Solid state fermentation of rapeseed cake with Aspergillus niger for degrading glucosinolates and upgrading nutritional value

Background： Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances, such as glucosinolates （GIs）, phytic acid, tannins etc. In the present study, a solid state fermentation （SSF） using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake （RSC）. The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake （FRSC） were investigated, and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined. Results： After 72 h of incubation at 34℃, a 76.89% decrease in GIs of RSC was obtained in solid medium containing 70% RSC, 30% wheat bran at optimal moisture content 60% （w/w）. Compared to unfermented RSC, trichloroacetic acid soluble protein （TCA-SP）, crude protein and ether extract contents of the FRSC were increased （P〈 0.05） 103.71, 23.02 and 23.54%, respectively. As expected, the contents of NDF and phytic acid declined （P〈 0.05） by 9.12 and 44.60%, respectively. Total amino acids （TAA） and essential amino acids （EAA） contents as well as AA in vitro digestibility of FRSC were improved significantly （P 〈 0.05）. Moreover, the enzyme activity of endoglucanase, xylanase, acid protease and phytase were increased （P 〈 0.05） during SSF. Conclusions： Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.

Study on Reduction of Heavy Metal Contents in Tobacco by Application of Rapeseed Cake

[Objective] This study was conducted to find an effective method to control heavy metals in tobacco. [Method] Field experiments were carried out in the culture process of flue-cured tobacco, and the effects of application of rapeseed cake at different amounts in reducing heavy metal contents in tobacco were investigated. [Result] The application of different amounts of rapeseed cake as the base fertilizer had a positive effect in reducing heavy metal contents in tobacco, and the treatment applied with oil cake accounting for 30% of total fertilizer showed an effect significantly different from that of the CK. [Conclusion] This study has a positive effect on the improvement of tobacco safety, and provides certain scientific guide for the improvement of tobacco safety by improving fertilization modes and fertilizer kinds and for the selection and pretreatment of fertilizers, which are of very important significance to practical production.

Effects of dietary inclusion with rapeseed cake containing high glucosinolates on nitrogen metabolism and urine nitrous oxide emissions in steers

Two consecutive trials were conducted to investigate the effects of glucosinolates(GLS)in rapeseed cake(RSC)on nitrogen(N)metabolism and urine nitrous oxide(N_(2)O)emissions in steers.In trial 1,8 steers and 4 levels of RSC,i.e.0,2.7%,5.4%and 8.0%dry matter(DM)(0,6.0,12.1,18.1 mmol GLS/g DM)were allocated in a replicated 4×4 Latin square.In trial 2,the static incubation technique was used for measuring the N_(2)O emissions of the urine samples collected from trial 1.The results of trial 1 indicated that dietary inclusion of RSC decreased the digested N and increased the fecal N excretion(P<0.01),whereas it did not affect the urinary N excretion,total N excretion and N retention(P>0.10).Dietary inclusion of RSC decreased the urinary excretion of urea while it increased allantoin,total purine derivatives,the predicted rumen microbial N flow and thiocyanate(SCN)(P<0.05).Dietary inclusion of RSC did not affect the plasma triiodothyronine and thyroxine while it down-regulated the plasma relative concentrations of 4-aminohippuric acid,3a,7a-dihydroxycoprostanic acid,phosphatidylserine(14:0/16:0),6b-hydroxyprogesterone,pyrrhoxanthinol,tatridin B,mandelonitrile rutinoside,taraxacoside(P<0.05),and up-regulated hypoglycin B,neuromedin N(1-4),dhurrin,5-deoxykievitone(P<0.01).The results of trial 2 indicated that dietary RSC increased the steer urine N_(2)OeN fluxes,the ratio of N_(2)OeN to N application and the estimated steer urine N_(2)OeN emissions(P<0.01).A close correlation was found between the estimated steer urine N_(2)OeN emissions and the output of urinary SCN(P<0.001).In conclusion,dietary RSC increased the fecal N excretion,whereas it did not affect the urinary N excretion and the N retention rate in steers.Dietary RSC increased rather than decreased the urine N_(2)OeN emissions even though it decreased the urinary excretion of urea.The SCN excreted in urine could be the major factor in increasing the urine N_(2)OeN emissions.Whether other metabolites excreted into urine from RSC have an impact on the urine N_(2)OeN emissions in steers needs to be investigated in the future.

Effect of Different Additive Combinations on Production Performance of Layer

To explore the effect of different additive combinations on double-low rapeseed cake （meal） utilization and layer production performance, we randomly divided 756 Roman brown shell layers around 50 weeks age into seven groups to detect production performance, of which group 1 was control group supplied with basic diet （added with 9% double-low rapeseed cake）, while groups 2 -7 were experimental groups added with Chinese herbal medicine, enzyme preparation, pro- biotics and peptide antibiotics in basic diet. The results showed that group 4 added with Chinese herbal medicine ＋ enzyme preparation ＋ peptide antibiotics re- ceived the best effect, resulting in significantly increased laying rate （70.50%, P 〈 0.05 ）, significantly reduced feed-egg ratio （2.46, P 〈 0.05 ）, and extremely increased egg Haugh unit （P 〈0.01 ）. This indicated that adding combination of Chinese herbal medicine ＋ enzyme preparation ＋ peptide antibiotics in layer bas- ic diet could improve egg production performance and egg quality of layers.