Stranded/metabolism , Fluorescent Dyes , Oligodeoxyribonucleotides/blood , Animals , Dose-Response Relationship, Drug , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Oligodeoxyribonucleotides/chemistry , Oligodeoxyribonucleotides/pharmacokinetics , Sensitivity and Specificity , Thionucleotides/blood , Thionucleotides/pharmacokinetics
16.
Biochem Pharmacol ; 53(10): 1465-76, 1997 May 15.
Article in English | MEDLINE | ID: mdl-9260874

ABSTRACT

Direct quantitative comparisons of cellular uptake across a wide variety of analogs and cell types are necessary for the design of oligonucleotide diagnostic and therapeutic applications. This work reports quantitative cellular uptake and nuclear localization of [14C]oligodeoxynucleoside phosphorothioates (PS), 3'-alkylamino oligodeoxynucleoside phosphodiesters (PO-NH2), 2'-O-methyl oligoribonucleoside phosphodiesters (2OM), peptide nucleic acids (PNA), and oligodeoxynucleoside methylphosphonates (MP) in several transformed or immortalized cell lines. All analogs demonstrated active cellular uptake in that intracellular concentrations greatly exceeded the extracellular 1 microM concentration within 1-3 hr. However, by 9-24 hr, cellular accumulations of PS exceeded those of PO-NH2 and 2OM by 3- to 5-fold, PNA by 6- to 7-fold, and MP by 8- to 10-fold. Similar results were observed in two transformed cell lines, HL-60 leukocytes and H-ras transformed fibroblasts, using three different heterogeneous sequences. H-ras and IGF-1R transformed fibroblasts had a 2- to 5-fold higher uptake of all analogs than non-transformed immortalized fibroblasts. Nuclear levels of the PO-NH2, PS, and MP analogs were approximately 25% of total cellular uptake, while nuclear percentages of 2OM and PNA were less than 20%, suggesting some differences in nuclear localization among the analogs. These observations provide a direct quantitative comparison of cellular uptake as a function of oligonucleotide modification, and imply that transformation enhances cellular uptake. From the perspective of therapy and diagnosis, clear trade-offs were apparent between efficiency of uptake on the one hand, and nuclease resistance and hybridization strength on the other.


Subject(s)
Oligodeoxyribonucleotides/metabolism , Oligonucleotides, Antisense/metabolism , Oligoribonucleotides/metabolism , Peptides/metabolism , Thionucleotides/metabolism , 3T3 Cells , Animals , Cell Compartmentation , Cell Line, Transformed , Drug Design , Fluoresceins/metabolism , HL-60 Cells , Humans , Mice , Oligonucleotides, Antisense/chemistry , Tumor Cells, Cultured
17.
Vet Parasitol ; 72(3-4): 345-57; discussion 357-66, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9460206

ABSTRACT

Research in the last 20 years has firmly established that it is possible to exploit genetic variation in resistance to the nematode parasites of sheep by selection. Selected sheep are more resistant to infection and commercial application of this research is under way in both Australia and in New Zealand. Not all the consequences of these breeding programs have been established, particularly long-term consequences for productivity and the interaction with other control measures, but the technology is available in the public domain with no commercial restrictions. Faecal worm egg count remains the most effective way of selecting sheep although many alternatives, such as DNA markers, host antibody and parasite antigen assays are being developed for use as selection criteria. Strategic nutritional supplementation is an immediate candidate for inclusion in worm control programs and although nematode vaccines remain elusive, it is likely that some will be field-tested in the next few years. For both of these approaches, nutritional and immunological, it is critical that the response of selected genotypes are assessed under commercial conditions and as components of worm control programs. There is evidence to support the possibility that selected sheep will be more responsive to vaccination while the long-term interaction between the effect of strategic nutritional supplements and resistant genotypes needs to be investigated.


