如皋鸡血浆酶活力及其与体重的相关性研究

为了研究如皋鸡血浆酶活力及其与体重的相关性,试验测定了如皋鸡2、4、6、8、10、12周龄体重及血浆LDH、HBDH、MAO、MDH、CK、5′-NT、ALT、ADA、ALP、ICDH的活力。结果表明:①2周龄体重与LDH、HBDH、MDH、CK相关极显著(P<0.01),8周龄体重与LDH、HBDH呈显著负相关(P<0.05),12周龄体重与ICDH相关极显著(P<0.01)。②周龄间,体重与5′-NT、ALP呈显著负相关(P<0.05)。③除5′-NT为中等遗传力外,LDH、HBDH、MAO、MDH、CK、ALT、ADA、ALP、ICDH均为高遗传力。④周龄内,血浆LDH与HBDH、MAO、MDH、CK,HBDH与MAO、MDH,MAO与MDH,CK与HBDH、MDH,ALP与5′-NT的偏相关程度较高。⑤周龄间,LDH与HBDH、MAO、MDH、CK、5′-NT、ALP,HBDH与MAO、MDH、5′-NT、ALP,MAO与MDH,CK与HBDH、MDH、ALP,ALT与ICDH,ALP与5′-NT间相关系数达到显著(P<0.05)或极显著水平(P<0.01)。因此,血浆酶活力的相关研究可以为体重等性状的选择提供理论依据。     

南荻种质资源表型性状遗传多样性

本研究测定了采自于黄淮平原亚地区(ⅢD9a),江汉平原亚地区(ⅢD9b),赣南-湘东丘陵亚地区(ⅢD9d)和川、鄂、湘亚地区(ⅢD10c)4个植物区系32份南荻(Miscanthus lutarioriparius)种质材料的干物质产量、冠层高、花茎高、茎径、茎密度、叶长、叶宽、叶茎比、含水量9个表型性状,并采用巢式方差分析、偏相关分析和UPGMA聚类分析方法进行了数据分析。结果表明,1)干物质产量、冠层高、花茎高、茎径、茎密度和含水量6个表型性状在区系间存在显著差异(P0.05),9个表型性状在区系内均存在极显著差异(P0.01),其变异系数范围为13.53%~45.54%。2)干物质产量与茎径显著正相关(P0.05),与叶茎比显著负相关(P0.05);冠层高与花茎高、含水量极显著正相关(P0.01);茎径与叶茎比极显著正相关(P0.01);叶宽与叶长显著正相关(P0.05),与含水量显著负相关(P0.05);海拔与冠层高、茎径显著负相关(P0.05),与茎密度极显著正相关(P0.01);经度与干物质产量显著负相关(P0.05);纬度与茎密度极显著正相关(P0.01),与茎径显著负相关(P0.05)。3)采用UPGMA聚类方法进行综合聚类,4个区系被分为3类,黄淮平原亚地区和赣南-湘东丘陵亚地区为第Ⅰ类,该类群南荻植株较矮、茎秆细小、产量较小;江汉平原亚地区和川、鄂、湘亚地区为第Ⅱ类,该类群南荻植株高大、茎秆粗壮、产量大;江汉平原、赣南-湘东丘陵和川、鄂、湘3个亚地区的南部地区为第Ⅲ类,该类群南荻介于第Ⅰ类和第Ⅱ类之间。     

