Problems in feed standard and suggestions for modification (8.28)

OA show ('918 '); Lei Zhengli, Bian Jianzhong, Xu Yili, 1.1 current health and product standard, 1.1 feed health standard (gb13078-91), 1.1.1 health standard, lack of chromium limit standard in feed and feed raw materials (such as meat powder) A considerable amount of meat powder on the market is processed from leather scraps The chromium content is very high, some of which are as high as 1%, which is very harmful to livestock and poultry The limit of chromium in China's food hygiene standard is ≤ 0.3-2 mg / kg, and that in fish meal standard (SC / T 3501-1996) is 10 mg / kg According to the current situation in China, it is suggested that the chromium limit of compound feed should be ≤ 30 mg / kg At the same time, the determination standard of inorganic chromium was established 1.1.2 the total number of molds is limited to 4 feed materials, the total number of bacteria is limited to fish meal, and there is no coliform group index, which is far from meeting the requirements of the market for product hygiene index It is suggested to increase the limit indexes of mould, bacteria and coliform in the mixture, concentrate and meat powder 1.1.3 sows and lactating sows are more sensitive to free gossypol than ordinary pigs Excessive intake can produce symptoms such as reduced sperm and weaning It is suggested to increase the limit index of free gossypol in feed for boars and sows Experts from the Animal Husbandry Institute of Henan Academy of agricultural sciences have done systematic feeding experiments When the free gossypol in the feed reaches 55 mg / kg, it begins to have an impact on the libido of boars When 110 mg / kg, it has obviously damaged the reproductive system of boars and sows The recommended index is ≤ 20 mg / kg 1.1.4 in order to prevent livestock and poultry diseases and accelerate the growth of livestock and poultry, antibiotics, fungicides, growth hormone, etc are mostly added to the feed at present If the amount is too high, it will remain in the meat and eggs of livestock and poultry, causing harm to human body It is suggested to increase the limit indexes of veterinary medicine, mildew inhibitor and hormone in feed 1.1.5 the pesticide residue items shall be adjusted according to the variety of pesticide For example, at present, herbicide acetochlor is widely used in corn and soybean, acetochlor is acetanilide, which will remain in the seeds; organophosphorus and pyrethroid pesticides are widely used in cotton It is suggested to add the above pesticide residue items to the standard 1.2 the balance between protein and effective amino acid should be considered in the standard of compound and concentrated feed GB / T 5916-93 "chicken compound feed" which specifies that the crude protein is ≥ 16%, but the effective amino acid content is not specified Suggested revision 1.3 the limit index of phosphorus in feed should consider the available phosphorus which is easy to be absorbed by animals At present, the phosphorus in various feed standards refers to total phosphorus, while 2 / 3 of the phosphorus in plant feed is phytate phosphorus, which is not easy to be absorbed by animals If phytase is added to the feed, the absorption rate of phytate phosphorus can be increased, so the total phosphorus index can be reduced correspondingly, or the phosphorus index can be changed to "effective phosphorus", and the determination method standard of effective phosphorus can be established at the same time 1.4 the main components of fish meal (SC / T 3501-1996) are methionine, lysine and cystine It is suggested that the total of methionine, lysine and amino acids should be added to the fish meal standard as the grading index According to the quality of more than 2000 fish meal samples tested by our center in the past three years, the recommended grading indexes are shown in Table 1 Table 1 recommended classification of quality of fish meal table% super grade I, grade II; methionine ≥ 1.80 ≥ 1.60 ≥ 1.40; lysine ≥ 4.80 ≥ 4.30 ≥ 3.80; total amino acids ≥ 58 ≥ 53 ≥ 48 1.5 fish oil (SC / T 3502-1996) there are low-cost fish oil such as lard in the current market According to the standard test, the acid value, peroxide value and other indicators of the adulterated fish oil are all qualified, which brings opportunities for adulteration In order to combat counterfeiting and protect the interests of consumers, it is suggested to increase the refractive index, specific gravity, freezing point or fatty acid and other oil characteristics to identify the true and false 1.6 the standard of feed grade dicalcium phosphate (Hg 2636-94) stipulates that the content of dicalcium phosphate is equal to or greater than 9% By calculation, 40% of calcium phosphate is added into the qualified calcium hydrophosphate, and its calcium, phosphorus and citric acid soluble phosphorus are 26.5% (over the theoretical value), 16.8% and 9.6% respectively, which still meet the requirements of the standard, bringing opportunities for adulteration Through the determination of dicalcium phosphate produced by more regular enterprises, it is found that the content of GOP is higher than 15%, some is over 17%, and GOP is over 99% of total phosphorus It is suggested to increase the index of soluble phosphorus to 15% and put it into the "technical index" table, and increase the item of "ratio of calcium to phosphorus" 1.7 "table salt" has the index of "table salt" in the standard of compound feed inconsistent with the product standard and test method, and it is determined according to GB / T 6439, but GB / T 6439 measures "water-soluble chloride", which may contain water-soluble chloride ions in salt, choline chloride, lysine hydrochloride and other substances If the measured chloride ions are converted into salt, the result will obviously be higher The nutritional components of NRC chicken in the United States indicate the requirements of sodium and chlorine respectively Therefore, it is suggested to change the index of "table salt" to "sodium" and "chlorine" 2 Analysis method standard 2.1 determination of fluorine (gb13083-91 and hg2636-94) When gb13083-91 and hg2636-94 are used to determine fluorine