生长阉牛十二指肠可吸收氨基酸供给量的预测模型研究

试验选用5头手术安装瘤胃、十二指肠和回肠末端T型瘘管的杂交改良阉牛,采用5×5重复设计,每期饲喂以玉米、棉粕、豆粕和氨化稻草为原料而配制的日粮,测定了十二指肠、回肠中内容物的干物质、粗蛋白和各种氨基酸的流量,并计算了各种氨基酸在十二指肠前端的理论浓度和实测浓度之间的回归方程。结果表明,到达十二指肠前端的粗蛋白实测流量(g/d,y)与理论流量(g/d,x)存在强相关,回归方程为:ycp=0.9647xcp+5.2998(R2=0.9636,n=5);各种氨基酸的实测浓度(y)与理论浓度(x)之间存在强相关(Ala、Val除外),它们分别为yAsp=0.7275xAsp+2.8943(R2=0.9964,n=5)、ySer=-3.1577xSer+20.864(R2=0.8474,n=5)、yGlu=0.9993xGlu-1.0355(R2=0.995,n=5)、yThr=0.8055xThr+0.7977(R2=0.8381,n=5)、yGly=0.5563xGly+3.6117(R2=0.8692,n=5)、yArg=1.5039xArg-3.0157(R2=0.8366,n=5)、yAla=-0.9182xAla+14.018(R2=0.5247,n=5)、yTyr=6.9071xTyr-22.162(R2=0.8235,n=5)、yPro=0.7962xPro+1.0732(R2=0.9207,n=5)、yVal=0.0758xVal+4.3453(R2=0.5597,n=5)、yPhe=-0.6437xPhe+8.6589(R2=0.9308,n=5)、yIle=4.4403xIle-17.329(R2=0.9509,n=5)、yLeu=1.8759xLeu-8.4109(R2=0.8723,n=5)、yHis=16.142xHis-35.564(R2=0.8962,n=5)、yLys=0.27     

Effects of propofol and fentanyl on duodenal motility activity in pigs

To investigate the effects of propofol and fentanyl on the postprandial duodenal motility the intraluminal impedance technique was used. Six pigs were instrumented with a central venous catheter, a percutaneous enterogastrostomy (PEG), and an impedance catheter, which was introduced via the PEG into the duodenum through endoscopy. Over the following 3 d, duodenal motility was measured for 8-hour periods. Measurements were taken on each subject under 3 different sets of conditions: in the conscious unrestrained pig, during propofol sedation, and during sedation with propofol-fentanyl. Both, after morning feeding and during gastric nutrition via the PEG, duodenal feeding patterns and duodenal phase II of the migrating motor cycle were shortened during propofol and propofol-fentanyl sedation. In contrast, the duration of phase I was prolonged by propofol and propofol-fentanyl. In conclusion, either propofol or propofolfentanyl sedation shortens duodenal feeding patterns, as well as phase II of the migrating motor cycle.     

Treatment of proximal hind-limb lameness in cattle

Lameness of the hind limb (tarsus and proximal) in cattle is considered from the viewpoint of diagnosis and prognosis. Indications and techniques for radiography are discussed, as well as when indicated.     

Effects of a single dose of ketamine on duodenal motility activity in pigs

In order to investigate the effects of a single dose of ketamine on duodenal motility, the present study focused on the electric impedance technique. Five pigs (32 to 40 kg, CVC group) were instrumented with a central venous catheter 1 d before measurements. The next day, general anesthesia was started and maintained via central venous catheter by propofol and fentanyl. In contrast, the pigs of the KETA group (n = 5) received ketamine intramuscularly prior to the induction of anesthesia by the injection of propofol-fentanyl via an ear vein. An intraluminal impedance catheter was manually introduced into the proximal duodenum. Measurements were recorded for 4 h. The KETA group showed a median duration of phase II that was shortened by 35%, while phase I was prolonged by 73% (P < 0.05). In conclusion, when gastrointestinal motility has to be investigated, the effects of a single dose of ketamine, even for premedication, should be taken into consideration.     

