棘胸蛙产卵量、卵子孵化率的比较研究

为选择适于闽北的棘胸蛙养殖品种,比较了异地引种棘胸蛙和本地引种棘胸蛙的产卵量和卵子孵化率。试验表明,异地经过几个世代驯化的棘胸蛙在总产卵量上要比本地引种的棘胸蛙要多两倍多,产卵总数为3071枚,本地引种的棘胸蛙产卵总数为863枚。异地引种棘胸蛙在卵子孵化率上也比本地引种棘胸蛙要高,平均为95.3%,而本地引种的棘胸蛙的卵子孵化率仅为64.18%,说明异地引种的棘胸蛙在闽北有较好的推广前景。     

Characterization of an intravenous lipopolysaccharide inflammation model in calves with respect to the acute-phase response

Our objective was to develop a lipopolysaccharide (LPS) inflammation model in calves to evaluate the acute-phase response with respect to the release of pro-inflammatory cytokines and acute-phase proteins, fever development and sickness behaviour. Fourteen 4-week-old male Holstein Friesian calves were included and randomly assigned to a negative control group (n = 3) and an LPS-challenged group (n = 11). The latter received an intravenous bolus injection of 0.5 μg of LPS/kg body weight. Blood collection and clinical scoring were performed at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12, 18, 24, 28, 32, 48, 54 and 72 h post LPS administration (p.a.). In the LPS group, the following clinical signs were observed successively: tachypnoea (on average 18 min p.a.), decubitus (29 min p.a.), general depression (1.75 h p.a.), fever (5 h p.a.) and tachycardia (5 h p.a.). Subsequent to the recovery from respiratory distress, general depression was prominent, which deteriorated when fever increased. One animal did not survive LPS administration, whereas the other animals recovered on average within 6.1 h p.a. Moreover, the challenge significantly increased plasma concentrations of tumour necrosis factor-α, interleukin 6, serum amyloid A and haptoglobin, with peaking levels at 1, 3.5, 24 and 18 h p.a., respectively. The present LPS model was practical and reproducible, caused obvious clinical signs related to endotoxemia and a marked change in the studied inflammatory mediators, making it a suitable model to study the immunomodulatory properties of drugs in future research.     

柞蚕丝素/丙二醇共混膜的制备及性能测试

为了开发适用于人工皮肤、创面覆盖等的生物材料,用硫氰酸锂溶液溶解柞蚕丝素纤维,制备不同配比的柞蚕丝素(TSF)/丙二醇共混膜。用X-射线衍射法、红外光谱法对不同配比共混膜的结构进行表征,并测定其溶失率和分析其力学性能变化。当TSF/丙二醇共混膜中丙二醇的质量分数<30%时,共混膜的聚集态结构主要以α-螺旋结构为主,此时共混膜的溶失率较高,仍有30%左右;随着共混膜中丙二醇的质量分数增加,共混膜的聚集态结构逐渐向β-折叠结构转变,溶失率也随之降低;当共混膜中丙二醇的质量分数达到45%以上时,共混膜基本不溶于水,溶失率<2%。同时,当共混膜中丙二醇的质量分数达到30%时,共混膜的断裂伸长率显著增大,虽然断裂强度有所减小,但即使丙二醇的质量分数达到45%时,断裂强度仍然有20 MPa左右。研究结果显示,丙二醇的加入能显著降低柞蚕丝素膜的溶失率,并改善其力学性能。     

Effects of a low dose infusion of racemic and S-ketamine on the nociceptive withdrawal reflex in standing ponies

ObjectiveTo investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies.Study designProspective, blinded, cross-over study.AnimalsSix healthy 5-year-old Shetland ponies.MethodsPonies received either 0.6 mg kg⁻¹ racemic ketamine (group RS) or 0.3 mg kg⁻¹ S-ketamine (group S) intravenously (IV), followed by a CRI of 20 μg kg⁻¹minute⁻¹ racemic ketamine (group RS) or 10 μg kg⁻¹minute⁻¹ S-ketamine (group S) for 59 minutes. The NWR was evoked by transcutaneous electrical stimulation of a peripheral nerve before drug administration, 15 and 45 minutes after the start of the bolus injection and 15 minutes after the end of the CRI. Electromyographic responses were recorded and analysed. Arterial blood was collected before stimulation and plasma concentrations of ketamine and norketamine were measured enantioselectively using capillary electrophoresis. Ponies were video recorded and monitored to assess drug effects on behaviour, heart rate (HR), mean arterial blood pressure (MAP) and respiratory rate.ResultsThe NWR was significantly depressed in group RS at plasma concentrations between 20 and 25 ng mL⁻¹ of each enantiomer. In group S, no significant NWR depression could be observed; plasma concentrations of S-ketamine (9–15 ng mL⁻¹) were lower, compared to S-ketamine concentrations in group RS, although this difference was not statistically significant. Minor changes in behaviour, HR and MAP only occurred within the first 5–10 minutes after bolus drug administration in both groups.ConclusionAntinociceptive activity in standing ponies, demonstrated as a depression of the NWR, could only be detected after treatment with racemic ketamine. S-ketamine may have lacked this effect as a result of lower plasma concentrations, a more rapid metabolism or a lower potency of S-ketamine in Equidae so further investigation is necessary.     