An evaluation of pulse oximeters in dogs, cats and horses

Objective Evaluation of five pulse oximeters in dogs, cats and horses with sensors placed at five sites and hemoglobin saturation at three plateaus. Study design Prospective randomized multispecies experimental trial. Animals Five healthy dogs, cats and horses. Methods Animals were anesthetized and instrumented with ECG leads and arterial catheters. Five pulse oximeters (Nellcor Puritan Bennett‐395, NPB‐190, NPB‐290, NPB‐40 and Surgi‐Vet V3304) with sensors at five sites were studied in a 5 × 5 Latin square design. Ten readings (SpO₂) were taken at each of three hemoglobin saturation plateaus (98, 85 and 72%) in each animal. Arterial samples were drawn concurrently and hemoglobin saturation was measured with a co‐oximeter. Accuracy of saturation measurements was calculated as the root mean squared difference (RMSD), a composite of bias and precision, for each model tested in each species. Results Accuracy varied widely. In dogs, the RMSD for the NPB‐395, NPB‐190, NPB‐290, NPB‐40 and V3304 were 2.7, 2.2, 2.4, 1.7 and 2.7% respectively. Failure to produce readings for the NPB‐395, NPB‐190, NPB‐290, NPB‐40 and V3304 were 0, 0, 0.7, 0, and 20%, respectively. The Pearson correlation coefficients for the tongue, toe, ear, lip and prepuce or vulva were 0.95, 0.97, 0.69, 0.87 and 0.95, respectively. In horses, the RMSD for the NPB‐395, NPB‐190, NPB‐290, NPB‐40 and V3304 were 3.1, 3.0, 4.7, 3.3 and 2.1%, respectively while rates of failure to produce readings were 10, 21, 0, 17 and 60%, respectively. The Pearson correlation coefficients for the tongue, nostril, ear, lip and prepuce or vulva were 0.98, 0.94, 0.88, 0.93 and 0.94, respectively. In cats, the RMSD for all data for the NPB‐395, NPB‐190, NPB‐290, NPB‐40 and V3304 were 5.9, 5.6, 7.9, 7.9 and 10.7%, respectively while failure rates were 0, 0.7, 0, 20 and 32%, respectively. The correlation coefficients for the tongue, rear paw, ear, lip and front paw were 0.54, 0.79,.0.64, 0.49 and 0.57, respectively. For saturations above 90% in cats, the RMSD for the NPB‐395, NPB‐190, NPB‐290, NPB‐40 and V3304 were 2.6, 4.4, 4.0, 3.5 and 4.8%, respectively, while failure rates were 0, 1.7, 0, 25 and 43%, respectively. Conclusions and clinical relevance Accuracy and failure rates (failure to produce a reading) varied widely from model to model and from species to species. Generally, among the models tested in the clinically relevant range (90–100%) RMSD ranged from 2–5% while failure rates were highest in the V3304.     

Udder edema in cattle: effects of diuretics (furosemide, hydrochlorothiazide, acetazolamide, and 50% dextrose) on serum and urine electrolytes

Blood and urine chemical values at parturition in clinically normal Holstein cows (n = 12) were compared with the same values in Holstein cows developing udder edema (n = 12). There was no statistically significant mean difference between the 2 groups for the serum and urine chemical data. Furosemide (500 mg) given IV caused a significant increase in serum calcium and sodium, urine chloride, potassium, and sodium, and fractional excretional ratio of chloride, potassium, and sodium. There was a significant mean decrease in the serum potassium, urine creatinine, osmolality, pH, and specific gravity. Hydrochlorothiazide (250 mg) given IV caused a significant mean increase in serum chloride, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride, potassium, and sodium. There was a significant mean decrease in serum potassium and sodium, urine osmolality, pH, and specific gravity. Acetazolamide (500 mg) given IV caused a significant mean increase in blood urea nitrogen, serum chloride and glucose, urine sodium, and fractional excretion ratio of sodium, while causing a significant mean decrease in serum potassium, sodium, and phosphorus, and urine creatinine. Dextrose (500 g) given IV as a 50% solution caused a statistical mean increase in serum glucose, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride and potassium. A statistical mean decrease occurred in the packed cell volume, blood urea nitrogen, serum calcium, potassium, sodium, and phosphorus, urine creatinine, osmolality, and pH.     

