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101.
R Jorritsma P Langendijk TAM Kruip TH Wensing JPTM Noordhuizen 《Reproduction in domestic animals》2005,40(1):68-72
This study was designed to elucidate associations between energy metabolism and LH pulsatility characteristics in early lactation, and days to first ovulation, in order to explain the relationship between energy balance and fertility observed in epidemiological studies. To this end, 10 multiparous HF cows were monitored during lactation, after the application of two different feeding strategies during the dry period. Days to first ovulation was assessed using blood progesterone measurements and LH pulsatility was measured in 8-h windows in the third week postpartum. The association between depth of negative energy balance and days to ovulation was confirmed. However, this study does not support the idea that LH pulsatility characteristics in early lactation are predictive for the interval between parturition and first ovulation. 相似文献
102.
Rapid chilling cannot prevent inferior pork quality caused by high preslaughter stress 总被引:8,自引:0,他引:8
Hambrecht E Eissen JJ de Klein WJ Ducro BJ Smits CH Verstegen MW den Hartog LA 《Journal of animal science》2004,82(2):551-556
The present experiment investigated whether increasing chilling rate could improve meat quality in pigs exposed to either minimal or high stress immediately preslaughter. Pigs (n = 192) were offspring of halothane-free lines. On various days, four groups of 48 pigs were processed at a commercial plant. Within each group, half the pigs were exposed to either minimal or high preslaughter stress. Before entering the cooler at 45 min postmortem, carcasses of both minimal and high preslaughter stress treatments were allocated randomly to either conventional (+4 degrees C for 22 h) or rapid (three-phase chilling tunnel: -15, -10, and -1 degrees C for 15, 38, and 38 min, respectively, followed by storage at 4 degrees C until 22 h postmortem) chilling. Temperature and pH were measured in the blood at exsanguination and in the longissimus lumborum (LL) and semimembranosus (SM) muscle at 0.5, 2.5, 4.5, 6.5, and 22 h postmortem. Meat quality attributes (water-holding capacity and objective color measurements) were assessed on the LL. Preslaughter stress level affected pH and temperature in both blood and muscle, with lower (P < 0.001) pH values and higher (P < 0.001) temperatures for pigs exposed to high vs. minimal stress. Rapid chilling led to a faster (P < 0.001) temperature decline regardless of preslaughter stress level. Rapid chilling did not (P > 0.05) influence the rate of pH decline in the LL muscle, but reduced (P = 0.061) pH decline in the SM. Rapid chilling, as opposed to conventional chilling, decreased (P < 0.05) electrical conductivity in the LL, regardless of preslaughter stress; however, it could not compensate for the detrimental effect (P < 0.05) of stress on drip loss, filter paper moisture absorption, and meat color (L* value). Results from the present study indicated that increasing chilling rate is not a suitable method to resolve pork quality problems caused by inadequate preslaughter handling. 相似文献
103.
L. A. MEIJER K. G. F. CEYSSENS W. TH. DEJONG B. I.J. A. C. DE GREVE 《Journal of veterinary pharmacology and therapeutics》1993,16(2):214-222
The pharmacokinetics of oxytetracycline were studied after both intravenous (i.v.) and intramuscular (i.m.) administration to a group of five veal calves. Blood samples were taken frequently during the terminal elimination phase in order to calculate a reliable elimination rate constant. Because of the low limit of quantification of the method of analysis used, oxytetracycline plasma concentrations could be monitored over a 12-day period of time.
After the intravenous administration of oxytetracycline, data were fitted according a three-compartment model. After i.m. administration, plasma-concentration-time curves could best be described by a two-compartment model. It was demonstrated that a very slow terminal elimination phase was present both after i.v. and i.m. administration with a half-life of approximately 95 h. The data show that this phase cannot be explained by slow absorption from the injection site and that release of oxytetracycline incorporated into bone is not a likely explanation. 相似文献
After the intravenous administration of oxytetracycline, data were fitted according a three-compartment model. After i.m. administration, plasma-concentration-time curves could best be described by a two-compartment model. It was demonstrated that a very slow terminal elimination phase was present both after i.v. and i.m. administration with a half-life of approximately 95 h. The data show that this phase cannot be explained by slow absorption from the injection site and that release of oxytetracycline incorporated into bone is not a likely explanation. 相似文献
104.
