Soybean meal quality can be judged by urease activity and protein solubility
Soybean meal quality and urease activity and protein solubility
Soybean meal quality and urease activity and protein solubility1 UREASE ACTIVITY AND PROTEIN SOLUBILITY AS INDICATORS FOR SOYBEAN MEAL QUALITY Professor Shen Huile, American Soybean Association Associate Professor Yang Xiuwen, Beijing Dairy Cattle Research Institute Introduction
Soybean protein is the most important and also the highest quality plant protein feed in poultry diets. Apart from a slight deficiency in methionine, all other amino acids are close to an ideal balance. Like other protein feeds, soybean meal quality is affected by the content of various nutrients, such as energy, protein, fiber and amino acids. For example, there are great differences between ordinary soybean meal and dehulled soybean meal in the above indicators (see Table 1). Dehulled soybean meal has a higher energy level because of its lower fiber content. However, soybean meal with a high protein level does not necessarily guarantee a low fiber and high energy level. For example, the protein content of some non-dehulled Chinese soybean meal can be as high as 48% or even 50%, while it still contains 6% to 7% fiber. Therefore, the metabolizable energy level of high-protein soybean meal may still decline because of high fiber content, and no measured metabolizable energy values for these high-protein "high-fiber" soybean meals have yet been seen. But it can generally be estimated that when the fiber content of dehulled soybean meal is above the normal level of 3.5%, each 1% increase in fiber reduces the metabolizable energy per kg of pig feed by 32 to 42 kcal, while for poultry feed per kg it decreases by nearly 60 kcal. On the other hand, soybean meal quality is to a large extent affected by processing problems, which in turn affect its amino acid content and amino acid digestibility and even energy. This article mainly discusses the variation in soybean meal quality caused by insufficient processing or excessive heating and its impact on production performance, and at the same time introduces the currently feasible methods for identifying soybean meal quality - urease activity (pH change value) and 0.2% potassium hydroxide protein solubility - and evaluates them.
I. Raw soybeans - trypsin inhibitor and urease It is well known that soybean meal must undergo moderate heat processing to destroy several anti-nutritional substances contained in soybeans. Among them, the one with the greatest impact on livestock and poultry is trypsin inhibitor (Tripsin Inhibitor). Fortunately, these anti-nutritional factors are all destroyed after heating. Moderate heating is the key to soybean meal processing, because insufficient or excessive heating will reduce the nutritional value of soybean meal.
1 Originally published in March 1999
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Table 1 Main nutritional indicators of ordinary soybean meal and dehulled soybean meal (NRC, 1994) Nutrient Ordinary soybean meal Dehulled soybean meal Dry matter (%)
89 90 Poultry metabolizable energy (kcal/kg)
2230 2440 Protein (%)
44.0 48.5 Fiber (%)
7.0 3.9 Lysine (%)
2.69 3.02
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It seems the content is still incomplete. Could you send a complete version????
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Yes, can you upload the article? Thank you
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I have the authoritative one, but the format is wrong, so it won't let me post it
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The core content of this post hasn't even appeared, alas,,,,
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4# [email protected]
Could you send me a copy? [email protected], I would be extremely grateful!!!
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Published by the American Soybean Association, feels pretty good! I reposted it on a forum before, this time I'm uploading it! Attachment:You need to log in to download or view attachments. No account? Register
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Good material, learned from it. Worth paying for
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Bookmarking first, thanks to the original poster for sharing...
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I can't stand it, I'm giving it away for free!! http://www.asaimchina.org/technical/feed/98-99-37.pdf You can download it directly
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What does it mean··?
Soybean protein is the most important and also the highest quality plant protein feed in poultry diets. Apart from a slight deficiency in methionine, all other amino acids are close to an ideal balance. Like other protein feeds, soybean meal quality is affected by the content of various nutrients, such as energy, protein, fiber and amino acids. For example, there are great differences between ordinary soybean meal and dehulled soybean meal in the above indicators (see Table 1). Dehulled soybean meal has a higher energy level because of its lower fiber content. However, soybean meal with a high protein level does not necessarily guarantee a low fiber and high energy level. For example, the protein content of some non-dehulled Chinese soybean meal can be as high as 48% or even 50%, while it still contains 6% to 7% fiber. Therefore, the metabolizable energy level of high-protein soybean meal may still decline because of high fiber content, and no measured metabolizable energy values for these high-protein "high-fiber" soybean meals have yet been seen. But it can generally be estimated that when the fiber content of dehulled soybean meal is above the normal level of 3.5%, each 1% increase in fiber reduces the metabolizable energy per kg of pig feed by 32 to 42 kcal, while for poultry feed per kg it decreases by nearly 60 kcal. On the other hand, soybean meal quality is to a large extent affected by processing problems, which in turn affect its amino acid content and amino acid digestibility and even energy. This article mainly discusses the variation in soybean meal quality caused by insufficient processing or excessive heating and its impact on production performance, and at the same time introduces the currently feasible methods for identifying soybean meal quality - urease activity (pH change value) and 0.2% potassium hydroxide protein solubility - and evaluates them.
I. Raw soybeans - trypsin inhibitor and urease It is well known that soybean meal must undergo moderate heat processing to destroy several anti-nutritional substances contained in soybeans. Among them, the one with the greatest impact on livestock and poultry is trypsin inhibitor (Tripsin Inhibitor). Fortunately, these anti-nutritional factors are all destroyed after heating. Moderate heating is the key to soybean meal processing, because insufficient or excessive heating will reduce the nutritional value of soybean meal.
1 Originally published in March 1999
—
37 —
Table 1 Main nutritional indicators of ordinary soybean meal and dehulled soybean meal (NRC, 1994) Nutrient Ordinary soybean meal Dehulled soybean meal Dry matter (%)
89 90 Poultry metabolizable energy (kcal/kg)
2230 2440 Protein (%)
44.0 48.5 Fiber (%)
7.0 3.9 Lysine (%)
2.69 3.02
--------------------------------------
It seems the content is still incomplete. Could you send a complete version????
--------------------------------------
Yes, can you upload the article? Thank you
--------------------------------------
I have the authoritative one, but the format is wrong, so it won't let me post it
--------------------------------------
The core content of this post hasn't even appeared, alas,,,,
--------------------------------------
4# [email protected]
Could you send me a copy? [email protected], I would be extremely grateful!!!
--------------------------------------
Published by the American Soybean Association, feels pretty good! I reposted it on a forum before, this time I'm uploading it! Attachment:You need to log in to download or view attachments. No account? Register
--------------------------------------
Good material, learned from it. Worth paying for
--------------------------------------
Bookmarking first, thanks to the original poster for sharing...
--------------------------------------
I can't stand it, I'm giving it away for free!! http://www.asaimchina.org/technical/feed/98-99-37.pdf You can download it directly
--------------------------------------
I can't stand it, I'm giving it away for free!! You can download it directlyWhat a good person, I happen to have no money! Endlessly grateful!
hawk3983 posted on 2009-11-11 20:32
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What does it mean··?