Study On The Effect Of Corn Straw Stored In Ventilation Cage On In Vitro Digestion And Lamb Fattening

This experiment was conducted to study the effect of corn straw stored in ventilation cage on in vitro digestion and lamb fattening,select a kind of method which could effectively reduce the water content of corn straw and achieved the long-term storage of corn straw and select a suitable for China's northeast region of corn straw storage mode.The significance of this experiment was to give a theoretical basis for the application of the ventilation cage method for the storage of corn straw,and to provide scientific data for the development and reform of corn straw collection and storage in china.In this experiment,three experiments were designed:Experiment 1: effect of ventilation cage and storage time on the nutrition and health indexes of corn strawThe experiment adopted 4 * 7 double factor design,which contained different levels of ventilation cage of 4 levels(1,0.8,0.5 m wide ventilation cage and traditional stacking method)and storage time of7 levels(0,30,60,90,120,150,180 d).Experiment 2: effect of corn straw stored in ventilation cage on in vitro digestionThe experiment adopted 4 * 6 double factor design,including corn straw stored in ventilation cages with different specifications of 4 levels(corn straw stored in 1,0.8,0.5 m wide ventilation cage and corn straw stored in traditional stacking method)and fermentation time of 6 levels(3,6,12,24,48,72 h),and set one blank.There was 3 same test in each group.Then tested indicators for in vitro digestion at specified time.Experiment 3: effect of corn straw stored in ventilation cage on lamb fatteningThis experiment was tested with a single factor which was designed completely randomized.The diets were variable,including 4 levels.They were divided into 4 groups,each group contained 4 lambs.The pre feeding period was 15 days,the official test time was 90 days.Every 15 days,the lamb production performance index was measured.The results of the experimental showed that:Experiment 1: the water content and ADF content of corn straw stored in traditional stacking method was significantly higher than that of other ventilation cage with different specifications(P<0.05),while there was no significant difference between the 1,0.8,0.5 m wide ventilation cages(P>0.05).With the increase of storage time,the water content of corn straw showed a decreasing trend.When the storage time was 150 days,the water content of corn straw stored in the four storage methods was lower than that of safe water by 14%.There was no significant difference in the contents of CP,NDF,and totalnumber of molds in different specifications of ventilation cages(P>0.05).Storage time had no significant effect on the CP content of corn straw(P>0.05),but had significant effect on the content of NDF,ADF and total number of mold(P<0.05).With the increase of storage time,the contents of NDF and ADF in straw straw increased first and then decreased,and the total number of mold increased.If the limit of aflatoxin B1 of corn straw and concentrate supplement was identical,the stored corn straw could meet the hygienic standard.Experiment 2: corn straw stored in ventilation cages with different specifications and fermentation time had a significant effect on gas production rate in vitro digestion(P<0.01).There was a significant difference in gas production rate(P<0.05)among different corn straw,and the gas production rate of the corn straw stored in 0.8m wide ventilation cage was the highest at 6 time points.There was no significant difference between 3 and 6 hours of gas production rate(P>0.05),which was significantly higher than that of the previous time after 6 hours(P<0.05).There was a significant interaction effect between corn straw stored in ventilation cages with different specifications and fermentation time on gas production rate in vitro digestion(P<0.01).The pH value of in vitro digestion of corn straw stored in traditional stacking method was significantly higher than that of the ventilation cage method(P<0.01),but there was no significant difference in the pH value of the in vitro digestion of corn straw stored in the ventilation cage method(P>0.05).There was no significant difference in the concentration of ammonia nitrogen,acetic acid,propionic acid and butyric acid in the four storage methods(P>0.05).Experiment 3: the effects of the four kinds of diets on the average daily feed intake,average daily gain,average feed meat ratio,the average daily feed intake of concentrated feed,average daily feed intake of roughage and average forage-to-concentrate ratio were not significant(P<0.05).In conclusion:(1)From the point of view of the change of corn straw nutrition and health index,the ventilation cage method was better than the traditional method.Among them,the effect of 0.8 m wide ventilation cage on corn straw was the best.(2)There was no significant difference between the effects of corn straw storaged in 0.8m wide ventilated cage and Leymus chinensis on lamb fattening.(3)There was no significant difference in the fattening effect between the “granular concentrate + whole corn” and the “granular feed” concentrate supplement with the same nutritional supplement of the two kinds of nutritional formula.