Subject(s)
Nematode Infections/veterinary , Sheep Diseases , Sheep/genetics , Animal Nutritional Physiological Phenomena , Animals , Australia , Immunity, Innate , Nematode Infections/immunology , Nematode Infections/prevention & control , New Zealand , Parasite Egg Count , Vaccination/veterinary
19.
Int J Parasitol ; 26(8-9): 869-77, 1996.
Article in English | MEDLINE | ID: mdl-8923136

ABSTRACT

In the Australian livestock industries, susceptibility to infectious diseases is generally greater in young than in mature ruminants. The increased susceptibility is manifest as respiratory and intestinal infections (viral and bacterial) of calves, as well as fleece rot, flystrike and, especially, gastrointestinal parasitic infestations of young sheep. Lower resistance to infectious disease in young ruminants appears to be due largely to immunological hyporesponsiveness, and is not simply a consequence of their not having been exposed sufficiently to pathogens to develop active immunity. Young sheep have significantly lower proportions of CD4+ and CD8+ lymphocytes, but similar proportions of T19+ and B lymphocytes in blood, lymph and skin compared with mature sheep. Blood lymphocytes from young sheep produce less interferon-gamma in culture and young sheep invariably mount smaller antibody responses than do mature animals. Taken together, these findings begin to explain why young ruminants are more susceptible to infectious diseases in general, and to gastrointestinal parasites in particular, when compared to mature animals. Haematological markers of disease resistance, the prevalence of non-selected diseases and immune responses to vaccination were examined in the internal parasite-resistance flocks in Armidale NSW and the fleece rot/flystrike selection flocks at Trangie NSW. Any programme that seeks to improve resistance to parasitic or any other disease should have the capacity to make contemporary measurements of resistance to other diseases which are important in, or threaten, the production system.


Subject(s)
Aging/immunology , Parasitic Diseases, Animal , Ruminants/parasitology , Sheep Diseases/immunology , Animals , Bluetongue/immunology , Clostridium Infections/immunology , Clostridium Infections/veterinary , Diarrhea/immunology , Diarrhea/veterinary , Foot Rot/immunology , Immunity, Innate , Intestinal Diseases, Parasitic/immunology , Intestinal Diseases, Parasitic/veterinary , Parasitic Diseases/immunology , Ruminants/immunology , Sheep
20.
Acad Emerg Med ; 2(6): 508-12, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7497051

ABSTRACT

OBJECTIVE: To document the incidence, source, and reasons for all complaints received by a large municipal emergency medical services (EMS) program. METHODS: A retrospective review of all complaints received during three consecutive years (1990-1992) in a centralized EMS system serving a large municipality (population 2 million). All cases were categorized by year, source, and nature of the complaint. RESULTS: In the three study years, EMS responded to 416,892 incidents with nearly a half-million patient contacts. Concurrently, 371 complaints were received (incidence of 1.12 per thousand); 132 in 1990, 129 in 1991, and 110 in 1992. Most complaints involved either: 1) allegations of "rude or unprofessional conduct" (34%), 2) "didn't take patient to the hospital" (19%), or 3) "problems with medical treatment" (13%). Only 1.6% (n = 6) were response-time complaints. Other complaints included "lost/damaged property," "taken to the wrong hospital," "inappropriate billing," and "poor driving habits." The most common sources were patient's families (39%) and the patients themselves (30%). Only 7.8% were from health care providers. CONCLUSION: Reviews of complaints provide information regarding EMS system performance and reveal targets for quality improvement. For the EMS system examined, this study suggests a future training focus on interpersonal skills and heightened sensitivities, not only toward patients, but also toward bystanders and family members.


Subject(s)
Consumer Behavior/statistics & numerical data , Emergency Medical Services/standards , Quality of Health Care , Urban Health Services/standards , Humans , Patient Satisfaction/statistics & numerical data , Professional-Family Relations , Retrospective Studies , Texas , Time Factors , Urban Health Services/trends
SELECTION OF CITATIONS
SEARCH DETAIL
...