Method for rapidly predicting net utilization rate of phosphorus in cottonseed meal by broiler chicken based on chemical component indexes and application

Abstract

The invention discloses a method for rapidly predicting the net utilization rate of phosphorus in cottonseed meal by broiler chickens based on chemical component indexes and application, and belongs to the technical field of feed. The method for rapidly predicting the net utilization rate of the broiler chicken to the phosphorus in the cottonseed meal based on the chemical component indexes comprises the following steps: measuring a crude fiber content CF value, a neutral detergent fiber content NDF value and a free gossypol content FG value in the cottonseed meal to be measured; the calculated values are substituted into a mathematical model: SMA (%) = 60.99-2.697 CF (%) + 1.124 NDF (%)-0.0211 FG (mg / kg); and calculating the phosphorus net utilization rate SMA. The invention further discloses application of the method in preparation of broiler feed. According to the method, the efficient prediction model is constructed by utilizing the chemical component data, the net phosphorus utilization rate of the broiler chicken to the cottonseed meal is accurately estimated, the problems of high professional condition requirements, complicated operation, large workload, relatively long time consumption and the like in a traditional determination method are solved, and the realization of accurate preparation of broiler chicken feed is promoted.

Description

Technical Field

[0001] This invention belongs to the field of feed technology, specifically relating to a method and application for rapidly predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition indicators. Background Technology

[0002] Phosphorus is a key nutrient in the feed industry and the third largest cost factor in poultry feed, after energy and protein. Improving phosphorus utilization efficiency is crucial for reducing feed costs, mitigating environmental pollution (such as eutrophication of water bodies caused by phosphorus emissions), and enhancing the economic and ecological benefits of aquaculture.

[0003] Phosphorus utilization rate is a core indicator for measuring the efficiency of animals in absorbing and utilizing phosphorus in feed ingredients, directly reflecting the metabolic efficiency of phosphorus in the animal's body. Currently, the determination of phosphorus utilization rate in broiler feed ingredients mainly uses two methods: relative utilization rate and absolute utilization rate. Relative utilization rate is a method that assesses the utilization rate by comparing the biological response of broilers to phosphorus. Specifically, it uses biological effects as an indicator, comparing the biological effect of phosphorus in the feed ingredient to be evaluated with a standard substance with the same phosphorus content to calculate the relative utilization rate (%). The formula is: Relative utilization rate (%) = 100 × M_feed ingredient / M_standard substance, where M represents the biological effect indicator value of phosphorus. These effect indicators typically include the broiler's production performance, the content of alkaline phosphatase in the blood, and the phosphorus content in the bones. However, relative biological utilization rate only provides a relative value and cannot reflect the true net utilization rate of phosphorus by animals. Its results are affected by various factors, such as the animal's physiological state, the selected effect indicator, and the choice of standard substance. In contrast, absolute phosphorus utilization rate reflects the degree to which mineral elements in feed are actually absorbed and utilized by animals. Depending on whether endogenous phosphorus loss is deducted, absolute utilization rate can be divided into apparent utilization rate and net utilization rate.

[0004] Apparent metabolizable availability (AMA) of phosphorus is calculated by measuring the intake of phosphorus from feed ingredients by poultry over a specific time period and subtracting the total phosphorus excretion in excrement during the same period. The calculation formula is as follows:

[0005]

[0006] The main methods for determining apparent bioavailability include the total feces collection method and the indicator method. Depending on the excrement collection site, apparent bioavailability can be further divided into ileal apparent bioavailability and whole intestinal apparent bioavailability. However, all apparent bioavailability measurements do not consider basal endogenous mineral losses (EML) in broilers. Due to the presence of endogenous losses, the results of apparent bioavailability measurements vary considerably and often underestimate the true efficiency of phosphorus utilization by animals. Therefore, this data has poor additivity in feed formulation design, limiting its application.

