莱茵鹅15项血清生化指标的测定及分析

为了更有效地保护和利用莱茵鹅的优良基因,对北方种鹅场和双鸭山种鹅场的莱茵鹅血清进行了15项生化指标的测定及分析。结果表明:北方种鹅场和双鸭山种鹅场莱茵鹅血清三酰甘油、肌酐、直接胆红素、氯、镁、尿素氮、白蛋白和钙等血清生化指标之间的差异达到了极显著水平(P<0.01);血清总蛋白和总胆红素之间的差异达到了显著水平(P<0.05);而葡萄糖、高密度脂蛋白胆固醇、总胆固醇、无机磷和尿酸含量之间差异不显著(P>0.05)。研究还初步建立了莱茵鹅15项血清生化指标的参考值及参考范围。     

湖北五峰后河国家级自然保护区果子狸秋冬季栖息地选择

2006年6月～2007年3月,在湖北五峰后河国家级自然保护区内,应用选择系数、选择指数、判别分析,对果子狸在秋冬季节栖息地的选择和利用进行了初步研究。研究结果表明,秋季与冬季果子狸对栖息地的选择有差异性。秋季在低海拔地区有较多林木果实、藤本果实成熟,不需要消耗太多能量即可满足自身需要。冬季气温下降,果子狸较喜欢选择海拔较高的阳坡活动,以获取更多热量。     

不同水平纤维素酶对肉鸡屠宰性能、免疫器官指数及血清生化指标的影响

试验选用1dAA＋肉鸡1050羽作为试验动物,随机分为7个组,每组5个重复,每个重复30羽,分别饲喂不同水平的纤维素酶,试验期42d,分别于21d、42d测定肉鸡的屠宰率、半净膛率和腹脂率;同时测定胸腺、脾脏和法氏囊的器官指数及血清中血糖和尿素氮含量。试验结果表明,添加不同水平的纤维素酶对21d肉鸡的屠宰性能并未产生显著影响;对42d肉鸡的屠宰率和半净膛率效果显著,试验组G屠宰率提高了3.94%（P〈0.05）,试验组E半净膛率提高了2.46%（P〈0.05）。肉鸡胸腺、脾脏、法氏囊器官指数有不同程度的提高,差异不显著。添加不同水平的纤维素酶能够显著提高1～21d和22～42d肉鸡血液内葡萄糖含量,试验组G提高了4.25%（P〈0.05）。添加不同水平的纤维素酶能够降低1～21d肉鸡血清内尿素氮水平,试验组G降低了6.14%（P〈0.05）。     

Attempts to stimulate mitosis in cultured trophoblast cells of cattle embryos

Trophoblast from Day-14 bovine embryos was cultured in medium containing mitogens to determine if the mitotic index could be altered. Trophoblast from each of 15 embryos was cultured in minimum essential medium (Eagles) with 20 % fetal calf serum (control) or in this medium supplemented with pokeweed mitogen (1 %, v/v), phytohemagglutinin (1 %, v/v), concanavalin A (1 %, v/v) or thymidine (2 mg/ml). No mitogenic effect was observed due to any of the treatments. However, mitotic indexes were significantly lower when pokeweed (P < 0.05) or thymidine (P < 0.01) was added to the medium. A highly significant (P < 0.001) variation in mitotic index between embryos was observed.     

Effects of Different Substrates on Fermentation Parameters

Fermenting different raw materials (corn, soybean meal and cottonseed meal) with three kinds of strains (Lactobacillus, yeast and Bacillus subtilis) were employed to optimize the fermentation parameter with sensory evaluation, pH and amount of probiotics retention.The results showed that the time to reach stable pH of materials with different substrates was different.Cottonseed meal had the longest time to reach stable pH followed by soybean meal, while corn had the shortest time under the condition of same water content.Different substrates had no effect on initial pH of corn, soybean meal and cottonseed meal.The count of the probiotics was also influenced by different substrates.When pH reached steady state, corn had the largest number of the probiotics followed by soybean meal and cottonseed meal.The color and smell of three materials after fermented had distinctive features.But cottonseed meal had the highest viscosity followed by soybean meal and corn.Because of shorter time and more microorganisms, corn was better than soybean meal and cottonseed meal to be fermenting medium.     

