Dairy-cattle health in Gyeongnam, Korea.

An animal-health monitoring system in the Gyeongnam area was started in 1997 to develop statistically valid data for use in estimating disease frequencies in dairy cattle, and the associated costs. The objectives of this study were to: (1) describe what was done to implement and maintain the system in Gyeongnam; (2) present selected disease frequencies; (3) discuss the epidemiological consideration of what was done and implications for results obtained.Veterinary medical officers (VMOs), comprising professors and graduate students from Gyeongsang National University, faculty of Gyeongnam Livestock Promotion Institute and clinic veterinarians, served as data collectors. After training on current disease and management problems of dairy cattle, interview techniques, sampling methods and data-collection instruments, the VMOs participated in selection of the sample herds and data gathering. Forty (n=40) of 167 dairy herds were selected randomly using a computer-generated list of random numbers and the VMOs visited farms once in a month for 12 months to collect data about management, disease, inventory, production, preventive treatment, financial and other relevant data. Strict data-quality control devices were used. Specific feed-back was developed for the producers and data collectors.The six disorders found most frequently in cows (from the highest to the lowest) were breeding problems, clinical mastitis, birth problems, gastrointestinal problems, metabolic problems and lameness. In young stock, respiratory, multiple system, breeding and gastrointestinal problems were predominant, whereas in calves, gastrointestinal, respiratory and integumental problems predominated.     

Chicken leptin: properties and actions

Chicken leptin cDNA shows a high homology to mammalian homologous, with an expression localized in the liver and adipose tissue. It is noteworthy, that the hepatic expression is most likely associated with the primary role that this organ plays in lipogenic activity in avian species. As in mammals, chicken leptin expression is regulated by hormonal and nutritional status. This regulation is tissue-specific and with a high sensitivity in the liver compared to adipose tissue. The blood leptin levels are regulated by the nutritional state with high levels in the fed state compared to the fasted state. The recombinant chicken leptin markedly inhibits food intake as reported in mammals, suggesting the presence of an hypothalamic leptin receptor. The chicken leptin receptor has been identified and all functional motifs are highly conserved compared to mammalian homologous. Chicken leptin receptor is expressed in the hypothalamus but also in other tissues such as pancreas, where leptin inhibits insulin secretion and thus may have a key role in regulating nutrient utilization in this species.     

Correlation between the clinical course of granulomatous meningoencephalomyelitis in dogs and the extent of mast cell infiltration

The data from 20 dogs with histopathologically confirmed granulomatous meningoencephalomyelitis were reviewed in an attempt to identify clinical signs and morphological and cellular parameters, particularly the infiltration of mast cells, which might be associated with the clinical course of the disease. Thirteen of the dogs had the acute form of the disease and seven had the chronic form. Young to middle-aged, small breed female dogs were over-represented. Central vestibular signs were observed in six of the dogs with the acute disease. Analyses of cerebrospinal fluid revealed moderate to severe pleocytosis and high protein concentrations in all cases. Histopathological investigations revealed disseminated perivascular cuffs, large confluent granulomata, tissue necrosis, infiltration with neutrophils and a large number of mitotic cells in the dogs with either of the clinical forms of the disease. Tryptase-positive mast cells were observed in all the cases, but there were significantly larger numbers in the dogs with the acute form.     

Endogenous N-losses in piglets estimated by a [15N]-isotope dilution technique: effect of xylanase addition to a wheat and rye based diet.

The nitrogen pool of piglets weighing 19.4 +/- 1.4 kg at the beginning of the experiment was labeled with an oral application of ([15N]H4)2SO4 (1.26 [15N]-atom percent excess of dietary N) over a period of 7 d. The labeling period was followed by an equilibration period of 7 d without feeding the labeling compound. The two experimental diets were based on wheat (53%) and rye (25%) and were fed either with or without a xylanase containing enzyme preparation over both experimental periods. Additionally, diets were supplemented with an indigestible marker during the 2nd period of the experiment to allow the calculation of endogenous N-losses in subsequent segments of the digestive tract of the pigs. These endogenous N-losses were estimated at the end of the experiment by analyzing feces, ingesta and urine for [15N]-enrichment assuming that [15N]-enrichment of urine represents the [15N]-enrichment of the precursor pool. Endogenous N-losses were not significantly affected by xylanase addition at any measurement site (stomach, 3 sections of the small intestine, total digestive tract). Endogenous N-proportions of total nitrogen amounted on average for the six pigs to 42 +/- 11% and 56 +/- 5% at the last section of the small intestine and over the whole digestive tract, respectively, which corresponded to endogenous N-losses of 2.8 +/- 1.3 g N/kg DM and 2.0 +/- 0.3 g N/kg DM, respectively.     

Treatment of methicillin-resistant Staphylococcus epidermidis infection following repair of an ulnar fracture and humeroradial joint luxation in a horse

A 27-month-old Rocky Mountain Horse was examined because of a fracture of the proximal portion of the ulna and luxation of the humeroradial joint (Monteggia fracture). Open reduction was performed, using a mechanical distractor, and the ulnar fracture was stabilized by application of a bone plate and screws. After surgery, the horse developed an infection of the surgical site, and bacterial culture of fluid from the surgical site yielded a pure growth of methicillin-resistant Staphylococcus epidermidis susceptible to oxytetracycline, erythromycin, rifampin, and vancomycin. Treatment with oxytetracycline did not result in a favorable clinical response. Therefore, the horse was treated systemically with vancomycin and rifampin, and vancomycin-impregnated polymethyl methacrylate beads were implanted at the surgical site. Six months after surgery, the horse was sound at a walk or trot, and bony union was evident on radiographs of the elbow joint.     

