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71.
The effect of vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination (AI) upon the site of AI (vaginal or cervical) and fertility was studied using a total of 87 estrous synchronized Serra da Estrela ewes (control n = 42 and treated n = 45). Artificial insemination was performed using refrigerated semen at 54–55 h after sponge removal. Lambing rate (fertility) and prolificacy were compared between control and treated ewes. The effect of the site of semen deposition on fertility was also evaluated. Prolificacy rate was not different between control (1.5) and treated (1.59) ewes. The proportion of cervical AI achieved in control (45.2%) and treated (37.8%) ewes was not significantly different. Overall, fertility was significantly lower in control than in treated ewes (42.9% vs 64.4%; p < 0.04). Fertility following vaginal AI was significantly lower for control for than treated ewes (30.4% vs 60.7%; p < 0.03) but the difference was smaller and not significant for cervical AI (control 57.9% vs 70.6%). It was concluded that vaginal administration of misoprostol plus terbutaline sulphate 6 h prior to artificial insemination did not affect the proportion of cervical inseminations but significantly improved the fertility of treated ewes. Although needing confirmation, it was hypothesized that drugs might have induced local secretory modifications leading to an increase of cervical ability to retain more viable spermatozoa for fertilization.  相似文献   
72.
73.

Burning effects on soil N are particularly important in the Caldenal region of Argentina because N is likely to be limited and is easily lost by volatilization during fire. Burning may cause an initial increase in the mineral N content of the surface soil and, perhaps more important, can reduce the proportion of N in hydrolyzable (that is, more mineralizable) forms. The modification in soil N fractions by fire is directly related to the degree of soil heating and to the proportion and amount of N fractions remaining in the ash. This research was aimed at studying the effects of a controlled burn on total N, inorganic (NO3 and NH4+) and organic (amino acids, ammonium, hexosamines) N forms, as well as hydrolyzable and nonhydrolyzable N compounds of top soils of the southern Caldenal. Soil samples were taken from beneath the canopy of shrubs and from the areas with herbaceous cover, before and after burning. In order to show that a greater proportion of N added to regularly burned soils will result in lower levels of mineralizable N, differences in the changes of the various pools of plant tissue N upon burning at different ignition tem peratures are also reported. The initial unburned top soils had no significant differences in total, inorganic, and organic N form concentrations between shrub and herbaceous vegetation-covered soil. Burning did not affect the net content of total N in soil under woody vegetation, but in the grassland soil a decrease of total N concentration was observed. Nitrate concentration increased and NH4+ concentration decreased in both shrub and grassland soils after burning. Controlled burning caused losses of amino acid and ammonium organic N forms from the soil under grass plants and gains of hexosamine N in both shrub-and herbaceous-coveredsoils. There was an observed tendency to increase the relative proportions of non hydrolyzable N forms in both the shrub and grassland soils after burning. Inorganic and organic N form concentrations were similar in initial shrub litter and grass, but litter had higher concentrations of total and nonhydrolyzable N than those of grass. Shrub litter ash obtained after muffling at 300 C contained higher NH4+-N, aminoacid N, ammonium N, and total and nonhydrolyzable N concentrations than those from grass. An increase of 100 C in the ignition temperature produced clear ashes, rich in mineral N with little concentration of total N and C. The organic N forms affected most by the ignition temperature increase were amino acid N and ammonium N, respectively, particularly in woody litter. The most striking feature was the constituent increase in the percentages of nonhydrolyzable N forms of the vegetation covers on passing from initial to 300 C to 400 C, particularly for the litter and its ashes. These results suggest that the soil mineralizable N pool may be reduced by frequent burning or by more severe burning than observed presently in the Caldenal region.  相似文献   
74.
Summary

Late in the season, a double-labelled solution containing 15N-enriched urea and 68Zn sulphate was painted on the entire leaf area of 15, 1-year-old ‘O’Henry/Nemaguard’ peach trees to quantify N and Zn movement out of leaves following foliar application, and redistribution of these nutrients to new growth in the following Spring. About 47% of the labelled N and only 7% of the labelled Zn painted on the leaf surfaces was recovered in the permanent structure of the trees after leaf fall. Thus, it is concluded that foliar applications of Zn in the Autumn are not very efficient at supplying Zn to peach trees, especially when compared to supplying N as urea sprays in the Autumn. These data raise the possibility that foliar applications of Zn may actually be considered as soil applications, because 90% or more of the foliar-applied Zn may be carried to the orchard floor at the time of leaf fall. Therefore, future research needs to focus on assessing the efficacy of foliar applications for Zn nutrition of fruit trees, and identification of potentially detrimental effects from possible excessive soil accumulation of Zn. Once within the tree, however, labelled Zn was quite mobile and was stored throughout the plant, including in the roots. Of the labelled N and Zn exported from treated leaves prior to leaf fall, a substantial redistribution from storage was evident by 2 weeks after bloom and, by 4 weeks after bloom, 38% and 56% of the labelled N and Zn, respectively, had been redistributed from storage in roots, trunk and 1-year-old shoots to new growth. The biomass of new, above-ground growth tripled between 2 – 4 weeks after bloom and was coincident with a conspicuous influx of both N and Zn from the soil.  相似文献   
75.
