新疆甜菜高产高效益优化农艺措施     

聂文魁  王燕飞  杨洪泽  刘华君  刘军  高卫时  张立明  热西提 《中国糖料》2002,(4):18-20

采用3因素5水平二次通用旋转回归试验设计方法,选取密度、种肥量、追肥量3项对甜菜高产、高效益起关键作用的农艺措施进行量化分析,提出直播方式下的高产、高效益模型,获得了60t/hm2以上和净收益7000元/hm2以上的优化农艺措施组合方案为:密度8.42～8.34万株/hm2,种肥222～248.4kg/hm2,追肥383～408.6kg/hm2。  相似文献   

The physiological response of Atlantic salmon, Salmo salar L., to a single experimental challenge with sea lice, Lepeophtheirus salmonis   总被引：1，自引：0，他引：1  

J M Bowers  A Mustafa  D J Speare  G A Conboy  M Brimacombe  D E Sims  J F Burka 《Journal of fish diseases》2000,23(3):165-172

The sea louse, Lepeophtheirus salmonis , is an ectoparasitic copepod of Atlantic salmon, Salmo salar L., capable of causing severe damage. This study was conducted to examine the physiological response of salmon to the stress of sea lice infestation. Smoltified salmon were acclimatized in 30‰ saltwater and exposed to high levels of lice infestation. The number of copepods per fish ranged from 15 to 285, with a mean of 106. The infested salmon were sampled six times over the 29-d experimental duration and examined for alterations in the primary and secondary stress indicators, including plasma concentrations of cortisol, glucose, electrolytes, thyroid hormones T3 and T4, as well as the haematocrit level. The results were examined for correlations between the stress indicators, the number of copepods per fish and the life stage of the copepods. The presence of L. salmonis elevated stress indicators in relation to the specific sea lice stage. By day 21, both cortisol (mean 63.1 nmol L−1 controls: 179.8 nmol L−1 for parasitized) and glucose (mean 3.545 mmol L−1 controls: 4.567 mmol L−1 for parasitized) levels were significantly increased due to the presence of the lice. This was believed to be a direct result of the sea lice development into the larger life stages, thus increasing the level of host damage.  相似文献   

βbT-mannosidosis in Salers calves in Australia     

PJ HEALY  GN KIDD  RE REUTE  C BUNCE  I HOSIE  T STAPLETON 《Australian veterinary journal》1992,69(6):145-145

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A comparison of two intramuscular doses of xylazine–ketamine combination and tolazoline reversal in llamas     

WR  DuBois  TM Prado  JCH Ko  RE Mandsager  GL Morgan 《Veterinary anaesthesia and analgesia》2003,30(2):114-115

