Decreased tear production associated with general anesthesia in the horse

Schirmer I tear tests were conducted on 14 horses. The test was performed before and after IV administration of xylazine hydrochloride, during maintenance anesthesia with halothane in oxygen, and 3 hours after discontinuation of anesthesia. Xylazine hydrochloride did not decrease tear production from the mean base-line value of 23.94 +/- 5.23 mm/min after its IV administration. Tear production was decreased to mean values of 15.57 +/- 4.29 mm/min at 30 minutes and 13.84 +/- 4.25 mm/min at 60 minutes during the maintenance of halothane anesthesia. Three hours after anesthesia was discontinued, tear production returned to a mean value of 22.58 +/- 4.12 mm/min.     

体外法评定南方4种经济作物副产品及3种暖季型牧草的营养价值研究

旨在评价南方4种经济作物副产品及3种暖季型牧草的营养价值,开发新的饲料资源。试验采用单因素设计,通过体外产气法对14种样品进行评定,主要测定096 h的产气量,24 h发酵液的挥发性脂肪酸产量、氨态氮、微生物蛋白浓度、pH值以及体外干物质消化率。结果表明:木薯叶的粗蛋白和粗脂肪含量显著高于其他经济作物副产品及牧草(P0.05);产气量方面从大到小依次,经济作物副产品是柚子皮木薯淀粉渣木薯叶薏米秸秆,而牧草则是象草(印尼引进)皇竹草高丹草;柚子皮和木薯淀粉渣的理论产气量显著高于其他经济作物副产品及牧草;柚子皮的乙酸、丙酸、异戊酸、戊酸及总挥发酸显著大于其他经济作物副产品及牧草(P0.05);氨态氮含量最高的是象草(印尼引进),且与其他经济作物副产品及牧草相比差异显著(P0.05);pH值和微生物蛋白无显著差异(P0.05)。本试验选用的南方经济作物副产品及牧草的粗蛋白与粗脂肪含量适宜,微生物活性高,易消化,能够提供反刍动物所需要的能量,适合作为反刍动物的粗饲料来源。且经济作物副产品中柚子皮的营养价值最高,其次是木薯淀粉渣、木薯叶和薏米秸秆;而牧草中依次为象草(印尼引进)、皇竹草、高丹草。     

Some metabolic and hormonal changes associated with general anaesthesia and surgery in the horse

Three different anaesthetic techniques were studied in normal, healthy Thoroughbred or Thoroughbred type horses. These were (a) acepromazine, thiopentone and suxamethonium; (b) acepromazine, glyceryl guaiacolate and a 'half-dose' of thiopentone; and (c) xylazine and ketamine. Anaesthesia was maintained with halothane vaporized in oxygen and nitrous oxide. All horses underwent either laryngeal or body surface surgery. Heart rate, packed cell volume, blood glucose and lactate, plasma non-esterified fatty acids, insulin and cortisol were measured before, during and after surgery. The greatest metabolic and hormonal changes occurred immediately after anaesthetic induction and were different in each group. The combination of acepromazine, glyceryl guaiacolate and a 'half-dose' of thiopentone was associated with the least change in the physiological and metabolic variables measured.     

Prevalence of equine herpesvirus types 2 and 5 in horse populations by using type-specific PCR assays

Equineherpesvirustypes 2 and 5 (EHV-2andEHV-5)have a rather unclearpathogenicity and distribution within the equid population. In order to gain more information on the prevalence of these two viruses, type-specific PCR assays were developed to detect viral DNA in nasal specimens and in peripheral blood leukocytes (PBLs) of adult horses and foals from various regions of Europe, i.e. Sweden, Hungary and the United Kingdom. In adult horses, the prevalence of EHV-2 in PBLs was up to 68% in Sweden and 71% in the United Kingdom. EHV-2 DNA was detected in the PBLs from all the foals tested in all countries and most (93%) of the nasal specimens also yielded positive results. The prevalence of EHV-5 DNA in the PBLs of foals in Hungary was 15 and 24% in adult horses in the United Kingdom. This observation was among the very few reports of the presence of EHV-5 in horses. In summary, the specific PCR assays revealed important data on the occurrence and distribution of EHV-2 and EHV-5 in large horse populations. The findings indicated that infection with EHV-5 occurred later than EHV-2 in foals. This study may contribute to a better understanding of the etiological role of these gammaherpesviruses in equine diseases.     

Development of a single-round and multiplex PCR method for the simultaneous detection of Babesia caballi and Babesia equi in horse blood

With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-round and multiplex PCR method offers a simple tool for the differential diagnosis of B. caballi and B. equi infections in routine diagnostic laboratory settings as well as in epidemiological studies.     

Measurement of certain plasma and serum enzymes in the horse

The study of the use of serum or plasma enzymes in the horse is reviewed.

Analyses of such enzymes in the horse have been performed mainly for the detection and monitoring of abnormalities which affect liver tissue and muscle fibres. Examples of muscle disorders are post-anaesthetic forelimb lameness and the clinical myopathy syndrome which varies from a mild “tying-up” to a severe paralytic myoglobinuria (EPM). Measurements have also been made during training periods in an endeavour to assess the effects of exercise on muscle tissue. One of the benefits of such a study could be the prediction of the period of optimum performance.