Background: Ketamine as continuous rate infusion (CRI) provides analgesia in hospitalized horses. Objective: Determine effects of prolonged CRI of ketamine on gastrointestinal transit time, fecal weight, vital parameters, gastrointestinal borborygmi, and behavior scores in healthy adult horses. Animals: Seven adult Thoroughbred or Thoroughbred cross horses, with permanently implanted gastric cannulae. Methods: Nonblinded trial. Random assignment to 1 of 2 crossover designed treatments. Ketamine (0.55 mg/kg IV over 15 minutes followed by 1.2 mg/kg/h) or lactated Ringer's solution (50 mL IV over 15 minutes followed by 0.15 mL/kg/h) treatments. Two hundred 3 × 5 mm plastic beads administered by nasogastric tube before drug administration. Every 2 hours vital parameters, behavior scores recorded, feces collected and weighed, and beads retrieved. Every 6 hours gastrointestinal borborygmi scores recorded. Study terminated upon retrieval of 180 beads (minimum 34 hours) or maximum 96 hours. Nontransit time data analyzed between hours 0 and 34. Results: No significant (P < .05) differences detected between treatments in vital signs or gastrointestinal borborygmi. Significant (P = .002) increase in behavior score during ketamine infusion (0.381) from hours 24–34 compared with placebo (0). Ketamine caused significant delay in passage of 25, 50, and 75% of beads (ketamine = 30.6 ± 5.3, 41.4 ± 8.4, 65.3 ± 13.5 hours versus placebo = 26.8 ± 7.9, 34.3 ± 11.1, 45.8 ± 19.4 hours), and significant (P < .05) decrease in fecal weight from hours 22 (12.6 ± 3.2 versus 14.5 ± 3.8 kg) through 34 (18.5 ± 3.9 versus 12.8 ± 6.4 kg) of infusion. Conclusions and Clinical Importance: Ketamine CRI delayed gastrointestinal transit time in healthy horses without effect on vital parameters.  相似文献   
76.
Background: Plasma α‐melanocyte‐stimulating hormone (α‐MSH) and adrenocorticotropin (ACTH) concentrations in horses vary with season, confounding diagnostic testing for pituitary pars intermedia dysfunction (PPID). Hypothesis: The goals of this study were to determine whether seasonal variation in plasma α‐MSH and ACTH concentrations in horses is influenced by geographic location, breed, or PPID. Animals: Healthy light breed horses residing in Florida, Massachusetts, and Finland (n = 12 per group); healthy Morgan horses (n = 13); healthy ponies (n = 9) and horses with PPID (n = 8). Methods: Monthly plasma α‐MSH and ACTH concentrations were measured by radioimmunoassay. Nonlinear regression analysis was used to estimate the time of peak hormone concentrations. Mean hormone concentrations in fall and nonfall months were compared. Results: The fall peak plasma α‐MSH concentration occurred earlier in horses residing at more northern locations. Mean seasonal α‐MSH concentrations were similar in all healthy groups at all locations, but in the fall, plasma ACTH concentrations were higher in horses living in more southern locations. Plasma ACTH but not α‐MSH concentrations were higher in Morgan horses compared with light breed horses from the same location. Hormone concentrations of ponies did not differ from those of horses during either season. Concentrations of both hormones were high in the fall compared with the spring in horses with PPID. Conclusions and Clinical Importance: These findings suggest geographic location of residence and breed may affect the onset, amplitude, or both of the seasonal peak of pars intermedia (PI) hormones and should be considered when performing diagnostic testing for PPID. Horses with PPID maintain seasonal regulation of PI hormone output.  相似文献   
77.