The anesthetic and cardiorespiratory effects of a low dose (LD, 0.4 mg kg^?1 xylazine and 4 mg kg^?1 ketamine) and a high dose (HD, 0.8 mg kg^?1 xylazine and 8 mg kg^?1 ketamine) of IM xylazine–ketamine combination were compared in a randomized cross‐over study using six castrated male llamas. Three llamas in each dosage group (LDT, HDT) were assigned to receive IM tolazoline (2 mg kg^?1) after 30 minutes of recumbency. All IM injections were given in the semitendinosus or semimembranosus muscles. Pulse, respiratory rate, and indirect arterial blood pressure were recorded every 10 minutes, and hemoglobin oxygen saturation was recorded every 5 minutes during lateral recumbency. Samples for arterial blood gas analysis were collected 5 minutes following recumbency and every 30 minutes thereafter. Base‐to‐apex ECG was monitored continuously. Analgesia was evaluated every 5 minutes by both a 30 minutes skin pinch and a needle prick of the toe. Most llamas breathed room air throughout anesthesia. Two llamas that developed severe hypoxemia (SpO₂ < 75%) received 5 minutes of nasal oxygen insufflation, but were maintained on room air for the rest of the anesthetic period. anova for repeated measures and Tukey's test were used to analyze cardiorespiratory data. Fischer's exact test was used to compare the ability of each to provide >30 minutes of lateral recumbency and analgesia. A p‐value < 0.05 was considered significant. Both dosages provided reasonably rapid induction following injection (LD: 10.8 ± 6.3 minutes; HD: 5.0 ± 1.1 minutes; p = 0.07). Duration of lateral recumbency and analgesia were 34.7 ± 6.7 and 27.3 ± 4.6 minutes, respectively, in the LDT llamas. None of the three remaining LD llamas remained in lateral recumbency for longer than 12 minutes. Duration of lateral recumbency and analgesia were 87.3 ± 18.5 and 67.7 ± 16.0 minutes, respectively, for the HD llamas that did not receive tolazoline. The HDT llamas were recumbent for a significantly shorter time (43.3 ± 0.6 minutes; p = 0.05). The ability to provide >30 minutes of recumbency and analgesia was better in the HD group (6/6) than in the LD group (2/6) (p = 0.03). No differences between dosages were seen in pulse rate, respiratory rate, or arterial pressures. No ECG abnormalities were seen. Transient hypoxemia was seen in the first 10 minutes of lateral recumbency in the HD group by both hemoglobin oxygen saturation (84 ± 9.5%) and by blood gas PaO₂ (44.5 ± 5.8 mm Hg). It was concluded that the HD provided more consistent results than the LD, but induced transient hypoxemia. Tolazoline shortened the recovery time in llamas receiving the HD.  相似文献   

A comparative physiological and behavioral study of freeze and hot-iron branding using dairy cows.     

D C Lay  T H Friend  C L Bowers  K K Grissom  O C Jenkins 《Journal of animal science》1992,70(4):1121-1125

A public debate has recently arisen, largely surrounding the issue of pain, over whether freeze or hot-iron branding should be the preferred method of permanently identifying cattle. This study addressed that question by quantifying the following accepted measures of distress and pain over a 25-min sampling period: elevated heart rate, concentrations of cortisol, epinephrine, and norepinephrine, and escape-avoidance reactions and vocalizations. Twenty-four dairy cows (15 Holsteins and 9 Jerseys) were assigned to one of three treatments: freeze-branded (F), hot-iron-branded (H), or sham-branded (S), in which a room-temperature brander was applied. Plasma epinephrine and norepinephrine concentrations showed no discernible trends. Plasma cortisol concentrations were elevated in the F and H cows from 5.5 min to 25.5 min postbranding (P = .04). Heart rate, analyzed as a proportion of the prebranding mean, showed that H cows had a greater, more acute, response than did F cows (P = .04), which exhibited a more prolonged response (P = .07). No cows vocalized during branding; however, H cows had a greater escape-avoidance reaction toward branding than did the F and S cows. Both methods of branding produced elevated heart rates and cortisol concentrations indicative of pain sensations. Because the cows exhibited a greater escape-avoidance reaction and heart rate proportions to hot-iron branding, freeze banding would be preferable to hot-iron branding when feasible.  相似文献   

三北防护林新无性系-美青杂种系列引进与苗期选择     

宋保民  高志华  王明智  刘玉军  任祥成  杨自湘 《防护林科技》2001,(3):13-15

１９９８年春从中国林科院的实验点甘肃临夏回族自治州林科所引入北方型美洲黑杨（Ｐ．ｄｅｌｔｏｉｄｅｓ）×青杨（Ｐ．ｃａｔｈａｙａｎａ）杂种无性系　１３７个,扦插在内蒙奈曼旗兴隆沼林场二分场。１９９８年秋选出　１３个无性系,加入我地区新近确定的推广无性系──白城　４１作对照,１９９９年建无性系测试圃,２０００年春平茬,２０００年秋对这　１３个无性系生长量和抗性的调查与评价,以白城　４１为对照,初步选择出　１０个无性系,高生长较对照大　３０％以上的有　４个,２０％以上　５个;径生长大　５０％的　３个,３０％以上　２个,２０％以上　４个;所有无性系的抗锈病情况都好于对照。为丰富三北地区营造杨树农田防护林品种和改善三北地区杨树品种单一的问题有望选出新无性系。  相似文献   

