水泥砼路面滑模施工单质材料控制与管理

结合水泥砼路面滑模摊铺技术实际情况。阐述了各种单质材料管理的方法和控制要点。     

气候对森林粗木质残体贮量的影响

森林中的粗木质残体（CWD）是生物圈与土壤圈养分配置的中介和纽带,CWD的贮量影响森林中元素的循环。文中通过比较世界各气候带森林系统中CWD的贮量,总结了造成各气候带森林中CWD贮量差异的气候因素。各气候带不同的气温、降水以及气温与降水的时间搭配关系,通过影响森林木材生产力、活立木死亡量及CWD的分解速率,进而影响CWD在林内的贮量。热带雨林、季雨林中CWD的平均贮量最低,仅为19.96～27.71 t/hm2;温带海洋性气候森林中CWD的平均贮量高达205.8～213.2 t/hm2。在全球变暖的大背景下,贮存在CWD中的C元素含量关乎着大气中CO₂含量,故应加强世界各气候带森林中CWD贮量格局的长期监测和系统调研。     

DNA在黑土胶体微界面的吸附与解吸特性

为了揭示DNA在黑土微生物的遗传进化和基因转移机制方面的重要意义,采用平衡法研究了含有机质黑土胶体(Coarse organic colloid,COC)和去有机质黑土胶体(Coarse inorganic colloid,CIC)对DNA的吸附与解吸特性。结果表明:CIC在快速吸附期吸附DNA的速率和数量都小于COC,且更快达到吸附平衡;随着pH值升高,黑土胶体表面吸附DNA数量逐渐减少;Langmuir吸附方程可较好地描述COC和CIC对DNA的等温吸附,COC和CIC的决定系数(R~2)分别为0.972和0.991,且COC的吸附平衡常数(K)大于CIC,说明COC对DNA的吸附亲和能力大于CIC;CIC和COC表面DNA的解吸率分别为63.5%和47.4%。研究结果证明,有机质在黑土胶体吸附DNA的数量和亲和力方面贡献较大,pH是影响黑土胶体吸附DNA的重要因子。     

中草药饲料添加剂的研究进展与展望

综述了中草药饲料添加剂的研究简史、特点及其作用机理,以及在畜牧生产中的应用。在展望我国中草药饲料添加剂发展前景的同时,提出了存在的问题和解决对策。     

The effect of concentrate feed level on the response of lactating dairy cows to a constant proportion of fodder beet inclusion in a grass silage-based diet

Abstract The effects of level of concentrate supplementation on the response of dairy cows to grass silage‐based diets containing a constant proportion of fodder beet were examined. Forty Holstein‐Friesian dairy cows of mixed parity were used in a 2 × 5 factorial design experiment. Two basal diet types [grass silage alone or grass silage mixed with fodder beet in a 70:30 dry matter (DM) ratio] were offered ad libitum, and the effects of five levels of concentrate supplementation (mean = 3·0, 5·3, 7·5, 9·8 and 12·0 kg DM per cow d^?1) were examined. Concentrate supplements were offered via an out‐of‐parlour feeding system. These treatments were examined in a three‐period (period length = 4 weeks) partially balanced changeover design experiment. Fodder beet inclusion had no significant effect on the estimated metabolizable energy (ME) concentration of the ration (P > 0·001). Total DM intake, estimated ME intake, milk yield, milk protein content and milk energy output all showed significant linear increases with increasing level of concentrate inclusion (P < 0·001) while, in addition, milk yield and milk energy output exhibited a significant quadratic increase (P < 0·01). The inclusion of fodder beet in the diet reduced silage DM intake (P < 0·01) but resulted in an increase in total DM intake and estimated ME intake (P < 0·001). However, inclusion of fodder beet had no significant effect on milk yield (P > 0·05), while increasing milk protein content and milk energy output (P ≤ 0·05). Milk energy output, as a proportion of estimated ME intake, was significantly (P < 0·001) reduced by fodder beet inclusion (0·44 vs. 0·38). Despite large increases in estimated ME intake with the inclusion of fodder beet at all levels of concentrate supplementation, milk energy output responses were small, resulting in an overall reduction in the efficiency of conversion of ME intake into milk energy output. An increased partitioning of dietary ME intake to tissue gain is suggested as the most likely explanation for the observations made.     

