The Study On Ruminal Degradation Rate And Fermentation Parameters Of Different By-products Of Maize Processing

The main purpose of this study was to study the effects of nutrient degradation rates in the rumen and the in vitro fermentation parameters of different processing by-products of corn.It was established that corn syrup,corn bran,corn germ meal and corn starch residue have complementary effects on ruminal degradation rate and in vitro fermentation parameters.Provides data support for the development of mixed corn processing by-product feeds.The ruminal nylon bag degradation method was used to determine the ruminal degradability of the nutritional components(DM,CP)of corn pulp,corn bran,corn germ meal and corn starch residue.The effect of different corn processing byproducts on the pH value,ammonia nitrogen and volatile fatty acid concentration in the rumen fluid was also studied by using an in vitro continuous culture system for in vitro fermentation experiments and collecting rumen fluid samples.The results show:?The dry matter rumen degradation rates of corn pulp,corn bran,corn germ meal and corn starch residue were 96.66%,46.20%,77.94% and 76.13%,respectively.The dry matter rumen degradation rate of corn pulp was highest,followed by corn germ meal.Corn bran was the lowest;ruminal degradability of corn protein,corn germ meal and corn starch residue was 46.19%,76.72%,and 52.8%,respectively.The crude protein rumen degrading rate of corn germ meal was the highest and corn bran was the lowest.?The ratio of pH to 0h in the rumen fluid of corn pulp,corn bran,corn germ meal and cornstarch slag was changed(0.21),(0.11),0.05,and 0.07.?After adding corn syrup,corn bran,corn germ meal and corn starch residue,the concentration of ammonia nitrogen in corn pulp and corn germ meal reached the highest after adding for 2 h,and the increments were 4.04 mg/100 ml and 3.19 mg/100 ml,respectively;After 4 h,the concentration of ammonia nitrogen in corn bran reached the maximum,and the increase amount was 2.68 mg/100 ml.After 0.5 h,the ammonia nitrogen concentration of maize starch residue reached the maximum,and the increase amount was 1.19 mg/100 ml.?After adding corn straw,corn bran,corn germ meal and corn starch residue,the concentration of acetic acid in the corn pulp and corn germ meal was increased to the maximum after 1 h,and the increments were 31.49 mM/L and 30.31 mM/L,respectively;After 2 h,the acetic acid concentration of corn bran and cornstarch slag reached the maximum,and the increments were 22.96 mM/L and 37.23 mM/L,respectively.After 1 h of addition,the propionic acid concentrations of corn steep liquor,corn steep liquor and corn germ meal and corn starch slag reached the maximum,and the increments were 9.78 mM/L,9.05 mM/L and 8.27 mM/L,respectively.After 2 h,corn was added.The levulinic acid concentration reached the maximum,and the increase was 5.77 mM/L.After 0.5 h,the concentration of butyric acid in corn steep liquor and corn starch residue reached the maximum,and the increase amount was 0.2 mM/L and 1.09 mM/L,respectively;after 1 h,the concentration of butyric acid in corn bran and corn germ meal reached the maximum.The increase amounts to 1.53 mM/L and 1.74 mM/L,respectively.?The preliminary mixing scheme for mixed corn processing by-products is: Option One,Appropriate proportion of the maximum amount of corn pulp and corn bran: 30%:35%:30%:5%.Option Two,Proportion of the maximum amount of sugar residue: 10%:25%:30%:35%.Option Three,Proportion of suitable nutrient use efficiency: 20%:5%:55%:20% and 20%:10%:55%:15%.