Genetic and Morphological Diversity of Temperate and Tropical Isolates of Phytophthora capsici     

Bowers JH  Martin FN  Tooley PW  Luz ED 《Phytopathology》2007,97(4):492-503

ABSTRACT Phytophthora capsici is a diverse species causing disease on a broad range of both temperate and tropical plants. In this study, we used cultural characteristics, amplified fragment length polymorphism (AFLP), and DNA sequence analyses of the ribosomal internal transcribed spacer (ITS) region and mitochondrial cytochrome oxidase II (cox II) genes to characterize temperate and tropical isolates from a wide range of host species. All but one temperate isolate grew at 35 degrees C, while all tropical isolates did not. All but two tropical isolates formed chlamydospores, while temperate isolates did not. There was strong bootstrap support for separation of temperate and tropical isolates using AFLP analysis; however, the temperate isolates appeared as a subgroup within the observed variation of the tropical isolates. The majority of temperate isolates clustered within a single clade with low variation regardless of host or geographical origin, while the tropical isolates were more variable and grouped into three distinct clades. Two clades of tropical isolates grouped together and were affiliated closely with the temperate isolates, while the third tropical clade was more distantly related. Phylogenetic analysis of the ITS regions resulted in similar groupings and variation within and between the temperate and tropical isolates as with the AFLP results. Sequence divergence among isolates and clades was low, with more variation within the tropical isolates than within the temperate isolates. Analysis of other species revealed shorter branch lengths separating temperate and tropical isolates than were observed in comparisons among other phylogenetically closely related species in the genus. Analysis of cox II sequence data was less clear. Although the temperate and tropical isolates grouped together apart from other species, there was no bootstrap support for separating these isolates. Restriction fragment length polymorphism (RFLP) analysis of the ITS regions separated the temperate and tropical isolates, as in the AFLP and ITS phylogenetic analyses. However, RFLP analysis of the cox I and II gene cluster did not distinguish between temperate and tropical isolates. The differences in grouping of isolates in these two RFLP studies should be helpful in identifying isolate subgroups. Our data do not fully clarify whether or not temperate and tropical isolates should be separated into different species. The available worldwide data are incomplete and the full range of variation in the species is not yet known. We suggest refraining from using the epithet P. tropicalis until more data are available.  相似文献   

In vivo administration of acepromazine or promethazine to horse decreases the reactive oxygen species production response of subsequently isolated neutrophils to stimulation with phorbol myristate acetate     

F. PÉTERS  T. FRANCK  M. PEQUITO  G. de la REBIÈRE  S. GRULKE  A. SALCCICIA  D. VERWILGHEN  L. CHIAVACCINI  G. DEBY-DUPONT  & D. SERTEYN 《Journal of veterinary pharmacology and therapeutics》2009,32(6):541-547

The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro . In this study the inhibition of the production of reactive oxygen species (ROS) by neutrophils was studied in two groups of horses, which received a dose of 0.1 mg/kg of either acepromazine or promethazine intravenously. Blood samples were collected before (T0) and 0.5, 1, 3 and 5 h after drug administration. The chemiluminescence (CML) response of neutrophils was measured ex vivo in the presence of luminol for a period of 10 min and the maximum CML value (peak value) recorded. There was a significant inhibition of the ROS production in the acepromazine treated group (49% inhibition) at 5 h after administration and in the promethazine group (24% inhibition) at 3 h after administration ( P  < 0.05 vs. T0). These findings are of therapeutic relevance in the use of phenothiazines in equine patients with inflammatory diseases where neutrophil activation and ROS production are implicated.  相似文献   

Interaction of saddle girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses     

Bowers J  Slocombe RF  Sides RH  Bayly WM  Kingston JK 《Australian veterinary journal》2005,83(1-2):62-67