牛病毒性腹泻病毒在绵羊垂直感染中的抗原分布

将新疆分离的病毒性腹泻病毒（BVDV）野毒株SHN－98和标准毒株Oregon C-24分别接种无BVDV感染的羔羊和怀孕100天左右的母羊，建立BVDV在绵羊垂直感染的动物模型，应用病毒抗原定位检测的免疫组化染色技术，探求BVDV在实验性感染绵羊经胎盘感染胚胎、羔羊过程中，病毒在感染组织、靶器官、靶细胞中的分布规律。结果表明：BVDV通过母羊的胎盘感染胚胎。BVDV在感染妊娠母羊体内主要分布于心肌、肝、肺、脾、淋巴结、胃肠粘膜、脑神经、子宫粘膜、胎盘等器官组织，其中以胃肠粘膜、脾、淋巴结、脑神经、子宫粘膜、胎盘等器官组织中分布量较多；BVDV在垂直感染胚胎体内主要分布于胸腺、淋巴结、脑、肝、肾、心肌、脾、肺、胃肠粘膜、脐带等器官组织，其中以胸腺、胃肠粘膜、脑神经等器官组织中分布量较多；BVDV在垂直感染羔羊体内主要分布于心、肾、胃肠粘膜、脾、胸腺、淋巴结、大脑、小脑、海马、视丘、视神经、眼球脉络膜等器官组织，其中以胃肠粘膜、大小脑、用、视神经、淋巴结等器官组织中分布较多，在组织分布中，BVDV对上皮细胞、神经胶质细胞、淋巴细胞有较强的亲嗜性，SHN－98和OregonC-24在垂直传播中组织器官的分布无明显差异。     

Development and validation of a method for simultaneous separation and quantification of 5 different sugars in canine urine.

The objective of this project was to develop and validate a method for concurrent separation and quantification of methylglucose, rhamnose, xylose, sucrose, and lactulose in canine urine by using high pressure anion exchange liquid chromatography and pulsed amperometric detection. The method was validated by evaluating dilutional parallelism, spiking recovery, intra-assay variability, and inter-assay variability. Observed to expected ratios for 3 urine samples, and all sugars, ranged from 77.6% to 106.9% for a 1:2 dilution, 85.2% to 121.4% for a 1:4 dilution, and 91.6% to 163.7% for a 1:8 dilution. Observed to expected ratios for spiking recovery of 3 urine samples, all sugars, and 5 different spiking solutions, ranged from 85.5% to 116.7 % (mean +/- SD, 100.5 +/- 6.0%). The intra-assay coefficients of variation were 1.6%, 3.4%, and 4.7% for methylglucose; 1.6%, 2.0%, and 3.6% for rhamnose; 2.7%, 1.4%, and 1.1% for xylose; 9.8%, 3.4%, and 4.0% for sucrose; and 3.2%, 3.3%, and 3.3% for lactulose. Inter-assay coefficients of variation were 3.2%, 5.7%, and 4.2% for methylglucose; 4.3%, 5.4%, and 6.4% for rhamnose; 3.3%, 5.0%, and 4.2% for xylose; 9.4%, 9.9%, and 9.4% for sucrose; and 6.1%, 4.9%, and 2.7% for lactulose. In conclusion, a method for simultaneous separation and quantification of 5 sugars in canine urine was established and found to be linear, accurate, precise, and reproducible. This method may prove useful in the simultaneous evaluation of gastric permeability, small intestinal permeability, and small intestinal mucosal function in dogs with gastrointestinal disorders.     

Estimated genetic parameters for carcass traits of Brahman cattle

Heritabilities and genetic and phenotypic correlations were estimated from feedlot and carcass data collected from Brahman calves (n = 504) in central Florida from 1996 to 2000. Data were analyzed using animal models in MTDFREML. Models included contemporary group (n = 44; groups of calves of the same sex, fed in the same pen, slaughtered on the same day) as a fixed effect and calf age in days at slaughter as a continuous variable. Estimated feedlot trait heritabilities were 0.64, 0.67, 0.47, and 0.26 for ADG, hip height at slaughter, slaughter weight, and shrink. The USDA yield grade estimated heritability was 0.71; heritabilities for component traits of yield grade, including hot carcass weight, adjusted 12th rib backfat thickness, loin muscle area, and percentage kidney, pelvic, and heart fat were 0.55, 0.63, 0.44, and 0.46, respectively. Heritability estimates for dressing percentage, marbling score, USDA quality grade, cutability, retail yield, and carcass hump height were 0.77, 0.44, 0.47, 0.71, 0.5, and 0.54, respectively. Estimated genetic correlations of adjusted 12th rib backfat thickness with ADG, slaughter weight, marbling score, percentage kidney, pelvic, and heart fat, and yield grade (0.49, 0.46, 0.56, 0.63, and 0.93, respectively) were generally larger than most literature estimates. Estimated genetic correlations of marbling score with ADG, percentage shrink, loin muscle area, percentage kidney, pelvic, and heart fat, USDA yield grade, cutability, retail yield, and carcass hump height were 0.28, 0.49, 0.44, 0.27, 0.45, -0.43, 0.27, and 0.43, respectively. Results indicate that sufficient genetic variation exists within the Brahman breed for design and implementation of effective selection programs for important carcass quality and yield traits.     