[0007] Net phosphorus utilization rate (NPG) is determined by eliminating the influence of endogenous phosphorus loss (EML) in broilers through appropriate methods during the measurement process, thus more accurately reflecting the true utilization of phosphorus. Its determination typically involves the following steps: First, broilers are fed a phosphorus-free monoculture diet according to a specific program, and the phosphorus content in their excrement is measured to obtain the endogenous fecal phosphorus loss (EML). Then, in a trial using the tested feed diet, based on total phosphorus intake, total fecal phosphorus excretion, and the measured EML, it is calculated using the following formula:

[0008]

[0009] Compared to other methods, net bioavailability (NPB) has significant advantages: its measured values ​​are less affected by changes in animal physiological state, the results are more stable and reliable, it more accurately reflects phosphorus utilization efficiency, and it has better additivity in feed formulation. However, determining NPB also faces severe challenges: the process is complex and requires extremely strict standards, necessitating the formulation of phosphorus-free monosodium phosphate diets (usually using reagent-grade raw materials), the provision of ultra-low phosphorus drinking water, and the strict prevention of environmental phosphorus contamination by facilities such as dedicated metabolic cages. It also demands a high level of expertise in experimental design and operation. These factors collectively result in a large workload, long cycle, and high cost, far exceeding that of apparent bioavailability and relative bioavailability. Therefore, although NPB best represents the true phosphorus utilization of broilers, its high practical application threshold and high cost severely hinder the widespread adoption of this method and its promotion and application in feed formulation practices.

[0010] Currently, some methods have been established for predicting the utilization rates of nutrients such as energy, crude protein, and amino acids in poultry feed ingredients. However, accurate and efficient prediction of the net utilization rate of mineral elements such as phosphorus remains a major technical challenge that has not yet been effectively solved, and related research reports are extremely limited. For example, although a patented technology (such as CN106501209A) attempts to construct a predictive model for the available phosphorus content in cottonseed meal using near-infrared spectroscopy (950nm~1650nm), this method has significant application bottlenecks: on the one hand, it relies on expensive near-infrared spectrometers, which exceeds the conventional equipment configuration level of most domestic breeding and feed enterprises; on the other hand, differences in the particle size of raw materials can significantly interfere with the stability and consistency of spectral characteristic signals, resulting in insufficient universality and reliability of model predictions. In addition, current predictive models for the utilization rate of nutrients such as energy in poultry feed mostly use conventional approximate nutrient indicators such as crude protein, crude fat, and crude fiber as parameters, but these indicators have a relatively limited impact on the utilization rate of mineral elements such as phosphorus.

[0011] In recent years, cottonseed meal has been increasingly used in broiler feed due to its high protein content and cost advantages. Although cottonseed meal has a high total phosphorus content, no studies have been reported on the systematic determination of its net total phosphorus utilization rate. Accurately assessing the net phosphorus utilization rate in cottonseed meal is of great value: it can significantly optimize the precise addition of phosphorus-rich mineral feeds (such as dicalcium phosphate), reduce feed costs, and effectively reduce phosphorus emissions in broiler excrement, alleviating environmental pressure and thus improving the overall efficiency of poultry farming. However, existing technologies face fundamental challenges in predicting net phosphorus utilization rate:

[0012] Lack of feasible methods: Methods that rely on sophisticated instruments (such as near-infrared) or complex biological experiments (such as metabolic experiments) are costly, time-consuming, and difficult to popularize.

[0013] Indicators are not applicable: Models based on conventional approximate nutrient indicators have weak predictive ability for phosphorus utilization.

[0014] Ignoring chemical complexity: Existing methods fail to systematically consider and integrate the profound impact of the complex and diverse chemical components in feed ingredients and their potential interactions on phosphorus utilization efficiency. In particular, for feed ingredients such as cottonseed meal, which contain a variety of special chemical components, the quantitative correlation mechanism between their intrinsic chemical properties and net phosphorus utilization has not been thoroughly elucidated and effectively utilized.

[0015] Therefore, there is an urgent need in the industry to develop a new predictive method that does not rely on expensive equipment, can overcome pretreatment variability, and can effectively integrate key chemical characteristics of raw materials, so as to achieve rapid, accurate, and low-cost assessment of the net phosphorus utilization rate of feed raw materials such as cottonseed meal. Summary of the Invention

[0016] This invention aims to provide a method for rapidly predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition indicators. It utilizes chemical composition data to construct an efficient prediction model, thereby accurately estimating the net phosphorus utilization rate of cottonseed meal by broilers. This method effectively overcomes the difficulties of traditional methods for determining the net phosphorus utilization rate of feed ingredients, such as high requirements for professional conditions, complex operation, large workload, and long time consumption, further promoting the realization of precise formulation of broiler feed.