甘肃省草原产草量动态监测模型

利用MODIS数据和地面实测资料,研究了甘肃省不同草原区的最适草原生物量遥感估算模型,并反演了甘肃省2005-2009年的草原产草量,分析了其空间分布特征。结果表明,不同草原区适合的植被指数和反演模型类型存异,其中河西走廊高平原荒漠草原区适合的植被指数是RVI、模型类型为对数模型,甘南高原草甸草原区适合的植被指数是EVI、模型类型为指数模型,而黄土高原温性草原区适合的植被指数是NDVI、模型类型为二次多项式模型。甘肃省2009年草原总产鲜草3 718.30万t,整体呈现东北低、西南高的空间变化过程,形成3个高产中心,分别是甘南高原、祁连山北麓中东段和陇南南部。与1985年相比,2005年草原明显减产(相对变化率V=19.34%),但2005-2009年间甘肃省草原产草量有总体上升的趋势。     

复合益生菌对乳鸽生长性能、屠宰性能、免疫器官指数和血清生化指标的影响

本试验旨在研究复合益生菌对乳鸽生长性能、屠宰性能、免疫器官指数和血清生化指标的影响。选取72对种鸽和144只1日龄乳鸽,乳鸽称量初始体重后随机分成4个组,每个组6个重复,每个重复3对种鸽及6只乳鸽。在饲喂相同基础饲粮的同时,对照组补饲保健砂,Ⅰ组补饲保健砂+复合菌Ⅰ(嗜酸乳杆菌+乳双歧杆菌),Ⅱ组补饲保健砂+复合菌Ⅱ(乳双歧杆菌+粪肠球菌),Ⅲ组补饲保健砂+复合菌Ⅲ(嗜酸乳杆菌+粪肠球菌)。试验期28 d。结果表明:与对照组相比,1)在生长性能方面,Ⅱ组显著提高了乳鸽的28日龄体重和平均日增重(P0.05)。2)在屠宰性能方面,Ⅱ组显著提高了乳鸽的屠宰率、半净膛率和全净膛率(P0.05);Ⅰ组和Ⅲ组显著降低了乳鸽的腹脂率(P0.05)。3)在免疫器官指数方面,Ⅱ组显著提高了乳鸽的胸腺指数(P0.05)。4)在血清生化指标方面,Ⅰ组和Ⅲ组显著降低了乳鸽血清中总蛋白和球蛋白的含量(P0.05);Ⅰ组、Ⅱ组和Ⅲ组均显著降低了乳鸽血清中肌酐的含量(P0.05);Ⅱ组和Ⅲ组显著降低了乳鸽血清中甘油三酯的含量(P0.05);Ⅱ组显著增加了乳鸽血清中高密度脂蛋白的含量(P0.05)。综上所述,保健砂中添加复合益生菌改善了乳鸽的生长性能、屠宰性能、免疫器官指数和血清生化指标。     

聚乙二醇引发对几种牧草种子发芽率和活力的影响

应用聚乙二醇（ＰＥＧ）引发法探讨了不同引发渗透势、时间处理对无芒雀麦、苏丹草、沙打旺、小冠花、紫花芷蓿等牧草种子萌发和活力和有性在适宜处理下供试种子发芽速度、发芽率及活力指数分别显著高于对照;ＰＥＧ的引发作用还表现为提高活力效应大于提高发芽率效应,学表明,低渗透势（－０．１、－１．２、－１．５ＭＰａ）引发处理对提高发芽率无作用;但处子早期萌发的效应对于沙打旺和小冠花种子的２仍很强烈,对苏丹草种子则     

Exploratory trials on reinforcement of veld with legumes in the south‐eastern transvaal highveld

Abstract

The feasibility and potential of reinforcing veld with legumes in the south‐eastern Transvaal highveld was assessed in a number of trials during the period 1974–84. Experience was gained with regard to methods of establishment, adaptation of legumes to the local environment, responses to fertilization, especially with lime and superphosphate, and the reaction of legumes to fire and grazing. In all, 17 legumes were involved, including the genera Coronilla, Desmodium, Glycine, Lespedeza, Lotus, Macroptilium, Medicago, Neoto‐nonia, Trifolium and Vigna. Only Coronilla varia (crownvetch) showed a satisfactory degree of persistence. However, crownvetch is slow to establish, is intolerant of waterlogging and has a relatively high requirement for lime and phosphate. Considering these features, and the probability of undesirable changes in grass species composition in reinforced veld, it is recommended that intensification be achieved through development of improved pastures for use in conjunction with veld, rather than by means of veld reinforcement.     

Prediction of response to marker-assisted and genomic selection using selection index theory

Selection index methods can be used for deterministic assessment of the potential benefit of including marker information in genetic improvement programmes using marker-assisted selection (MAS). By specifying estimates of breeding values derived from marker information (M-EBV) as a correlated trait with heritability equal to 1, it was demonstrated that marker information can be incorporated in standard software for selection index predictions of response and rates of inbreeding, which requires specifying phenotypic traits and their genetic parameters. Path coefficient methods were used to derive genetic and phenotypic correlations between M-EBV and the phenotypic data. Methods were extended to multi-trait selection and to the case when M-EBV are based on high-density marker genotype data, as in genomic selection. Methods were applied to several example scenarios, which confirmed previous results that MAS substantially increases response to selection but also demonstrated that MAS can result in substantial reductions in the rates of inbreeding. Although further validation by stochastic simulation is required, the developed methodology provides an easy means of deterministically evaluating the potential benefits of MAS and to optimize selection strategies with availability of marker data.