Efficacy of itraconazole as a combined continuous/pulse therapy in feline dermatophytosis: preliminary results in nine cases

This study evaluated the efficacy of itraconazole as a combined continuous/pulse therapy for feline dermatophytosis. Nine cats with dermatophytosis caused by Microsporum canis were treated with itraconazole at 10 mg kg(-1) orally once daily for 28 days and then on an alternate week regimen (1 week off, 1 week on) at the same dosage. Cats were re-evaluated by physical examination and fungal culture at days 28, 42, 56 and 70 if necessary. Treatment was stopped when two consecutive negative fungal cultures were obtained. Eight cats were cured after 56 days, with two negative cultures obtained at days 28 and 42. In one case, a positive culture was obtained at day 28, but negative cultures were achieved at days 42 and 56. This protocol appears to be effective in the treatment of feline dermatophytosis, although these preliminary results should be confirmed by a controlled study.     

ASAS centennial paper: Lactation biology for the twenty-first century

Knowledge of general aspects of mammary gland function, including metabolic pathways and hormonal regulation of mammary gland development and lactation, in livestock species was obtained several decades ago. As basic biological information of growth factor action, apoptotic mechanisms, and signal transduction events has exploded, the mouse became the model of choice for studying fundamental mechanisms regulating mammary function. A complete sequenced genome also has made the mouse amenable for studies of mammary gene network expression. Advances in molecular biology techniques currently allow researchers to genetically modify mice to either overexpress or completely lack specific genes, thereby studying their function in an in vivo setting. Furthermore, the use of mammary-specific promoters has allowed genes related to mammary gland function to be eliminated from the mammary gland in a developmental and tissue-specific manner. These studies have demonstrated the complexity that underlies mammary gland development and function in rodents and may provide insight into the mechanisms that ultimately allow the ruminant or swine mammary gland to function in a coordinated fashion throughout puberty, pregnancy, lactation, and involution. The challenge facing animal scientists is how to obtain similar information in much larger and expensive livestock. One possible approach is to manipulate gene expression in vitro using mammary cell culture models derived from domestic animals (e.g., genes can be "knocked down" using small interfering RNA approaches). Ultimately, major advances in understanding lactation biology may come from coupling basic mechanistic information with functional genomics, proteomics, and metabolomics approaches. A strong foundation in bioinformatics will also be required to optimize use of these new technologies. Stem cell biology also represents an exciting area in the next decade that holds promise for improving lactation efficiency. Strong training of our future scientists in these areas should facilitate livestock-focused mammary gland research that will allow basic information to be gained at unprecedented amounts, ultimately leading to optimization of livestock production.     

添加复合预混料对奶牛抗氧化作用影响的试验研究

[目的]研究复合预混料对奶牛抗氧化作用的影响.[方法]把20头奶牛随机分成2组,分别为试验组和对照组,试验组奶牛精料补充料中添加2%预混料,180 d后测定试验组和对照组血清中T-SOD、GSH-Px活性和MDA含量.[结果]与对照组相比,试验组可以提高T-SOD和GSH-Px的活性,降低MDA含量.[结论]添加复合预混料可以提高奶牛的抗氧化能力.     

Plasma and Pulmonary Fluid Endothelin in Horses with Seasonal Recurrent Airway Obstruction

Background: Summer pasture-associated recurrent airway obstruction (SPA-RAO), a seasonal airway obstructive disease of horses, is characterized by clinical exacerbation after exposure to pasture during warm months of the year. Endothelin (ET)-1, potent bronchoconstrictor, mitogen, secretagogue, and proinflammatory mediator, has been implicated in the pathogenesis of asthma and equine heaves.
Hypothesis: Immunoreactive ET-1 concentrations increase during clinical exacerbation and return to basal values during periods of disease remission.
Animals: Twelve horses, 6 affected with SPA-RAO and 6 nonaffected.
Methods: Prospective, observational study. Bronchoalveolar lavage fluid (BALF), arterial and venous plasma samples, and clinical variables were obtained from affected horses during clinical exacerbation and remission. Samples and data of nonaffected horses were collected during the summer and winter on dates similar to affected horses. Immunoreactive ET-1 was determined using a commercial ELISA.
Results: The median and range ET-1 concentrations (pg/ml) in arterial (1.3, 0.7–1.8) and venous (1.3, 1.2–1.7) plasma and in BALF (0.3, 0.2–0.4), and pulmonary epithelial lining fluid (PELF) (25.5, 21–50) were greater in affected horses during clinical exacerbation compared with remission ( P < .01). The concentrations of immunoreactive ET-1 were greater in affected horses during clinical exacerbation compared with nonaffected horses ( P < .05).
Conclusions and Clinical Importance: During clinical exacerbation of SPA-RAO, ET-1 is increased in circulation and pulmonary secretions. Intervention with ET receptor antagonists should provide further information on the role of ET-1 in SPA-RAO.     

Estimation of accuracies and expected genetic change from selection for selection indexes that use multiple‐trait predictions of breeding values

Procedures are described for estimating selection index accuracies for individual animals and expected genetic change from selection for the general case where indexes of EBVs predict an aggregate breeding objective of traits that may or may not have been measured. Index accuracies for the breeding objective are shown to take an important general form, being able to be expressed as the product of the accuracy of the index function of true breeding values and the accuracy with which that function predicts the breeding objective. When the accuracies of the individual EBVs of the index are known, prediction error variances (PEVs) and covariances (PECs) for the EBVs within animal are able to be well approximated, and index accuracies and expected genetic change from selection estimated with high accuracy. The procedures are suited to routine use in estimating index accuracies in genetic evaluation, and for providing important information, without additional modelling, on the directions in which a population will move under selection.