Hematologic, biochemical, blood-gas, and acid-base values in greyhounds before and after exercise

After racing 722 m, 16 Greyhounds were evaluated to determine changes in hematologic, biochemical, blood-gas, and acid-base values following exercise. Values were determined before racing (T0), immediately after racing (T1), and 3 hours after racing (T2). Significant changes detected immediately after racing included increased heart rate, respiratory rate, and rectal temperature. Significant changes in hematologic values included increases in PCV, total plasma protein, hemoglobin, RBC, WBC, neutrophils, and lymphocytes. Change was not detected in values for monocytes, eosinophils, and neutrophil/lymphocyte ratio. Other increases included those for plasma concentrations of sodium, chloride, calcium, lactic acid, aspartate transaminase, alanine transaminase, alkaline phosphatase, creatine kinase, lactate dehydrogenase, and glucose. Concentrations of potassium and urea did not change. Measurement of blood-gas and acid-base status revealed significant increases in PaO2 and base deficit, whereas PaCO2, pH, and bicarbonate decreased. Three hours after exercise, all vital signs and blood-gas and acid-base values, except for PaCO2, which was still slightly low, had returned to baseline (T0) values. Most biochemical values had also returned to baseline, although sodium, chloride, aspartate transaminase, and creatine kinase were still high, and urea was low. Many hematologic values were still different from baseline values, with high values for WBC, neutrophils and neutrophil/lymphocyte ratio, and low values for PCV, total plasma protein, hemoglobin, RBC, and lymphocytes.     

The effect of natural toxins on reproduction in livestock.

Reproductive efficiency is the most important economic factor in livestock production. Thus, the hypothalamo-pituitary-gonadal regulatory axis, accessory sexual organ functionality, and the complex events involved in fertilization, implantation, and embryonic and fetal development may be sensitive to therapeutic agents, environmental pollutants, and natural toxicants. There are many factors that adversely affect reproduction, one of which is toxic substances in the diets of animals. Toxic materials can affect reproductive success by causing abortions, interfering with libido, estrus, oogenesis, or spermatogenesis, causing emaciation and subsequent abnormal mating behavior, birth defects, and increasing the time between parturition and rebreeding. Examples of natural toxicants in poisonous plants interfering with reproduction are numerous. Abortion in livestock from locoweeds, ponderosa pine needles, broom snakeweeds, fescue, and others are reported in studies. Selenium and seleniferous forage inhibit estrus in cattle and swine. Emaciation and temporary illness from sneezeweeds, bitterweed, locoweed, larkspur, lupines, and others may interfere with mating. Embryonic loss and birth defects from Veratrum, lupines, locoweeds, poison hemlock, and so on, may occur. As suggested, toxins have many diverse and economically adverse effects on reproductive performance in livestock.     

