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.     

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.     

Morphological adaptation of the skull for various behaviors in the tree shrews

Skull size and shape were examined among 14 species of the tree shrews (Tupaia montana, T. picta, T. splendidula, T. mulleri, T. longipes, T. glis, T. javanica, T. minor, T. gracilis, T. dorsalis, T. tana, Dendrogale melanura, D. murina, and Ptilocercus lowii). The bones of face were rostro-caudally longer in T. tana and T. dorsalis, contrasting with T. minor and T. gracilis, D. melanura, D. murina and P. lowii which have smaller facial length ratios. The arbo-terrestrial species (T. longipes and T. glis) were similar to terrestrial species in length ratios of bones of face unlike the other arbo-terrestrial species (T. montana, T. picta, T. splendidula, and T. mulleri). We propose that T. longipes and T. glis have adapted to foraging for termites and ants as have T. tana and T. dorsalis. Additionally small body size in T. javanica may be the result of being isolated in Java. We separated the species into 5 groups from the measurment values of skulls: 1) Terrestrial species; T. tana and T. dorsalis, 2) Arboreal species; T. minor and T. gracilis, 3) Arbo-terrestrial species group 1: T. montana, T. splendidula, T. picta and T. mulleri, and T. javanica, 4) Arbo-terrestrial species group 2: T. glis and T. longipes, 5) Arboreal species of Dendrogale and Ptilocercus. Principal component analysis separated species into 8 clusters as follows: 1) T. tana, 2) T. dorsalis, 3) T. montana, T. splendidula, T. picta and T. mulleri, 4) T. glis and T. longipes, 5) T. javanica, 6) T. minor and T. gracilis, 7) D. melanura and D. murina, and 8) P. lowii. We suggest that these clusters correspond to behavioral strategies and peculiarities observed in foraging, feeding and locomotion in each species.     

Genetic relationships among direct and maternal components of milk yield and maternal weaning gain in a multibreed beef herd.

Data spanning 1980 to 1993 from a multibreed beef herd including primarily eight breeds (Angus, Charolais, Gelbvieh, Hereford, Maine-Anjou, Pinzgauer, Simmental, and Tarentaise) were used to obtain 2,207 records on 200-d weaning gain (WG) and 1,826 records on 200-d milk yield (MY), obtained by machine milking after oxytocin injection. Estimates of (co)variances for the two traits (WG and MY) were obtained with REML with breed of calf, breed of cow, and heterotic effects modeled for the two traits. Animal effects of calf (CalfWG, CalfMY) and cow (CowWG, CowMY) contributions to each trait were modeled including 2,926 animals. The permanent environmental effect of the cow was modeled for MY, with 693 levels. Estimates of breed differences were generally similar to literature estimates. Simmental, Charolais, and Maine-Anjou were highest for CalfWG, and Tarentaise, Simmental, Gelbvieh, and Maine-Anjou were highest for CowMY. Heterosis was estimated at 8.00, 2.58, 4.05, and 5.50% of the mean for CalfWG, CowWG, CalfMY, and CowMy, respectively. Variance attributable to repeated records on CowMy represented 9% of phenotypic variance. Heritabilities estimated were .22 and .24 for CalfWG and CowWG and .04 and .35 for CalfMY and CowMY. Genetic correlations estimated between CalfWG and CowWG and between CalfMY and CowMY were -.35 and -.64, respectively. A genetic correlation between CowWG and CowMY of .76 indicates that maternal weaning gain evaluations are a good predictor of a cow's potential for milk yield.     

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.     

Effect of including relationships in the estimation of genetic parameters of beef calves.

