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1.
Nutrient digestibility studies in Heteropneustes fossilis (Bloch), Clarias batrachus (Linnaeus) and C. gariepinus (Burchell) 总被引:1,自引:0,他引:1
The apparent digestibility coefficient (ADC %) for protein in catfishes, Clarias batrachus (Linnaeus) (16–18 cm; 45–50 g), C. gariepinus (Burchell) (21–22 cm; 60–65 g) and Heteropneustes fossilis (Bloch) (10–12 cm; 10–15 g) was estimated for nine feedstuffs of plant and animal origin. Fat digestibility was tested for C. batrachus and C. gariepinus, wherein the influence of feeding frequency on protein digestibility was also examined. The digestibility trials were conducted with triplicate groups of 25 fish each in 70‐L polyvinyl indoor flow‐through (1–1.5 L min?1) circular tanks (water volume=55 L). Fish were fed to satiation daily, at 08:00 and 18:00 hours, and faecal matter was collected through slow siphoning. For studying the effect of feeding frequency, fish were fed the experimental diets at 08:00, 11:00, 14:00 and 17:00 hours. The protein digestibility of the feedstuffs varied significantly within each test species. However, the protein digestibility values for most of the ingredients tested were comparable between the three catfish species. The most efficient utilization of protein in these fishes was noted for soybean meal followed by lab‐prepared fishmeal. The lowest protein digestibility was recorded for rice bran. Similarly, the utilization of fat from the feedstuffs was also significantly different within each of the two species, C. batrachus and C. gariepinus. Fat digestibility of feed ingredients was similar between the two species. With respect to the fat, soybean meal, lab‐prepared fishmeal, full‐fat soybean meal and dried fish were more efficiently utilized, while the lowest fat digestibility was obtained for rice bran. A marked decline in protein utilization was observed in the two species where the feeding frequency was increased from two to four times a day. 相似文献
2.
Mohammad Afzal Khan Ahmad Khalil Jafri & Narendra Kumar Chadha 《Aquaculture Research》2004,35(13):1277-1285
Growth, reproductive performance, muscle and egg composition were investigated in grass carp, Ctenopharyngodon idella (Valenciennnes), fed hydrilla or formulated diets with varying protein levels. Five experimental diets, with varying levels (20%, 25%, 30%, 35% and 40%) of crude protein (CP), were used. One of the fish groups was fed hydrilla. Fish (44.1±0.3 cm; 913±9 g) were stocked (20 tank?1) in outdoor concrete tanks (20 × 10 × 1.5 m) in duplicate, and fed to satiation, twice daily, at 09:00 and 17:00 hours for the experimental duration of 360 days. High (P<0.05) weight gain was recorded in fish fed 30% and 35% CP diets. However, values for gonadosomatic index (GSI), egg diameter, relative fecundity (eggs kg?1 body weight), fertilizability and hatchability (%) were comparable (P>0.05) in fish at ≥25% of dietary protein intake. Hydrilla‐fed fish exhibited lower (P<0.05) values for the measured parameters. Crude protein content in muscle increased with dietary protein level. Highest (P<0.05) muscle protein was obtained in fish fed 35% CP diet. Muscle fat was comparable (P>0.05) among fish receiving formulated diets. Ash content was not significantly (P>0.05) different among fish of different dietary groups. Moisture content in fish fed formulated diets, with the exception of 20% CP diet, did not vary significantly (P>0.05). Eggs of fish fed formulated diets contained higher CP and fat contents than those of hydrilla‐fed fish. High (P<0.05) moisture content was noted in the eggs of hydrilla‐fed fish. Ctenopharyngodon idella fed formulated diet, with a minimum of 25% CP, showed better reproductive performance than those fed hydrilla. 相似文献
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Prabhakar S Visel A Akiyama JA Shoukry M Lewis KD Holt A Plajzer-Frick I Morrison H Fitzpatrick DR Afzal V Pennacchio LA Rubin EM Noonan JP 《Science (New York, N.Y.)》2008,321(5894):1346-1350
Changes in gene regulation are thought to have contributed to the evolution of human development. However, in vivo evidence for uniquely human developmental regulatory function has remained elusive. In transgenic mice, a conserved noncoding sequence (HACNS1) that evolved extremely rapidly in humans acted as an enhancer of gene expression that has gained a strong limb expression domain relative to the orthologous elements from chimpanzee and rhesus macaque. This gain of function was consistent across two developmental stages in the mouse and included the presumptive anterior wrist and proximal thumb. In vivo analyses with synthetic enhancers, in which human-specific substitutions were introduced into the chimpanzee enhancer sequence or reverted in the human enhancer to the ancestral state, indicated that 13 substitutions clustered in an 81-base pair module otherwise highly constrained among terrestrial vertebrates were sufficient to confer the human-specific limb expression domain. 相似文献
5.
