全文获取类型
收费全文 | 411篇 |
免费 | 36篇 |
专业分类
林业 | 56篇 |
农学 | 14篇 |
80篇 | |
综合类 | 12篇 |
农作物 | 16篇 |
水产渔业 | 79篇 |
畜牧兽医 | 147篇 |
园艺 | 6篇 |
植物保护 | 37篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 35篇 |
2020年 | 35篇 |
2019年 | 50篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 24篇 |
2012年 | 26篇 |
2011年 | 37篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 9篇 |
2007年 | 4篇 |
2006年 | 19篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1973年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有447条查询结果,搜索用时 390 毫秒
91.
92.
Brenna de Sousa Barbosa Herlon Victor Rodrigues Silva Beatriz Evaristo de Almeida Tabosa Thalles Gothardo Pereira Nunes Francisco Felipe de Magalhes Lúcia Daniel Machado da Silva 《Reproduction in domestic animals》2019,54(12):1630-1636
Sperm morphometry is the tool that confers objectivity to the morphological evaluation by accurately measuring the dimensions of the gamete and its structures. Thus, the aim of the study was to perform a morphometric characterization of the domestic cat sperm. Therefore, sperm samples were collected from twenty pairs of epididymis in a TRIS extender at 37ºC. An aliquot of the sample was used to make a smear with Rose Bengal solution, and afterwards, the morphology and morphometry were analysed. In the morphology, were quantified the percentage of normal sperm cells, morphological changes of head, midpiece and tail. In morphometry, each normal sperm cell was measured for length, width, area and perimeter of head and midpiece, tail length and total length. The parameters ellipticity, elongation, regularity and rugosity were also determined. The percentage of normal sperm was 67.21%. Of the abnormalities, the curled/folded tail, followed by the curved midpiece, abnormal shaped head and detached head were the most quantified. The sperm head presented 5.56 ± 0.01 μm and 3.10 ± 0.01 μm of length and width, respectively. The head area was 16.94 ± 0.05 μm2, while the perimeter was 16.16 ± 0.03 μm. In the derived parameters, the values were as follows: ellipticity of 1.81 ± 0.00; elongation of 21.39 ± 0.12; regularity of 0.81 ± 0.00; and rugosity of 0.14 ± 0.00. The midpiece presented length and width of 7.96 ± 0.01 μm and 0.76 ± 0.01 μm, respectively. The mean length of the sperm tail was 45.12 ± 0.06 μm, and the total cell size was 58.67 ± 0.06 μm. Thus, it was concluded that the cat sperm is an elongated cell, with high rugosity and regularity. The spermatic tail represents more than ¾ of the total length of the cell and the midpiece exceeds the length of the head. 相似文献
93.
94.
de Almeida Daniel Mageste Marcondes Marcos Inácio Rennó Luciana Navajas Pereira Silva Luiz Henrique Martins Leandro Soares Marquez David Esteban Contreras Castaño Villadiego Faider Alberto Velez Saldarriaga Felipe Franco Julian David Castaño Moreno Deilen Paff Sotelo de Moura Felipe Henrique Paulino Mário Fonseca 《Tropical animal health and production》2019,51(1):79-87
Tropical Animal Health and Production - The objective of this study was to evaluate the effects of strategic supplementation in the dry period and dry/rainy transition period on the performance and... 相似文献
95.
Marcella Teixeira Linhares Joo Pedro Scussel Feranti Gabriela Pesamosca Coradini Letícia Reginato Martins Arthur Rodrigues Martins Vanessa Zanchi Sarturi Felipe Baldissarella Gavioli Marco Augusto Machado Silva Michelli Westphal de Ataíde Luciana Gonalves Teixeira Maurício Veloso Brun 《Veterinary surgery : VS》2019,48(Z1):O74-O82
96.
Rafael Arturo Torres-Fajardo Jorge Augusto Navarro-Alberto Javier Ventura-Cordero Pedro Geraldo González-Pech Carlos Alfredo Sandoval-Castro José Israel Chan-Pérez Juan Felipe de Jesús Torres-Acosta 《Strength and Conditioning Journal》2019,72(6):946-953
Feeding behavior is a multifactorial process with pivotal relevance for the maintenance and survival of ruminants. This study evaluated the effect of gastrointestinal nematodes (GIN), condensed tannin (CT) content of plants, and their possible interaction on the intake and selection of feed resources by Criollo goats in a heterogeneous vegetation. An 8-wk field experiment was conducted in the tropical deciduous forest (TDF) during the rainy season with adult Criollo goats (35.1 ± 6.7 kg body weight [BW]). Goats were assigned to four groups (n = 6): 1) MOX: suppressive treatment with moxidectin (Cydectin 0.4 mg/kg BW subcutaneous every 4 wk), 2) INF: with natural GIN infection, 3) MOX + PEG: treated with moxidectin and dosed with a CT-neutralizing agent (50 g of polyethylene glycol [PEG] diluted in 50 mL of water, per os), and 4) INF + PEG: with natural GIN infection and PEG dosage. Intake was measured using a direct observation method in a 2.2-ha TDF plot. Plant availability was obtained from 30 exclusion quadrants (2 × 2 m). Selection was estimated with the Cheeson index using the ratio of consumed plants and their availability by grouping plant species as shrubs and herbs (with high CT [> 10%], medium CT [> 3% to < 10%], or low CT [< 3%]), vines, and grasses. Neither GIN infection nor CT neutralization influenced intake or selection of feed resources. All groups showed high selection toward grass species (P < 0.001), which may represent a strategy to reduce intake of crude protein and CT from shrubs and herbs. In conclusion, GIN infection and CT neutralization do not influence intake or selection of goats with browsing experience in the TDF. Selection toward grass suggested a trade-off between nutrient harvest optimization and the health risk of GIN infective larvae consumption. Thus, it is necessary to revalorize the TDF as a sustainable feed resource for goats. 相似文献
97.
98.
99.