Summary of the nutritional value of rapeseed meal
Summary:Rapeseed cake and meal are by-products of rapeseed as raw material after oil extraction, which is light gray-brown. After pressing and extracting oil, it is called cake, and after extracting or pre-pressing extracting oil, it is called meal. The crude protein content of rapeseed cake and meal is between 34% and 38%, and the holding point of amino acid composition is high methionine content (second only to sesame cake and meal).The content of lyshelic acid is also high, especially the digestibility of digestible sulfur-containing amino acids. The arginine content is low, which is the lowest content in cake and meal feed. The effective energy value of rapeseed cake and meal is low (low starch content and rapeseed husk are difficult to digest and utilize). Among the minerals, calcium and phosphorus are high, as well as selenium and manganese. In particular, the selenium content is the highest among commonly used plant feeds. However, rapeseed also contains antinutrients such as glucoside, erucic acid, tannins, and phytic acidThe main one of these is glucoglucoside. This paper briefly analyzes and summarizes the domestic market overview of rapeseed meal, the nutritional value of rapeseed meal, especially the available nutrient content and its anti-nutritional components, combined with the latest raw material data statistics of the National Feed Engineering Technology Research Center, especially the available amino acid and other data are more in line with the current domestic reality than China's feed database, so as to facilitate the reference of feed and animal husbandry enterprise technicians.
Keywords:Rapeseed meal, nutritional value, digestibility.
Oilseed rape is the world's largest oil crop. China, India, Canada and Europe are the world's four major rapeseed producers, and China's rapeseed area and output rank first in the worldAmong them, Sichuan, Anhui, Jiangxi, Hunan, Hubei and Jiangsu are the major rapeseed producing provinces in China, and their rapeseed area and output account for more than 70% of the total area and output of the country. According to the statistics of the German "Oil World", China's rapeseed output in 2006 was about 11 million tons, and the annual output of rapeseed meal in 2006 was about 6.8 million tons according to the 62% rapeseed meal yield; In 2006, China imported a total of 71 rapeseed10,000 tons, of which 70 are imported from Canada10,000 tons, accounting for 98 percent of total imports6%, according to the yield of 62% rapeseed meal, which is equivalent to indirect imports 4350,000 tons of rapeseed meal; In 2006, China directly imported rapeseed meal 4260,000 tons, of which 40 were rapeseed meal imports from India30,000 tons, accounting for 94% of China's total rapeseed meal imports6%, 230,000 tons, accounting for 5 of China's total rapeseed meal imports4%；In 2006, China exported a total of 3750,000 tons. That is, in 2006, a total of 793 rapeseed meal was available for domestic use70,000 tons. Table 1 shows China's (domestic and imported) 793 in 2006Analysis table of 70,000 tons of rapeseed meal**.
1 Conventional nutrients
The table below lists the typical nutrient content of rapeseed meal. Through comparison, it is found that the latest statistical results of the National Feed Engineering Technology Research Center (2007) are basically the same as those of the Chinese feed database in terms of conventional nutrient content, but the crude protein is two percentage points lower than the latter, but because the domestic rapeseed oil extraction level is relatively low compared with foreign countries, and many of the data used in China's feed database refer to foreign databases, the fat content of domestic rapeseed meal should be relatively high, about 34%。
However, due to the current high oil prices, oil mills can only find ways to extract more oil, so the oil content of rapeseed meal will definitely decline compared to the past few years. Compared with soybean meal, rapeseed meal has a lower crude protein content, more than twice the crude fiber content of soybean meal, and the calcium and total phosphorus content are higher than that of soybean meal. Compared with rapeseed, the crude fat content of rapeseed cake meal decreased, while the content of other nutrients increased to varying degrees, and the crude protein content increased by 136%~15.0%, the crude fiber content increased by 39%~4.2%, the crude ash content increased by 41%~3.6%, calcium and total phosphorus content increased by 02% and 05%。The main reason for the increase in these nutrient content is the high crude fat content of rapeseed at 381%~40.2%, most of the crude fat is removed after oil extraction, so it will inevitably lead to an increase in the content of other nutrients in rapeseed cake. The crude protein content of rapeseed and its cake was 40%~5.4%, the crude protein content of ordinary rapeseed meal is higher than that of ordinary vegetable cake. The crude fat content was greatly affected by the oil extraction method, and the crude fat content of ordinary vegetable cake was more than 4 times higher than that of ordinary rapeseed meal. The contents of acid detergent fiber and neutral detergent fiber in double low rapeseed meal were greatly affected by the varietyThe contents of acidic detergent fiber and neutral detergent fiber varied greatly among different varieties, and the coefficient of variation was 29., respectively3% and 308%。
2 amino acids
The table below lists the amino acid content of rapeseed cake meal. Compared with soybean meal, except that the lysine content is lower than that of soybean meal, the content of other amino acids is similar to that of soybean meal, and the content of sulfur-containing amino acids is slightly higher than that of soybean meal. It can be seen from the values in the table that the contents of essential amino acids (except isoleucine and valine) in rapeseed and its cake are similar to those in rapeseed meal, which are similar to those in rapeseed meal and its cake. The contents of all essential amino acids, non-essential amino acids and total amino acids in ordinary rapeseed meal are higher than those in ordinary vegetable cakes, and in the essential amino acids of rapeseed and its cake mealThe higher amino acids were leucine, arginine, lysine and valine; Lower levels of amino acids are tryptophan, methionine, and histidine.
