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1.
The effect of heat stress on protein oxidation and myofibrillar proteolysis in chick myotubes was investigated. Myotubes were incubated at 37 or 41°C for 6 and 24 h. Protein carbonyl content, as an index of protein oxidation, increased more at 41°C than at 37°C for 6 and 24 h incubations. Nτ‐methylhistidine release as an index of myofibrillar proteolysis also increased more at 41°C than at 37°C for 6 and 24 h incubations. Proteasome activity also increased more under those same conditions. Calpain and cathepsin D but not B + L activities showed a greater increase at 41°C than at 37°C for 24 but not the 6 h incubation. These results indicate that heat stress increases protein oxidation and proteasome activity, resulting in an increase in myofibrillar proteolysis for short‐term incubation and, for long‐term incubation, it increases calpain, proteasome and cathepsin D activities, finally accelerating myofibrillar proteolysis in chick myotubes.  相似文献   
2.
Thirty‐four Holstein dry cows and 16 lactating cows were used in balance trials to identify the effects of feeding and animal performance on nitrogen (N), phosphorus (P) and potassium (K) excretion by dairy cows, and to develop prediction models for these excreta. Orchard grass silage, corn silage, alfalfa silage or timothy hay were offered to dry cows. Orchard grass silage or alfalfa silage, and concentrates were offered to lactating cows. In the statistical analysis, the independent variables were bodyweight (kg), dry matter (DM) intake (kg/day), milk yield (for lactating cows only, kg/day), water intake (free water plus water in feed, kg/day), intake (g/day) of N, P and K and dietary contents (% of DM) of crude protein, P and K. The dependent variables were N, P and K excretion (g/day) in feces and urine. In both dry and lactating cows, intake of N, P and K had large effects on corresponding excretion. The results indicated that a decrease in the intake of N, P and K could decrease the corresponding excretion. Further research by path analysis showed that K intake positively affected urinary N excretion in dry cows indirectly, through water intake and urine volume.  相似文献   
3.
In this study, scaling, polishing and daily tooth brushing were performed in 20 beagle dogs, and the number of oral bacteria was determined using a bacterial counter. The dogs were randomized into the scaling (S), scaling + polishing (SP), scaling + tooth daily brushing (SB) and scaling + polishing + tooth daily brushing (SPB) groups. Samples were collected from the buccal surface of the maxillary fourth premolars of the dogs immediately after scaling and every week thereafter from weeks 1 to 8. Throughout the study, the number of bacteria was significantly lower in the SB and SPB groups compared with the S group. The findings suggest that daily tooth brushing inhibited oral bacterial growth in the dogs.  相似文献   
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5.
In fish culture, cannibalism, which induces critical damage, is separated into two types: type I, which occurs in early larval stages when size heterogeneity is low; and type II, which starts in later larval and/or early juvenile stages following type I when size heterogeneity is high. In type II, the cannibal's maximum prey size is limited by its gape size relative to the prey fish body size. Ratios of prey to cannibal body size changes are associated with allometric factors and feeding behaviour with growth. In a previous study on grouper, the maximal prey size was estimated morphologically (i.e., the relationship between gape size and body height). This method is very simple and useful; however, it does not consider allometric factors and feeding behaviour changes; therefore, it probably causes a large estimation error. To overcome this, we present a new method for estimating maximal prey size to determine the size ranges for size grading of longtooth grouper, Epinephelus bruneus, juveniles using predation experiments. It is shown that grouper type II cannibalism is affected by two factors; in early juvenile stages by morphology and in later (TL over 50 mm) by prey size selectivity.  相似文献   
6.
The medicinal plant Brucea javanica (L.) Merr. (Simaroubaceae) is widely distributed throughout Asia where its bitter fruits have been used in traditional medicine for various ailments. Fifteen C-20 quassinoids were isolated from the fruits of B. javanica and examined for their in vitro antitrypanosomal activities against trypomastigotes of Trypanosoma evansi. Bruceine A, bruceantinol, bruceine C, brusatol, and bruceine B showed strong antitrypanosomal activities with IC(50) values in the range of 2.9-17.8nM, which compared well with the standard trypanocidal drugs diminazene aceturate (IC(50)=8.8nM) and suramin (IC(50)=43.2nM). However, dehydrobruceine A, dehydrobruceine B, and dehydrobrusatol were about 2100, 900, and 1200 times less active, respectively, than bruceine A, bruceine B, and brusatol. The relationship of the structure and antitrypanosomal activity of these quassinoid compounds suggested that the presence of a diosphenol moiety in ring A and the nature of the C-15 side chain are important for their activities against T. evansi. This is the first report on the antitrypanosomal activity of isolated quassinoids.  相似文献   
7.