Variances and covariances for birth weight, gain from birth to weaning (ADG), and 205-d weight were obtained from a sire-dam model and a sire-maternal grandsire model for a herd of Angus and a herd of Hereford cattle. Estimates of direct additive genetic variance (sigma 2A), maternal additive genetic variance (sigma 2M), covariance between direct and maternal additive genetic effects (sigma AM), permanent environmental variance (sigma 2PE), and residual variance (sigma 2e) were obtained both with and without the inverse of the numerator relationship matrix (A-1) included. Estimates of heritability for direct genetic effects (h2A), maternal genetic effects (h2M), and the correlation between direct and maternal effects (rAM) for birth weight were .37, .18, and -.01 in Angus and .53, .23, and -.19 in Herefords, respectively, for the analyses without A-1. For the analyses with A-1, estimates of h2A, h2M, and rAM were .42, .22, and -.12 for Angus and .58, .22, and -.13 for Herefords, respectively. Estimates of h2A, h2M, and rAM for ADG were .43, .15, and -.44 in Angus and .52, .38, and -.03 in Herefords, respectively, without A-1. With A-1, estimates of h2A, h2M, and rAM were .57, .15, and -.32 for Angus and .58, .39, and -.05 for Herefords, respectively. Estimates of h2A, h2M, and rAM for 205-d weight were .49, .15, and -.46 for Angus and .58, .43, and -.06 for Herefords, respectively, without A-1. With A-1, estimates of h2A, h2M, and rAM were .63, .16, and -.36 for Angus and .66, .43, and -.08 for Herefords, respectively. Estimates of h2A were higher with A-1 than without A-1, but estimates of h2M were similar. Using variances and covariances obtained from analyses including A-1 generally gave higher estimates of direct breeding values than using variances and covariances obtained from analyses not including A-1. Both Pearson product-moment and Spearman rank correlations were high (.99) between estimates of breeding values from the two analyses, although some changes in rank did occur.     

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.     

Heterosis and recombination effects on pig growth and carcass traits

The primary objective was to estimate breed, heterosis, and recombination effects on growth and carcass traits of two different four-breed composite populations of pigs. Experiment 1 (Exp. 1) included purebred and crossbred pigs originating from Yorkshire, Landrace, Large White, and Chester White breeds, and Experiment 2 (Exp. 2) included pigs from Duroc, Hampshire, Pietrain, and Spot breeds. Data were recorded on purebred pigs, two-breed cross pigs, and pigs from generations F1 through F6, where F1 pigs were the first generation of a four-breed cross. Pig weights were recorded at birth and at 14, 28, 56, 70, and 154 d of age. Average daily gain was calculated for intervals between weights, and ultrasonic backfat measurements (A-mode) were taken at 154 d of age. Feed intake was measured between 70 and 154 d of age on mixed pens of boars and barrows. Carcass backfat, length, and loin muscle area were measured on barrows at slaughter. Mixed-model analyses were done separately by experiment, fitting an animal model. Fixed effects included farrowing group and sex for growth traits and farrowing group for carcass traits. For ADFI, a weighted mixed-model analysis was done fitting farrowing group as a fixed effect, sire nested within farrowing group as a random effect, and weighting each observation by the number of pigs in each pen. To test feed efficiency, a second analysis of ADFI was done adding ADG as a covariate in the previous model. Included as covariates in all models were direct, maternal, and maternal grandam breed effects, direct and maternal heterosis effects, and a direct recombination effect. Recombination is the breakup of additive x additive epistatic effects present in purebreds during gamete formation by crossbred parents. Effects of direct heterosis significantly increased weights at birth, 14, 56, 70, and 154 d of age in Exp. 1. Effects of direct heterosis significantly increased ADG from birth to 14, 28 to 56, and 70 to 154 d of age in Exp. 1. In Exp. 2, effect of direct heterosis significantly increased weights and ADG at all ages. In Exp. 1, recombination significantly reduced loin muscle area. In Exp. 2, recombination significantly increased weights at birth, 14, 28, and 56 d, ADFI from 70 to 154 d, and ADFI adjusted for ADG. The correlation between maternal heterosis and recombination effects for all traits in Exp. 1 and Exp. 2 was approximately -0.90. Maternal heterosis and recombination effects were estimable, but greatly confounded.     