[0017] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0018] The first aspect of this invention provides a method for rapidly predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition indicators, the method comprising the following steps:

[0019] S1. Determine the crude fiber content (CF value), neutral detergent fiber content (NDF value), and free gossypol content (FG value) in the cottonseed meal to be tested;

[0020] S2. Substitute the crude fiber content (CF), neutral detergent fiber content (NDF), and free gossypol content (FG) values ​​obtained in step S1 into the mathematical model.

[0021] SMA(%)=60.99-2.697CF(%)+1.124NDF(%)-0.0211FG(mg / kg);

[0022] S3. Calculate the net phosphorus utilization rate (SMA).

[0023] In some embodiments of the present invention, the crude fiber content (CF value) of cottonseed meal is determined according to the method specified in standard GB / T 6434 "Determination of Crude Fiber Content in Feed".

[0024] In some embodiments of the present invention, the neutral detergent fiber (NDF) content of cottonseed meal is determined according to the method specified in standard GB / T20806 "Determination of Neutral Detergent Fiber (NDF) in Feed".

[0025] In some embodiments of the present invention, the free gossypol content (FG value) of cottonseed meal is determined according to the method specified in standard GB / T13086 "Determination of Free Gossypol in Feed".

[0026] In some embodiments of the present invention, the coefficient of determination R of the mathematical model 2 It is 0.940.

[0027] The second aspect of the present invention provides an application of the above-mentioned method for predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition, wherein the application is in the formulation of broiler feed.

[0028] A third aspect of the present invention provides a method for preparing broiler feed, comprising the following steps:

[0029] Step 1. Calculate the SMA value of net phosphorus utilization in cottonseed meal using the method described above;

[0030] Step 2. Input the SMA value as the effective phosphorus conversion factor for cottonseed meal into the feed formulation system;

[0031] Step 3. Based on the conversion factor, dynamically calculate the effective phosphorus level of the cottonseed meal formulation and adjust the raw material combination in real time to meet the phosphorus requirements of broiler chickens.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention utilizes readily available and technically mature chemical composition data (coarse fiber value (CF), neutral detergent fiber value (NDF), and free gossypol content value (FG)) to construct an efficient prediction model, effectively overcoming the difficulties of traditional animal feeding and balance test methods, such as high requirements for professional conditions, complex operation, large workload, and long time consumption.

[0034] This invention significantly simplifies the testing process, avoids complex animal experiments, thereby greatly reducing testing costs and significantly shortening the testing cycle. The method of this invention is suitable for the rapid assessment of net phosphorus utilization in cottonseed meal in production practice. Its predictive results can improve the accuracy of feed formulation, providing a reliable guarantee for precision broiler farming, and is of great significance for promoting the precision formulation of poultry feed and even the entire animal husbandry industry.

[0035] This invention uses stepwise regression analysis, based on the maximum coefficient of determination (R²). 2 The optimal prediction model was determined by using the minimum root mean square error (RMSE) and the minimum Akaike information criterion (AIC) values. Experimental results show that the predicted values ​​of this model differ little from the measured values. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. The described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0037] Example 1

[0038] This embodiment discloses a method for establishing a predictive model for the net phosphorus utilization rate of cottonseed meal by broilers. The specific steps are as follows:

[0039] 1. Determination of chemical composition indicators of various cottonseed meal samples

[0040] Moisture content: determined according to the method specified in the People's Republic of China National Standard "Determination of Moisture in Feed" (GB / T6435-2014).

[0041] Crude protein (CP) content: determined according to the method specified in the People's Republic of China National Standard "Determination of Crude Protein in Feed" (GB / T6432-2018).

[0042] Crude fiber (CF) content: determined according to the method specified in the People's Republic of China National Standard "Determination of Crude Fiber Content in Feed" (GB / T6434-2022).

[0043] Crude fat (EE) content: determined according to the method specified in the People's Republic of China National Standard "Determination of Crude Fat in Feed" (GB / T6433-2006).

[0044] Crude ash content: determined according to the method specified in the People's Republic of China National Standard "Determination of Crude Ash in Feed" (GB / T6438-2007).