The antispermatongenic effects of furazolidone on the testes of mature Wistar rats were investigated using histological and morphometric methods. The sections showed a varying degree of depopulation of the germinal epithelium, a shrinking and a deformation of the Tubuli contorti, and an enlargement of the intertubular lymphatic sinuses. The strain led to a standstill in the spermatogenesis at the primary-spermatocyte stage. After administering furazolidone, the following results could be seen: – a weightloss of up to 42.1% and a decrease in testes volume by up to 30.2% – a decrease in the volume of the nuclei of the Leydig-cells by up to 51.6% – a reduction in the diameter, perimeter and area covered by Tubuli seminiferi contorti of up to 33.5%, 30.8%, and 53.4%, respectively – an increase in the number of Tubuli seminiferi contorti per mm2 by up to 44.8% – a decrease in the percentage of Tubuli seminiferi contorti of the total testes tissue by up to 39.1% 相似文献
105.
CASE HISTORY: A 6-year-old, spayed, female, domestic short-haired cat presented with severe erythroderma and scaling skin. She showed disturbed gait and mild behavioural changes. CLINICAL FINDINGS: The cat had a generalised, erythematous, scurfy dermatitis with marked, multifocal crusting and skin thickening. The skin was painful and contracted, which appeared to prevent normal freedom of movement. DIAGNOSIS: The cat was suspected to have a paraneoplastic syndrome. A mediastinal mass was located and histologically confirmed as thymoma. The cat was diagnosed with a thymoma-associated cutaneous paraneoplastic syndrome. CLINICAL RELEVANCE: This is a rare condition with few reports in the literature. The skin changes, both grossly and histologically, were considered to be different from those described in cases of paraneoplastic dermatosis associated with pancreatic neoplasia. The clinical presentation was characteristic and more cases may occur in practice than are recognised. In this case, as in previous reports, the tumour was grossly resectable, which could lead to cure of the clinical condition. 相似文献
106.
A. Keen T. F. C. Smits 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(1):37-49
A function that approximates the curve of the growth rate of the mycelium of the imperfect fungusSphaeropsis sapinea in relation to temperature is proposed. This function contains three free parameters, representing maximum growth rate, optimum temperature and shape of the curve. It was applied to data from an experiment with 27 isolates, in which the growth rate was measured in two replications at ten temperatures ranging from ?2 °C to 45 °C. Fitting the function to data from each isolate in each replication resulted in estimates of three parameters in which the information about the curve contained in the ten original observations is compressed. The estimates of the optimum temperature and of the shape were used in a further statistical analysis aimed at comparing the isolates and at ascertaining whether they could be divided into a few distinct groups, possibly related to different strains. The latter proved not to be the case. 相似文献
107.
108.
An automated semi-industrial system with in-line near-infrared reflectance (NIR) for the characterization of the chemical composition of potatoes was designed and constructed, and its performance was tested. The system consisted of the following subsystems: sample crate manipulator, weighing unit for the gross sample weight, potato washing machines with a washing water recycling system, belt for visual inspection of the potatoes, unit for measuring the underwater weight (UWW), industrial rotary saw blade rasp for pulping the potatoes equipped with a sulfite dosage system for inhibiting enzymatic browning of the pulped potatoes, and industrial NIR system for the measurement of the potato composition. The whole system was controlled and operated by a programmable logic controller and process personal computer system. The system was able to process 12 potato samples per hour. Measurements were done to establish the sample carry-over in the system. The carry-over was proven to be well below the maximum acceptable level of 2%. The UWW values established with the automatic system corresponded very well with the UWW data obtained by manual weighting. The day-to-day reproducibility of the UWW system was tested with golf balls. These balls have about the same specific gravity and size as potatoes. The day-to-day reproducibility coefficient of variation of the UWW unit was 0.4%. As a principle of proof, two tentative partial least squares calibration models, one for the starch concentration and one for the coagulating protein concentration in the potato samples, were calculated, applying leaving one out cross-validation. Both models were very promising. The by NIR-predicted starch concentrations showed to be at least as good or even better than the by UWW-obtained starch concentrations. The average difference between the by NIR-predicted and the chemically measured starch concentration was 0.0 ± 0.3% (w/w). For the coagulating protein concentration, the average difference between the by NIR-predicted and the chemically measured concentration was 0.00 ± 0.06% (w/w). In future years, potatoes of a wider range of varieties, growing locations, and growing seasons have to be added to the present tentative model, in order to get a robust NIR model. 相似文献
109.
