Effects of citric acid supplementation on growth performance, intestinal morphology and microbiota, and blood parameters of geese from 1 to 28 days of age.

This study was conducted to investigate the effects of citric acid (CA) supplementation on growth performance, intestinal morphology, intestinal microbiota, and blood parameters of geese from 1 to 28 d of age and evaluate the optimum additional level of citric acid. A total of 180 one-day-old male goslings were randomly allotted to 5 treatment groups of 36 birds with 6 replications. The control group was fed a basal diet, and the other groups were fed the basal diet supplemented with 0.25, 0.50, 1.00, and 2.00% of citric acid, respectively. The results showed that goslings fed the diet supplemented with 1.00% CA had higher final body weight (FBW) and average daily gain (ADG) than other groups (P < 0.05). The CA supplementation at 0.25 to 1.00% improved the morphology of duodenum or jejunum (P < 0.05). The jejunal content pH value was significantly reduced with the addition of CA compared with the control group (P < 0.05). As citric acid levels increased, the IgA concentrations in plasma increased and then decreased, and the goslings fed 1.00% CA supplementation had the highest IgA concentrations (P < 0.05). The supplementation of 1.00% and 2.00% CA in diet significantly reduced the malondialdehyde (MDA) concentration in plasma (P < 0.05). No significant difference was found on some indices related to liver function in plasma (P > 0.05), while creatinine significantly increased by the 2.00% CA supplementation (P < 0.05). Besides, the higher Coliform level in cecal content and worse intestinal morphology were observed when CA supplementation was up to 2.00%. Hence, the dietary CA supplementation (especially 1.00%) in goslings improves the growth performance, intestinal morphology, immunity and antioxidant, while excessive CA addition may cause negative effects. According to the quadratic polynomial model, the addition of CA in diet for obtaining maximum average daily feed intake (ADFI) should be 1.09% (10.9 g/kg diet) for goslings from 1 to 28 d of age.

[Extraction and separation of antitumor components from Ganoderma lucidum (Leyss. ex Fr.) Karst].

OBJECTIVE: To examine the variation of alcohol extraction rates of Ganoderma lucidum spores with different rates of wall-wrack, and analyze the antitumor components of alcohol extract by chromatography. METHOD: The G. lucidum spores were soaked and extracted with absolute alcohol. The alcohol extract was chromatographed on a silica gel column and HPLC in proper order, and the antitumor activity of every eluted fraction was represented by its cytotoxicity towards Hela cells. RESULT: Extraction rates 5%, 25% and 33% corresponded to wall-wrack rates 0%, 60%-80% and 99% respectively. The alcohol extract from spores with the highest wall-wrack rate was chromatographed on a silica gel column, eluting successfully with CHCl3, EtOAc and CH3OH in order. The CHCl3 fraction had not any antitumor activity, while this activity of CH3OH fraction was 34 times greater than that of EtOAc fraction. HPLC analysis found out that two mixtures(II1 and II3) possess significant antitumor activity in vitro. CONCLUSION: The weight of alcohol extract from spores with wall-wrack was far greater than that of spores without. The antitumor components of G. lucidum spores could be analyzed with methanol-water on a reverse HPLC.