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Gianneechini R Concha C Rivero R Delucci I Moreno López J 《Acta veterinaria Scandinavica》2002,43(4):221-230
Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20 degrees C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300,000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%. 相似文献
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Behnke E Collar JI Cooper PS Crum K Crisler M Hu M Levine I Nakazawa D Nguyen H Odom B Ramberg E Rasmussen J Riley N Sonnenschein A Szydagis M Tschirhart R 《Science (New York, N.Y.)》2008,319(5865):933-936
Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection. 相似文献
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Cell types and their immunological functions in bovine mammary tissues and secretions--a review of the literature 总被引:1,自引:0,他引:1
C Concha 《Nordisk veterinaermedicin》1986,38(5):257-272
In this work the literature concerning cells related to bovine mammary gland defence mechanisms has been reviewed. The cells considered in this review include leucocytes from mammary secretions, leucocytes located in the mammary tissues, and nonsecretory epithelial cells which line the teat and the lactiferous sinuses of the udder. The mammary secretions and tissues basically contain three types of cells: polymorphonuclear leucocytes, macrophages, and lymphocytes. The number of each type of cell varies, depending on the physiological and pathological states of the udder, and all cell functions are associated with the immuno-defence mechanisms of the mammary gland. 相似文献
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Grass greenness flush can influence breeding phenology and fertility in equatorial thoroughbred mares in the absence of photoperiod variation
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Juan Carranza Washington A. Yoong Belén Caño Vergara Abel Briones Concha Mateos 《Animal Science Journal》2018,89(6):919-924
Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green‐grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seasonality. Actual births could not be used to infer natural phenology because they were influenced by management decisions. Instead, we used variations in the probability of pregnancy after a service as a measure of the natural tendency of mares to show breeding phenology. We found that although managers tended to schedule pregnancies in two periods within the year, mares were more prone to become pregnant after the increase in grass greenness that takes place at the beginning of the year (February). Our finding has potential applications to improve the success of services and the welfare of animals, by providing green‐grass stimuli in the appropriate season. 相似文献
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Luis Daniel Jimnez‐Martínez Dariel Tovar‐Ramírez Carlos Alfonso lvarez‐Gonzlez Emyr Pea‐Marín Susana Camarillo‐Coop Rafael Martínez‐García Elena Palacios‐Mechetnov Rosario Martínez‐Yaez Bartolo Concha‐Frías 《Aquaculture Research》2020,51(7):2629-2640
Five experimental diets containing different lipid sources, fish oil (D1), soybean lecithin (D2), corn oil (D3), canola oil (D4) and olive oil (D5), were evaluated in Atractosteus tropicus larvae for the relative gene expression of the enzymes fatty acid synthase (fas), acetyl‐CoA carboxylase 1 (acc1) and carnitine palmitoyltransferase 1C (cpt1c), in addition to their effects on larval growth, survival and cannibalism during a 30‐day feeding trial. Higher growth and survival were obtained in treatments D1 and D2, and lower performance in diets D3, D4 and D5. The highest levels of expression of fas and acc1 occurred in larvae fed with D1, which contained high amounts of n‐3 long‐chain polyunsaturated fatty acids (LC‐PUFA), mainly DHA and EPA FA are regulators of lipogenesis. The higher cpt1c expression in plant‐based diets is attributed to the fact that these diets are rich in α‐linolenic acid (ALA) and low DHA, EPA and ARA levels that favour ß‐oxidation. In conclusion, the diets with fish oil (D1) and soybean lecithin (D2) were the best treatments for larval growth, survival and cannibalism and thus appear to meet both lipid and energy requirements of A. tropicus larvae, meanwhile the use of vegetable oils influences the expression of intermediary lipogenic genes. 相似文献
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The aim of this study was to examine the effect of dietary fibre addition to partially baked and frozen wheat rolls on the glycaemic index (GI). 相似文献
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Gelatinization and Retrogradation Kinetics of High‐Fiber Wheat Flour Blends: A Calorimetric Approach
The impact of dietary fiber (DF) mixtures on dough thermal properties needs to be investigated when designing high‐fiber wheat bread. Effects of flour replacement at different levels (6–34%) by soluble (inuline [FN]), partially soluble (sugar beet [FX], pea cell wall [SW]), and insoluble (pea hull [EX]) DF on wheat dough thermal profiles have been investigated by simulating baking, cooling, and storage in differential scanning calorimetry (DSC) pans. In general, DF incorporation into water‐flour systems delayed endothermic transition temperatures for both gelatinization and retrogradation phenomena except for the peak temperature (Tp) of retrogradation. With some exception, the pattern of the enthalpy of amylopectin retrogradation was lower and slower (lower constant of proportion, k) over 10 days of storage in gelatinized hydrated flour‐fiber blends when compared with control without DF. FX, a partially soluble fiber, provided major effects on gelatinization (Tp decrease and ΔH increase) and retrogradation kinetics (the Avrami exponent, n, increase). Single presence of EX allowed a significant reduction in the Avrami exponent n leading to slower kinetics for amylopectin retrogradation when included in the blends. 相似文献
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