Improvement Of Determination Method Of Feed Conventional Analysis

This experimental research has been improved in feed routine analysis of moisture, crude ash,crude fat, crude fiber on measurement parameters and key points, and supplemented the newly revised national standard, then provide the basis for the revised again, also provided a reference for the production of rapid determination.This experiment was divided into four parts:(1)Moisture: soybean meal, cottonseed meal, chicken concentrates and complete feed of pig were two experimental samples. A 4×4 double factors cross-group was adopted in experiment 1.This part researched effect of sample weight and drying time for moisture content. A 3×4 double factors cross-group was adopted in experiment 2. This part researched effect of drying temperature and drying time for moisture content.(2)Crude ash: soybean Meal, corn, winter wheat, wildrye, chicken concentrates, complete feed of pig and other 10 kinds of feed ingredients and finished feed samples were two experimental samples. GB/T 6438-2007 was adopted in experiment 1(conteol group), the experimental group without carbonization researched the effect of carbonization on the ash content. A 3× 3 double factors cross-group was adopted in experiment 2. This part researched the effect of temperature on ignition and burning quality on crude ash content.(3)Crude fat: soybean meal, cottonseed meal, corn, chicken concentrates, complete feed of pig and other 8 kinds of feed ingredients and finished feed samples were experimental samples. A3 × 3 double factors cross-group was adopted in experiment. This part researched the effect of extraction solution and extraction time on the fat content.(4)Crude fiber: soybean meal, cottonseed meal, chicken concentrates and complete feed of pig were there comparative experimental samples. Experiment 1 researched that the effect of 200 filter and 100 filter mesh on crude fiber. Experiment 2 researched that the effect of different alkaline cleaning solution, sodium hydroxide and potassium hydroxide, on crude fiber. Experiment 3researched the effect of different cleaning methods, hand washing method and washing method bag fiber tester on crude fiber.The results showed that:(1)With the increasing of the drying time, the result of moisture measurement was larger, the soybean meal and the complete feed of pig had a significant difference(P<0.05). With the increasing of the sample weight, the result of moisture measurement was significantly lower(P<0.05). With the increasing of the drying temperature, the result of moisture measurement significantly increased(P<0.05). With the increasing of the drying time, the moisture content increased as well. The interaction between drying time and the sample weight, and the interaction between drying time and the drying temperature, both had significant influence(P<0.05).(2)Whether had a carbonization process or not showed no significant effect on crude ash content(P>0.05). The interaction between ignition temperature and the sample weight had significant influence on the determination of crude ash(P<0.05). With the increasing of the drying temperature, the result of crude ash content was lower, burning under 650 ℃ was lower than burning under 550℃ or 600℃(P<0.05). With the increasing of the sample weight, the crude ash content of each sample increased significantly(P<0.05).(3)The selection of the extraction time and extract had significant influence on the content of crude fat(P<0.05).With the increasing of the extraction time, the content of crude fat of each sample increased as well, and the content of crude fat of extracting for 3 hours was significantly lower than extracting for 5 hours and 7 hours(P<0.05). In the aspect of the influence of different extract for crude fat content, the measurement results of ether and the 30 ~ 60 ℃ boiling range petroleum ether had no significant difference(P>0.05). But the 30 ~ 60 ℃ boiling range petroleum ether was significant lower than the former two(P<0.05).(4)The filter mesh was100 mesh or 200 mesh, the content of crude fiber had a significant difference(P<0.05), the alkaline cleaning solution was sodium hydroxide or potassium hydroxide,the content of crude fiber showed no significant effect(P>0.05). The cleaning method was hand washing method and washing method bag fiber tester, the content of crude fiber had a significant(P<0.05), the former measured value is significantly lower.Conclusion:1. The appropriate drying temperature of determining the moisture is 103 ℃ ± 2 ℃, the drying time is 4 ~ 5h, the sample weight is 2 ~ 5g.2. The carbonized steps can be omitted when 550 ℃ ± 20 ℃ for rapid determination of crude ash. Crucible sample size and weight have significant effects on the determination of feed crude ash, diameter of 30 mm porcelain crucible with the sample of 2g is advisable.3. 30 ~ 60℃ boiling range of petroleum ether is much more advisable to serve as crude fat extraction agent, and the suitable extracting time with 5 hours is advisable.4. In the determination of crude fiber, potassium hydroxide and sodium hydroxide solution can be replaced, and the filter screen for washing residue should not be less than 200 mesh. Using the method of filter bag is more appropriate when digesting and washing.