首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   31篇
  免费   0篇
林业   3篇
基础科学   1篇
  10篇
综合类   1篇
水产渔业   5篇
畜牧兽医   11篇
  2019年   1篇
  2017年   1篇
  2014年   1篇
  2013年   7篇
  2012年   3篇
  2011年   5篇
  2010年   1篇
  2009年   2篇
  2008年   1篇
  2007年   1篇
  2005年   2篇
  2003年   1篇
  2002年   1篇
  1989年   1篇
  1987年   2篇
  1986年   1篇
排序方式: 共有31条查询结果,搜索用时 359 毫秒
1.
This study was designed to evaluate changes in the dynamics of soil phosphorus and cationic balances of a savannah soil subjected to 45 years of continuous cultivation under different fertilizer management and later left fallow for 15 years. It was conducted on the experimental plots at the Institute for Agricultural Research, Ahmadu Bello University, Nigeria. Treatments consisted of nitrogen (N), phosphorus (P), potassium (K), cow dung manure (D) and their combination (DNPK). Results of P fractionation and cationic distribution were compared with previous studies on the same plot 15 years ago. Organic carbon increased from a range of 3–5 g kg?1 in 1997 to 10.9 g kg?1 in 2012. Similarly, the cation exchange capacity (CEC) of the soil increased from 6.40 cmolc kg?1 in 1997 to 16.4 cmolc kg1 in the present study. The degree of saturation of the CEC by Ca2+ was 68–79% and 10–20% for Mg2+, while that of K+ was 1.5–2%. Although there was an uneven trend in depletion and enrichment of the various P pools, however, the fallow period substantially improved the CEC and the plant available P pools of the soil by more than 200% and 6–259%, respectively.  相似文献   
2.
3.
Nonconventional agro-industrial by-products such as traditional liquor residues (locally called katikala atella) are widely used by livestock farmers in Ethiopia. The objective of this experiment was to evaluate the supplementary value of katikala atella and malt sprout (MS) on performance of sheep fed a basal diet of Rhodes grass hay. Thirty intact yearling male sheep with an average initial body weight of 17.4?±?0.74 kg (mean?±?SD) were assigned to the treatments in a completely randomized block design: atella alone (T1), 75 % atella?+?25 % malt sprout (MS) (T2), 50 % atella?+?50 % MS (T3), 25 % atella?+?75 % MS (T4), MS alone (T5), and Rhodes grass hay alone (T6). Grass hay was fed ad libitum to all treatments. The total dry matter (DM) and organic matter (OM) intakes of sheep fed T4, T5, and T3 diets were the highest (P?<?0.05), while sheep receiving T6 had the lowest DM intake. The highest (P?<?0.05) total crude protein (CP) intake was for sheep fed T5 diet, while the lowest was for those fed T6 diet. Sheep receiving T3 diet had higher (P?<?0.05) DM, OM, CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility as compared with those fed T1, T2, and T6 diets. Sheep supplemented with 50–100 % malt sprout had similar (P?>?0.05) DM, OM, CP, NDF, and ADF digestibility. The highest (P?<?0.05) average daily gain was for sheep fed T3, T4, and T5 diets, while sheep in T6 lost body weight. Sheep fed T5 diet had the highest (P?<?0.05) nitrogen retention, while those fed T6 diet had the lowest. The study has shown that a mixture diet consisting of equal parts of katikala atella and malt sprout (T3) are found to be superior in most of the required nutrient characteristics.  相似文献   
4.
ABSTRACT

Malnutrition in children is a current global burden. A common snack for children is biscuits prepared from cereals. However, these types of biscuits have low protein content. Therefore, producing healthier biscuits enriched with essential amino acids (EAAs) and other micronutrients is of great interest to researchers and manufacturers. In this study, biscuits produced from low gluten wheat flour fortified with sturgeon fillet powder (SFP) in various mixing ratios (100:0, 95:5, 93:7, and 90:10, respectively) were investigated. The results revealed that the nutritional and proximate composition of biscuits were significantly (P ≤ 0.05) improved: moisture (6.77 ± 0.06–7.65 ± 0.06), protein (13.23 ± 0.35–17.12 ± 0.02), fat (15.57 ± 0.18–15.85 ± 0.25), ash (0.84 ± 0.07–0.92 ± 0.06), spread ratio (14.0 ± 0.92–14.33 ± 0.21), and hardness (2,057.90 ± 28.33–3,089.02 ± 51.53). Total amino acids were 6.91, 9.34, 10.32, and 10.58; and EAAs were 2.43, 3.97, 4.48, and 4.22 g/100 g for 0%, 5%, 7%, and 10% SFP, respectively. Leucine was the major amino acid with 5% and 10% SFP, while methionine was the major amino acid with 7% SFP. Fungal counts were not observed, and quality indices were below the maximum acceptable limits in the products. Biscuits supplemented with 7% SFP showed the highest sensory evaluation score. Overall, the inclusion of 7% SFP could produce protein enriched cereal-based fortified biscuits with acceptable sensory and quality attributes and ultimately could insure effective fish utilization and solve malnutrition problems.  相似文献   
5.
In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed.  相似文献   
6.