A latex agglutination test for detecting Echinococcus multilocularis coproantigen in definitive hosts was developed using latex beads sensitized with EmA9 monoclonal antibody raised against somatic antigens of adult E. multilocularis. A primary test (LA 1) was performed on 82 fecal samples of necropsied foxes, of which 46 were infected, and resulted in 61% sensitivity and 86% specificity. To increase the sensitivity, 4 ng/mL of excretory/secretory antigens of adult worms was added to the samples in a secondary test (LA 2), resulting in 91% sensitivity and 61% specificity. The positive predictive value of the LA 1 test and the negative predictive value of the LA 2 test were both 85%. The combination of the LA 1 and LA 2 tests is applicable and practical for use in situations that require quick diagnosis or screening based on the following interpretation: the samples that are positive in the LA 1 test are positive; the samples that are negative in the LA 2 test are negative; and the samples that are negative in the LA 1 test and positive in the LA 2 test are classified as suspicious.  相似文献   
8.
We observed the effects of a commercial microbiological additive (MA) on the beef manure composting process and investigated the changes in its physical and chemical components and microbial populations in the composting process. When beef manure compost was inoculated with the MA, its temperature rapidly increased at the beginning of the process, and after the first turning, the ammonia emission from the compost pile and nitrate production decreased quicker than that in the composting process without the MA. During the composting process, the manure inoculated with MA showed a larger numbers of mesophilic and thermophilic aerobes, and a smaller number of thermophilic anaerobes than in the process without the MA. These results suggested that mesophilic aerobes increased in number and metabolized ammonia by assimilation rather than nitrification to accelerate the temperature elevation in the composting process with the MA.  相似文献   
9.
We investigated microorganisms that assimilated ammonia in lagoon treatment processes. Ammonia‐assimilating microorganisms were detected by nitrogen‐limited medium that contained ammonia as the sole nitrogen source. Numbers of ammonia‐assimilating aerobes (log CFU/g) were 3.4, 4.8, 5.0, 4.8 and 5.0 (log CFU/mL) on the culture plate incubated at 4°C, 10°C, 15°C, 20°C and 25°C, respectively. Many isolates used ammonia in high rates when they were purely cultivated in nitrogen‐limited medium added to sterilized lagoon extract. Many of them used ammonia even when they were cultivated in media containing viable microbial flora of the lagoon. Among them, enterobacteriaceae and Pseudomonas sp. were identified by analysis of 16S ribosomal DNA.  相似文献   
10.
Anthelmintic (praziquantel) baiting of wild red foxes against Echinococcus multilocularis infection was studied in a highly epizootic suburban area of Otaru, Hokkaido (the northern island of Japan) during the summer and autumn in the years 1999-2004. Acceptance of baits containing the biomarker tetracycline (TC) was evaluated. The prevalence of E. multilocularis infection in foxes before baiting (1999-2000) was 58% (88/153), whereas in the fourth year of bait distribution year (2004), it decreased to 11% (5/45). Analysis of TC marking in the teeth of foxes showed that 39% (77/195) of those captured after baiting were estimated to have consumed baits in the year of capture. Importantly, more juvenile (56%, 49/87) than adult foxes (26%, 28/108) were marked, indicating efficient baiting of juveniles, which tended to have a higher worm burden of E. multilocularis. Of 77 marked foxes, E. multilocularis and Alaria alata (monitored as the second indicator species of deworming) were not detected in 70 (90%) and 76 (99%) foxes, respectively. The results suggest effective deworming by bait consumption. However, it was also demonstrated that 9% of the marked foxes were infected or re-infected after bait consumption, suggesting high infection pressure and the importance of frequent baiting.  相似文献   
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