An 8-week feeding trial was conducted to determine lysine requirement of juvenile yellow catfish (Pelteobagrus fulvidraco) by feeding formulated diets containing crystalline L L-lysine.Six isonitrogenous and isoenergetic diets (405 g kg )1 protein, 18 kJ g )1 gloss energy) containing fish meal together with soybean protein concentrate as protein sources and fish oil together with soybean oil as lipid sources were formulated. Crystalline L L-lysine was added into the six diets to acquire lysine concentrations of 17. 3, 21.8, 26.0, 31.3, 35.5 and 41.9 g kg )1 dry diets, respectively. Mixture of crystalline amino acid was supplemented to simulate the amino acid profile in muscle of yellow catfish. The results indicated that final body weight (FBW), weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency (PE) increased with the increase in dietary lysine level from 17.3 to 31.3 g kg )1 of diet and then decreased as the dietary lysine levels further increased. No significant difference in survival rate was found among all the dietary treatments. One-slope, quadratic broken-line analysis on the basis of SGR showed that the dietary L L-lysine requirement of juvenile yellow catfish was 33.1 g kg )1 of dry diet (83.2 g kg )1 of dietary protein).

Summary Polyphenols in Eucalyptus leaves (PE) were value resources due to various pharmacological activities, but data on the effect on laying hens are very scare. This study was conducted to determine the effect of PE on the laying performance, egg traits, meat quality, antioxidant status and liver tissues of laying hens. One hundred and twenty 256‐day‐old Yueqinhuang laying hens were randomly assigned to four treatment groups (different levels of PE at 0, 0.5, 0.8 and 1.2 g/kg diet) for 63 days with 15 replicates per group. Addition of 0.8 g/kg PE not only improved the egg trait by increasing the eggshell thickness and decreasing MDA production and cholesterol content in the egg yolk, but also significantly enhanced meat quality of hens, as suggested by the increase pH45 min (p < .01) and a* value, and decrease drip loss rate (p < .01). Meanwhile, under acute ethanol‐induced oxidative damage condition, supplementation of 0.8 g/kg PE enhanced the serum antioxidant status by increasing enzymatic activities (GSH‐PX, T‐SOD, T‐AOC), inhibited oxidative damage and provided protective effect to liver tissue. In conclusion, addition of 0.8 g/kg PE not only improved the egg traits and meat quality without obvious adverse effects, but also increased the serum antioxidant status of the hens and protected their liver tissue from ethanol‐induced oxidative damage. This study indicated that PE could be utilized as an effective feed additive for laying hens to improve health performance and egg traits.

To generate new breed lines of bermudagrass and reduce management costs of turfgrass, gamma-ray irradiation was used for induction of dwarf mutants from a native bermudagrass (Cynodon dactylon) germplasm. Three dwarf-type mutant lines (7-9, 10-5 and 10-12) were isolated from 3000 irradiated stolons. The data from 3-year greenhouse tests and 2-year field tests indicated that the dwarf mutant lines had lower canopy height, shorter internodes and shorter leaves. The line 7-9 had a similar turf coverage rate to the wild-type control, while the lines 10-5 and 10-12 had a slower turf coverage rate than the wild-type control. Under drought stress, all three dwarf mutant lines maintained higher relative water content and lower ion leakage than the wild type in the greenhouse tests. The field tests showed that the dwarf mutant lines had lower leaf firing during a progressive drying of soil. Our results indicated that bermudagrass mutants induced by gamma radiation exhibited dwarf characteristics and improved drought resistance, which was probably associated with unbalance of plant hormones in vivo.

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Antifeedant activities of the isolated chemical compounds from Ajuga nipponensis, were studied against adult of striped leaf beetles. The methanol, petroleum ether, ethyl acetate and n-butanol extracts at 1.0 mg/ml, were used in this study. All four extracts exhibited more than 65 antifeedant index at 24 h and ethyl acetate extract showed significant activity against striped leaf beetles with 83.12 antifeedant index. Six compounds and one fraction were isolated by chromatography and their structures were identified by NMR, MS and FTIR spectra. At 2.0 mg/ml for 24 h the three compounds 20-hydroxyecdysone, acacetin and apigenin showed considerable activities with antifeedant indexes 59.29, 51.22 and 61.55, respectively. In contrast to this the antifeedant indexes of acacetin and apigenin, were sharply reduced as the time extended and that of 20-hydroxyecdysone remained unchanged. In addition, the synergistic effects of two mixtures of secondary metabolites, were studied and no sharp difference was observed.

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