氟对牛脾淋巴细胞膜ATP酶活性的影响

取健康牛脾脏,常规方法分离培养淋巴细胞,用不同浓度氟化钠（NaF）染毒24h。低渗溶胞法提取细胞膜,检测膜上ATP酶活性。结果显示,与对照组相比较,染氟组淋巴细胞膜ATP酶活性降低,组间差异显著或极显著。表明：氟能抑制牛脾淋巴细胞膜ATP酶活性。     

Effects of protozoa on the antioxidant activity in the ruminal fluid and blood plasma of cattle

The objective of this study was to investigate the antioxidant status in ruminal fluid and blood plasma among three faunated and two defaunated (protozoa‐free) cattle (average bodyweight of 225 kg), fed hay plus concentrate. The extra cellular antioxidant activity of the mixed protozoa and bacteria suspensions were also studied in vitro. The antioxidant activity was detected by means of the free radical scavenging ability. The activity (units/microbial nitrogen) of the protozoal suspension increased from 59 (0 h) to 318 (18 h), and decreased to 40 (24 h) during incubation. The activity of the bacterial suspension also increased from 111 (0 h) to 644 (18 h), and decreased to 533 (24 h). The antioxidant activity (units/mL, U/mL) in the ruminal fluid of faunated (ranging from 116 to 254) and defaunated (ranging from 66 to 110) cattle was increased after 2 h and decreased after 5 h of feeding, being significantly higher in the faunated cattle. The antioxidant activity of blood plasma (U/mL) ranged from 248 to 316 in the faunated and 121–170 in the defaunated cattle during 0–5 h after feeding, being significantly higher in the faunated cattle. Therefore, defaunation possibly causes a decrease in the antioxidant level in the ruminal fluid, and may impair the health and performance of ruminants through an oxidant–antioxidant imbalance.     

Effects of intravenous lidocaine overdose on cardiac electrical activity and blood pressure in the horse

This study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to administration of lidocaine, blood samples for lidocaine analysis, heart rate, mean arterial blood pressure, systolic blood pressure, diastolic blood pressure, respiratory rate and electrocardiographic (ECG) data were collected. After recording baseline data, repeat data were collected at 5 min intervals until signs of intoxication were observed. The range of serum lidocaine concentrations at which the clinical signs of intoxication were observed was 1.85-4.53 microg/ml (mean +/- s.d. 3.24 +/- 0.74 microg/ml). Statistically significant changes in P wave duration, P-R interval, R-R interval and Q-T interval were observed in comparison to control values, as a result of lidocaine administration. These changes in ECG values did not fall outside published normal values and were not clinically significant. Heart rate, blood pressures and respiratory rates were unchanged from control values. This study establishes toxic serum lidocaine levels in the horse, and demonstrates that there were no clinically significant cardiovascular effects with serum lidocaine concentrations less than those required to produce signs of toxicity.     

Killing of cattle via electrical stunning

For disease control in the case of epidemics killing of cattle via electrical stunning is a method of choice. The official veterinarian is responsible for monitoring the adhesion to animal welfare principles during electrical stunning and killing.This requires specialised knowledge and experience as the symptoms of effective stunning are quite variable in cattle. Signs of effective and ineffective stunning are described below. In addition to suitable technical equipment, restraint of the animals and correct use of the equipment, neurophysiological processes have to be considered. Calm handling of the animals avoiding stress is a prerequisite for ensuring animal welfare and minimising pain especially when killing cattle using electrical methods.     

Ultrasound‐guided proximal paravertebral anaesthesia in cattle

ObjectiveTo develop and evaluate a method for ultrasound-guidance in performing the proximal paravertebral block for flank anaesthesia in cattle through a cadaveric study, followed by clinical application.Study designprospective experimental cadaveric study and clinical series.AnimalsPreviously frozen lumbar sections of cows without known spinal abnormalities were used. The clinical case group comprised of ten animals for which a right flank laparotomy was indicated.MethodsTwenty cow cadavers were used to perform ultrasound-guided bilateral injections of 1.0 mL dye (1.0 mL 1% Toluidine Blue in 1% Borax) at the intervertebral foramen at the level of T13, L1 and L2 spinal nerves. Distance and depth of injection, staining of the dorsal and ventral nerve branches, and deviation from the target were evaluated. The investigator’s confidence as to visualisation and expected success at staining the nerve was assessed. Ten clinical cases received the ultrasound-guided proximal paravertebral anaesthesia. Analgesic success was evaluated using a 4-grade scoring system at 10 minutes after the injection and during surgery, respectively. Categorical variables were described using frequencies and proportions.ResultsBoth dorsal and ventral branches of the spinal nerves T13, L1 or L2 were at least partially stained in 41% of injections, while in 77% of injections one of the branches was stained. Five out of ten clinical cases had a satisfactory anaesthesia. There was no significant association between confidence at injection and either staining or analgesic success.ConclusionResults from the cadaveric and clinical study suggest no significant improvement using ultrasound guidance to perform proximal paravertebral block in cows compared to our previous clinical experience and to references in the literature using the blind method.Clinical relevanceFurther research should be conducted to improve the ultrasound-guided technique described in this study.     