A Single Sample Method for Evaluating 51Chromium-Ethylene Diaminic Tetraacetic Acid Clearance in Normal and Hyperthyroid Cats

Background: Chronic kidney failure is frequently seen in middle-aged and elderly cats. ⁵¹Chromium-ethylene diaminic tetraacetic acid (⁵¹Cr-EDTA) clearance and single blood sample (SBS) method are used in several species to estimate the glomerular filtration rate (GFR).
Hypothesis: The hypothesis of this study was that ⁵¹Cr-EDTA clearance could be determined using an SBS method in normal and hyperthyroid cats.
Animals: Forty-six cats were included in this study, with an average age of 9.5 years. Of these cats, 27 had hyperthyroidism; 19 were healthy.
Methods: After IV injection of ⁵¹Cr-EDTA (average dose: 4.25 MBq), 7 blood samples were obtained between 5 and 240 minutes. Reference clearance was calculated in mL/min and mL/min/kg body weight, using a 2-compartment model. Optimal time for clearance measurement with SBS was then determined by systematically comparing each individual plasma concentration to the reference multisample clearance.
Results: The average reference plasma clearance of ⁵¹Cr-EDTA for all cats was 14.9 mL/min (3.7 mL/min/kg). The clearance in hyperthyroid cats averaged 16.4 mL/min (4.3 mL/min/kg) and in normal cats averaged 10.3 mL/min (2.4 mL/min/kg).
The optimal time for the SBS was 48 minutes after injection of tracer ⁵¹Cr-EDTA ( R ²= 0.9414), giving the following converting equation: clearance = (0.0066 × DV_{48 minutes}) – 0.9277 (in mL/min).
Conclusions and Clinical Importance: In this study, the single sample ⁵¹Cr-EDTA clearance method was used to estimate the global GFR in cats. The method identified differences in clearance between normal and hyperthyroid cats. The optimal time for an SBS was 48 minutes.     

Short-term transportation in a small vehicle affects the physiological state and subsequent water consumption in goats

We investigated the physiological effects on goats of transportation for one hour in a small truck. We also investigated food and water consumption after transportation. Eight adult goats (four castrated males and four ovariectomized females) were used. Plasma levels of cortisol, glucose and free fatty acids increased significantly within 15 min of the start of transportation, and these higher levels were maintained throughout transportation. These results indicate that transportation in a small truck activates the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system in goats. Despite activation of the sympathetic nervous system, heart rate (HR) in subjected animals during transportation did not differ from during the control animals, which were housed in their usual pen. However, after the transportation had ended and the goats started to eat fodder, HR increased significantly. There was no difference in the amount of food consumption between the control and transported goats. Water consumption in the first three hours after transportation was significantly lower in the transported goats than in the controls for the equivalent period. In the subsequent three hours, however, the transported goats consumed more water than the controls. Consequently, the total water consumption of the transported goats did not differ from that of the controls during the six hours after transportation. In conclusion, short-term transportation with a small vehicle activated the HPA axis and the sympathetic nervous system in goats. HR was not increased during transportation, but after the transportation had ended HR in transported goats was higher than that in control goats. After transportation, goats had consumed the same amount of food as control goats, but water consumption during three hours after the transportation was lower than that of control goats.     

