The Study Of Feeding Extruded Full-fat Double-low Rapeseed For Enriched Oleic Acid Eggs

The promotion of double-low rapeseed and the application of the non-fishy gene laying hens increased the supplementation of rapeseeed meal in laying hens diet.With the discovery of oleic acid function,the breeding of high oleic acid double-low rapeseed has become popular.The development of high oleic acid eggs is expected to be welcomed by consumers.In this paper,the process parameters of extruded full-fat double-low rapeseed were explored,and the extruded full-fat double-low rapeseed instead of rapeseed meal plus rapeseed double-low oil was used to preliminarily develop high oleic acid eggs.Test 1:This experiment took whole double-low rapeseed as raw material,twin-screw extruder as processing equipment,the temperature of extrusion chamber III zone、the moisture content of rapeseed and the rotating speed of host screw as test factors.The orthogonal test was designed according to L₉（3⁴）,and the content of crude fat,isothiocyanate and oxazolidinethione were used as the evaluation indexes.The scanning electron microscope,paraffin section,protein solubility were used to verify to explore the better technological parameters.The results are as follows:the temperature of extrusion chamber III zone is 110℃,the moisture content of rapeseed is 15%,and the rotating speed of host screw is 204r/min.At this time,the crude fat of extruded double-low rapeseed is close to the raw material.The content of isothiocyanate and oxazolidinethione drop greatly,and the seed coat structure after extrusion is destroyed,which is beneficial to the entry of digestive enzymes and the utilization of nutrients.The protein solubility is moderate,and the heating degree is suitable.Test 2:A total of 360 sixteen-week-old Zhengda Brown laying hens were randomly assigned to 4 dietary treatments,with 6 pens per treatment and 15 birds per pen.The 4 groups were rapeseed meal plus corn oil group（RMCO group）,rapeseed meal plus double-low rapeseed oil group（RMDRO group）,extruded full-fat double-low rapeseed group（EFDR group）,extruded full-fat double-low rapeseed plus compound enzyme group（EFDRCE group）.After 6 weeks of prefeeding,the formal test lasted for 6 weeks from 23 weeks old.The performance and nutrient digestibility of RMDRO group,EFDR group and EFDRCE group were determined.The yolk fatty acids contents were measured in RMCO group,RMDRO group and EFDRCE group.The effect of full-fat double-low rapeseed adding compound enzyme on the diet of laying hens and its regulation on the egg yolk fatty acid composition were studied,and high oleic acid eggs were produced.The results show that:1.The production performance.Compared with RMDRO group,the average egg weight of EFDR group was decreased significantly（P<0.05）,feed egg ratio was significantly increased（P<0.05）,the average egg weight and feed egg ratio of EFDRCE group showed no significant difference（P>0.05）.Compared with the EFDR group,the average egg weight of EFDRCE group was increased significantly（P<0.05）,and the ratio of egg was significantly decreased（P<0.05）.These data support the need for non-starchy polysaccharides complex enzyme supplements when extruded full-fat double-low rapeseed instead of rapeseed meal plus double-low rapeseed oilseed in poultry diets.2.The nutrients apparent digestibility.Compared with RMDRO group,the crude fat apparent digestibility of EFDR group was significantly decreased（P<0.05）,the crude fat apparent digestibility of EFDRCE group showed no significant differences（P>0.05）.Compared with EFDR group,the crude fat apparent digestibility of EFDRCE group was increased significantly（P<0.05）.It can be seen that the non-starch polysaccharides compound enzyme can relieve the nutrient-encapsulating effect of cell walls,and improve the extruded full-fat double-low rapeseed crude fat apparent digestibility.3.The yolk fatty acid content.Compared with RMCO group,the content of palmitic acid,stearic acid,oleic acid and linolenic acid in yolk of RMDRO group and EFDRCE group were increased significantly（P<0.05）,and the linoleic acid content was decreased significantly（P<0.05）.Compared with RMDRO group,the yolk fatty acids content of EFDRCE group showed no difference（P>0.05）.After 3 weeks of experiment,the fatty acid composition of yolk tended to be stable,and the oleic acid content of EFDRCE group was 2185.96mg/egg,which was much higher than the1362.69mg/egg of RMCO group.It can be seen that extruded full-fat double-low rapeseed plus compound enzyme can improve the yolk oleic acid content and produce high oleic acid eggs.In summary,whole double-low rapeseed can produce extruded full-fat double-low rapeseed by twin-screw extrusion technology.It is necessary to supplement non-starch polysaccharides compound enzyme in laying hens diet containing extruded full-fat double-low rapeseed.The extruded full-fat double-low rapeseed plus compound enzyme can replace the application of rapeseed meal plus double-low rapeseed oil in the diet,and improve the yolk oleic acid content and produce high oleic acid eggs.