全文获取类型
收费全文 | 566篇 |
免费 | 59篇 |
专业分类
林业 | 14篇 |
农学 | 3篇 |
基础科学 | 3篇 |
45篇 | |
综合类 | 102篇 |
农作物 | 15篇 |
水产渔业 | 16篇 |
畜牧兽医 | 405篇 |
园艺 | 5篇 |
植物保护 | 17篇 |
出版年
2019年 | 4篇 |
2018年 | 4篇 |
2016年 | 7篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 20篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 17篇 |
2005年 | 26篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 13篇 |
2001年 | 17篇 |
2000年 | 27篇 |
1999年 | 23篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1994年 | 4篇 |
1992年 | 15篇 |
1991年 | 12篇 |
1990年 | 13篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 19篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1974年 | 12篇 |
1973年 | 26篇 |
1972年 | 20篇 |
1971年 | 8篇 |
1970年 | 10篇 |
1969年 | 10篇 |
1968年 | 9篇 |
1967年 | 9篇 |
1966年 | 7篇 |
1960年 | 3篇 |
排序方式: 共有625条查询结果,搜索用时 15 毫秒
81.
Egenvall A Bonnett BN Ohagen P Olson P Hedhammar A von Euler H 《Preventive veterinary medicine》2005,69(1-2):109-127
The main objective of this study was to describe the incidence of mammary tumors (MTs) and the survival after MTs, in female dogs between 3 and 10 years of age (insured for veterinary care and with life insurance in a Swedish animal-insurance company) from 1995 to 2002. Measures of incidence are presented crudely, by breed and across age categories and birth cohorts (1991-1998). The survivals until MT diagnosis and after a MT diagnosis were computed. The overall incidence for any MT claim was 111 dogs per 10,000 dog-years at risk (DYAR). The overall MT rate in the 1992 and 1993 birth cohorts was 154 dogs per 10,000 DYAR. The incidence for any MT claim increased with age and varied by breed, from 319 dogs per 10,000 DYAR in the English springer spaniel to 5 dogs per 10,000 DYAR in the rough-haired collie. At the ages 6, 8 and 10 years, 1%, 6% and 13% respectively, of all females had at least one MT claim. The MT mortality was 6 deaths per 10,000 DYAR and increased with age. The overall-case fatality was 6%. 相似文献
82.
Casas E White SN Riley DG Smith TP Brenneman RA Olson TA Johnson DD Coleman SW Bennett GL Chase CC 《Journal of animal science》2005,83(1):13-19
Objective of this study was to assess the association of SNP in the diacylglycerol O-acyltransferase 1 (DGAT1), thyroglobulin (TG), and micromolar calcium-activated neutral protease (CAPN1) genes with carcass composition and meat quality traits in Bos indicus cattle. A population of Brahman calves (n = 479) was developed in central Florida from 1996 to 2000. Traits analyzed were ADG, hip height, slaughter weight, fat thickness, HCW, marbling score, LM area, estimated KPH fat, yield grade, retail yield, sensory panel tenderness score, carcass hump height, and cooked meat tenderness measured as Warner-Bratzler shear force at 7, 14, and 21 d postmortem. Single nucleotide polymorphisms previously reported in the TG and DGAT1 genes were used as markers on chromosome 14. Two previously reported and two new SNP in the CAPN1 gene were used as markers on chromosome 29. One SNP in CAPN1 was uninformative, and another one was associated with tenderness score (P < 0.05), suggesting the presence of variation affecting meat tenderness. All three informative SNP at the CAPN1 gene were associated with hump height (P < 0.02). The TG marker was associated with fat thickness and LMA (P < 0.05), but not with marbling score. No significant associations of the SNP in the DGAT1 gene were observed for any trait. Allele frequencies of the SNP in TG and CAPN1 were different in this Brahman population than in reported allele frequencies in Bos taurus populations. The results suggest that the use of molecular marker information developed in Bos taurus populations to Bos indicus populations may require development of appropriate additional markers. 相似文献
83.