Persistent activity of doramectin injectable formulation against experimental challenge with Haemonchus placei in cattle.

Two studies were conducted in North America to evaluate the persistent activity of doramectin injectable formulation against experimental challenge with Haemonchus placei. In both studies, calves were randomly assigned to 1 of 4 treatment groups (n = 10 per group) or a larval viability group (n = 2). Calves were treated subcutaneously in the lateral midline of the neck with saline (1 ml/50 kg) on Day 0, or with doramectin (200 mg/kg = 1 ml/50 kg) on Day 0, 7, or 14. Animals used to assess larval viability did not receive any treatment. Beginning on Day 14 and continuing through Day 28, each of the 40 treated calves were given approximately 300 infective larvae of H. placei per os. The two larval viability animals received approximately 10,000 larvae as a single dose on Day 28. Approximately two weeks later, all animals were slaughtered and the abomasum from each calf processed for nematode recovery. A 2% aliquot of abomasal contents plus wash was examined for enumeration and identification of nematodes. Geometric mean H. placei counts were calculated from the log (H. placei count +1) and used to estimate percentage reduction. Overall, doramectin was > or =96.9% efficacious in reducing infection with H. placei when challenged daily 14-28 days after treatment.     

Effect of starch application into the proximal duodenum of ruminants on starch digestibility in the small and total intestine.

Four Slovakian Black-and-white bulls (LW 410 +/- 12 kg; Exp. 1) and four Slovakian Black-and-white non lactating dairy cows (LW 475 +/- 14 kg; Exp. 2) with permanent ruminal cannulas, duodenal T-cannulas and ileal re-entrant cannulas were used in a 4 x 4 Latin square design to determine the postruminal capacity of starch digestion. In Exp. 1 bulls received 5.4 kg DM from corn silage and 3.6 kg DM from alfalfa hay, in Exp. 2 cows consumed only 2.1 kg DM corn silage and 1.9 kg DM alfalfa hay. Additionally, either 750 or 1500 g (Exp. 1) or resp. 1000 or 2000 g (Exp. 2) gelatinized corn or wheat starch per animal and day were applied as pulse doses or as infusion into the proximal duodenum. In both experiments the duodenal and ileal nutrient flow, as well as the faecal excretion without starch application, were measured in a pre-period. After starting starch application ileal digesta and faeces were sampled over 120 h after 9 or 23 days of adaptation respectively. Cr2O3 was used as a flow marker. It was shown, that the capacity of starch utilisation in the small intestine was limited. The effect of different doses of bypass-starch was more pronounced than the effect of different starch sources. Starch digestibility decreased with increasing amounts of starch in the intestine (Exp. 1: corn starch: from 74.3 to 68.0%, P < 0.001; wheat starch: from 76.7 to 67.4%, P < 0.001; Exp. 2: corn starch: from 71.4 to 50.3%. P < 0.001; wheat starch: from 73.8 to 53.1%, P < 0.001). Corn starch was 0.6 to 2.4% units (P < 0.05) and 2.4 to 2.8% units (P < 0.001) less digested than wheat starch in Exp. 1 and Exp. 2, respectively.     

Effects of loperamide hydrochloride on experimental diarrhea and gastrointestinal myoelectrical activity in calves

The antidiarrheal action of loperamide hydrochloride was tested against diarrhea experimentally induced in calves by intraduodenal infusion of castor oil or hypertonic solution of mannitol. The motility of 4 levels of the digestive tract (abomasum, jejunum, and proximal and spiral loops of the colon) was concomitantly recorded, using an electromyographic technique. Loperamide hydrochloride given per os at 0.4 mg/kg or intraduodenally or subcutaneously at 0.1 mg/kg 1 hour before mannitol or castor oil was given delayed diarrhea. Loperamide hydrochloride given alone orally at a dosage of 0.4 mg/kg did not modify the motility pattern of the digestive tract. Intraduodenally administered loperamide hydrochloride (0.1 mg/kg) increased the frequency of the cyclic activity of the jejunum, whereas subcutaneously administered loperamide hydrochloride at the same dose selectively inhibited the motility of the jejunum. Intraduodenal infusion of mannitol was followed by a disruption of the cyclic activity of the jejunum, and this effect was not antagonized by loperamide hydrochloride, whatever the route of administration. Castor oil infusion was not accompanied with changes in gastrointestinal motility. These results indicate that loperamide hydrochloride is active against an experimentally induced diarrhea in calves and that this action is not mediated through an effect on the digestive motility, at least monitored by this electromyographic technique.