Geoffrey R. Tick Colleen M. McColl Irfan Yolcubal Mark L. Brusseau 《Water, air, and soil pollution》2007,184(1-4):355-362
Robust measurements of porous-medium tortuosity are one of the many components needed for accurate characterization and prediction of fluid flow and contaminant transport in the subsurface. A gas-phase diffusive tracer-test method is evaluated for the in-situ measurement of tortuosity in the vadose zone. This technique presents an alternative to employing widely-used correlations to estimate tortuosity. A small-scale field study was conducted using a single well and a non-reactive gas-phase tracer (sulfur hexafluoride; SF6). Gas samples were collected from the injection point periodically after tracer injection into the soil matrix. An effective radius of influence of 50 cm was determined for the tests. An analytical solution was calibrated to the measured temporal concentration distribution, producing a fitted value for tortuosity. The value obtained from the tracer tests was compared to values estimated with several widely-used correlations. The value obtained from the tracer tests was generally larger than the values estimated with the correlations, which spanned a relatively wide range. The tracer-test method provides a means by which to determine in-situ measurements of tortuosity, allowing for better characterization of contaminant transport in the vadose zone. 相似文献
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ABSTRACT Resistance to Soybean mosaic virus (SMV) was identified in PI 88788 soybean, a germ plasm accession from China that is used widely as a source of resistance to soybean cyst nematode. Strains SMV-G1 through -G7 infected the inoculated leaves of PI 88788 but were not detected in upper, noninoculated trifoliolate leaves. Inheritance of resistance was determined by inoculating progenies of crosses of PI 88788 with susceptible cvs. Essex and Lee 68 with SMV strains G1 and G7. Allelomorphic relationships with known genes for resistance to SMV were tested in crosses with the resistant genotypes PI 96983, L29, and V94-5152, possessing Rsv1, Rsv3, and Rsv4 genes, respectively. Data analyses showed that resistance in PI 88788 to SMV-G1 is controlled by a single, partially dominant gene; however, to SMV-G7, the same gene was completely dominant. The PI 88788 gene was independent of the Rsv1 and Rsv3 loci, but allelic to Rsv4 in V94-5152. Expression of the Rsv4 gene in PI 88788 resulted in a reduced number of infection sites and restricted short- and long-distance movement of virus, rather than hypersensitivity. A unique late susceptible phenotype was strongly associated with heterozygosity. This gene has potential value for use in gene pyramiding to achieve resistance to several SMV strains, as well as for rate-reducing resistance. 相似文献
8.
Alkuraya FS Saadi I Lund JJ Turbe-Doan A Morton CC Maas RL 《Science (New York, N.Y.)》2006,313(5794):1751
The posttranslational modification sumoylation can have multiple effects on its substrate proteins. We studied a patient with isolated cleft lip and palate and a balanced chromosomal translocation that disrupts the SUMO1 (small ubiquitin-related modifier) gene, resulting in haploinsufficiency. In mouse, we found that Sumo1 is expressed in the developing lip and palate and that a Sumo1 hypomorphic allele manifests an incompletely penetrant orofacial clefting phenotype. Products of several genes implicated in clefting are sumoylated, and the Sumo1 hypomorphic allele interacts genetically with a loss-of-function allele for one of these loci. Thus, sumoylation defines a network of genes important for palatogenesis. 相似文献
9.
Awais MM Akhtar M Iqbal Z Muhammad F Anwar MI 《Tropical animal health and production》2012,44(2):323-328
The present paper reports the prevalence of coccidiosis in industrial broiler chickens in Faisalabad, Punjab, Pakistan to
determine the occurrence of different species of Eimeria in the area and to assess their correlation with the environmental conditions including temperature, humidity and rainfall.
The study was conducted from January 2009 to December 2010. Examination of chicken guts revealed 43.89% (n = 3,283/7,480) prevalence of coccidiosis. The highest prevalence (27.04%) was recorded of Eimeria tenella followed by Eimeria maxima (22.42%), Eimeria acervulina (19.89%) and Eimeria necatrix (4.02%). The prevalence of disease was significantly higher (P < 0.05) in autumn (60.02 ± 4.38) followed by summer (47.42 ± 2.92), spring (36.92 ± 2.27) and winter (29.89 ± 3.43). Likewise,
prevalence of different species of Eimeria also varied (P < 0.05) in different seasons of the year except that of E. necatrix. A strong correlation (P < 0.05) of environmental conditions with the overall and species-wise prevalence of coccidiosis was recorded except E. necatrix. 相似文献
10.
Kazmi I Rahman M Afzal M Gupta G Saleem S Afzal O Shaharyar MA Nautiyal U Ahmed S Anwar F 《Fitoterapia》2012,83(1):142-146
A new stearoyl glucoside of ursolic acid, urs-12-en-3β-ol-28-oic acid 3β-d-glucopyranosyl-4′-octadecanoate and other compounds were isolated from the leaves of Lantana camara L. The structure of this new glycoside was elucidated and established by standard spectroscopic methods. In streptozotocin-induced diabetic rats it showed significant reduction in blood glucose level. 相似文献