营养液对雾化栽培不同品种马铃薯生长的影响

用3种营养液MS,MX和MY对雾化栽培室3种不同品种马铃薯进行培养处理。结果表明,营养液对全株鲜重、全叶鲜重、叶面积系数、叶绿素含量、茎长、根系鲜重的影响达到显著或极显著水平,对茎鲜重、茎粗、根系体积影响不显著;根系生长对全株鲜重、全叶鲜重、茎鲜重均达到显著相关或根显著相关;对叶绿素含量为负相关;植株全N％、全P％、全K％皆随着生长的进行而逐步减小;最佳营养液配方为MX。     

The influence of body mass and thoracic dimensions on arterial oxygenation in anaesthetized horses and ponies

ObjectiveTo examine the relationship between body mass and thoracic dimensions on arterial oxygen tensions (PaO₂) in anaesthetized horses and ponies positioned in dorsal recumbency.Study designProspective clinical study.AnimalsThirty six client-owned horses and ponies, mean [±SD (range)] age 8.1 ± 4.8 (1.5–20) years and mean body mass 467 ± 115 (203–656) kg.MethodsBefore general anaesthesia, food and water were withheld for 12 and 1 hours respectively. Body mass (kg), height at the withers (H), thoracic circumference (C), thoracic depth (length between dorsal spinous process and sternum; D), thoracic width (between point of shoulders; W), and thoracic diagonal length (point of shoulder to last rib; L) were measured. Pre-anaesthetic medication was with intravenous (IV) romifidine (0.1 mg kg⁻¹). Anaesthesia was induced with an IV ketamine (2.2 mg kg⁻¹) and diazepam (0.05 mg kg⁻¹) combination and maintained with halothane in 1:1 oxygen:nitrous oxide (N₂O) mixture. Animals were positioned in dorsal recumbency and allowed to breathe spontaneously. Nitrous oxide was discontinued after 10 minutes, and arterial blood samples obtained and analysed for gas tensions at 15, 30 and 60 minutes after connection to the anaesthetic breathing circuit. Data were analysed using anova and Pearson's correlation co-efficient.ResultsThe height per unit body mass (H kg⁻¹) and thoracic circumference per unit body mass (C kg⁻¹) correlated strongly (r = 0.85, p < 0.001 and r = 0.82, p < 0.001 respectively) with arterial oxygen tensions (PaO₂) at 15 minutes.ConclusionsThere is a strong positive correlation between H kg⁻¹ and C kg⁻¹ and PaO₂ after 15 minutes of anaesthesia in halothane-anaesthetized horses positioned in dorsal recumbency.Clinical relevanceReadily obtained linear measurements (height and thoracic circumference) and body mass may be used to predict the ability of horses to oxygenate during anaesthesia.     

Gastrointestinal ultrasonography in normal adult ponies

The objective of this study was to determine the characteristics based on ultrasonographic examination of the stomach, duodenum, jejunum, cecum, and peritoneal fluid in normal adult ponies. Abdominal ultrasonographic examination was performed in nine unsedated standing ponies. The duodenum was examined at three sites and the jejunum in 12 regions. Wall thickness, contractility, distention, and luminal contents were recorded. Stomach wall thickness and location, cecal wall thickness, and peritoneal fluid location and character were recorded. Statistical analysis was performed. Wall thicknesses (in cm) were 0.431 +/- 0.069 for the stomach, 0.188 +/- 0.033 for the duodenum (at all sites), 0.195 +/- 0.031 for the jejunum (at all regions), and 0.179 +/- 0.031 for the cecum. Duodenal contractions per minute were 3.78 +/- 1.10. The stomach spanned 5.14 +/- 0.9 intercostal spaces, with the 8th intercostal space being the most cranial and the 15th intercostal space being the most caudal space through which the stomach was identified. It was possible to identify the jejunum in all ponies dorsal to the left dorsal colon and from the ventral abdominal wall. Peritoneal fluid was identified in six ponies. Peritoneal fluid was usually seen transiently and most commonly in the ventral aspect of the abdominal cavity or around the duodenum. Overall, the ponie's abdominal ultrasonographic examinations revealed wall thicknesses that were less than the published normal ranges for horses. It appears that ponies may have increased duodenal contractility than horses and that the conformation of ponies may change the locations for imaging the stomach.     

南亚小型马近缘关系的研究

通过血液蛋白质多态型的遗传学分析和历史学的考证，认为南亚小型马与中国西南马有着近缘关系。西南丝绸之路和海上丝绸之路的开通，为中国西南马的扩延创造了必要的条件。尼泊尔小型马的来源与藏马有关，但它也可能混有中国西南马的血液。     

Effects of a constant‐rate infusion of dexmedetomidine on the minimal alveolar concentration of sevoflurane in ponies

