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91.
Tiago Orlandi Claudio A. Pozo Jordana Schiavo Lisandre Oliveira Gilberto V. Kozloski 《Animal Science Journal》2020,91(1)
This study was carried out to evaluate the impact of including Acacia mearnsii tannin extract (TA) as a feed additive on nutrition and productive performance of dairy cows grazing a high‐quality temperate pasture and receiving supplementation with a concentrate feedstuff. Fourteen multiparous Holstein cows were assigned to either of the following treatments: concentrate without or with 20 g TA/kg dry matter (DM). Concentrate intake accounted for 32% of the total DM intake. Tannin addition increased the herbage DM intake by 22% (p < .05). There was no effect of TA inclusion on milk yield, milk composition, milk nitrogen (N) excretion, milk and plasma urea‐N concentration, urinary excretion of total N, urea‐N, and purine derivatives. However, TA inclusion increased the N intake and retention, total N excretion in manure, fecal N to urine N ratio, and decreased the dietary N efficiency for milk production and the percentage of ingested N excreted in urine (p < .05). In conclusion, supplementing dairy cows grazing a high‐quality temperate pasture with a concentrate containing 20 g TA/kg DM showed the potential of decreasing the proportion of ingested N excreted in urine without affecting the productive performance. 相似文献
92.
N. Anantasook M. Wanapat A. Cherdthong 《Journal of animal physiology and animal nutrition》2014,98(1):50-55
Four rumen‐fistulated dairy steers were used in a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. The main factors were two roughage‐to‐concentrate ratios (R:C, 60:40 and 40:60) and two supplementation levels of rain tree pod meal (RPM) [0 or unsupplemented and 60 g/kg of total dry matter (DM) intake]. Chopped 30 g/kg of urea‐treated rice straw was used as a roughage source. All animals received dietary according to respective R:C ratios at 25 g/kg body weight. The RPM contained condensed tannins and crude saponins at 84 and 143 g/kg of DM respectively. It was found that total volatile fatty acids (VFAs) and propionate concentrations were increased (p < 0.01), while acetate concentration, acetate‐to‐propionate ratio, CH4 production and protozoal numbers were decreased (p < 0.01) when steers were supplemented with RPM and 600 g/kg of concentrate. Allantoin excretion was found different by both R:C ratio and supplementation of RPM, with the highest value at R:C of 40:60 with 60 g/kg RPM (123.6 mmol/day) (p < 0.05). Allantoin absorption and microbial crude protein were increased (p < 0.05) with an increasing concentrate ratio. Moreover, efficiency of microbial protein synthesis was increased (p < 0.05) by feeding a higher ratio of concentrate (R:C 40:60) and supplementation of RPM. Based on this study, it is suggested that supplementation of RPM was beneficial for dairy cows fed on high roughage ratio, which could improved rumen fermentation by reducing fermentation gas loss, thus improving VFA profiles and thus enhancing efficiency of microbial protein synthesis. 相似文献
93.
94.
Four species of Leucaena (L. leucocephala, L. diversifolia 2n and 4n, andL. pallida) and three interspecific hybrids KX1 (L. diversifolia × L. pallida), KX2 (L. leucocephala × L. pallida), and KX3 (L. leucocephala × L. pallida) were evaluated for forage yield on a cool upland site at the Mealani Research Station on the island of Hawaii (900 m elevation). Two-month-old seedlings were planted at a density equivalent to 40,000 trees/ha and coppiced (harvested) every six months for a two-year period. Leaf material collected from the plots was oven-dried, finely ground, and evaluated for forage components and digestibility.Two Holstein steers fitted with cannulae in the rumen and proximal duodenum were used to conduct a replicated trial to examine rumen and post-rumen dry matter and crude protein digestibility of leaf material. Nylon bags containing leaf material from K636 (L. leucocephala), KX2 (L. leucocephala × L. pallida), or K376 (L. pallida) were suspended in the rumen for periods of 0, 4, 8, 12, 24, 36, and 48 hours. Weight loss was measured and nitrogen content of each sample was determined using a macro-Kjeldahl procedure. Subsequently, rumen-incubated material was placed in nylon bags, inserted into the duodenal cannulae of the two steers and collected in the feces for periods of 24 h after insertion.Results indicate that varieties and hybrids of Leucaena are adapted to cool sites and produce good yields of high quality forage. No significant difference was found in either ruminal or intestinal dry matter or crude protein disappearance between K636 and KX2 whereas K376 was significantly lower for both values. Nearly 40% of dietary crude protein in the K636 and KX2 leaf material escaped ruminal digestion whereas nearly 70% was non-digested for K376. For K636 and KX2, intestinal availability of that protein which escaped ruminal digestion was nearly 50% whereas only 20% of ruminal escape protein of K376 was available in the intestines. Because KX2 produced higher forage yields, plantings on cool sites would favor the use of KX2 over K636 if animal acceptability and rumen retention of dry matter are not problems. 相似文献
95.
96.