攀西芒果园土壤pH与有效养分的相关性研究

采集攀西芒果主产区果园土壤样本42个,探讨土壤pH、有效养分状况及两者的相关性。结果表明,攀西芒果园土壤pH变化范围为4.8~8.4,中性、酸性土壤占76.2%。果园土壤有机质、碱解氮、交换性钙和有效锌表现为严重缺乏状态,有效铜和硼整体处于低水平,有效钾含量为中下水平,而有效磷、交换性镁、有效硫、有效铁和有效锰5种元素的含量表现较为丰富。果园土壤pH和大部分有效养分存在显著的相关性,土壤pH与有机质、碱解氮、有效钾、有效铜、有效锌、有效铁、有效锰呈极显著负相关,与交换性钙、有效硫呈极显著正相关,而与有效性磷、有效硼、有效钼的相关性则不显著。从三种函数类型的回归分析来看,土壤pH与有机质关系符合幂函数,与碱解氮、有效锌、有效硫呈线性相关,与有效钾、交换性钙、有效铜、有效铁、有效锰则符合指数函数,而与交换性镁则符合二次函数,各相关系数均达极显著水平。总体上,土壤pH在中性偏酸的范围内,养分相对较为平衡,pH过酸或过碱,都容易造成养分的失衡,因此土壤pH过酸的果园,应注意适量施用石灰或含钙镁的肥料,与之相反,碱性土壤则应避免再次施用石灰或碱性肥料。     

Milk production of crossbred daughters of high- and low-milk EPD Angus and Hereford bulls.

Milk yield from 273 Angus- and Hereford-sired cows and preweaning performance of their calves were used to determine how accurately milk EPD of Angus and Hereford sires predicted milk production of crossbred daughters and subsequent calf performance. Mean milk EPD (kg) for high Angus (HA), low Angus (LA), high Hereford (HH), and low Hereford (LH) bulls (n = 41) selected as sires were +8.7, -6.2, +7.6, and -4.8, respectively. Cows calved in spring or fall from 1992 to 1997 and yielded a total of 660 records. Twenty-four-hour milk production of the cows was estimated by two weigh-suckle-weigh measurements at monthly intervals. The statistical model included breed, milk EPD level, sire of cow within breed and milk EPD level, year, season, cow age, calf sire, sex, and all two- and three-way interactions. Means were obtained for monthly milk production, total milk production, time and yield of peak production, monthly calf weights, monthly cow weights and body condition scores (1 through 9), and calf birth and weaning data. The least squares means for 24-h milk production (kg) of HA, LA, HH, and LH with P-values for high vs low, across breeds, were, respectively, as follows: mo 1: 6.9, 5.9, 7.1, and 5.7 (P < 0.01); mo 2: 7.2, 6.1, 6.9, and 5.7 (P < 0.01); mo 3: 6.1, 5.1, 5.1, and 4.3 (P = 0.01); mo 4: 6.1, 4.9, 4.9, and 4.8 (P = 0.01); mo 5: 4.8, 4.0, 4.2, and 3.8 (P = 0.01); mo 6: 4.7, 3.4, 3.2, and 3.0 (P < 0.01); and mo 7: 3.7, 2.5, 3.0, and 3.0 (P = 0.05). Least squares means for total milk (kg) were 911.4, 729.6, 758.0, and 664.2 (P < 0.01); for yield at peak (kg/d) were 7.0, 5.7, 6.1, and 5.2 (P < 0.01); for birth weight (kg) were 37.1, 37.9, 38.3, and 38.8 (P = 0.31); for 205-d weight (kg) were 237.3, 218.2, 222.2, and 214.1 (P < 0.01); for final cow weight (kg) were 482.4, 505.4, 509.5, and 511.7 (P = 0.11); and for final cow BCS were 4.9, 5.3, 5.1, and 5.2 (P < 0.01). The correlations of total production with the monthly productions were 0.52, 0.56, 0.52, 0.54, 0.35, 0.37, and 0.31 (P < 0.01) and were 0.12 with birth weight, 0.45 with 205-d weight, -0.12 with final cow weight, and -0.26 with final cow body condition score (all P < 0.01). Daughters of high-milk EPD sires produced more milk and weaned heavier calves than those of low-milk EPD sires at the expense of body condition. These results suggest that sire milk EPD are sufficiently associated with milk yield and calf performance to be useful tools in genetic improvement of preweaning performance.     