RapidChek SELECET方法与GB/T13091要2002方法检测饲料中沙门氏菌比较研究

进行RapidChek SELECET方法和GB/T13091-2002方法检测饲料中沙门氏菌的效果研究,结果表明：相同的样品采用2种方法检测出的结果完全相同,且RapidChek SELECT检测时间比GB/T13091-2002检测时间少。     

Using farmers' criteria to assess profitability of fodder shrubs in the desert margins of West Africa

This paper presents the results of a study carried out in the Ségou region of Northern Mali to analyse the use of fodder shrubs. The farmer‐level fodder banks consisted of three perennial legumes (Gliricidia sepium, Pterocarpus erinaceus and Pterocarpus lucens). The main question addressed is whether this new type of fodder was more profitable for smallholder farmers compared to alternative fodder options. To test hypotheses for profitability, farmers were grouped in two different ways. The first grouping was based on the different village communities the farmers belonged to. The second grouping consisted of three user groups based on individual (non‐) use patterns of the fodder banks. ‘Passives’ were non‐users because of apparent disinterest. ‘Actives’ were the group of users whose fodder banks performed well and who harvested in time while ‘Unfortunates’ were non‐users unable to harvest fodder mostly through high mortality rates of the shrubs. Profitability was measured by increases in income or increases in the productivity of labour spent on feeding livestock. Profitability was shown to be dependent on the use pattern of the fodder shrubs. In the actual situation no user group had gained any concrete financial benefits. The several scenarios in which other use modalities were modelled, did show gains of using fodder shrubs, but only under conditions where alternative options were expensive. The perceived value of this technology was high. The use patterns indicated that this did not necessarily reflect farmers' long term interest in the technology itself. Rather, farmers were motivated by perceived opportunities to gain short term material and social benefits from the project promoting the shrubs. Copyright © 2007 John Wiley & Sons, Ltd.     

高原鼠兔饵料引诱剂的试验研究

为寻求一种饵料引诱剂 ,增加毒饵的适口性 ,以提高对高原鼠兔的防治效果 ,自制了五种引诱剂 ,采用笼养试喂的方法 ,进行引诱剂的试验研究 ,结果表明y1、y2 两种引诱剂对高原鼠兔的引诱效果较好     

发展木本饲料前景及其在水土保持中的地位

中国国民人均营养摄入水平在过去20年中有了显着提高,但摄入的动物蛋白还较低,随着生活水平的改善,国民对肉类食品的需求也从量的需求转到对质的需求,加快发展畜牧业是解决这些问题的重要途径,但我国面临的精饲料、蛋白饲料、绿色饲料缺乏和饲料总量不足的现实限制了畜牧业的快速发展。讨论了利用我国农区丰富多样的气候资源,利用荒山荒坡、地埂、田边地角等土地资源发展蛋白质含量高、生物量大、可多年受益、具有多种效益的木本饲料的重要性、可行性及前景,发展木本饲料在经济发展、水土保持和环境保护方面的作用和意义。     

Nutrient digestibility of angling baits for carp, Cyprinus carpio, with implications for groundbait formulation and eutrophication control

Abstract  To evaluate the suitability of angling groundbaits as a fish feed and the potential for nutrient loss, the macronutrient digestibility of four groundbaits was investigated in carp, Cyprinus carpio L., using a sieving method of faeces collection and chromic oxide. Apparent digestibility coefficients (ADCs) of protein and lipids were >80% for all angling baits. ADCs of nitrogen-free extracts and phosphorus (P) differed significantly between the test diets, probably because of divergent feed compositions and ingredient treatments. The generally high digestibility estimates indicated that fish feeding on angling groundbait will benefit from this food source. The differences in nutrient digestibility suggested that type of groundbait and ingredient used will have a major effect on potential eutrophication and fish production caused by groundbaiting. The principle of groundbaits to protect the environment should be to minimise the P-content of the groundaits and maximising P-digestibility and P-retention efficiency.