饲粮钙、磷水平对泌乳期伊犁母马营养物质消化代谢和血浆生理生化指标的影响

本试验旨在探讨饲粮钙、磷水平对泌乳期伊犁母马体重、胸围、营养物质表观消化率和代谢以及血浆生理生化指标的影响,为确定泌乳期伊犁母马钙、磷适宜需要量提供参考。选取年龄(11~14周岁)、体重[(371±21)kg]和胎次(4~6胎)接近的处于第2泌乳月的伊犁母马25匹,随机分为5组,每组5匹。第3泌乳月Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组母马钙饲喂水平分别为45.03、48.50、51.96、55.43和58.89 g/d,磷饲喂水平分别为30.05、32.03、34.01、35.99和37.97 g/d;第4和第5泌乳月Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组母马钙饲喂水平分别为43.60、46.42、49.25、52.07和54.92 g/d,磷饲喂水平分别为27.63、29.24、30.86、32.47和34.12 g/d。试验为期90 d,每30 d为1个试验周期。结果显示:饲粮钙、磷水平对母马体重和胸围以及干物质、有机物和中性洗涤纤维的表观消化率均无显著影响(P0.05)。Ⅴ组的粗蛋白质表观消化率最高,分别比Ⅱ、Ⅲ和Ⅳ组提高12.26%、12.37%和18.28%(P0.05);Ⅰ组的总能表观消化率最高,分别比Ⅱ、Ⅲ和Ⅳ组提高8.32%、7.19%和11.24%(P0.05);Ⅰ和Ⅲ组的钙表观消化率分别较Ⅳ组提高17.74%和14.49%(P0.05);Ⅲ组的磷表观消化率最高,比Ⅱ组提高35.39%(P0.05)。饲粮钙、磷水平对母马氮和钙代谢均无显著影响(P0.05)。Ⅰ组的代谢能较Ⅱ和Ⅳ组分别增加7.95%和11.33%(P0.05);Ⅰ组的能量沉积率较Ⅱ、Ⅲ和Ⅳ组分别提高9.30%、8.50%和12.10%(P0.05);Ⅰ、Ⅲ和Ⅴ组的磷沉积量显著高于Ⅱ组(P0.05),其中Ⅲ组在各组中最高,比Ⅱ组提高42.59%;Ⅰ和Ⅲ组的磷沉积率显著高于Ⅱ和Ⅳ组(P0.05),其中Ⅰ组在各组中最高,分别比Ⅱ和Ⅳ组提高49.67%和46.32%;Ⅰ、Ⅲ和Ⅴ组的磷利用率显著高于Ⅱ组(P0.05),分别比Ⅱ组提高17.74%、18.80%和16.79%。饲粮钙、磷水平对血浆中离子钙、磷、降钙素、骨钙素、胎盘催乳素、垂体泌乳素、雌二醇、孕酮和雌酮水平均无显著影响(P0.05)。Ⅲ组的血浆中甲状旁腺素水平显著高于Ⅳ和Ⅴ组(P0.05),分别提高70.61%和47.58%。由此得出,Ⅰ组饲粮(在第3泌乳月钙、磷饲喂水平分别为45.03和30.05 g/d,第4和第5泌乳月钙、磷饲喂水平分别为43.60和27.63 g/d)即可满足伊犁母马泌乳期的钙、磷需要。适宜的饲粮钙、磷水平有助于维持较高水平的能量和钙的表观消化率以及能量和磷的沉积和利用。     

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。     

Effects of hypercalcemia on serum concentrations of magnesium, potassium, and phosphate and urinary excretion of electrolytes in horses

OBJECTIVE: To determine effects of experimentally induced hypercalcemia on serum concentrations and urinary excretion of electrolytes, especially ionized magnesium (iMg), in healthy horses. ANIMALS: 21 clinically normal mares. PROCEDURES: Horses were assigned to 5 experimental protocols (1, hypercalcemia induced with calcium gluconate; 2, hypercalcemia induced with calcium chloride; 3, infusion with dextrose solution; 4, infusion with sodium gluconate; and 5, infusion with saline [0.9% NaCl] solution). Hypercalcemia was induced for 2 hours. Dextrose, sodium gluconate, and saline solution were infused for 2 hours. Blood samples were collected to measure serum concentrations of electrolytes, creatinine, parathyroid hormone, and insulin. Urine samples were collected to determine the fractional excretion of ionized calcium (iCa), iMg, sodium, phosphate, potassium, and chloride. RESULTS: Hypercalcemia induced by administration of calcium gluconate or calcium chloride decreased serum iMg, potassium, and parathyroid hormone concentrations; increased phosphate concentration; and had no effect on sodium, chloride, and insulin concentrations. Hypercalcemia increased urinary excretion of iCa, iMg, sodium, phosphate, potassium, and chloride; increased urine output; and decreased urine osmolality and specific gravity. Dextrose administration increased serum insulin; decreased iMg, potassium, and phosphate concentrations; and decreased urinary excretion of iMg. Sodium gluconate increased the excretion of iCa, sodium, and potassium. CONCLUSIONS AND CLINICAL RELEVANCE: Hypercalcemia resulted in hypomagnesemia, hypokalemia, and hyperphosphatemia; increased urinary excretion of calcium, magnesium, potassium, sodium, phosphate, and chloride; and induced diuresis. This study has clinical implications because hypercalcemia and excessive administration of calcium have the potential to increase urinary excretion of electrolytes, especially iMg, and induce volume depletion.     