Posterior paresis/paralysis in farmed mink is responsible for significant morbidity and mortality, with individual farms reporting the loss of as many as 700 animals each year. Although this disease has been recognized by North American mink farmers for approximately 40 years, there are few published reports focusing on this entity. The objective of this study was to investigate the etiology and pathogenesis of the disease. Complete necropsy examinations were done on 40 clinically affected mink, ranging from 7 to 10 weeks of age, and on three normal animals in the same age range from two mink farms. Thirty-two of the 40 clinically affected animals had an isolated vertebral lesion characterized by bone lysis and proliferation that usually was centered on an intervertebral disk space in the midthoracic area. An inflammatory reaction, composed primarily of neutrophils, was present within the vertebral sections in 25 of the 40 affected animals (62.5%), and the presence of gram-positive cocci was confirmed in 8 of 10 animals (80%) in which bacterial organisms were observed histologically. Bacterial cultures from 15 affected animals yielded Streptococcus sp. from the intervertebral disk space in 13 of 15 (86.7%) animals and from heart blood in 6 of 8 (75%). A farm visit revealed no history or evidence of traumatic wounds as a source of infection in these animals, and the diet appeared to be adequate for skeletal development. We conclude that posterior paresis/paralysis in farmed mink is associated with bacterial diskospondylitis, likely occurring secondary to bacteremia/septicemia. 相似文献
84.
Garossino KC Ralston BJ Olson ME McAllister TA Milligan DN Genswein BM 《Veterinary parasitology》2005,129(1-2):35-41
A 95-day study (June 25-September 27, 2001) was conducted using 120 steers (311.9+/-2.4 kg) randomly allocated to two treatments: (1) mineral containing 0.55% fenbendazole (FBZ) and (2) control, no FBZ in the mineral. Animals in the FBZ group were individually identified by an electronic tag that was read each time an animal attended the mineral feeder. The feeder was equipped with load cells that enabled individual mineral intakes to be estimated. The FBZ group was provided with non-medicated mineral during a 14-day adaptation period (July 23-August 5) and an 8-day post-medication period (September 17-24). The intake of FBZ was monitored for 14 days during each of the two treatment periods; August 6-19 and September 3-16, separated by a 14-day non-medicated period, August 20-September 2. Control animals had access to non-medicated mineral for the entire 95-day study period. All steers were grazed on alfalfa-grass pasture for the duration of the study and had free access to flocculated, filtered and chlorinated water via an automatic waterer. Fecal samples were collected from steers three times during the experiment July 23, August 27 and September 27, and analyzed for nematode eggs and Giardia sp. cysts. Seventy-five and 83% of the steers in the FBZ group visited the mineral feeder during the first and second treatment periods, respectively. Individual daily mineral and FBZ intake for the first and second treatment periods was 52.9+/-6.6g per day and 10.1+/-1.2mg/kg BW; 72.3+/-8.4 g per day and 11.8+/-1.4 mg/kg BW, respectively. FBZ animals were separated into three groups during each treatment period based on the recommended dose (RD) of FBZ (5 mg/kg/BW), those that received > the RD, those that received < RD but > 50% RD and those that received < 50% of RD. Nematode egg counts and the number of animals infected with nematodes was reduced (p < 0.05) in all cattle that consumed FBZ as compared to control animals. In contrast to nematode eggs, numbers of Giardia cysts was not reduced (p > 0.05) by FBZ as compared to controls in either treatment period. These results may be a reflection of Giardia re-infection occurring following treatment and highlight the need for variation in treatment regimes specifically targeted at the parasite of interest. 相似文献
85.
86.
87.
T B Goehring I S Palmer O E Olson G W Libal R C Wahlstrom 《Journal of animal science》1984,59(3):733-737
A total of 96 crossbred pigs received various levels of sodium selenite to determine the effect of dietary selenium (Se) on growing swine fed corn-soybean meal diets. Levels of supplemental Se were 0, 4, 8, 12, 16 and 20 micrograms/g. There were linear decreases (P less than .01) in both gain and feed intake with increasing levels of dietary Se. Feed/gain increased numerically as dietary Se increased. Hair Se increased quadratically (P less than .01) and blood Se increased linearly (P less than .01) with increasing level of dietary Se. Cell volume and hemoglobin were not affected by dietary treatment. Increasing dietary Se significantly increased glutathione peroxidase (GSH-Px), glutamic-oxalacetic transaminase (GOT). and glutamic-pyruvic transaminase (GPT). External signs of selenosis were noted in some pigs fed 12 or 20 micrograms/g of Se. The toxic level of Se in a corn-soybean meal diet for crossbred pigs appears to be between 4 and 8 micrograms/g. Of variables studied, growth rate was the most sensitive indicator of chronic selenosis in swine. 相似文献
88.
Recovery of pigs from rabies 总被引:4,自引:0,他引:4
89.
J Storz M L Miner M E Marriott A E Olson 《American journal of veterinary research》1966,27(116):110-114
90.
Acute diarrheal disease in the horse 总被引:1,自引:0,他引:1
N E Olson 《Journal of the American Veterinary Medical Association》1966,148(4):418-421