The aim of the current study was to determine the possible effects of progestagen oestrous synchronization on vascular endothelial growth factor (VEGF) expression during sheep luteogenesis and the peri‐implantation period and the relationship with luteal function. At days 9, 11, 13, 15, 17 and 21 of pregnancy, the ovaries from 30 progestagen treated and 30 ewes cycling after cloprostenol injection were evaluated by ultrasonography and, thereafter, collected and processed for immunohistochemical evaluation of VEGF; blood samples were drawn for evaluating plasma progesterone. The progestagen‐treated group showed smaller corpora lutea than cloprostenol‐treated and lower progesterone secretion. The expression of VEGF in the luteal cells increased with time in the cloprostenol group, but not in the progestagen‐treated group, which even showed a decrease between days 11 and 13. In progestagen‐treated sheep, VEGF expression in granulosa‐derived parenchymal lobule capillaries was correlated with the size of the luteal tissue, larger corpora lutea had higher expression, and tended to have a higher progesterone secretion. In conclusion, the current study indicates the existence of deleterious effects from exogenous progestagen treatments on progesterone secretion from induced corpora lutea, which correlate with alterations in the expression of VEGF in the luteal tissue and, this, presumably in the processes of neoangiogenesis and luteogenesis.  相似文献   
78.
The aim of the present study was to evaluate the effects of different medium replacement intervals on the viability, antral cavity formation, growth and in vitro maturation (IVM) of oocytes from caprine and ovine pre‐antral follicles. Pre‐antral ovarian follicles (≥150 μm) were isolated from the ovarian cortex of goats and sheep and were individually cultured for 24 days using two different medium replacement intervals [2 days (T1) or 6 days (T2)]. Follicle development was evaluated on the basis of antral cavity formation, increases in follicular diameter and the presence of healthy cumulus oocyte complexes and fully grown oocytes. For caprine species, results showed a higher percentage (p < 0.05) of viable follicles in T1 than T2 from day 6 until the end of the culture. In addition, when comparing both treatments after the same culture duration, the rate of antrum formation was significantly higher in T1 than in T2 from day 12 onwards. Yet, in ovines, when both treatments were compared on day 24 of the culture, there were more viable follicles in T2 than in T1 (p < 0.05). In the caprine species, percentages of fully grown oocytes (≥110 μm) acceptable for IVM after 24 days of culture were significantly higher in normal follicles cultured in T1 (30.0%) than in T2 (6.7%; p < 0.05). On the other hand, in ovines, at the end of the culture, the percentage of oocytes destined for IVM was higher in T2 than in T1 (23.5% vs 2.9%; p < 0.05). In conclusion, under the same conditions, the frequency of medium replacement significantly affected the in vitro development of caprine and ovine pre‐antral follicles. To improve the efficiency of the culture system, the medium must be replaced every 2 and 6 days for goat and sheep pre‐antral follicles, respectively.  相似文献   
79.
This paper reviews recent progress in the development of syndromic surveillance systems for veterinary medicine. Peer-reviewed and grey literature were searched in order to identify surveillance systems that explicitly address outbreak detection based on systematic monitoring of animal population data, in any phase of implementation. The review found that developments in veterinary syndromic surveillance are focused not only on animal health, but also on the use of animals as sentinels for public health, representing a further step towards One Medicine. The main sources of information are clinical data from practitioners and laboratory data, but a number of other sources are being explored. Due to limitations inherent in the way data on animal health is collected, the development of veterinary syndromic surveillance initially focused on animal health data collection strategies, analyzing historical data for their potential to support systematic monitoring, or solving problems of data classification and integration. Systems based on passive notification or data transfers are now dealing with sustainability issues. Given the ongoing barriers in availability of data, diagnostic laboratories appear to provide the most readily available data sources for syndromic surveillance in animal health. As the bottlenecks around data source availability are overcome, the next challenge is consolidating data standards for data classification, promoting the integration of different animal health surveillance systems, and also the integration to public health surveillance. Moreover, the outputs of systems for systematic monitoring of animal health data must be directly connected to real-time decision support systems which are increasingly being used for disease management and control.  相似文献   
80.
The effect of two titanium (IV) compounds, titanium ascorbate and titanium chloride, on some enzymatic activities, such as catalase, peroxidase, lipoxygenase and nitrate reductase in seeds, embryos, and seedlings and adult plants of red pepper (Capsicum annuum L.), was studied. A stimulatory effect of titanium was observed for every iron‐depending enzyme studied at all developing stages as well as for nitrate reductase but only for whole plants. This occurs because Ti+3/Ti+4 catalizes the activity of iron and enhances iron‐dependent enzymes.  相似文献   
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