[0045] Neutral detergent fiber (NDF) content: determined according to the method specified in the National Standard of the People's Republic of China "Determination of Neutral Detergent Fiber (NDF) in Feed" (GB / T 20806-2022).

[0046] Calcium (Ca) content: determined according to the method specified in the People's Republic of China National Standard "Determination of Calcium in Feed" (GB / T6436-2018).

[0047] Phytic acid (PA) content: determined according to the method specified in the National Standard of the People's Republic of China "National Food Safety Standard Determination of Phytic Acid in Food" (GB 5009.153-2016).

[0048] Free gossypol (FG) content: determined according to the method specified in the National Standard of the People's Republic of China "Determination of Free Gossypol in Feed" (GB / T 13086-2020).

[0049] Acid detergent fiber content: determined according to the method specified in the People's Republic of China agricultural industry standard "Determination of Acid Detergent Fiber in Feed" (NY / T 1459-2022).

[0050] 2. Determine the standardized net phosphorus utilization rate of yellow-feathered broilers.

[0051] The standardized net phosphorus utilization rate of cottonseed meal in yellow-feathered broiler chickens was determined through a mineral element balance experiment of yellow-feathered broiler chickens. To ensure the rigor of the experimental process and data, the animal experiments were conducted at an animal testing base in Sichuan.

[0052] 2.1 Experimental Animals: Medium-growth yellow-feathered broiler roosters were selected and fed a complete formulated diet from 1 to 60 days of age (see Table 1). At 54 days of age, the yellow-feathered broiler roosters were housed individually in an environmentally controlled metabolic chamber. After 7 days of acclimatization (i.e., 61 days of age), a manure collection bottle cap suturing procedure was performed to install a manure collection bottle or bag to collect the broiler's excrement. The manure collection bottle cap suturing procedure was as follows: A plastic bag (bottle) with a volume of approximately 60 mL was selected as the manure collection bag (bottle). The cap diameter was approximately 40 mm. A round hole with a diameter of approximately 30 mm was drilled in the center of the cap, and eight symmetrical small holes were drilled around the perimeter of the cap for easy fixation. Using a sterilized surgical curved needle and suture, the round hole in the center of the cap was aligned with the cloaca of the chicken and sutured to the skin to collect excrement. The temperature in the metabolic chamber was 22℃~25℃, humidity 40%~60%, and light intensity 10lx~20lx; artificial lighting was used, with a light duration of 12h / d. After the surgery, the broilers were given a 3-day recovery period to confirm the success of the surgery. During this period, they were fed a complete broiler feed (see Table 1).

[0053] 2.2 Grouping: Successfully operated yellow-feathered broilers were randomly assigned to different treatment groups. Each cottonseed meal diet group had 8 replicates, with 4 broilers per replicate after successful cap suturing of the manure collection bottle caps. An additional mineral-free diet group (Table 2) was also set up, with 8 replicates, 4 broilers per replicate after successful cap suturing of the manure collection bottle caps. The mineral-free diet was a homologous diet composed of glucose, gelatin, soybean oil, cellulose, synthetic crystalline amino acids, and various vitamins; the nutritional levels of the diet were formulated according to the People's Republic of China Agricultural Industry Standard "Nutritional Requirements for Yellow-feathered Broilers" (NY / T 3645-2020). The cottonseed meal diet was formulated based on the mineral-free diet by adjusting the content of glucose, gelatin, soybean oil, cellulose, and synthetic amino acids, ensuring that the main nutritional components of the test diet were similar to those of the mineral-free diet.

[0054] 2.3 Determination of Standardized Net Phosphorus Utilization Rate in Yellow-feathered Broilers

[0055] Sixty-three-day-old broilers whose manure collection bottle caps were successfully sutured were fasted for 8 hours starting at 10:00 PM. At 6:00 AM on day 64, all broilers were fed a mineral-free diet for 4 hours, ending at 10:00 AM; feed consumption during this period was accurately recorded. At 10:00 AM on day 64, all broilers were fasted for 24 hours. At 10:00 AM on day 65, the mineral-free diet group was fed a mineral-free diet, while the cottonseed meal test diet group was fed a cottonseed meal test diet; feeding lasted 4 hours, ending at 2:00 PM on day 65. At 10:00 AM on day 65, broilers were fed either a mineral-free diet or the cottonseed meal test diet; all feces and excrement were collected using manure collection bottles (bags) for 52 hours, ending at 2:00 PM on day 67. The standardized phosphorus utilization rate determination procedure for yellow-feathered broilers is shown in Table 3. Throughout the entire formal trial period, all chickens had free access to deionized water and free access to tap water at other times.

