两种家兔血常规和血液流变学参数的正常值

用全自动血细胞计数仪、自动血沉分析仪和全自动血液流变分析系统测定了新西兰白兔和本地杂种兔血常规、血沉和血液流变学参数的正常值。结果表明,新西兰白兔的平均红细胞体积、血小板分布宽度、血浆黏度值和血沉方程K值显著大于本地杂种兔,高切和低切全血还原黏度和红细胞刚性指数显著小于本地杂种兔,其余参数值的差异不显著。提示,品种对家兔的血常规、血沉和血液流变学参数值影响不大。     

The effects of sodium ampicillin, sodium cefazolin, and sodium cefoxitin on blood pressures and heart rates in healthy, anesthetized dogs

This study determined the effects of intravenous ampicillin, cefazolin, and cefoxitin on blood pressures and heart rates in healthy, anesthetized dogs. Forty dogs were each randomly assigned to a control, ampicillin, cefazolin, or cefoxitin group. Antibiotics or saline was delivered by intravenous bolus prior to surgical stimulation. Heart rate; systolic, mean, and diastolic arterial pressures; oxygen saturation; end-tidal halothane; and end-tidal carbon dioxide (CO2) were recorded before and every minute for 10 minutes after the test drug was administered. No significant differences were recorded between the antibiotic and control groups. The prophylactic use of these antibiotics should be considered safe in healthy, anesthetized dogs.     

Reference values for a field test to estimate inadequate glutathione peroxidase activity and selenium status in the blood of cattle.

A clinical screening procedure was developed for estimating glutathione peroxidase (GSH-Px) activity and selenium status in the blood of dairy and beef cattle. The test is based on the rate of defluorescence under long waveform UV irradiation of reduced nicotinamide adenine dinucleotide phosphate in a coupled enzyme reaction involving glutathione reductase. Defluorescence rates were significantly correlated with blood GSH-Px activity and blood selenium concentrations as determined by conventional laboratory procedures. Blood selenium concentrations and blood GSH-Px activity in several herds were compared with the selenium content of the complete ration consumed to establish reference or base-line values for these blood characteristics under field conditions. The GSH-Px screening procedure provides rapid results, is relatively inexpensive, and appears to be useful in differentiating between the reference values and grossly inadequate selenium status in cattle.     

Methods and normal values for echocardiography in adult dairy cattle

ObjectiveThe objective of the study was to report normal ultrasonographic appearance and intra-cardiac dimensions in two dairy breeds and to calculate cardiac output (CO) using echocardiography.BackgroundIntra-cardiac dimensions, time indices and CO estimation have not previously been reported in adult cattle.Animals, materials and methodsEchocardiograms were obtained from healthy adult dairy cows (10 Jersey (J) and 12 Holstein Friesians (HF)) in the body weight range of 400 to 700 kg. Standard echocardiographic images were obtained from the left and right hemithoraces. Velocity time integrals were obtained in order to calculate CO using pulsed wave Doppler of aortic flow in the J cows. Measurements obtained included pulmonary artery and aortic diameters, left and right ventricular diameters (and calculated fractional shortening and left ventricular ejection fraction), left atrial size and time indices assessing valve function.ResultsHF cows had significantly (p < 0.05) larger pulmonary artery and aortic diameters, larger left atrial diameters and left ventricular internal diameters during diastole, but these were not different when corrected for body weight. Left and right ventricular dimensions, adjusted for body weight, were significantly larger (p = 0.02 and p = 0.035 respectively) in J cows when compared to HF cows. No differences were noted in the time indices between the two groups. No significant differences were noted in intra-operator variability and the only significant difference in inter-operator variability was in measurement of the pulmonary artery (p = 0.03; ICC = 0.63).ConclusionsIt is possible to obtain repeatable, reliable echocardiograms in order that meaningful intra-cardiac dimensions can be obtained in adult dairy cattle.     

Reference values of blood parameters in beef cattle of different ages and stages of lactation.