猪GDF11基因部分序列的克隆及组织表达分析

为了探讨生长分化因子11(Growth differentiation factor11,GDF11,又名BMP11)在胸腰椎数变异中的作用,本试验克隆了该基因包含外显子2在内的部分编码区,并进一步采用RT-PCR技术对其在猪胚胎和初生仔猪中的表达进行了分析。结果表明,在35d的猪胚胎中,后肢、牙龈、脑、肝脏、肾脏、胸椎、腰椎各组织均有明显的表达,而在前肢、眼、心脏、肺脏中的表达较弱,在颈椎和荐尾椎中没有观察到GDF11的表达。在45d猪胚胎的后肢、脑、眼、胸椎组织中GDF11的表达较强,而在前肢、牙龈、肺脏、肾脏、腰椎和荐尾椎的表达相对较弱,在肝脏中的表达极其微弱。在心脏和颈椎中没有检测到GDF11的表达。在55d的猪胚胎中,前肢、后肢、脑、眼、肝脏、颈椎、胸椎、腰椎组织中有明显的表达,肺脏和肾脏组织中的表达较强,牙龈和荐尾椎中的表达较弱,而在心脏中没有检测到GDF11的表达。3d仔猪的后肢、牙龈、脑、肾脏和腰椎组织中GDF11有明显的表达,脾脏组织的表达量较高,前肢、肝脏、心脏、背腰最长肌和肺脏中的表达相对较弱,在眼、颈椎和荐尾椎中的表达极弱,在胸椎中没有检测到表达。在所检测的不同时期的所有组织中,脑和肾脏组织表达明显地高于其他组织。     

Using simulation models to predict feed intake: phenotypic and genetic relationships between observed and predicted values in cattle

The objectives of this study were to evaluate the accuracy of the Decision Evaluator for the Cattle Industry (DECI) and the Cornell Value Discovery System (CVDS) in predicting individual DMI and to assess the feasibility of using predicted DMI data in genetic evaluations of cattle. Observed individual animal data on the average daily DMI (OFI), ADG, and carcass measurements were obtained from postweaning records of 504 steers from 52 sires (502 with complete data). The experimental data and daily temperature and wind speed data were used as inputs to predict average daily feed DMI (kg) required (feed required; FR) for maintenance, cold stress, and ADG; maintenance and cold stress; ADG; maintenance and ADG; and maintenance alone, with CVDS (CFRmcg, CFRmc, CFRg, CFRmg, and CFRm, respectively) and DECI (DFRmcg, DFRmc, DFRg, DFRmg, and DFRm, respectively). Genetic parameters were estimated by REML using an animal model with age on test as a covariate and with genotype, age of dam, and year as fixed effects. Regression equations for observed on predicted DMI were OFI = 1.27 (SE = 0.27) + 0.83 (SE = 0.04) x CFRmcg [R2 = 0.44, residual SD (s(y.x)) = 0.669 kg/d] and OFI = 1.32 (SE = 0.22) + 0.8 (SE = 0.03) x DFRmcg (R2 = 0.53, s(y.x) = 0.612 kg/d). Heritability of OFI was 0.27 +/- 0.12, and heritabilities ranged from 0.33 +/- 0.12 to 0.41 +/- 0.13 for predicted measures of DMI. Phenotypic and genetic correlations between OFI and CFRmcg, CFRmc, CFRg, CFRmg, CFRm, DFRmcg, DFRmc, DFRg, DFRmg, and DFRm were 0.67, 0.73, 0.41, 0.63, 0.78, 0.73, 0.82, 0.45, 0.77, and 0.86 (P < 0.001 for all phenotypic correlations); and 0.95 +/- 0.07, 0.82 +/- 0.13, 0.89 +/- 0.09, 0.95 +/- 0.07, 0.91 +/- 0.09, 0.96 +/- 0.07, 0.89 +/- 0.09, 0.88 +/- 0.09, 0.96 +/- 0.06, and 0.96 +/- 0.07, respectively. Phenotypic and genetic correlations between CFRmcg and DFRmcg, CFRmc and DFRmc, CFRg and DFRg, CFRmg and DFRmg, and CFRm and DFRm were 0.98, 0.94, 0.99, 0.98, and 0.95 (P < 0.001 for all phenotypic correlations), and 0.99 +/- 0.004, 0.98 +/- 0.017, 0.99 +/- 0.004, 0.99 +/- 0.005, and 0.97 +/- 0.021, respectively. The strong genetic relationships between OFI and CFRmcg, CFRmg, DFRmcg, and DFRmg indicate that these predicted measures of DMI may be used in genetic evaluations and that DM requirements for cold stress may not be needed, thus reducing model complexity. However, high genetic correlations for final weight with OFI, CFRmcg, and DFRmcg suggest that the technology needs to be further evaluated in populations with genetic variance in feed efficiency.     