[0056] 2.4 Processing of fecal and urinary excrement and feed samples

[0057] All excrement was collected and dried (or freeze-dried) at 65°C to constant weight, then allowed to rehydrate at room temperature for 24 hours. The weight of each replicate air-dried excrement sample was recorded. The cottonseed meal, feed grains, and air-dried excrement samples were then pulverized or ground using a stainless steel pulverizer or grinder, and all samples were passed through a 0.45mm standard plastic sieve. After thorough mixing, the samples were placed in sample bags, dried, and stored for analysis. Special care was taken to prevent cross-contamination of mineral elements during pulverization or grinding.

[0058] 2.5 Phosphorus content analysis and calculation of standard phosphorus net utilization rate

[0059] The phosphorus content in feed and excrement was determined according to the People's Republic of China National Standard "Determination of Total Phosphorus in Feed - Spectrophotometric Method" (GB / T6437-2002). Based on feed consumption, total excrement volume, and phosphorus content in feed and excrement, the total phosphorus intake and total phosphorus excretion of different treatment diets were calculated. Using a mineral-free group, the endogenous phosphorus loss in yellow-feathered broilers was obtained by the difference between total phosphorus intake and total phosphorus excretion. The net phosphorus utilization rate of cottonseed meal in yellow-feathered broilers was calculated using the cottonseed meal test diet group; this is the measured value. The calculation formula is as follows:

[0060]

[0061] 3. Establish a predictive model for the standard net phosphorus utilization rate of cottonseed meal in broiler chickens.

[0062] All chemical composition indicators of cottonseed meal raw materials were used as independent variables, and the corresponding actual values ​​of phosphorus net utilization rate in yellow-feathered broiler chickens were used as dependent variables. Statistical analysis was performed using a multiple linear fitting model in SAS 9.4 statistical software. A predictive model for standardized phosphorus net utilization rate of cottonseed meal in yellow-feathered broiler chickens was established using the stepwise regression method in the fitting model program, where the coefficient of determination (R²) was used. 2 The root mean square error (RSME) and the Akaike Information Criterion (AIC) are used as indicators to evaluate the optimal prediction model, with the largest RSME value. 2 The prediction model with minimum RSME and AIC is the optimal model.

[0063] The optimal standardized net phosphorus utilization prediction model is established as follows:

[0064] Standardized net phosphorus utilization rate SMA (%) = 60.99 - 2.697 × crude fiber (CF) + 1.124 × neutral detergent fiber (NDF) - 0.0211 × free gossypol content (FG).

[0065] Table 1. Composition and nutrient levels of complete diets for yellow-feathered broilers (basal feeding)

[0066]

[0067]

[0068] In Table 1, "%" indicates the percentage content by mass.

[0069] The stone powder, dicalcium phosphate, sodium chloride, L-lysine hydrochloride, DL-methionine, L-threonine, and trace components in Table 1 are all feed grade.

[0070] The trace components listed in Table 1 are as follows: For broilers aged 1–30 days, the following should be added per kilogram of feed: Vitamin A (all-trans retinoic acid ester) 12000 IU; Vitamin D 3600 IU; Vitamin E (racemic-α-tocopherol acetate) 45 IU; Vitamin K (menaquinone sodium bisulfite) 2.5 mg; Vitamin B1 (thiamethoxam mononitrate) 2.5 mg; Vitamin B2 2.4 mg; Vitamin B6 5.0 mg; Vitamin B... 12 0.016 mg; Calcium pantothenate 12.0 mg; Niacin 42 mg; Folic acid 1.0 mg; Biotin 0.12 mg; Choline (choline chloride) 1300 mg; Copper (CuSO4·5H2O) 7 mg; Zinc (ZnSO4·7H2O) 80 mg; Manganese (MnSO4·H2O) 60 mg; Iron (FeSO4·7H2O) 80 mg; Iodine (KI) 0.70 mg; Selenium (Na2SeO3) 0.15 mg;