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。     

无角陶塞特、波德代、萨福克与小尾寒羊杂交试验研究

引进无角陶塞特、波德代、萨福克与张掖市本地饲养的小尾寒羊进行杂交改良,杂一代表现出明显的杂种优势和肉用特征。在相同的饲养条件下,与小尾寒羊比较,陶寒杂交Fl羔羊公母平均初生重比小尾寒羊提高20.5%,1月龄、3月龄和6月龄体重分别提高21.4%、14.4%和14.5%,初生至6月龄的平均日增重提高14.5%;6月龄平均体高增加13.3%,体长增加16.7%,胸围增加19.1%,管围增加10.7%;6月龄胴体重提高38.21%,净肉重提高47.09%。波寒杂交Fl羔羊公母平均初生重比小尾寒羊提高17.7%,1月龄、3月龄和6月龄体重分别提高19.1%、20.8%和16.0%,初生至6月龄的平均日增重提高16.0%;6月龄平均体高增加14.5%,体长增加16.1%,胸围增加17.8%,管围增加10.7%;6月龄胴体重提高47.07%,净肉重提高58.52%。萨寒杂交Fl公母平均初生重比小尾寒羊提高14.0%,1月龄、3月龄和6月龄体重分别提高12.8%、13.3%和14.4%,初生至6月龄的平均日增重提高14.4%;6月龄平均体高增加31.5%,体长增加17.6%,胸围增加19.2%,管围增加11.4%;6月龄胴体重提高45.36%,净肉重提高57.64%。     

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。     

A bioeconomic simulation model for a hierarchical swine breeding structure.

A stochastic computer model was developed to simulate individual pigs in a hierarchical breeding system. The bioeconomic model was designed as a tool to facilitate the evaluation of selection, culling, and management strategies for a three-tiered breeding structure. Events such as mating, farrowing, and selection occurred weekly. Variables included number of pigs born alive, survival rate from birth to weaning, average daily gain and backfat at 110 kg, number of pigs weaned, feed per gain, days from weaning to 110 kg, age at puberty, and growth rate and weight of sows and service boars. Also included were probabilities of conception, return to estrus by week, survival, involuntary culling, male infertility, and unacceptable conformation. Variables important for selection were determined by breeding value, individual and maternal heterosis, parity, size of birth litter, sex, age of dam, genetic and environmental relationships between variables, and common litter, permanent, and random environmental effects. Variables derived from selection variables were computed by regression using phenotypic relationships between all variables. Also, a random environmental effect was added to predicted performance. Means and variances of variables differed between genetic lines. Production costs included feed, non-feed operating, fixed, and replacement stock costs. Income included market animals, culls, and replacements sold to lower tiers. Effects of changes in backfat on market value and sow maintenance feed costs were not modeled. An example is given to illustrate model output.     

