Quality analysis of protein raw materials in piglet feed
At the beginning of the new year, increasing efficiency and reducing costs is still the way for the sustainable development of the industry! The selection and combination of raw materials in feed formulations directly affect the quality and cost. Among them, the proportion of protein raw materials accounts for 25% or more, and the cost accounts for 40% or more. Reasonable selection and combination of protein raw materials have become one of the key measures to increase efficiency and reduce costs!
How to choose protein raw materials reasonably? For piglet feed with relatively complex raw material composition, we recommend the principle of "three highs and one low", in which nutritional value and health value can be quickly evaluated by the laboratory. What indicators to evaluate, what testing methods to use, and how to analyze test results? I hope our content can help you!
We will introduce the content in two phases in detail. In this issue, let's take a look at the evaluation indicators of nutritional value, detection methods, and the detection results of common protein raw materials!
High nutritional value
【Measurement index】: High total absorbable sedimentary protein provided (protein content * protein digestibility * protein deposition rate)
【Indicator significance】: The higher the value, the more it can promote the growth and development of functional organs of suckling piglets such as intestine and liver, increase muscle protein deposition, and speed up the growth rate.
1 Protein content
1.1 Detection method
1.2 Test results
1.3 Result analysis
Crude protein does not represent real protein: by detecting the composition and total amount of 18 kinds of amino acids, reflecting the total amount of protein, the content of other nitrogenous substances (this part contains components that are harmful to the health of suckling pigs) is indirectly calculated.
The composition of other nitrogen-containing substances in different protein raw materials: ordinary vegetable protein is within 2%, mainly from organic nitrogen-containing substances such as amides and a small amount of nucleic acid; Fermented soybean meal 3-4%, mainly from nitrogen sources in microbial fermentation substrates, and nitrogen-containing metabolites produced by fermentation; fish meal 6-9%, mainly from biogenic amines such as histamine, putrescine, cadaverine produced by protein spoilage etc.; yeast hydrolyzate 6-8%, mainly from nitrogen sources in yeast fermentation substrates, nitrogen-containing bases in nucleic acids (10-12%), etc.
2 Protein digestibility
2.1 Detection method
2.2 Test results
A、Apparent digestibility of porcine terminal ileal protein
【Result analysis】
Apparent digestibility of protein in terminal ileum: a comprehensive reflection of raw protein digestibility and animal digestibility; piglets of different weights have different protein digestibility of the same raw material, and with the growth and development of suckling piglets, the digestibility continues to improve.
Piglets of the same weight have different protein digestibility of different raw materials: on the one hand, it depends on the digestibility of the raw material itself, and on the other hand, it depends on whether it contains ingredients that have a positive or negative effect on the digestibility of piglets.
Deep processing of plant protein: improve the digestibility of the body, reaching or even exceeding animal protein.
B、In vitro protein digestibility
【Result analysis】
In vitro protein digestibility: it can only reflect protein digestibility, not animal digestibility (if the raw material contains ingredients that have positive or negative effects on piglet digestibility, the in vitro and in vivo data will have different laws; for example, soybean meal has high in vitro digestibility, but low in vivo digestibility, mainly because soybean meal contains anti-nutritional factors that damage intestinal health and reduce digestion and absorption capacity).
The results of the bionic digester and the double-enzyme method:
The performance rules are consistent: the raw materials with low digestibility are low, and the raw materials with high digestibility are high.
The absolute values are different: the biomimetic digester uses biofilm dialysis for separation, and the double-enzyme method uses precipitation centrifugation. The value of the biomimetic digester is 8-15% lower than that of the double-enzyme method. Therefore, the same method needs to be used to compare the digestibility of different raw materials.
3 Protein deposition rate
【Measurement index】Content of 150-1000Da small molecule peptide (2-6 peptide)
【Indicator significance】150-1000Da small molecule peptides are directly absorbed by animals and enter the body to participate in protein deposition. The protein deposition efficiency is 1.5 times that of amino acids.
3.1 Detection method
GB/T 22492-2008 Appendix A of "Soybean Peptide Powder" (HPLC method, determination of molecular weight of water-soluble protein, conversion to total protein ratio)
3.2 Test results
【Result analysis】
The proportion of the 150-1000Da range in the total protein: the higher the 150-1000Da range in the total protein, the higher the content of 2-6 peptides, and the higher the protein deposition efficiency.
Deep processing of raw materials: fermentation or enzymatic hydrolysis treatment can increase the content of 150-1000Da small molecule peptides. However, the content of different processes varies greatly, and it is necessary to prevent excessive hydrolysis or enzymatic hydrolysis from producing a large amount of free amino acids.
【Summary】
The high nutritional value of protein raw materials means that the total amount of protein that can be absorbed and deposited is high. The evaluation indicators and detection methods are shown in the following table:
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