Reference (normal) values for 12 blood serum components were determined for 48 Shorthorn cows (2-10 years old) and their 48 calves, 357 crossbred cows (12-14 years old), 36 feedlot bulls and 36 feedlot steers. In addition, hemoglobin, hematocrit, triiodothyronine, thyroxine and cortisol levels were determined for the crossbred cows, and feedlot bulls and steers. Reference values were tabulated according to sex, age and stage of lactation. Serum concentrations of urea, total protein and bilirubin, and serum activity of aspartate aminotransferase and lactate dehydrogenase increased with age (P less than 0.05), while calcium, phosphorus and alkaline phosphatase decreased with age (P less than 0.05) from birth to the age of ten years. The Shorthorn cows had the highest levels of glucose at parturition (P less than 0.05) with decreasing levels during lactation. Creatinine concentration decreased during lactation and increased during postweaning. Both lactate dehydrogenase and aspartate aminotransferase levels increased (P less than 0.05) during lactation. Urea and uric acid were present at higher concentrations in lactating than nonlactating cows (P less than 0.05). The values reported, based on a wide age range and large number of cattle, could serve as clinical guides and a basis for further research.     

Chemical composition and nutritive values of cassava pulp for cattle

We evaluated the chemical compositions of cassava pulp samples produced by four cassava starch factories at different locations in northeast Thailand and the metabolizable energy (ME) of the cassava pulp for cattle. There were significant differences in the P (0.03% ± 0.02%) and K (0.36% ± 0.2%) contents of the samples from different factories (p < .05). Moreover, we found interactions between factory and season in the neutral detergent fiber (36.02% ± 8.8%) and nonfibrous carbohydrate contents (59.33% ± 9.1%) (p < .05). For the evaluation of ME, a crossover‐design experiment with four cattle maintained in each of two groups was conducted. There were two dietary treatments at a maintenance level of 1.27% body weight: (1) a control diet, and (2) a cassava pulp diet, containing the control diet at 70.2% and cassava pulp at 29.8% (dry matter [DM] basis). Feeding cassava pulp did not affect energy intake, energy loss, heat production, energy utilization efficiency (except for the urine‐to‐gross energy ratio), methane production, fecal N, or nutrient digestibility (except for crude protein digestibility). The total digestible nutrients, digestible energy, and ME contents of cassava pulp were 74.4%, 12.9 MJ/kg DM, and 11.3 MJ/kg DM, respectively.     

Blood magnesium values in healthy cattle and in cattle affected with anaplasmosis and eperythrozoonosis

Magnesium (Mg) concentrations in plasma, serum, and erythrocytes (RBC) of calves subjected to splenectomy (SP), splenectomy-induced eperythrozoonosis (EP), and experimentally induced anaplasmosis (AN) were determined and compared with pre-SP, pre-EP, and pre-AN values. Mean serum and plasma Mg concentrations varied in parallel through most periods of the trial. Both were highest after SP, but neither value was significantly different from the pre-SP concentrations. Mean serum and plasma Mg values varied inversely with mean RBC values after SP and EP. Mean RBC Mg values increased significantly from previous periods during EP and AN and after AN, with the values after AN being significantly higher than those at all other periods. Mean plasma, serum, and RBC Mg concentrations were correlated to both mean percentage of parasitemia (%P) and packed-cell volume (PCV). The RBC Mg values increased significantly after mean %P reached 20 and the PCV began to decrease. There was evidence for a distinct lag variation in increasing RBC Mg concentrations with respect to both mean %P and PCV during AN. A strong correlation was observed between the RBC Mg values and the %P occurring 5 days previously and the PCV occurring 3 days previously.     

Genetic parameter estimates for preweaning traits of beef cattle in a stressful environment

Data collected from 1957 through 1985 from a Hereford herd located in the Southwest were analyzed separately for each sex to evaluate the heritabilities of and genetic correlations among preweaning growth traits within groups of environmentally similar years. Data were grouped into years with poor, moderate and good environments based on contemporary group means for male calves' weaning weight. A total of 7,690 records were analyzed for birth weight, weaning weight and preweaning daily gain with a model that included year of birth, sire within year of birth, age of dam and a covariate of day of birth for birth weight or age at weaning for the weaning traits. Year of birth was a significant source of variation in all environments for all traits, accounting for more of the variation in the good and poor years than in moderate years. Heritability estimates for all traits were greater in good and moderate years than in poor years for bull calves. For heifers, however, estimates for weaning weight and preweaning daily gain were greater in the poor environment. Genetic correlations among birth weight and preweaning gain increased from the good environment to the poor environment (-.49 +/- .26 to .82 +/- .56 for male calves and -.09 +/- 2.6 to .46 +/- .25 for female calves) but phenotypic correlations were near zero in all environments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hematology and biochemistry reference values for female Holstein cattle.