Reasons for performing study: Dexmedetomidine has been administered in the equine as a constant‐rate infusion (CRI) during inhalation anaesthesia, preserving optimal cardiopulmonary function with calm and coordinated recoveries. Inhalant anaesthetic sparing effects have been demonstrated in other species, but not in horses. Objectives: To determine the effects of a CRI of dexmedetomidine on the minimal alveolar concentration (MAC) of sevoflurane in ponies. Methods: Six healthy adult ponies were involved in this prospective, randomised, crossover, blinded, experimental study. Each pony was anaesthetised twice (3 weeks washout period). After induction with sevoflurane in oxygen (via nasotracheal tube), the ponies were positioned on a surgical table (T0), and anaesthesia was maintained with sevoflurane (expired sevoflurane fraction 2.5%) in 55% oxygen. The ponies were randomly allocated to treatment D (dexmedetomidine 3.5 µg/kg bwt i.v. [T10–T15] followed by a CRI of dexmedetomidine at 1.75 µg/kg bwt/h) or treatment S (bolus and CRI of saline at the same volume and rate as treatment D). After T60, MAC determination, using a classic bracketing technique, was initiated. Stimuli consisted of constant‐current electrical stimuli at the skin of the lateral pastern region. Triplicate MAC estimations were obtained and averaged in each pony. Monitoring included pulse oximetry, electrocardiography, anaesthetic gas monitoring, arterial blood pressure measurement and arterial blood gases. Normocapnia was maintained by mechanical ventilation. Analysis of variance (treatment and period as fixed factors) was used to detect differences between treatments (α= 0.05). Results: An intravenous (i.v.) dexmedetomidine CRI decreased mean ± s.d. sevoflurane MAC from 2.42 ± 0.55 to 1.07 ± 0.21% (mean MAC reduction 53 ± 15%). Conclusions and potential relevance: A dexmedetomidine CRI at the reported dose significantly reduces the MAC of sevoflurane.     

Length of winter coat in horses depending on husbandry conditions

This paper analyzes changes in the length of coat on selected body areas in horses and ponies kept under different husbandry (stable) conditions during the winter‐spring period. The study included 12 Ma?polski geldings and 12 geldings of Felin ponies aged 10–15 years. Horses were kept in two stables (six horses and six ponies in each stable). The type of performance, husbandry conditions and feeding of the studied animals were comparable. As of December 1, samples of hair coat from the scapula, sternum, back and abdomen areas of both body sides were collected seven times. The lengths of 20 randomly selected hair fibers were measured. Daily measurements of air temperature in the stables were also taken. An analysis of variance (ANOVA) was performed using the following factors: the body part from where the coat was sampled, the subsequent examination and the stable as well as the interaction between these factors. The significance of differences between means was determined with a t‐Tukey test. The relations between air temperature in the stable and hair length were calculated using Pearson's correlation. It was found that air temperature in the stable impacts the length of winter coat in horses and ponies. The effect of this factor is more pronounced in ponies; as in the stables with lower temperatures it produces a longer hair coat which is more evenly distributed over the body in comparison with horses. Keeping horses and ponies in stables with a low air temperature accelerates coat shedding by approximately 25 days. Coat shedding begins from the scapula area.     

Investigation of the EEG effects of intravenous lidocaine during halothane anaesthesia in ponies

OBJECTIVE: To record the electroencephalographic changes during castration in ponies anaesthetized with halothane and given intravenous (IV) lidocaine by infusion. The hypothesis tested was that in ponies, IV lidocaine is antinociceptive and would therefore obtund EEG changes during castration. ANIMALS: Ten Welsh mountain ponies referred to the Department of Clinical Veterinary Medicine, Cambridge for castration under general anaesthesia. MATERIALS AND METHODS: Following pre-anaesthetic medication with intramuscular acepromazine (0.02 mg kg(-1)) anaesthesia was induced with IV guaiphenesin (60 mg kg(-1)) and thiopental (9 mg kg(-1)) and maintained with halothane at an end-tidal concentration (FE'HAL) of 1.2%. A constant rate infusion of IV lidocaine (100 microg kg(-1) minute(-1)) was administered throughout anaesthesia. The electroencephalogram (EEG) was recorded continuously using subcutaneous needle electrodes. All animals were castrated using a closed technique. The raw EEG signal was analysed after completion of each investigation, and the mean values of EEG variables (median frequency, spectral edge frequency, total amplitude) recorded during a baseline period (before surgery began) and the removal of each testicle were compared using anova for repeated measures. RESULTS: Spectral edge frequency (SEF) 95% decreased during removal of the second testicle compared with baseline recordings. No other significant EEG changes during castration were measured. CONCLUSIONS: Lidocaine obtunded the EEG changes identified during castration in a previous control study, providing indirect evidence that lidocaine administered peri-operatively was antinociceptive and contributed to anaesthesia during castration. CLINICAL RELEVANCE: The antinociceptive effect of lidocaine combined with its minimal cardiovascular effects indicate a potential use for systemic lidocaine in clinical anaesthetic techniques.     

Miniature Ponies: Similarities and Differences from Larger Breeds in Follicles and Hormones during the Estrous Cycle

Recent direct and indirect comparisons between Miniature ponies and larger breeds during the estrous cycle are reviewed. There were many similarities but profound differences in the Miniature ponies, including (1) greatly reduced follicle population within each of several follicle diameter classifications, (2) smaller number of growing follicles 10 mm or larger per ovulatory wave (1.5 ± 0.3 vs. 5.8 ± 0.9 in Miniature ponies vs. horses), (3) lower incidence of detectable diameter deviation, (4) ovulatory luteinizing hormone (LH) surge that involved three distinct phases, and (5) LH increase and decrease during the early luteal phase that followed the ovulatory surge. Diameter of the preovulatory follicle was smaller in Miniature ponies than in horses, but the difference was slight (38 vs. 44 mm; 14%) when compared with an extreme difference in median body weight (123 vs. 465 kg; 74%). The great reduction in follicle population with only a slight reduction in diameter of the preovulatory follicle in Miniature ponies compared with larger breeds is an important consideration during both experimental and clinical examinations.