Fan Liu Emily M. de Ruyter Rebecca Z. Athorn Chris J. Brewster David J. Henman Rebecca S. Morrison Robert J. Smits Jeremy J. Cottrell Frank R. Dunshea 《Journal of animal physiology and animal nutrition》2019,103(1):251-257
Lactating sows are susceptible to heat stress (HS). Part of the thermoregulatory response to HS is to increase peripheral blood flow, which is mediated in part by the vasodilator, nitric oxide (NO). Therefore, the aim of this experiment was to determine the effect of supplementation of L‐citrulline, a NO precursor, on symptoms of HS, lactation performance and subsequent reproductive performance of sows in summer. A total of 221 summer farrowing mixed parity sows were fed either a control diet or supplemented with 1% L‐citrulline upon entry to the farrowing house (6 ± 1.8 days for mean ± standard deviation [SD] before farrowing) until weaning (26 ± 1.5 days). The average daily minimum and maximum temperature in the farrowing house was 21.0 ± 1.88 and 29.2 ± 3.82°C (mean ± SD). Rectal temperature, respiration rate, and plasma and urinary nitrite and nitrate (NOx) of sows were measured on the 19th day post‐farrowing. Supplemental L‐citrulline in the diet did not affect the number of piglets born alive, feed intake of sows, body weight or backfat thickness of sows at weaning, or litter weight gain. L‐citrulline tended to reduce piglet pre‐weaning mortality rate from 18.6% to 15.6% (p = 0.058). L‐citrulline reduced the respiration rate of sows compared to the control diet at 17:00 hr (Time × Diet, p < 0.001); however, rectal temperature was not affected. L‐citrulline tended to increase urinary NOx concentrations (127 vs. 224 µM, p = 0.057) but not plasma NOx concentrations. L‐citrulline did not affect farrowing rate or number of piglets born alive in the subsequent parity. In conclusion, L‐citrulline supplementation reduced respiration rate of lactating sows and reduced piglet pre‐weaning mortality rate in summer. Whether the effects were due to a NO‐dependent mechanism requires further validation. 相似文献
110.
中国东南地区两土链土壤中土壤性质和水稻产量的空间变异研究 总被引:4,自引:0,他引:4
In the light of an increasing demand for staple food, especially rice, in southeast China, investigations on the specific site potential expressed as the relationship between soil and crop yield parameters gain increasing importance. Soil texture and several soil chemical parameters as well as plant properties such as crop height, biomass and grain yield were investigated along two terraced catenas with contrasting soil textures cropped with wet rice. We were aiming at identifying correlative relationships between soil and crop properties. Data were analyzed both statistically and geostatistically on the basis of semivariograms. Statistical analysis indicated a significant influence of the relief position on the spatial distribution of soil texture, total carbon and total nitrogen contents. Significant correlations were found for the catena located in a sandstone area (Catena A) between rice yield and silt as well as total nitrogen content. Corresponding relationships were not detectable for paddy fields that developed from Quaternary clays (Catena B). As suggested by the nugget to sill ratio, spatial variability of soil texture, total carbon and nitrogen was mainly controlled by intrinsic factors, which might be attributed to the erosional transport of fine soil constituents, indicating the importance of the relief position and slope in soil development even in landscapes that are terraced. The crop parameters exhibited short ranges of influence and about one third of their variability was unexplained. Comparable ranges Of selected crop and soil parameters, found only for Catena A, are indicative of close spatial interactions between rice yield and soil features. Our findings show that especially in sandstone-dominated areas, a site-specific management can contribute to an environmentally safe rice production increase. 相似文献