3 Digestible amino acids
Through the statistical results of the National Feed Engineering Technology Research Center (2007) in the following table, we can find that the results are much lower than the average value of China Feed Database (2005) and INRA (2002), close to 10%, but INRA (2002) is mainly for Europe and Canada double low rapeseed meal, its own variety of advantages plus foreign processing technology, its amino acid digestibility is significantly higher than that of domestic ordinary rapeseed meal, National Feed Engineering Technology Research Center (2007) The statistical amino acid digestible data are mainly in the Ministry of Agriculture Feed Industry Center Dr. Xi Pengbin, the determination of rapeseed meal from different regions of the country rapeseed varieties, more in line with the actual situation in China, so in the use of rapeseed meal to understand the raw materials ** is very critical, in the preparation of full-price rations to use targeted and accurate effective data is crucial. It should be pointed out that rapeseed meal not only has a high total amount of sulfur-containing amino acids, but also has a relatively high ileal true digestibility in each database, which is similar to that of soybean meal, especiallyThe digestibility of cysteine in high-quality rapeseed meal is significantly higher than that of soybean mealTherefore, in the current situation of high methionine**, adding rapeseed meal can make up for the lack of methionine and save costs compared with other miscellaneous meals.
4 Performance
Rapeseed cake and meal have the highest energy value for pigs, followed by cattle and the lowest for chickens(See Table 5). The main factor affecting the energy value of rapeseed cake and meal is its shell (accounting for about the weight of the seed. 16%) and crude fibre content (9% 14%) and tannins in the shell; Secondly, the oil extraction processing technology also has a great influence on the energy value of rapeseed cake meal, and the energy value of high residual oil is relatively higher than that of low residual oil. The processing method of pneumatic separation of rapeseed husk and the cultivation of thin-shell rapeseed can improve the energy value of rapeseed cake in foreign countries, so the energy value is higher than that of domestic rapeseed meal. Feed manufacturers should set their effective energy value according to the purchase of rapeseed meal ** and variety.
5 Toxic and harmful substances
The crude protein content of rapeseed cake and meal is high, and the amino acid composition is close to that of soybean cake, but it is limited by many practical applications, mainly because rapeseed cake contains many harmful substances and anti-nutritional factors. Glucosinolates are the main toxic and harmful components in rapeseed cake. The following five hydrocarbon thioglucosinolates are mainly present in oilseed rape (see Table 6). The content and types of glucosinolates in different varieties and types of rapeseed and its cake meal are different.
Table 7 shows the approximate levels of harmful components in rapeseed and its cake in China. Double low rapeseed meal is low erucic acid, low sulfur grape glycoside content of rapeseed meal. It can be seen from the values in the table that compared with ordinary rapeseed meal, the contents of total glucosinolate, oxazolidinthione, isothiocyanate and sinanine in rapeseed meal are low, and the contents of phytic acid and tannins are higher. The allowable standard stipulated in China is total glucosinolate <30x103mg kg and isothiocyanate <40x10mg/kg。There are many varieties of rapeseed cake meal in China, and there are many kinds of oil extraction technology, resulting in uneven quality of rapeseed cake meal, and the toxin content in most rapeseed cake meal is high, so before using rapeseed cake meal with high toxin content, it must be detoxified, and then used to feed livestock and poultry.
6. Effects of different oil extraction processes on the nutrients and toxic and harmful substances content of rapeseed cake
There were significant differences in crude protein, crude fat, acidic detergent fiber and total energy content of rapeseed corresponding to different oil extraction methods. Compared with rapeseed, the crude fat and total energy content of rapeseed cake were significantly reduced, and the crude protein content was significantly increased after oil extraction. There were significant differences in dry matter, crude protein, crude fat, acidic detergent fiber, neutral detergent fiber, total phosphorus and total energy content of rapeseed cake produced by different oil extraction methods. The material content of high-temperature pressed mustard biscuits was higher than that of pre-pressed and extracted rapeseed meal and low-temperature pressed rapeseed cake. The crude protein content of high-temperature pressed rapeseed cake and pre-pressed rapeseed meal was significantly higher than that of low-temperature pressed rapeseed cake. There were significant differences in the crude fat content of rapeseed cake produced by the three oil extraction methods, among which the crude fat content of low-temperature pressed cake was the highest, the high-temperature pressed cake was lower, and the pre-pressed-extracted meal was the lowest. The total energy content of low-temperature pressed cake was significantly higher than that of the other two types of rapeseed cake, while that of high-temperature pressed rapeseed cake was slightly higher than that of pre-pressed-extracted rapeseed meal, but the difference was not significant.
Due to the lack of soybean protein resources in China, it is very important to better use rapeseed meal to prepare low-cost miscellaneous meal diets, reduce feed costs and improve miscellaneous meals. Whole feed formulation is conducive to improving the utilization value of raw materials, more accurate formulation of low-cost miscellaneous meal diets, reducing feed costs and improving animal performance.
About the import of rapeseed meal:
Since rapeseed meal belongs to the single feed category of 1773 feed raw materials, it is necessary to apply for the import feed registration certificate approved by the Ministry of Agriculture, and at the same time, the manufacturer can import in compliance with the General Administration of Customs.
At present, Russia, India, Ukraine, Pakistan and other countries all have the access list of rapeseed meal exported to China.