In order to assess and identify the determinants of sheep price and price variation across time, a time series data were collected from four selected markets in North Shewa, Northeastern Ethiopia on weekly market day basis for a period of 2 years. Data on animal characteristics and purpose of buying were collected on a weekly basis from randomly selected 15–25 animals, and a total of 7,976 transactions were recorded. A general linear model technique was used to identify factors influencing sheep price, and the results showed that sheep price (liveweight sheep price per kilogram taken as a dependent variable) is affected by animal characteristics such as weight, sex, age, condition, season, and color. Most of the markets’ purpose for which the animal was purchased did not affect significantly the price per kilogram. This may be due to the similarity of the markets in terms of buyer’s purpose. The results suggest that there will be benefit from coordinated fattening, breeding, and marketing programs to take the highest advantage from the preferred animals’ characteristics and selected festival markets. Finally, the study recommends for a coordinated action to enhance the benefit generated for all participant actors in the sheep value chain through raising sheep productivity, improving the capacity of sheep producers and agribusiness entrepreneurs to access and use latest knowledge and technologies; and strengthening linkages among actors in the sheep value chain.  相似文献   
7.
ABSTRACT

The aim of the present study was to evaluate the quality of wheat flour noodles supplemented with 0%, 10%, 20% and 30% grass carp protein concentrate (GCPC). Proximate composition, color analyses, cooking properties (cooking time, cooking loss, swelling index and water absorption index), texture profile analyses (TPA), and sensory evaluations were performed. Significant (p ≤ 0.05) increases in the crude protein (18.94–35.19%), crude fat (0.88–1.06%), and ash (0.89–1.02%) were recorded for GCPC supplemented cooked noodles. Brightness (L*), redness (a*) and yellowness (b*) of GCPC 10–30% fortified cooked noodles was recorded as 77.00–69.97, 1.50–2.81 and 19.08–22.25, respectively. Cooking loss (CL) and optimal cooking time were significantly (p ≤ 0.05) increased with increased level of GCPC from 0%-30%, with readings of 6.13% ?8.90% and 7.53–11.77 min, respectively. Swelling and water absorption indices showed a decreasing trend at 2.33–1.77 and 102.6–78.49%, respectively. A significant (p ≤ 0.05) decreasing trend in hardness (24.50–19.03N) was observed for cooked noodles with increased level of GCPC, while the remaining TPA parameters were significantly different at p> .05. Sensory analyses showed higher preference for control noodles and noodles fortified with 10% GCPC.  相似文献   
8.
The use of Eucalyptus trees, in association with other plants, has the potential to reduce the growth of neighbouring plants or grasses by competing for resources or releasing allelochemicals that may cause other plants to grow slowly. Our purpose here is to assess whether border planting of Eucalyptus is harmful to the establishment,growth, and production of Cymbopogon winterianus at various distances from tree lines in the Wondo Genet Agricultural Research Center in Southern Ethiopia. Several factors were studied: growth performances and yield of aromatic grasses; soil properties, including total nitrogen,organic carbon, and moisture content; and plant leaf nutrient content(NPK) at various distances away from the Eucalyptus citriodora border line were studied. Chemical compositions of hydro-distilled essential oils obtained from selected C. winterianus grasses leaves were analysed by gas chromatography. Plant height, biomass yield, amount of essential oil yield, and essential oil composition all were significantly affected due to Eucalyptus effect in the first10-m distance as compared to beyond 10 m from the tree border line. There were increases in soil total nitrogen,organic carbon, and moisture content with decreasing distances to the Eucalyptus tree border. The result of plant leaf nutrient content(NPK) differed across treatment and distance. The pot experiment(15 cm 9 20 cm), shoot length,and number of leaves of aromatic plants varied in the degree of inhibition based on the concentration of the aqueous extract. Significantly higher inhibitions of the shoot length and number of leaf parameters were observed when using 25% fresh leaf extract compared to other extract levels.  相似文献   
9.
The morphological and chemical properties of homegardens in the beach ridges with interspersed swales (BRIS) soils were evaluated in order to find a clue for developing sustainable agricultural management. Field survey and soil sampling were conducted at the homegardens and secondary forests in Sungai Ular Village and in the experimental farm of Malaysian Agriculture Research Institute (MARDI), Cherating Station. Chemical fertilizers including ash, charcoal waste and plant litter were applied to the homegardens in both the inland-ward area (HG-I) and in the shoreline area (HG-S). Manure was applied in HG-I and seafood waste from fish processing was buried in the soils in HG-S. High correlation was found between total carbon (T-C) and cation exchange capacity (CEC), indicating soil organic matter was the determinant factor for CEC in the very sandy BRIS soils. The levels of T-C, total nitrogen (T-N), and CEC at 0–10 cm in HG-I in parallel with increasing ages of homegardens. The soils in 0–10 cm and 20–30 cm showed higher levels of T-C and T-N with higher C/N ratios in HG-I than in HG-S and the MARDI farm. The high levels of exchangeable Ca, Mg, and K in HG-I compared with the MARDI farm, suggesting that improved CEC with increasing soil organic matter in HG-I heighten the retention of basic cations supplied as chemical fertilizer, ash, and manure. The level of available P was higher in HG-S than HG-I, attributed by the seafood waste application in the shoreline area. Thus, on the BRIS, the levels of soil organic matter and nutrients can be sustained by the homegarden management although it cannot be regarded as a closed system compared with those in the other tropical regions because chemical fertilizer was used and a certain amounts of nutrients seemed to leach down beyond plant rooting depth.  相似文献   
10.
P A Abdu 《Avian diseases》1987,31(1):204-205
Infectious bursal disease and spirochetosis were diagnosed simultaneously in a flock of 100 six-week-old babcock pullet chicks. Larvae of the fowl tick Argas persicus were found on the bodies of the chicks. Thirty-nine of the chicks died 5 days after the onset of clinical signs.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号