Biruk Kebede Kim Van De Wiel Jill Derix Taye Tolemariam Veronique Dermauw Marta Lourenço Geert Paul Jules Janssens 《Journal of animal physiology and animal nutrition》2021,105(5):841-848
The dry season in tropical regions urges livestock to feed on nutritionally very poor diets. It has not been explored how tropical sheep—assumed grazers—and tropical goats—intermediate browsers—cope with a high-fibre tannin-rich diet. This study was designed to determine the effects of a high-fibre and tannin-rich diet on the flow of important microminerals iron (Fe), zinc (Zn) and copper (Cu) throughout the digestive tract of tropical sheep and goats. The feeding trial was set up with twelve adult male animals, six sheep with mean body weight (BW) of 30.3 ± 1.6 kg and six goats with mean BW of 26.4 ± 2.2 kg. The feed consisted of 36% leaves of Millettia ferruginea, 61% hay and 3% concentrate and was offered at 3% of BW (all on dry matter (DM) basis). The total faecal collection was carried out for 7 consecutive days. At the end of the experimental period, the animals were slaughtered to collect liver and digesta samples from the gastrointestinal tract. Feed, digesta and faecal samples underwent analysis of Fe, Zn, and Cu and total tannins (TT). Goats had significantly higher reticulum Cu concentrations expressed on DM as compared to sheep. Faecal Cu concentrations were higher for goats compared to sheep. Reticulum and colon digesta Zn levels were higher in goats than sheep. Abomasum and colon Fe levels were higher in sheep than goats when expressed on DM. These results suggest differences in feed intake, micromineral absorption, secretion and excretion between sheep and goats, pointing to a divergent mineral metabolism as an adaptation to the challenge of a dry season diet having very low nutritive value. 相似文献
97.
98.
Nutrient ions entering the plant root from the soil solution, whether directly or through mycorrhizal fungi, first encounter the apoplast, a chemically complex compartment. The movement of ions in unmodified walls occurs in water-filled channels (diameter about 10 nm) and is influenced by electrical charges. Some positive charges occur in the wall, but the majority are negative. The permeability of the wall is variable, depending on its age and whether or not it has been further modified. Very young walls are less permeable than older walls, and the permeability of mature walls may be reduced by suberin and/or lignin deposits. It is not clear whether or not the other two main wall-modifying substances, mucilages and condensed tannins, also significantly reduce wall permeability. Casparian bands, which consist of suberin and lignin within radial and transverse walls, occur in the endodermis and exodermis. These layers form continuous cylinders within the root so that ion movement into the entire areas they surround is prevented. An important corollary is that Casparian bands dictate which cells are accessed by the soil solution and thus are in a position to absorb ions. It is postulated that a Casparian band-like modification also occurs in the walls of cork cells, based on observations of their impermeability to dyes. Suberin can occur in the form of lamellae which are deposited on all walls of endodermal, exodermal and cork cells. Unlike the Casparian bands, these lamellae limit movement between the apoplast and plasmalemma surface of the individual cells in which they occur. Condensed tannins, an addition to the walls of tree roots which results in them becoming brown, appear to function as antimicrobial agents rather than as permeability barriers. Further research is needed to investigate the structure of both unmodified and modified walls in a variety of species and under a variety of growing conditions. 相似文献
99.
对油茶炭疽病的发病率进行多年定株、定期调查,筛选出感病程度不同的油茶植株作为研究对象;在生长季节不同月份,对不同抗病植株的果皮内含物(单宁、花青素)、缓冲容量进行了测定分析。结果表明,在发病季节,各油茶品种的果皮单宁含量随着果实成熟度的增加呈下降趋势,高抗品种含量比感病品种高出0.33%;花青素含量随着果实成熟度增加而增加,抗病品种含量(11~19.5)远高于感病品种(6.8~10.3);抗病品种油茶果皮滤液的pH值分别小于5,低于感病品种;抗病品种果皮的缓冲容量(5.33~7.48)在趋势上稍低于感病品种的(5.45~7.12)。 相似文献
100.
Sanna Kanerva Veikko Kitunen Jyrki Loponen Aino Smolander 《Biology and Fertility of Soils》2008,44(4):547-556
The aim of this study was to monitor the concentration of some plant secondary metabolites, such as low- and high-molecular-weight
phenolics, condensed tannins (proanthocyanidins), and sesqui-, di- and triterpenes, in litter (L), fermentation (F) and humified
(H) layers of the soil organic horizon in stands dominated by silver birch (Betula pendula Roth.), Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.), and from samples taken from birch leaves and spruce and pine needles. Concentrations of low- and high-molecular-weight
phenolics and terpenes from the four most dominant species of ground vegetation taken from the stands were also determined.
In general, the L layer showed higher concentrations of both phenolic compounds and terpenes than the F and H layers did.
Concentrations of terpenes decreased relatively more with soil depth than did concentrations of total phenolics (=low + high)
or condensed tannins. Of the total phenolics, the proportion of low-molecular-weight phenolics increased from the L to the
H layer with all tree species. Concentrations of all terpenes were highest under pine and lowest under birch. Concentrations
of the studied secondary metabolites in the ground vegetation species were similar under different tree species. Blueberry
(Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) contained considerably higher concentrations of total phenolics than did feather moss (Pleurozium schreberi (Brid.) Mitt.) and wavy hair-grass (Deschampsia flexuosa (L.) Trin.). Concentration of total phenolics in soil correlated positively with soil respiration and microbial biomass C,
and terpenes showed positive correlation with soil C-to-N ratio. 相似文献