| Response surface analysis was used to optimize the conditions of enzymatic hydrolysis of barley in vitro and analysis the utilization rate of enzymatic barley on60-day-old yellow feather broilers.And the effect of the enzymatic-hydrolysis barley diets on performance,visceral organ index,and serum biochemical indicators and intestinal morphology in 21-day yellow broilers was designed to study the feed value of enzymatic barley.The study was divided into two parts:First,the optimization of enzymatic hydrolysis of barley in vitro and the the appearance of barley by enzymatic hydrolysis:The experiment used pea barley as a feed ingredient and added three enzymes,namely,an acid protease(Aspergillus niger),a xylanase(Trichoderma reesei),and a beta-glucanase(Trichoderma reesei),which were passed under shake flask conditions.Single factor experiments and Box-Behnken response surface design in Design-Expert 8.0.6 software optimize in vitro hydrolysis conditions.The results were as follows: In the enzymatic hydrolysis of barley,the additing amounts of acid protease,xylanase,and β-glucanase were407.63,562.58,and 122.23 U/g,respectively.The optimized conditions for response flask optimization were as follows: Buffer initial pH 4.57,temperature 61.83°C,volume 120 mL.After scanning electron microscopy,there were more pores on the surface of enzymolyzed barley.Second,enzymatic barley animal feeding trials:(1)Metabolic tests.Sixteen 60-day-old,yellow feather broilers with similar weights were randomly assigned to two treatments,namely the enzymolysis barley group and the barley group with 4 replicates per treatment of 2 broilers each.The gavage method was performed and dry matter,crude protein,and energy utilization in the feed and feces samples were determined.The results were as follows: Compared with feed barley directly,the apparent utilization of dry matter after barley enzymolysis had a tendency on increasing(P>0.05),and the apparent utilization rate of crude protein had no significant difference(P>0.05),but the apparent utilization rate of energy was significantly increased by15.48%(P<0.05).(2)Feeding test.Forty-eight one-day-old healthy yellow feather broilers were selected and randomly divided into A,B,C and D groups with 12 replicates of 1 chicken each.group A(control group)was fed with basal diet,group B was fed with barley diet,group C was fed with barley enzyme diet,and group D was fed with enzymatic barley diet.The trial period was 21 days and the results are as follows:Compared with control group A,there was no significant difference in average daily gain between group B and group C(P>0.05),and average daily gain in group D was significantly lower(P<0.05).After feeding the enzymatic barley diet,the average daily feed intake was significantly lower(P<0.05),and the feed-to-weight ratio was not significantly different(P>0.05).The villus height in group B was significantly lower than that in other groups(P<0.05).There was no significant difference in villus height between group A,C,and D(P>0.05).The crypt depth and V/C ratio were not significantly different(P<0.05).However,the crypt depth of group B and group D was higher than that of group A and B,and V/C was lower than that of control group.Compared with group A,serum glucose concentration in group B was significantly decreased,and there was no significant difference between group C and D(P>0.05).There was no significant difference in serum total protein concentration between group A and B,which was significantly higher in group C than in group A and B.Compared with group A,the total protein concentration in group D was significantly increased by 26.79%(P<0.05).In summary,barley can release more reducing sugars by enzymatic hydrolysis in vitro.When enzymatically digesting barley as an energy feed,the apparent energy utilization and the total protein concentration in serum of adult chickens could be increased,but the growth performance was decreased. |
PDF Full Text Request