全文获取类型
收费全文 | 111篇 |
免费 | 7篇 |
专业分类
林业 | 4篇 |
7篇 | |
综合类 | 27篇 |
农作物 | 8篇 |
畜牧兽医 | 69篇 |
园艺 | 2篇 |
植物保护 | 1篇 |
出版年
2023年 | 1篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1973年 | 1篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1953年 | 1篇 |
1951年 | 1篇 |
1937年 | 1篇 |
1917年 | 1篇 |
排序方式: 共有118条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Five crossbred beef steers (329 kg) were used in a 5 x 5 Latin square experiment with 14-d periods to determine the effects of supplementation with high-nitrogen (N) feeds alone or mixed with tallow on sites of digestion with a basal diet of bermudagrass hay. Hay was 1.93% nitrogen, 75% neutral detergent fibre and fed at 1.83% of body weight (dry matter; DM). Supplements were basal (B; 105 g DM): 81.8% dried molasses product (DMP) and 18.2% calcium carbonate (CC); soybean meal (S; 942 g DM): 88.0% soybean meal, 9.8% DMP and 2.2% CC; S mixed with 9.8% tallow (SF; 1041 g DM); corn gluten and blood meals (CB; 662 g DM): 62.5% corn gluten meal, 20.8% blood meal, 13.6% DMP and 3.0% CC; CB mixed with 13.2% tallow (CBF; 757 g DM). Total N intake was 117, 185, 187, 174 and 172 g/d, and duodenal N flow was 121, 148, 143, 162 and 169 g/d for B, S, SF, CB and CBF, respectively, being lower for B than for other treatments and higher for supplements with the corn gluten and blood meal mix than for soybean meal (P less than 0.05). Duodenal microbial N flow was 39, 51, 49, 38 and 45 g/d for B, S, SF, CB and CBF, respectively, being greater (P less than 0.05) for supplements with soybean meal than with corn gluten and blood meals. Duodenal flow of feed N was greater (P less than 0.05) with than without high-N feeds and for supplemental corn gluten and blood meals than for soybean meal (78, 90, 86, 117 and 116 g/d for B, S, SF, CB and CBF, respectively). In conclusion, mixing of tallow and high-N feeds did not affect the extent of ruminal N disappearance, and soybean meal supplementation increased duodenal N flow less than did supplementation with corn gluten and blood meals. Increased duodenal N flow with soybean meal was associated with about equal elevations of ruminal outflow of microbial and feed N, whereas the corn gluten-blood meal mix affected the intestinal protein supply by increasing ruminal escape of feed protein. 相似文献
6.
本论文研究了饲料加工的两个关键参数(调质温度和时间)对育肥猪颗粒饲料淀粉糊化度和维生素沉积的影响。日粮配方为含30%干酒糟及其可溶物的玉米-豆粕型基础日粮。整个试验中配方保持不变。本试验采用2×3双因子设计,调质温度分别为77℃和88℃,调质时间分别15秒、30秒和60秒。此外,本试验还设置一个对照组,对照组饲料不采用调质制粒工艺,而是采用粉料饲喂。因此,本试验共有7个处理组。采集调质后制粒前(热干粉)、制粒后冷却前(热制粒)、以及制粒冷却后(冷制粒)的样品,并分析这三种样品的总淀粉率、淀粉糊化 相似文献
7.
