全文获取类型
收费全文 | 49篇 |
免费 | 6篇 |
专业分类
林业 | 5篇 |
6篇 | |
综合类 | 3篇 |
农作物 | 2篇 |
水产渔业 | 2篇 |
畜牧兽医 | 34篇 |
园艺 | 1篇 |
植物保护 | 2篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1986年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1967年 | 1篇 |
1923年 | 1篇 |
排序方式: 共有55条查询结果,搜索用时 17 毫秒
1.
The practice of horse rugging has important implications for horse welfare and performance, but in Australia, rugging practices have not been properly documented. The objective of this study was to obtain an understanding of Australian horse rugging practices. An online survey reviewed the management of 2659 Australian horses over 12 months. Of the reported horses a total of 84.8% were rugged, although most owners (69.5%) indicated that they were unsure whether horses needed to be rugged at all. Rugging was felt by 59.8% of owners to be a requirement for horses in competition. Riding and competition were significantly associated with the use of rugs. Nearly all respondents (89.0%) felt that ‘over-rugging’ was a concern. However, 4.8% of owners would use up to 4 rugs at any one time on their horse and 21.4% of horses were still rugged in temperatures above 20°C in Australia. Many Australian horse owners (42.8%) also believe that horses feel cold if they are not rugged. Anthropomorphism when it comes to rugging horses cannot be justified as the horse has a much wider thermoneutral zone (TNZ) than humans. Australian climate, owner opinions, equestrian discipline and whether a horse is used for riding influence Australian horse rugging practices. However, current practices are based on limited available research and are not necessarily to the benefit of the horse. The major limitation was that the survey likely attracted respondents who are interested in the topic creating a self-selection bias. 相似文献
2.
Regulation by gonadal steroids of estrogen and progesterone receptors along the reproductive tract in female lambs. 总被引:2,自引:0,他引:2
A Meikle EG Garófalo M Rodríguez-Pi?ón C Tasende L Sahlin 《Acta veterinaria Scandinavica》2001,42(1):161-169
The regulation of estrogen and progesterone receptor (ER, PR) expression by estradiol (E2) and progesterone (P4) in the oviduct, uterus and cervix of female lambs was studied. The animals received three intramuscular injections of E2, P4 or vehicle with an interval of 24 h and they were slaugthered 24 h after the third injection. Determinations of ER and PR were performed by binding assays and mRNAs of ER alpha and PR by solution hybridization. High levels of ER and PR in both cervix and oviduct were found in the female lamb, differing from other mammalian species. No significant effects by either E2 or P4 treatment on ER and PR levels in the cervix and oviduct could be observed. E2 treatment increased the mRNA levels of ERa and PR more than 3-fold in the cervix, while P4 treatment increased the mRNA levels of ERa and PR in the uterus. The results show differential effects of gonadal steroids on sex steroid receptor expression along the reproductive tract in female lambs, suggesting that steroid target tissues can modulate responses to the same circulating levels of steroid hormones. 相似文献
3.
4.
Malm O Guimarães JRD Castro MB Bastos WR Viana JP Branches FJP Silveira EG Pfeiffer WC 《Water, air, and soil pollution》1997,97(1-2):45-51
Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994). 相似文献
5.
Principal component analysis (PCA) and cluster analysis werecarried out on beach litter found primarily along theBristol Channel, U.K., together with beaches located aroundthe Principality of Wales. Both techniques indicated threebeach survey sites as outliers, with distinctive beachlitter profiles. PCA distinguished between riverine, sewagerelated, fishing and shipping sourced items, but did notproduce a coherent grouping for beach user litter. This wasattributed to a difference in modes of transport. Beachesfrom mid and north Wales, which had small litter amounts,were not differentiated from the central grouping. Thewestern edge of the Channel was more heavily influenced byshipping and fishing inputs than was the eastern portion.Cluster analysis showed a discrete group of beaches locatedmainly on the southern side of the Bristol Channel. 相似文献
6.
Tudor H. Thomas 《Pest management science》1974,5(1):87-100
The use of growth regulators to induce specific modifications in the growth of crops produced for processing is discussed. Increases in yield may be obtained by some treatments but more important effects on uniformity, quality, ease of harvesting and short-term storage may also be achieved. The results of experiments on stem extension of calabrese, chemical stopping and defoliation of Brussels sprouts, root/shoot ratio modification of root crops and short-term storage of green vegetables are presented. It is concluded that although so far, few commercial applications have been discovered, the requirements for growth regulation justify the search for new, more reliable synthetic growth regulators by improving screening tests and more efficient field trials. The use of herbicides on crops grown for processing is also discussed briefly and it is concluded that the prime requirement is for more efficient post-emergence herbicides. 相似文献
7.
8.