Cytogenetic characterization of the Madin-Darby bovine kidney cell line.

The permanent bovine cell line, Madin-Darby bovine kidney, was cytogenetically analyzed. Chromosomal staining indicated 52 metaphase chromosomes with variations from 49 to 54. The isochromosomes 5, 12, and 13, and centric fusions between chromosomes 1 and 26, 9 and 11, 9 and 24, 17 and 25, 18 and 23, 20 and 24, and 24 and 27 were considered marker chromosomes.     

BOOK REVIEWS

Book reviewed in this article:
The Clostridia: Molecular Biology and Pathogenesis, JI Rood, BA McClane, JG Songer and RW Titball
Zoonoses and Communicable Diseases Common to Man and Animals, 2nd edn.
Poultry Diseases, 4th edn, edited by FTW Jordan and M Pattison, WB Saunders Co, Distributed by Harcourt Brace Co
Anaesthesia and Analgesia in Laboratory animals, DF Kohn, SK Wixson, WJ White and GJ Benson
Controlled Reproduction in Cattle and Buffaloes
The 5 Minute Veterinary Consultation: Canine and Feline, LP Tilley and FWK Smith Jr, Mosby-Williams and Wilkins     

A genetic analysis of the concentrations of blood metabolites and their relationships with age and liveweight gain in young British Friesian bulls

Blood samples were taken from 428 young British Friesian bulls, the sons of 72 sires, between 3 and 15 months of age. The concentrations of blood glucose and haemoglobin and serum cholesterol, urea, albumin, globulin, inorganic phosphate, Ca, Mg, Na, K and Cu were measured and correlated with age and growth rate.Most of the constituents showed highly significant but small changes in concentration with age. The largest changes occurred in the concentrations of urea, albumin and haemoglobin which increased as bulls reached maturity. The concentrations of urea, albumin and globulin were also lower and concentrations of glucose, inorganic phosphate, Ca and K higher than usually occur in older cattle.Highest estimates of heritability, based on the mean of 3 samples, were for K and globulin (> 0.6) and for haemoglobin, cholesterol, inorganic phosphate, Cu and glucose (0.4–0.6). Phenotypic correlations between 0.2 and 0.4 occurred with growth rate for albumin and glucose between 24 and 35 weeks and with body weight for albumin between 27 and 50 weeks of age; however, the phenotypic correlations with average growth rate up to 53 weeks were only 0.15 and 0.07 for albumin and glucose, respectively. Genetic correlations with growth rate were also determined, but standard errors were large.     

纳罗克非洲狗尾草良种繁育技术研究进展

纳罗克非洲狗尾草在世界上热带和亚热带地区广泛栽培,具有再生性强,适口性好,持久性好,耐牧性强,耐旱、耐寒、耐涝、抗病虫害等特性,牛羊喜食,适合建植永久性放牧草地和割草地。在我国推广种植已有30多年,是我国南方天然草地改良、人工草地建植、石漠化治理和草牧业生产的主要骨干草种之一。但是,目前该品种存在种用性状退化和种子产量低等问题,为了提高其种子产量和良种繁育效率,文章对纳罗克非洲狗尾草的利用现状、种性复壮、种子产量构成因子和施肥、刈割、收种等良种繁育关键技术进行了详细阐述和分析,得出种性复壮、施肥、刈割、收种等是纳罗克非洲狗尾草良种繁育的重要因素,今后应从田间选择优异植株、施肥、刈割和收种等良种繁育关键环节进行进一步研究,可为该优良牧草品种的良种繁育和产业化提供理论技术支撑。     

