Yeast Germanium Production And Toxicological Test And Its Application In The Production Of Weaned Piglets

The aim of this issue was to study the production of yeast-germanium and its application to the production of weaning piglets.The effects of yeast germanium on the growth of piglets were studied.The optimum dosage of yeast-germanium for weaned piglets was determined according to the issue results.The study of this issue was carried out by the following three tests:The first experiment took the organic rice bran as the fermentation substrate to study the biological accumulation function of the yeast to germanium.The biomass and germanium-enriched yeast were measure for optimizing the experiment conditions.The result showed:Under the optimized conditions that the initial pH value was unchanged,the filling volume of organic rice bran was 32g/250mL,the filling volume of liquid medium was 80ml/250mL,the inoculum was 10%(v/v),the cultural time was 60h,the cultural temperature was 30℃,Ge02 concentration was 100mg/L,the organic germanium production-level of the organic rice bran fermented by yeast was 11.83mg/Kg.In the second experiment,mice were tested to investigate the safety of yeast-germanium as a feed additive and to determine the safe dose when it was added to the feed.The results showed that the low dose of yeast-germanium could significantly improve the growth performance of the female rats and significantly promote the antioxidant capacity of the female rats without damage to the liver(P<0.05).The medium dose of yeast-germanium could enhance the growth performance and antioxidant properties of the male rats(P<0.05).High dose and medium dose of yeast-germanium could damage the liver of the female rats significantly,which cause the severe fatty degeneration of female rats’ liver.The high dose of yeast-germanium significantly decreased antioxidant performance of female rats(P<0.05).Conclusion:The highest safe intake dosage of yeast-germanium when as a feed additive is 40 mg/Kg/d.The third experiment was intended to study the application of different dose of yeast-germanium on the production of weaned piglets.22 days of age,healthy and no difference in body condition weaned piglets as experimental animals.100 head of piglets were divided into five groups with RCB(control group and experimental groupⅠ,Ⅱ,Ⅲ group),male and female in half.Each group had 10 piglets and 5 repeats.The effective content of organic germanium in the experimental group was 15mg/Kg,25mg/Kg,35mg/Kg,45mg/Kg,the test period was 49 days,divided into 7 days of pre-feeding period and 42 days of formal test period.The formal test period was divided into three stages according to the diet formula of piglets and each stage had 14 days.The growth and the diarrhea rate of piglets were recorded during the experiment.The piglets were weighed at the first day,the 15th day,the 29th day and the forty-third day of the experiment.Fecal samples were collected in the way of total faces collection method at the first three days at the end of each experiment stage.At the end of each trial phase,the contents in the pig’s rectum were scraped with a sterilized cotton swab and were placed in a sterile container at low temperature.Blood samples were taken on the 42nd day of the end of the trial.The results show:(1)On the growth performance:When yeast-germanium reached 35mg/Kg,average daily gain,average daily feed intake and feed/weight ratio of piglets were very significantly different from those in the control group(P<0.01),and piglets’diarrhea rate of the experiment groups was very significantly reduced in the first trial and second trial(P<0.01).The growth performance of the piglets was improved effectively.(2)On nutrient metabolism:the apparent digestibility of dry matter,crude protein,crude fat,crude ash and Ca in diets were significantly increased when the concentration of yeast-germanium was 35mg/Kg in diets(P<0.05).The apparent digestibility of phosphorus in diets was significantly decreased(P<0.05).The utilization rate of feed was improved on the whole.Compared with the control group,the contents of BUN,TG and CHO in blood were very significantly decreased(P<0.01)and the metabolism of protein and fat was improved when the concentration of yeast-germanium was 35mg/Kg.(3)On immune performance:Compared with the control group,the serum IgG in each test group were increased.When the concentration of yeast-germanium in the diet reached 35mg/Kg,the serum IgG was significant increased(P<0.05).The content of serum IgA and IgM in piglets increased in every control groups(P>0.05).The WBC content and LYM of piglets were significantly increased when the concentration of yeast germanium was 35 mg/Kg in diets(P<0.05),LYM%increased very significantly(P<0.01),which effectively improved the immune performance of piglets;(4)On antioxidant activity:Compared with the control group,when the concentration of yeast-germanium in the diet reached 35mg/Kg,the content of GSH-Px,SOD and T-AOC increased very significantly(P<0.01),the content of MDA was decreased very significantly,which effectively improved the antioxidant activity of piglets.Conclusion:The application effect and feed cost were the best,and the concentration of yeast germanium was 35mg/Kg.