《无机分析化学实验》课中学生创新能力的开发

在《无机及分析化学实验》中,通过采取让学生参与实验准备,因材施教,个别指导,改革考核方法,开放实验室等措施,挖掘每一个学生的潜能,提升学生的创新能力。     

学术期刊影响因子的应用研究

学术期刊影响因子已经由一种模糊的指标,成为衡量期刊、学术论文、作者、机构等学术研究水平高低的重要的定量测定指标。通过对学术期刊影响因子的使用进行了系统分析,提出影响因子的偏差的负面影响,对如何利用期刊影响因子公正有效的对成果鉴定进行了相关阐述。     

卧龙自然保护区功能区的模糊划分

自然保护区功能区的划分是保护区规划和建设的一项十分重要的基础工作。长期以来,我国自然保护区功能区的划分一直采用人为定性划分方法,主观随意性较大,缺乏科学依据。卧龙自然保护区的功能区,是１９８４年人为确定以磨子沟大桥为界,以西划为核心区,以东划为试验区。实践证明,这种划分不符合卧龙的实际,结果未能发挥出功能区划分应有的作用,本文在大量调查,计算和分析的基础上,选择出旅游、农业活动、距离公路的远近,海     

Testing genetic determinism in rate of hoof growth in pigs using Bayes Factors

Excessive growth and consequent deformity of hooves is a frequent disorder in some purebred pig populations. A test to detect possible genetic determinism related with this phenomenon was performed using the Bayes Factor (BF). Data were available for females from three purebred selection lines: Landrace (561 records), Pietrain (183) and Large White (225). Animals were scored in four categories, according to the overall growth rate of their hooves. A Bayesian analysis was performed separately for each line using a threshold model with a probit approach, and Bayes Factors between models with and without additive genetic effects were computed. Results from the three lines showed that models exhibiting genetic variability were much more probable than those that did not include a genetic component, with BF values of 312, 35 and 40 (and posterior probabilities of 0.99, 0.97 and 0.98), respectively, for the Landrace, Pietrain and Large White lines. Monte Carlo estimates of posterior means of heritabilities were medium to high (0.25, 0.41 and 0.38, respectively), and the highest posterior density region for heritability at 99% did not include zero in any of the three lines. These results allow us to conclude that genetic determinism has an important influence upon the rate of hoof growth in the pig. A potential genetic response can be achieved in the populations analysed, but further studies are needed to determine the genetic architecture of hoof growth disorders in pigs.     

影响畜禽矿物质利用的抗营养因子

文章叙述了植酸、棉酚、单宁、硫代葡萄糖甙、草酸、粗纤维这些抗营养因子对动物体在矿物质吸收中的影响,为今后科学组织畜牧业生产提供参考。     

夏南牛核心群母牛部分生长性状影响因素的分析与研究

利用SAS统计分析软件中的GLM过程分析了不同出生年度、不同出生季节和不同代次对夏南牛体尺性状的影响。结果表明:出生年度和代次对夏南牛各年龄阶段体尺性状的影响显著(P<0.05);出生季节对夏南牛各年龄阶段体尺性状的影响不显著(P>0.05)。     

In vitro analyses for predicting standardised ileal digestibility of protein and amino acids in actual batches of feedstuffs and diets for pigs

In vitro digestibility analyses of feedstuffs and diets are integrated in the new Danish feed evaluation system for pigs. This system is based on potential physiological energy and standardised digestible amino acids. For characterisation of the energy value of actual batches of feedstuffs and complete diets for pigs, two different in vitro methods have been developed and proved to analyse precisely the digestibility of organic matter at faecal, as well as at ileal, level in the pigs. For characterisation of the protein value in the diet, table values for standardised digestibility of amino acids from the individual feedstuffs are used for calculation of their contribution to the amino acid recommendations for the specific pig category. The results in the present paper indicate that in vitro analyses for digestibility of crude protein in feedstuffs are a reliable tool for calculation of standardised ileal digestibility of the individual amino acids. Thus, the results may question the need for future experiments with surgically modified pigs for analysing ileal digestibility of amino acids in protein sources. Alternatively, in vitro digestibility analyses appear to have a general potential for a precise evaluation of amino acid digestibility in actual batches of feedstuffs and pig diets.     

Direct and maternal additive effects are not the main determinants of Iberian piglet perinatal mortality

Data of 127,800 Iberian piglets were used to study genetic parameters of mortality at birth at the piglet level. These records proceed from three data sets: 4,987 litter of 2,156 sows of a dam line, 2,768 litter of 817 sows of a complete diallel cross between four Iberian strains and 7,153 litter of 2,113 sows of the Torbiscal composite line. Perinatal mortality was considered as a binary trait, and Bayesian threshold animal models were fitted to separately analyse the three data sets. The posterior means of direct heritability were 0.010, 0.004 and 0.003, and those of maternal heritability were 0.034, 0.011 and 0.014 for dam line, diallel cross and Torbiscal line, respectively. Important effects of litter size and parity order were inferred in the three data sets, of within‐breed cross‐breeding parameters in the diallel cross and of sex and sow handling in the Torbiscal line Therefore, the inclusion of perinatal mortality in the objective of selection is questionable in this breed and strategies for reducing piglet mortality successful in other breeds should be considered.     

影响胚胎移植成功率的主要因素

本文针对在胚胎移植过程中可能预见的各种影响胚胎移植技术的实施的因素进行了较为全面的分析,并针对不同影响因素提出了自己独特的见解,以期在生产实践中对胚胎移植技术的应用和推广有所借鉴。     

禽类采食量生理调节因子的研究进展

采食量是影响禽类生长最重要的因素之一。认识采食量的调节规律和机制,旨在更有效地调节家禽的采食量,为生产实践提供重要指导。禽类采食量的生理调节机制十分复杂,涉及许多神经通路和体液因子的调节。本文将重点介绍采食量生理调节因子。