同源异型框基因Prrx功能的研究进展

同源异型框（homeobox,HoX）基因是具有较高遗传等级并能控制细胞分化和形态发育的重要基因。同源异型框基因主要在胚胎时期高度表达,对胚胎的发育、分化及对肢体结构和器官发育有重要影响。同源异型框基因Prrx主要包括3种,分别是Prrx1、Prrx2和Prrx3。Prrx基因家族在人和鼠的腭裂、颌骨、四肢、胫腓骨的组织发育中有重要作用,并与大脑、脊髓、神经、心脏等器官的发育密切相关。其中Prrx1和Prrx2基因主要参与胚胎中骨骼和心血管系统的发育,如四肢、颅面、软骨和动脉管。Prrx3基因主要参与胚胎中骨、软骨、大脑、脊髓等的发育。文章针对Prrx基因的功能进行概述,以期为这些基因功能的研究及相关疾病的防控提供一定的参考。     

Genetic response to selection for weaning weight or yearling weight or yearling weight and muscle score in Hereford cattle: efficiency of gain, growth, and carcass characteristics

An experiment involving crosses among selection and control lines was conducted to partition direct and maternal additive genetic response to 20 yr of selection for 1) weaning weight, 2) yearling weight, and 3) index of yearling weight and muscle score. Selection response was evaluated for efficiency of gain, growth from birth through market weight, and carcass characteristics. Heritability and genetic correlations among traits were estimated using animal model analyses. Over a time-constant interval, selected lines were heavier, gained more weight, consumed more ME, and had more gain/ME than the control. Over a weight-constant interval, selected lines required fewer days, consumed less ME, had more efficient gains, and required less energy for maintenance than control. Direct and maternal responses were estimated from reciprocal crosses among unselected sires and dams of control and selection lines. Most of the genetic response to selection in all three lines was associated with direct genetic effects, and the highest proportion was from postweaning gain. Indirect responses of carcass characteristics to selection over the 20 yr were increased weight of carcasses that had more lean meat, produced with less feed per unit of gain. At a constant carcass weight, selected lines had 1.32 to 1.85% more retail product and 1.62 to 2.24% less fat trim and 10/100 to 25/100 degrees less marbling than control. At a constant age, heritability of direct and maternal effects and correlations between them were as follows: market weight, 0.36, 0.14, and 0.10; carcass weight, 0.26, 0.15, and 0.03; longissimus muscle area, 0.33, 0.00, and 0.00; marbling, 0.36, 0.07, and -0.35; fat thickness, 0.41, 0.05, and -0.18; percentage of kidney, pelvic, and heart fat, 0.12, 0.08, and -0.76; percentage of retail product, 0.46, 0.05, and -0.29; retail product weight, 0.44, 0.08, -0.14; and muscle score, 0.37, 0.14, and -0.54. Selection criteria in all lines improved efficiency of postweaning gain and increased the amount of salable lean meat on an age- or weight-constant basis, but carcasses had slightly lower marbling scores.     

塔里木马鹿血液蛋白多态性的研究

本研究采用垂直聚丙烯酰胺凝胶电泳技术 ,分析了 3 3头塔里木马鹿的血清白蛋白 (Alb) ,后白蛋白 (Po) ,转铁蛋白 (Tf) ,后转铁蛋白 (Ptf) ,血清蛋白酶抑制物 1 (Pi Ⅰ) ,血清蛋白酶抑制物 2 (Pi Ⅱ) ,后白蛋白 1 (Po Ⅰ) ,后白蛋白 2 (Po Ⅱ)共 8个蛋白座位的基因型频率、基因频率和群体遗传变异指标。结果表明 ,Po Ⅱ和Alb座位呈单态 ,其余各蛋白座位均呈多态。在多态座位中Pi Ⅱ和Po Ⅰ各有 3种基因型 ,分别受两个等位基因所控制。Ptf有 6种基因型 ,受3个复等位基因控制。Po有 4种基因型 ,Tf和Pi Ⅰ各有 3种基因型。群体遗传变异指标 (杂合度 )计算结果表明 ,Ptf,Tf和Po的杂合度较高 ,分别为 0 .6 3 0 5 ,0 .6 1 2 9和 0 .5 94 6 ,有效基因数也较多 ,分别为 2 .70 6 1 ,2 .5 83 6和 2 .4 6 6 6。