[0071] For broilers aged 31–60 days, add the following per kilogram of feed: Vitamin A (all-trans retinoic acid ester) 9000 IU; Vitamin D 3500 IU; Vitamin E (racemic-α-tocopherol acetate) 35 IU; Vitamin K (menaquinone sodium bisulfite) 2.2 mg; Vitamin B1 (thiamethoxam mononitrate) 2.3 mg; Vitamin B2 5.0 mg; Vitamin B6 2.4 mg; Vitamin B2... 12 0.015mg; Calcium pantothenate 10.0mg; Niacin 35.0mg; Folic acid 0.7mg; Biotin 0.10mg; Choline (choline chloride) 1000mg; Copper (CuSO4·5H2O) 7mg; Zinc (ZnSO4·7H2O) 60mg; Manganese (MnSO4·H2O) 60mg; Iron (FeSO4·7H2O) 80mg; Iodine (KI) 0.60mg; Selenium (Na2SeO3) 0.15mg;

[0072] For broilers aged ≥61 days, add the following per kilogram of feed: Vitamin A (all-trans retinoic acid ester) 6000 IU; Vitamin D 3500 IU; Vitamin E (racemic-α-tocopherol acetate) 25 IU; Vitamin K (menaquinone sodium bisulfite) 1.7 mg; Vitamin B1 (thiamethoxam mononitrate) 1.0 mg; Vitamin B2 4.0 mg; Vitamin B6 0.6 mg; Vitamin B... 12 0.008 mg; Calcium pantothenate 8.0 mg; Niacin 20.0 mg; Folic acid 0.3 mg; Biotin 0.02 mg; Choline (choline chloride) 750 mg; Copper (CuSO4·5H2O) 7 mg; Zinc (ZnSO4·7H2O) 55 mg; Manganese (MnSO4·H2O) 60 mg; Iron (FeSO4·7H2O) 80 mg; Iodine (KI) 0.60 mg; Selenium (Na2SeO3) 0.15 mg.

[0073] Table 2. Composition and nutrient levels of mineral-free diets (basic feeding guidelines)

[0074] raw material Content (wt.%) Nutritional indicators Nutritional level glucose 75.74 Metabolizable energy, MJ / kg 12.82 gelatin 15.25 Crude protein, % 16.00 soybean oil 2.76 Methionine, % 0.35 Cellulose 3.00 Methionine + Cystine, % 0.61 L-Lysine hydrochloride 0.26 Lysine, % 0.76 DL-methionine 0.24 / / L-cysteine 0.24 / / L-threonine 0.31 / / L-Tryptophan 0.13 / / L-Isoleucine 0.36 / / L-Leucine 0.46 / / L-valine 0.32 / / L-phenylalanine 0.24 / / L-tyrosine 0.30 / / L-histidine 0.19 / / Multivitamins 0.20 / / total 100.00 / /

[0075] In Table 2, "%" indicates the percentage content by mass.

[0076] The glucose and cellulose in Table 2 are reagent grade.

[0077] The soybean oil, L-lysine hydrochloride, DL-methionine, L-cysteine, L-threonine, L-tryptophan, L-isoleucine, L-leucine, L-valine, L-phenylalanine, L-tyrosine, and L-histidine in Table 2 are food grade.

[0078] The vitamins listed in Table 2 are all food grade. The recommended dosage per kilogram of feed is: Vitamin A (all-trans retinoic acid ester) 6000 IU; Vitamin D3 500 IU; Vitamin E (racemic-α-tocopheryl acetate) 25 IU; Vitamin K (menaquinone sodium bisulfite) 1.7 mg; Vitamin B1 (thiamethoxam mononitrate) 1.0 mg; Vitamin B2 4.0 mg; Vitamin B6 0.6 mg; Vitamin B... 12 0.008 mg; Calcium pantothenate 8.0 mg; Niacin 20.0 mg; Folic acid 0.3 mg; Biotin 0.02 mg; Choline (choline chloride) 750 mg.

[0079] The content of mineral elements in various raw materials must be strictly controlled to prevent contamination during feed formulation. At the same time, ensure that the final content of macroelements such as calcium, phosphorus, magnesium, and potassium in mineral-free diets is <0.01%, and the content of microelements such as copper, iron, manganese, and zinc is <10.00 mg / kg.