KC Silva‐Santos CR Ferreira GMG Santos MN Eberlin LS Siloto CO Rosa TN Marcantonio MM Seneda 《Reproduction in domestic animals》2014,49(5):711-718
The aim of the present study was to compare the lipid profile in oocytes of indicus and 1/2 indicus × taurus cows with high and low antral follicle count (AFC)/oocyte yields. After an OPU procedure (D0), antral follicles ≥3 mm were counted by ultrasonography (D4, 19, 34, 49, 64), and cows were assigned to groups with either high AFC (≥30 follicles; indicus, NH group; 1/2 indicus × taurus, AH group) or low AFC (≤15 antral follicles; indicus, NL group; 1/2 indicus × taurus, AL group). The lipid profiles of the oocytes were determined by MALDI‐MS. For GI, GII and GIII oocytes, the indicus samples tend to cluster separately from the 1/2 indicus × taurus samples. The lipid species [PC (P‐38:5) + H]+ and/or [PC (P‐36:2) + Na]+, [PC (38:2) + H]+, [PC (38:5) + Na]+ and [TAG (60:8) + NH4]+ were more abundant in indicus (NH and NL groups) than 1/2 indicus × taurus. The higher lipid content in the indicus oocytes likely reflects differences in the rate of lipid metabolism and may contribute to oocyte competence and embryo development. 相似文献
8.
Charles R. Sweet Giancarlo M. Alpuche Corinne A. Landis Benjamin C. Sandman 《Marine drugs》2014,12(7):4126-4147
Lipid A is the essential component of endotoxin (Gram-negative lipopolysaccharide), a potent immunostimulatory compound. As the outer surface of the outer membrane, the details of lipid A structure are crucial not only to bacterial pathogenesis but also to membrane integrity. This work characterizes the structure of lipid A in two psychrophiles, Psychromonas marina and Psychrobacter cryohalolentis, and also two mesophiles to which they are related using MALDI-TOF MS and fatty acid methyl ester (FAME) GC-MS. P. marina lipid A is strikingly similar to that of Escherichia coli in organization and total acyl size, but incorporates an unusual doubly unsaturated tetradecadienoyl acyl residue. P. cryohalolentis also shows structural organization similar to a closely related mesophile, Acinetobacter baumannii, however it has generally shorter acyl constituents and shows many acyl variants differing by single methylene (-CH2-) units, a characteristic it shares with the one previously reported psychrotolerant lipid A structure. This work is the first detailed structural characterization of lipid A from an obligate psychrophile and the second from a psychrotolerant species. It reveals distinctive structural features of psychrophilic lipid A in comparison to that of related mesophiles which suggest constitutive adaptations to maintain outer membrane fluidity in cold environments. 相似文献
9.
Mechanical comparison of materials used for extra-capsular stabilisation of the stifle joint in dogs
Objective The mechanical properties of three materials (No. 2 polypropylene, No. 5 polybutilate-coated multifilament polyester and 18, 27 and 36 kg test monofilament nylon leader material) commonly used for extra-capsular stabilisation of the stifle in dogs with cranial cruciate ligament insufficiency were determined. The ability of No. 5 polybutilate-coated multifilament polyester and 36 kg test monofilament nylon leader material, when placed as extra-capsular sutures, to mitigate cranial drawer was evaluated in hindlimbs of cadavers. Design An in vitro mechanical study. Animals Seven pairs of hindlimbs harvested from adult greyhound dogs recently euthanased for other reasons. Procedure Samples of each material, including samples of 27 kg test leader material that had been sterilised by one of three methods (ethylene oxide, one or five cycles in an autoclave), were loaded to determine tensile and stress relaxation properties. The effect of cyclic loading on a No. 5 polybutilate-coated multifilament polyester and 36 kg test leader material was also determined. Using the harvested hindlimbs, cranial drawer was measured before and after transection of the cranial cruciate ligament and on the first and twelfth cycle following extra-capsular stabilisation with either No. 5 polybu-tilate-coated multifilament suture or 36 kg test leader material. Results Leader material was found to have the most suitable mechanical characteristics for use as extracapsular stabilisation of the cranial cruciate ligament deficient stifle. Of the sterilisation methods, ethylene oxide was found to have the least detrimental effects on the handling and material characteristics of the leader material. Stifles stabilised with 36 kg test leader material had significantly less drawer than those stabilised with No. 5 polybutilate-coated multifilament polyester suture. Clinical implications Monofilament nylon leader material would appear to have suitable mechanical properties for extra-capsular stabilisation of the cranial cruciate ligament deficient stifle. If possible the material should be sterilised using ethylene oxide. 相似文献
10.