in phosphate ore and calcium hydrophosphate, different sample weight and dilution ratio of test solution will result in different determination results, and the results of the same sample determined by the above two methods are also different The reason is that the activity measured by the fluoride ion selective electrode is not the concentration When the concentration of fluoride ion and other components in the test solution is high, the activity is less than the concentration Therefore, if the test solution is not diluted or the dilution ratio is not appropriate, the measurement results will deviate In addition, the factors that affect the accuracy of the results are acidity, chloride concentration and so on However, the chloride concentration of the test solution and the standard working solution in the "hg2636-94" fluorine determination method is not the same, which may result in the determination result being about 9% lower According to the results of many tests, we suggest that the fluoride concentration of the test solution should be controlled between 1-9 mg / L (when the electrode sensitivity is reduced, the range should be reduced accordingly), and the conditions of acidity, chloride concentration and ionic strength of the test solution and the standard working solution should be kept consistent 2.2 the pH value of EDTA complexation with calcium in hg2636-94 standard is 10 Under this condition, magnesium can also complexate with EDTA and be calculated as calcium However, the calcium hydrophosphate produced from ore contains more than 9% magnesium, so the results are often on the high side The standard uses the copper sulfate standard solution back titration method, the standard solution calibration needs two steps to complete, the determination also needs to add the EDTA standard solution, the operation steps are many, easy to produce the big error It is suggested to refer to GB / t6436-92 EDTA rapid titration method for improvement 2.3 determination of choline chloride (gb13083-91) recently, choline chloride powder mixed with sodium chloride or quaternary amine salt appeared on the market According to the non-aqueous perchloric acid titration method, chloride ions will also participate in the reaction, consume a certain amount of perchloric acid, and be calculated as choline chloride A feed factory deliberately mixed salt into 50% choline chloride powder and sent it to our center for detection The result was 70% We use reference sodium chloride instead of choline chloride to determine by non-aqueous titration It is found that 0.1g sodium chloride can consume 8ml of perchloric acid of 0.2mol/l Even if the insoluble substance (table salt) in glacial acetic acid is filtered out, it can still consume 3.3ml of perchloric acid Further tests show that 0.95 g of sodium chloride can be dissolved per 90 mL of methanol (dosage in the standard) and 0.04 g of sodium chloride can be dissolved per 20 ml of glacial acetic acid Therefore, the interference of sodium chloride cannot be excluded according to this standard Water products are more difficult to detect accurately It is suggested to use Reynold salt Colorimetry (refer to GB / t17481-1998, determination of choline chloride in premix) or high-pressure liquid chromatography for determination 2.4 determination of trace element additives due to the needs of feed processing technology, there are trace element additives with carriers in the market, such as 8% potassium iodide, 1% ～ 3% sodium selenite, etc it is hoped that the standards of such products will be formulated as soon as possible to meet the market demand Due to the rapid development of feed industry and the emergence of new feed varieties, there are no standards for product testing, so it is hoped that such standards can be formulated For example: various fish feed standards; 40% chicken concentrate standards; 15%, 20%, 23%, 25 %Standards for added amount of concentrated pig feed, quality standards and detection methods for yeast and yeast containing feed of liquid fermentation, methods for determination of effective phosphorus in feed, methods for determination of phytase in feed, methods for determination of organic and inorganic arsenic in feed, methods for determination of betaine, etc At present, the raw materials are mixed, the processing technology is rough, and the product quality is worrying In addition to chromium, due to its high nitrogen content, it is particularly easy to breed microorganisms in storage After detection, some bacteria reach tens of millions per gram, and coliform bacteria reach more than 10000 per 100g (the limit of edible meat enema is ≤ 30 / 100g) Water is one of the important factors causing deterioration According to the experience of enterprises, it is difficult to store meat flour with moisture content over 7% It is suggested that the product standard of meat meal should be established, water, chromium, protein, bacteria, coliform and Salmonella should be taken as important test items, and the storage conditions should be specified 4 Summary Based on the practical experience of implementing standards in the past few years after the promulgation of standards, we believe that: 1) standards should be formulated according to the needs of the market, and updated and revised in time according to the continuous development and change of the market; 2) standards should be formulated with full consideration of the needs of users, and it is better for producers, users and quality inspection departments to participate in the formulation and revision of standards, so as to make standards objective , practicability; 3) the possibility of adulteration and other interference factors should be taken into account when formulating the standard The standard should be conducive to take measures to resist interference and interference, so that the standard can truly become "the guard of high-quality products, the killer of low-quality products" Author unit: agricultural product quality inspection center of the Ministry of agriculture (Zhengzhou) mailing address: No.1, Nongye Road, Zhengzhou City, zip code: 450002 source: China feed 1999.23 China feed industry information network 2L8 (author:)