The present study investigated the effects of pre‐weaning energy substitutions on follicular development, endocrine characteristics and subsequent litter size in primiparous sows. Sows were fed a standard lactation diet (14.1 DE MJ/kg) and then allocated to a Control (C, n = 24), Fat (F, n = 23), Sugar (S, n = 23) or post‐weaning Regumate (positive control; R, n = 22) treatment at 9 days before weaning of the C, F and S treatments. During the treatment period (8 days), 1 kg of the lactation diet was substituted with 1 kg of a fat‐rich (F, 23.85 DE MJ/kg) or sugar‐rich (S, 15.75 DE MJ/kg) substitution for F and S sows, respectively. For the R treatment, sows were weaned 8 days earlier than other treatments and fed a lactation diet at 3.5 kg with two doses of altrenogest as topdressing from 1 day before weaning until the day on which the other sows were weaned. The F treatment aimed to increase energy intake, and the S treatment aimed to elevate post‐prandial glucose and insulin concentrations. Weaning‐to‐ovulation interval tended to be reduced in the S treatment compared with C (p = 0.06) and F (p = 0.08) treatments. Body weight (BW) loss during the treatment period, post‐weaning follicle development, plasma oestradiol and pre‐weaning leptin did not differ among C, F and S sows, although BW loss was lower and leptin was higher in the R treatment. Post‐ovulatory progesterone concentration in the S treatment was higher (p < 0.05). Sows in the S and R treatments had a greater proportion of litters with larger litter sizes (p < 0.05). The outcome suggests that increasing circulating insulin and glucose concentrations during late lactation or a week of metabolic recovery positively improves subsequent litter size in primiparous sows. 相似文献
9.
R A Tudor M G Papich W R Redding 《Journal of the American Veterinary Medical Association》1999,215(4):503-506
OBJECTIVE: To evaluate pharmacokinetics of once daily i.v. administration of gentamicin sulfate to adult horses that had abdominal surgery. DESIGN: Prospective study. ANIMALS: 28 adult horses that underwent abdominal surgery for colic. PROCEDURE: 14 horses were treated with each dosage of gentamicin (i.e., 6.6 or 4 mg/kg, i.v., q 24 h) and blood samples were collected for pharmacokinetic analysis. Plasma gentamicin concentrations were measured by use of a fluorescence polarization immunoassay. Pharmacokinetic analysis measured the elimination half-life, volume of distribution, and gentamicin total systemic clearance. Treatment outcome, CBC, and serum creatinine concentrations were recorded. RESULTS: 1 horse in the high-dosage group died. All other horses successfully recovered, and did not develop bacterial infection or have evidence of drug toxicosis resulting in renal injury. Mean pharmacokinetic variables for gentamicin administration at a high or low dosage (i.e., 6.6 or 4 mg/kg, i.v., q 24 h) were half-life of 1.47 and 1.61 hours, volume of distribution of 0.17 and 0.17 L/kg, and systemic clearance of 1.27 and 1.2 ml/kg/min, respectively. Mean serum creatinine concentration was 1.74 and 1.71 for the high and low dosages, respectively, and serum creatinine concentration was not correlated with gentamicin clearance. CONCLUSIONS AND CLINICAL RELEVANCE: Gentamicin administration at a dosage of 4 mg/kg, i.v., every 24 hours, will result in plasma concentrations that are adequate against susceptible bacteria with a minimum inhibitory concentration (MIC) of < or = 2.0 micrograms/ml. Gentamicin administration at a calculated dosage of 6.8 mg/kg, i.v., every 24 hours will result in optimum plasma concentrations against susceptible bacteria with a MIC of < or = 4.0 micrograms/ml. 相似文献
10.
AISB Villaverde EG Fioratti FC Landim-Alvarenga JC de Carvalho Balieiro CM Melo FO Papa MD Lopes 《Reproduction in domestic animals》2009,44(S2):309-312
This study was aimed at assessing the changes in sperm motion patterns and the percentage of acrosome reaction (AR) in domestic cat semen after treatment with either ionomycin or progesterone (P4 ). Ten ejaculates were collected from five tomcats using an artificial vagina, and were diluted, centrifuged and resuspended in a capacitation medium. Samples were evaluated and divided into seven equal aliquots and, after 2 h at 25°C, were incubated for 30 min at 38°C in 5% CO2 and then analyzed. Computer-assisted sperm analysis and a combination of three fluorescent probes were used to assess sperm plasma, acrosomal membrane integrity and mitochondrial transmembrane potential. Thirty minutes after the start of incubation, P4 was added (10 μg/ml) to the P1 group. Groups P2 and P3 were supplemented with P4 (10 and 20 μg/ml, respectively) only after 2 h of incubation, and groups I1 and I2 were supplemented with ionomycin (4 and 8 μ m , respectively) 2 h after incubation. Group E was supplemented with ethanol (0.6%) at 2 h after incubation and group C received no supplementation. Ionomycin and P4 treatments led to a hyperactivation-like sperm motion and an increase (p < 0.05) in the percentage of AR. Although a higher (p < 0.05) percentage of AR was obtained in group I2 when compared with all P4 groups, a decrease (p < 0.05) in total and progressive motility was observed in I2 group. As I1 group was similar to I2 to induce AR without diminishing sperm motility, we can conclude that ionomycin at 4 μ m seems to be more suitable to trigger AR in domestic cat sperm. 相似文献