OBJECTIVE: To determine the effect of girth construction and tension on respiratory mechanics and gas exchange during supramaximal treadmill exercise in horses. METHODS: Six healthy detrained Thoroughbred horses were exercised on a treadmill inclined at 10% at 110% VO2max. Horses were instrumented for respiratory mechanics and gas exchange studies, and data were recorded during incremental exercise tests. The animals were exercised for 2 min at 40% VO2max, and samples and measurements were collected at 1 min 45 sec. After 2 min, speed was increased to that estimated at 110% VO2max and data was collected at 45 sec, 90 sec and every 30 sec thereafter at this speed until the horses fatigued. Horses were run on three occasions with the same racing saddle and saddle packing but using two different girths, either an elastic girth (EG) or a standard canvas girth (SCG) which is nonelastic. A run with 5 kg tension applied to a standard canvas girth was the control for each horse, with additional runs at 15 kg using either the standard canvas girth or using the elastic girth. The runs were randomised and tensions applied were measured at end exhalation whilst at rest. RESULTS: Increasing girth tension was not associated with changes in respiratory mechanical or gas exchange properties. Although girths tightened to 15 kg tension had short run to fatigue times this was not found to be significantly different to girths set at 5 kg resting tension. Girth tensions declined at end exhalation in horses nearing fatigue. CONCLUSIONS: Loss in performance associated with high girth tensions is not due to alteration of respiratory mechanics. Loss in performance may be related to inspiratory muscles working at suboptimal lengths due to thoracic compression or compression of musculature around the chest. However, these changes are not reflected in altered respiratory mechanical or gas exchange properties measured during tidal breathing during supramaximal exercise. Other factors may hasten the onset of fatigue when horses exercise with tight girths and further studies are required to determine why excessively tight girths affect performance.  相似文献   

Comparison of girth materials, girth tensions and their effects on performance in racehorses     

Bowers J  Slocombe RF 《Australian veterinary journal》2005,83(1-2):68-74

OBJECTIVE: To compare the effect of girth materials and commonly used girth tensions on athletic performance of race-horses and to test the length tension properties of commercially available girths. PROCEDURE: Seven horses were exercised at speeds to produce 95% of maximal heart rates on 15 occasions using a randomised block design, and girthed with 5 different girths at 3 nominal tensions of 6, 12 or 18 kg. The girths used were a standard elastic race girth, an 'American' elastic race girth, an elastic race girth twice the normal width, a standard canvas race girth and a canvas race girth at twice the normal width. Tension in the girth was recorded continuously using an in-line load cell connected to a physiograph. Horses ran to fatigue on a treadmill inclined at 10% slope. Tensions were measured at peak inhalation (T/inh) and exhalation (T/exh), recorded at rest (rest) and during exercise (ex). An analysis of variance was used to compare the mean run to fatigue times (RTFT) between girth types and tensions, multiple pair-wise comparisons were then carried out using Tukey's test where significant differences were found. The length-tension relationships of five commercially available girths for training and racing of Thoroughbred racehorses were studied by the application of standardized weights in series to multiple samples of each type of girth. Measurements were taken in a controlled environment and analysis of variance was used to compare the means for length-tension of each girth type. RESULTS: The elastic and the 'American' elastic girths produced significantly longer RTFT when compared to the standard canvas girth (P = 0.01 and P = 0.001 respectively). Also girths tensioned at Texhrest 6 kg and Texhrest 12 kg produced significantly longer RTFT than when girthed at Texhrest 18 kg (P = 0.03 and P = 0.08 respectively). There were significant differences between the commercially available girth types at each tension (P < 0.05), but differences were not significant between girths of the same type. Girths with an elastic component reached their peak for maximum extension at 14.5 kg and thereafter their extension declined. CONCLUSION: The type of girth and the tension at which it is applied affects athletic performance. Lower girth tensions and the use of elastic materials in the girth would appear to optimise performance. However according to this study and our previous study, none of the commercially available girths studied would adequately protect against the potentially detrimental effects of overtightening on athletic performance.  相似文献