Genetic parameters for dairy production of Australian Black and White cowsParamètres génetiques de la production laitière des vaches Pie Noires AustraliennesGenetische Parameter für die Milchleistung von australischen Schwarzbunten Kühen

An initial study on the inheritance of first and second lactation dairy production in Australian Black and White cows is presented for the states of New South Wales, Victoria, Queensland and Tasmania. A total of 116,043 first and 14,767 second lactation records for 326 young and 415 old, and 200 young and 31 old sires, respectively, were analyzed using a multivariate Restricted Maximum Likelihood procedure. Analyses were carried out for a mixed model fitting herd-year-seasons and proven sires as fixed, young sires as random effects and age at calving as a linear and quadratic covariable. In addition, the effects of lactation length and month of calving were investigated.The within-HYS phenotypic variation was high with distinct differences between states. As a consequence, heritability estimates were low compared to literature values. Pooled estimates were 0.17, 0.15, 0.38, 0.13 and 0.25 for first lactation milk yield, fat yield, fat content, protein yield and protein content, respectively. Correlations among yields were high, ranging from 0.71 to 0.91 genetically, and from 0.90 to 0.95 phenotypically. Milk yield was negatively related to concentration of constituents, genetic and phenotypic correlations being of the order of ?0.4 and ?0.2, respectively.Heritabilities for second lactation milk yield, fat yield and fat content were 0.18, 0.17 and 0.45, respectively, of similiar magnitude to first lactation values. The respective genetic correlations between first and second lactation were 0.96, 0.98 and 0.98, suggesting that production in both lactations is genetically identical. These high estimates can be attributed to the method of analysis, which accounts for culling based on first lactation performance.     

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.     

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。     

Procedurally similar competitive immunoassay systems for the serodiagnosis of Babesia equi, Babesia caballi, Trypanosoma equiperdum, and Burkholderia mallei infection in horses.

Procedurally similar competitive enzyme-linked immunoassay (cELISA) methods were developed for the serodiagnosis of Babesia equi and Babesia caballi (piroplasmosis), Trypanosoma equiperdum (dourine), and Burkholderia mallei (glanders) infections in horses. Apparent test specificities for the B. equi, B. caballi, T. equiperdum, and B. mallei cELISAs were 99.2%, 99.5%, 98.9%, and 98.9%, respectively. Concordances and kappa values between the complement fixation (CF) and the cELISA procedures for the serodiagnosis of B. equi, B. caballi, T. equiperdum, and B. mallei infections in experimentally exposed horses were 76% and 0.55, 89% and 0.78, 97% and 0.95, and 70% and 0.44, respectively. The cELISA method may be a technically more reproducible, objective, and convenient approach for piroplasmosis, dourine, and glanders serodiagnosis in qualifying animals for international movement and disease eradication programs than the CF systems currently in use. Use of the cELISA method also obviated the problems associated with testing hemolyzed or anticomplementary sera.     

虎纹蛙肠道微生物结构与功能分析

利用高通量测序方法对虎纹蛙前肠、中肠和后肠微生物结构和功能进行分析。结果表明,虎纹蛙(Rana rugulosa)肠道核心菌群是厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、梭杆菌门(Fusobacteria)和放线菌门(Actinobacteria)。Romboutsia属、鲸杆菌属(Cetobacterium)、叶杆菌属(Phyllobacterium)是绝对优势菌属。肠道中存在弧菌(Vibro)、邻单胞菌(Plesiomonas)、气单胞菌(Aeromonas)、爱德华氏菌(Edwardsiella)不动杆菌属(Acinetobacter)、黄杆菌属(Flavobacterium)、脱硫弧菌属(Desulfovibrio)、鞘脂单胞菌属(Sphingomonas)、伊丽莎白菌(Elizabethkingia)等常见的条件致病菌和芽孢杆菌(Bacillus)、乳酸杆菌(Lactobacillus)和双歧杆菌(Bifidobacterium)等潜在益生菌。比较发现,前肠和中肠微生物丰度和多样性显著高于后肠,且在门和属水平菌群结构差异明显;前肠和中肠微生物功能相似,与能量代谢、维生素代谢、氨基酸代谢、脂代谢、外源物质降解和代谢关联微生物丰度较高,而后肠中与核酸代谢、碳水化合物代谢关联微生物丰度较高。前肠和中肠中与信号转导、神经系统、内分泌系统、转运和分解等关联微生物丰度较高,后肠中与信号分子互作、细胞过程与信号、增殖与修复、免疫系统、翻译、转录、酶家族、环境适应、膜转运等关联微生物丰度较高。本研究解析了虎纹蛙肠道菌群结构和功能,为虎纹蛙健康养殖提供理论基础。