Reference intervals are presented for 14 hematology and 32 biochemistry variables from four age groups of female Holstein cattle (n = 172) selected randomly from six well managed farms. Each animal was examined by a clinician and with the history available considered to be clinically normal at the time of blood collection. The variable observations were examined for outliers and Gaussian distribution prior to parametric or where necessary, nonparametric analysis. Many differences were noted between age groups but few between farms.     

Genetic parameter estimates for postweaning traits of beef cattle in a stressful environment

Postweaning growth data, collected from a Hereford herd located in the Southwest, were used to estimate genetic parameters for weights and gains. The herd was maintained on unsupplemented range forage, and average weight losses from weaning to yearling age were 9% for bulls and 12% for heifers. Data were grouped into years with poor and good environments based on contemporary group means for gain from 8 to 12 mo. Postweaning growth data (12- and 20-mo weights, 8- to 12-mo gain and 12- to 20-mo gain) were analyzed by least squares methods with a model that included year of birth, sire within year of birth, age of dam and a covariate of age for 12- and 20-mo weights. Heritability estimates of 12- and 20-mo weights for bulls were .58 +/- .15 and .55 +/- .22 in good environments vs .32 +/- .11 and 1.09 +/- .15 in poor environments; for heifers these estimates were .19 +/- .08 and .35 +/- .12 in good environments vs .38 +/- .07 and .47 +/- .09 in poor environments. Heritability estimates of 8- to 12-mo and 12- to 20-mo gain for bulls were .32 +/- .14 and .51 +/- .24 in good environments vs .16 +/- .11 and .09 +/- .14 in poor environments; for heifers these estimates were .21 +/- .08 and .14 +/- .10 in good environments vs .10 +/- .06 and .44 +/- .10 in poor environments. Genetic correlations among the preweaning traits of birth and weaning weight and postweaning weight traits were positive and of a moderate to large magnitude, with the exception of birth and 12-mo weight in a poor environment (-.06 +/- .49). Genetic correlations between 8- to 12-mo gain and birth weight in poor environment and weaning weight in all environments were negative (range from -.06 +/- .33 to -.53 +/- .41). Genetic correlations among 12- and 20-mo weights were large and positive in all environments. Relationships among gains were more variable.     

Potassium concentration in equine red blood cells: Normal values and correlation with potassium levels in plasma

The concentration of potassium in plasma and in red blood cells was determined in 948 horses. The coefficient of correlation between the two parameters was low. In 436 of these horses, which were clinically healthy, the red blood cell potassium (RBCK⁺) levels did not fit within a normal distribution curve, but a bimodal distribution was observed with a section point at 90 mmol/litre. In 90 per cent of these normal horses, mean RBCK⁺ content was 97.5 mmol/litre. In the remaining 10 per cent, mean RBCK⁺ concentration was 93.8 mmol/litre. A subdivision into a ‘low potassium group’ and a ‘high potassium group’ was made. In 10 out of 15 horses in the ‘low potassium group’, bimonthly sampling over a period of one year showed that RBCK⁺ content remained low. In the remaining five horses an increase was observed.     

Background lead levels in dairy cattle: updated values for 1986

Lead poisoning continues to be a problem in cattle. The toxicologic significance of blood lead levels requires the differentiation of background blood lead from toxic levels. A ten-fold variation of background blood lead levels reported in previous studies has prompted us to conduct our own survey. Our results indicate significantly lower background blood lead levels in New York State cattle analyzed in 1986 than in those levels previously reported elsewhere.     

清水、张家川两县牛羊生活环境及体内矿物元素含量测定

经测定 ,两地外环境及牛羊体内硒、锌水平低下 (P <0 0 1) ,铜、锰、铁、钙含量在部分地区处于亚临床缺乏状态 (P <0 0 5 )。