The two enzymes most frequently used for. muscle studies have been glutamic oxaloacetic transaminase (GOT) (aspartate aminotransferase) and creatine Phosphokinase (CPK). The former, while not muscle specific and less sensitive than CPK to small amounts of muscle tissue damage, has a slower clearance rate from blood than CPK. Determination of both enzymes together has some advantages in determining the prognosis in cases with severe muscle damage. Later studies have included aldolase, which is a sensitive skeletal muscle specific enzyme and lactic dehydrogenase (LDH), which is widely distributed by various tissues at high concentrations. Most of the work on serum LDH has centred on its separation into 5 isoenzymes, and on relating the isoenzyme pattern to the various tissues. More studies on this, and on the isoenzymes of CPK, are required.

Apart from cost, one of the major problems in enzymology has been lack of a standardisation of laboratory methods which has led to a wide range of published normal values. Reliance on such values may lead to difficulties in interpretation, particularly when serum changes are small.     

Effect of sedation with detomidine and butorphanol on pulmonary gas exchange in the horse

Background

Sedation with α₂-agonists in the horse is reported to be accompanied by impairment of arterial oxygenation. The present study was undertaken to investigate pulmonary gas exchange using the Multiple Inert Gas Elimination Technique (MIGET), during sedation with the α₂-agonist detomidine alone and in combination with the opioid butorphanol.

Methods

Seven Standardbred trotter horses aged 3–7 years and weighing 380–520 kg, were studied. The protocol consisted of three consecutive measurements; in the unsedated horse, after intravenous administration of detomidine (0.02 mg/kg) and after subsequent butorphanol administration (0.025 mg/kg). Pulmonary function and haemodynamic effects were investigated. The distribution of ventilation-perfusion ratios (V_A/Q) was estimated with MIGET.

Results

During detomidine sedation, arterial oxygen tension (PaO₂) decreased (12.8 ± 0.7 to 10.8 ± 1.2 kPa) and arterial carbon dioxide tension (PaCO₂) increased (5.9 ± 0.3 to 6.1 ± 0.2 kPa) compared to measurements in the unsedated horse. Mismatch between ventilation and perfusion in the lungs was evident, but no increase in intrapulmonary shunt could be detected. Respiratory rate and minute ventilation did not change. Heart rate and cardiac output decreased, while pulmonary and systemic blood pressure and vascular resistance increased. Addition of butorphanol resulted in a significant decrease in ventilation and increase in PaCO₂. Alveolar-arterial oxygen content difference P(A-a)O₂ remained impaired after butorphanol administration, the V_A/Q distribution improved as the decreased ventilation and persistent low blood flow was well matched. Also after subsequent butorphanol no increase in intrapulmonary shunt was evident.

Conclusion

The results of the present study suggest that both pulmonary and cardiovascular factors contribute to the impaired pulmonary gas exchange during detomidine and butorphanol sedation in the horse.     

Evaluation of associative effects on ruminal digestion kinetics between pasture and grains using in vitro gas production method

In vitro gas production (GP) method was used to investigate associative effects on ruminal digestion when grains (corn or barley) were supplemented to spring pasture and autumn pasture. Pasture (75%) was incubated with 25% corn or barley and gas production was monitored up to 96 h. After incubation, the residues were used to determine dry matter and organic matter digestibility (DMD and OMD). Gas production parameters were analyzed by applying a single exponential equation. Organic matter effective degradability (OMED) was determined from GP parameters and OMD. The positive associative effects on the rate of GP, DMD, OMD and OMED were observed when spring pasture was incubated with corn. However, similar effects were not observed in a barley mixture. However, for autumn pasture, both corn and barley mixtures showed positive associative effects on rate of GP, OMD and OMED. The results of this study indicated that supplementation of corn would be better than barley for spring pasture with high water‐soluble carbohydrate contents, whereas both grain supplementations were effective to obtain positive associative effects on the rate of GP and OMED for autumn pasture with high cell wall content.     

中药血清药理学的研究方法及其应用

综述了中药血清药理学研究中对动物的选择、灌胃次数与时间间隔、给药剂量、含药血清的采集、含药血清是否灭活等问题的解决方法,介绍了中药血清药理学方法在国内临床研究中的应用现状.     