Effect of banding or burdizzo castration on plasma testosterone, acute-phase proteins, scrotal circumference, growth, and health of bulls

The objective was to assess the effect of banding or burdizzo castration performed on farms on plasma testosterone, acute-phase proteins, scrotal circumferences, growth, and well-being of bulls. 243 Continental bulls (12 months; 399.2 ± 5.72 kg) from three different farms were allocated at random, after stratification on weight within breed type, to one of three treatment groups: banding castration (BAND; n = 80), burdizzo castration (BURD; n = 83), or controls (CON; n = 80). The castration methods were conducted under local anaesthesia, and tetanus toxoid vaccine and antibiotic were also injected at castration. BAND and BURD castrates had lower (P < 0.001) plasma testosterone concentration than control bulls, with no difference between BAND and BURD castrates on 28 d post-castration. From days 0 to 14 post-castration, BAND (P = 0.0002) and BURD (P < 0.0001) castrates had lower average daily gain (ADG) than CON bulls, no difference (P = 0.46) was found between BAND and BURD castrates. From days 15 to 28, BAND castrates had lower ADG compared with BURD castrates (P = 0.03) and CON bulls (P = 0.01), while no difference (P = 0.76) was found between BURD and CON. From days 29 to 56, BAND (P = 0.01) and BURD (P = 0.002) castrates had lower ADG than CON bulls, no difference (P = 0.55) was found between BAND and BURD. From days 57 to 84, the ADG of BAND castrates was not different compared with BURD castrates (P = 0.12) and CON bulls (P = 0.38), while BURD had lower (P = 0.02) ADG compared with CON. The integrated ADG from day 0 to 112 of BAND (P = 0.0001) and BURD (P = 0.02) groups were lower compared with CON, while there was no difference (P = 0.09) between BAND and BURD castrates. On d 14 post-castration, BAND castrates had lower scrotal temperature than BURD (P < 0.0001) and CON (P < 0.0001), and BURD castrates had greater (P < 0.006) scrotal temperature than CON; BAND castrates had lower scrotal latitudinal and longitudinal circumferences than BURD castrates (P < 0.001) and CON bulls (P < 0.001), and BURD castrates had greater (P < 0.001) scrotal latitudinal and longitudinal circumferences than CON bulls. BAND (P < 0.0001) and BURD (P = 0.01) castrates had greater glucose concentration than CON bulls, and BAND castrates had greater (P = 0.04) glucose concentration than BURD. In conclusion, BAND or BURD castration significantly reduced plasma testosterone concentration; reduced average daily weight gain mainly during the first 2 weeks, which was not compensated during the subsequent 16 weeks; increased withdrawal of stored energy and increased plasma protein concentration. BURD showed an advantage over BAND in growth during days 15 to 28 following castration.     

Relation of reproductive performances and rectal palpation for luteum function of heifers 7 days after estrus

Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP‐based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1 ± 3.1 mm on US and a mean P4 concentration of 8.1 ± 2.3 ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4 ± 5.4 mm, 4.0 ± 2.8 ng/mL) (P < 0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18–25 days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P < 0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7 days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P < 0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post‐estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL.     

Regional and circadian variations of sweating rate and body surface temperature in camels (Camelus dromedarius)

It was the aim of this study to investigate the regional variations in surface temperature and sweating rate and to visualize body thermal windows responsible for the dissipation of excess body heat in dromedary camels. This study was conducted on five dromedary camels with mean body weight of 450 ± 20.5 kg and 2 years of age. Sweating rate, skin and body surface temperature showed significant (P < 0.001) circadian variation together with the variation in ambient temperature. However, daily mean values of sweating rate, skin and body surface temperature measured on seven regions of the camel body did not significantly differ. The variation in body surface temperature compared to the variation in skin temperature was higher in the hump compared to the axillary and flank regions, indicating the significance of camel's fur in protecting the skin from daily variation in ambient temperature. Infrared thermography revealed that flank and axillary regions had lower thermal gradients at higher ambient temperature (T_a) and higher thermal gradients at lower T_a, which might indicate the working of flank and axillary regions as thermal windows dissipating heat during the night. Sweating rate showed moderate correlation to skin and body surface temperatures, which might indicate their working as potential thermal drivers of sweating in camels.     

PMSG对甘肃高山细毛羊同期发情和繁殖率的影响

在甘肃省肃南县康乐乡对甘肃高山细毛羊应用阴道栓与孕马血清促性腺激素(PMSG) 结合处理,结果表明,不同注射剂量和处理方式对母羊的同期发情和繁殖率均有影响,在埋栓后12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓后的0-48 h发情率显著高于其他试验组(P<0.05);在埋栓后13 d注射600 IU PMSG同时撤除阴道栓的试验组繁殖率最高(P<0.05)。但综合繁殖率和经济效益考虑,在埋栓后间隔12.5 d注射550 IU PMSG并在放栓后14 d撤除阴道栓0-48 h的试验组效果最好,平均每只母羊净收入可达773.7元。