Aflatoxin B1, zearalenone and deoxynivalenol in feed ingredients and complete feed from different Province in China

Background： The current study was carried out to provide a reference for monitory of aflatoxin B_1（AFB_1）,zearalenone（ZEN） and deoxynivalenol（DON） contamination in feed ingredients and complete feeds were collected from different Province in China from 2013 to 2015.Methods： A total of 443 feed ingredients, including 220 corn, 24 wheat, 24 domestic distillers dried grains with soluble（DDGS）, 55 bran, 20 wheat shorts and red dog, 37 imported DDGS, 34 corn germ meal and 29 soybean meal as well as 127 complete feeds including 25 pig complete feed（powder）, 90 pig complete feed（pellet）, six duck complete feed and six cattle complete feed were randomly collected from different Province in China,respectively, by high-performance chromatography in combined with UV or fluorescence analysis.Results： The incidence rates of AFB_1, ZEN and DON contamination of feed ingredients and complete feeds were80.8, 92.3 and 93.9 %, respectively. The percentage of positive samples for DON ranged from 66.7 to 100 %.Domestic DDGS and imported DDGS presented the most serious contamination AFB_1, ZEN and DON contamination levels of feeds ranged from 61.5 to 100 %, indicated that serious contamination over the studied 3-year period.Conclusion： The current data provide clear evidence that AFB_1, ZEN and DON contamination of feed ingredients and complete feeds in different Province in China is serious and differs over past 3-year. The use of corn, domestic DDGS, imported DDGS and corn germ meal, which may be contaminated with these three mycotoxins, as animal feed may triggered a health risk for animal. Feeds are most contaminated with DON followed by ZEN and AFB_1.Mycotoxins contamination in feed ingredients and complete feeds should be monitored routinely in China.

Level and characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans in feed and feed additives

Feed security is a prerequisite for safe animal food products.In this study,13 groups of feed and feed ingredients,totaling 2067 samples,were collected in the period of 2011 to 2014 from China.The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs） was found in fish meals and shell powders,with a concentration of 60.35 ng/kg,followed by mineral origin materials.In terms of the toxicity equivalent concentration,the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain,with an average concentration of 1.26 ng WHO-TEQ/kg,while the lowest level was observed in compound feed for chickens and pigs,with an average value of0.16 ng WHO-TEQ/kg.OCDD and OCDF were the predominant congeners in all groups except fish oils,in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF.For zinc chloride samples,different from other zinc-based compound samples,the main congeners were 1,2,3,4,6,7,8-HpCDF（17%）,1,2,3,4,7,8,9-HpCDF（15%）,1,2,3,4,7,8-HxCDF（12%） and OCDF（30%）.Considering toxicity equivalency factors,the dominant congeners were 2,3,4,7,8-PeCDF,1,2,3,4,7,8-HxCDF,2,3,7,8-TCDF and 1,2,3,7,8-PeCDD,and the contribution to the total TEQwas29%,16%,14%and 12%,respectively.Overall,2.1%（43 out of 2067） of all the analyzed samples exceeded the different individual ＇European Union maximum limited levels for PCDD/Fs.This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.

Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture

The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.