Detection of serum adiponectin in the cat, bear, and horse using antibody from a commercial ELISA kit

Adiponectin is a hormone secreted from adipose tissue that closely associates with insulin resistance. In contrast to other adipokines, adiponectin levels decrease as fat mass increases. The ability to measure adiponectin in veterinary species will allow researchers to assess hormone function and may lead to improved screening tests and treatments for insulin resistance and type II diabetes. A commercial ELISA kit (B-bridge International) is available for adiponectin quantification in mice and rats. To test this assay's ability to bind adiponectin in several veterinary species known to develop insulin resistance with obesity, we conducted a Western blot analysis comparing mouse, cat, bear, and horse serum using the antibody provided with the assay. The proteins were subjected to denaturing SDS-PAGE and transferred to a nitrocellulose membrane. Blocking was performed in 5% milk solution. The membrane was then incubated with the rabbit anti-mouse adiponectin antibody provided with the ELISA kit, followed by incubation with peroxidase-labeled goat anti-rabbit IgG. Detection of bound antibody was performed using enhanced chemoluminescence. Bands corresponding to the adiponectin monomer (30 kDa) were apparent for each sample tested. Therefore, the antibody provided in the ELISA kit appears to bind with adiponectin in all species tested. Our laboratory has previously validated the ELISA mouse/rat adiponectin kit for use in cats. High DNA homology across species and strong antibody binding at the 30 kDa site warrant validation of the kit's accuracy in other species at risk for insulin resistance (eg. horses and bears).     

Repair of physeal fractures of the tuber olecranon in the horse, using a tension band method

Physeal fractures of the tuber olecranon of 4 horses were treated, using the tension band method of compression fracture repair. A cortical bone screw and Steinmann pin were placed through the proximal fragment into the distal parent bone parallel to the palmar border of the olecranon. The tension band was placed dorsal to the Steinmann pin and anchored in a hole through the shaft of the ulna 10 cm distal to the tuber olecranon. Of the 4 foals, 2 became pasture sound, 1 is now being worked under saddle, and the 4th showed no signs of lameness 5 months after surgery.     

Rumen fermentation and degradability in buffalo and cattle using the in vitro gas production technique

An in vitro trial was conducted to investigate the effect of different inoculum sources (buffalo vs. cattle) on rumen fermentation and degradability. Incubations were carried out using rumen fluid obtained from buffalo or cattle fed the same diet [60% grass hay and 40% concentrate; 18 kg dry matter (DM)/day]. The fermentation kinetics of eight feeds commonly used in ruminant nutrition (alfalfa hay, barley meal, beet pulp, corn meal and silage, ryegrass hay and silage and soya bean meal s.e.) were studied with the in vitro gas production technique and rumen fermentation parameters (substrate disappearance, pH and volatile fatty acids production) were determined after 120 h of incubation. The linear relationship indicates that the microbial metabolic pathways of the two inocula for all the substrates were qualitatively similar, albeit often quantitatively different. In this in vitro study, a significant influence of rumen inoculum (buffalo vs. cow) on fermentation and degradability of the examined substrates was found. The differences in buffalo and cattle rumen fermentation can be explained with a different microbial activity of the two ruminant species, because of different amount of microbial population or microbial population constituted by different species of bacteria and protozoa.     

Monitoring the circadian rhythm of serum and salivary cortisol concentrations in the horse

Daily fluctuations of cortisol concentration in the blood or saliva have been repeatedly reported. However, several contradictions in the existing literature appear on this subject. The present study was performed to definitively establish options for testing adrenocortical function. To the best of our knowledge, this is the first study to evaluate parallel circadian rhythms in salivary and serum cortisol concentrations during a 24-h period. Twenty horses were examined under the same conditions. Blood and saliva samples were taken every 2 h for 24 h to determine the daily changes in cortisol concentrations of saliva and serum at rest and to determine the relationship between salivary and serum cortisol levels. Cosinor analysis of group mean data confirmed a significant circadian component for both serum and salivary cortisol concentrations (P < 0.001 in both cases). The serum cortisol circadian rhythm had an acrophase at 10:50 AM (95% CI, 10:00 AM–11:40 AM), a MESOR of 22.67 ng/mL, and an amplitude of 11.93 ng/mL. The salivary cortisol circadian rhythm had an acrophase at 10:00 AM (95% CI, 9:00 AM–11:00 AM), a MESOR of 0.52 ng/mL, and an amplitude of 0.12 ng/mL. We found a significant but weak association between salivary and serum cortisol concentrations; the Pearson correlation coefficient was 0.32 (P < 0.001). The use of salivary cortisol level as an indicator of hypothalamic-pituitary-adrenal axis activity may be warranted. However, the salivary cortisol levels are more likely to be correlated with free plasma cortisol than with the total plasma cortisol concentration.     

利用体外产气法研究戊酸对山羊瘤胃发酵的影响

应用体外产气法模拟瘤胃发酵,通过测定24 h体外累计产气量、细菌氮含量和中性洗涤纤维(NDF)的降解率,评价戊酸的不同添加水平对山羊瘤胃发酵的影响.试验采用单因子设计,戊酸的添加水平分别为0%、0.3%、0.6%、0.9%、1.2%,每个水平4个重复.结果表明与对照组相比,添加0.6%的戊酸组能显著提高24 h累计产气量(P＜0.05)和极显著提高细菌氮含量(P＜0.01);在添加戊酸水平为0%～0.3%时,NDF降解率有提高的趋势,但是差异不显著(P＞0.05),在0.3%～1.2%时,其NDF降解率显著下降(P＜0.05).建议日粮中戊酸的适宜添加水平为0.6%.