[0080] Table 3 Standardized Phosphorus Net Utilization Rate Determination Procedure in Yellow-feathered Broiler Feed

[0081]

[0082] Example 2

[0083] This embodiment performs external validation on the prediction model established in Embodiment 1.

[0084] After the standardized net phosphorus utilization rate prediction model for cottonseed meal in broiler chickens was established in Example 1, it was externally validated using datasets of five cottonseed meal raw materials.

[0085] First, the crude fiber value (CF), neutral detergent fiber value (NDF), and free gossypol content (FG) in five cottonseed meal samples were determined respectively; the determination method was the same as in Example 1, and the results are shown in Table 4.

[0086] Table 4. Chemical composition values ​​of cottonseed meal (dry matter basis)

[0087] Sample number Place of origin Crude fiber (wt%) Neutral detergent fibers (wt%) Free gossypol (mg / kg) 1 Aksu City, Xinjiang 9.88 24.36 714.04 2 Kuitun City, Xinjiang 3.94 11.41 580.71 3 Changji Prefecture, Xinjiang 4.9 12.84 409.93 4 Urumqi, Xinjiang 10.48 43.35 877.09 5 Kashgar region of Xinjiang 5.41 28.36 2063.24

[0088] The measured values ​​were then substituted into the prediction model established in Example 1 to obtain the predicted value of net phosphorus utilization.

[0089] Standardized net phosphorus utilization rate SMA (%) = 60.99 - 2.697 × crude fiber (CF) + 1.124 × neutral detergent fiber (NDF) - 0.0211 × free gossypol content (FG).

[0090] The predicted net phosphorus utilization rate was compared with the measured net phosphorus utilization rate of yellow-feathered broilers. The method for determining the net phosphorus utilization rate of yellow-feathered broilers was carried out according to the method in "2. Determination of the standardized net phosphorus utilization rate value of yellow-feathered broilers" in Example 1. The comparison results are shown in Table 5.

[0091] Table 5 Comparison of measured and predicted net phosphorus utilization rates of cottonseed meal in yellow-feathered broiler chickens (%)

[0092] Sample number Place of origin Measured value (%) Forecast value (%) Absolute error (%) Relative error (%) 1 Aksu City, Xinjiang 49.64 46.66 -2.98 -6.19％ 2 Kuitun City, Xinjiang 50.72 50.94 0.22 0.43％ 3 Changji Prefecture, Xinjiang 52.95 53.56 0.69 1.15％ 4 Urumqi, Xinjiang 61.27 62.94 1.77 2.69％ 5 Kashgar region of Xinjiang 36.60 34.74 -1.86 -5.21％

[0093] As shown in Tables 4 and 5, the absolute error of the prediction results for all samples is within ±3.0%, and the relative error is within ±10%. Even for the five cottonseed meal samples with significant differences in chemical composition, the prediction results are still within this accuracy range. This fully demonstrates that the prediction model proposed in this invention has high accuracy and wide applicability.

[0094] In summary, the techniques for determining crude fiber (CF), neutral detergent fiber (NDF), and free gossypol (FG) are mature (and can be accurately measured in domestic research institutes and enterprise laboratories). This invention can quickly predict the net phosphorus utilization rate of cottonseed meal by broilers by measuring the above three indicators, avoiding animal feeding and balancing experiments, effectively reducing costs and shortening the cycle, and is of great significance for the precise formulation of poultry feed.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been verified above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for rapidly predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical component indicators, characterized in that, Includes the following steps: S1. Determine the crude fiber content (CF value), neutral detergent fiber content (NDF value), and free gossypol content (FG value) in the cottonseed meal to be tested; S2. Substitute the crude fiber content (CF), neutral detergent fiber content (NDF), and free gossypol content (FG) values ​​obtained in step S1 into the mathematical model. SMA(%)=60.99-2.697CF(%)+1.124NDF(%)-0.0211FG(mg / kg); S3. Calculate the net phosphorus utilization rate (SMA).

2. The method for predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition according to claim 1, characterized in that, The crude fiber content (CF value) of cottonseed meal was determined according to the method specified in standard GB / T 6434 "Determination of Crude Fiber Content in Feed".

3. The method for predicting the net utilization rate of phosphorus in cottonseed meal by broilers based on chemical composition according to claim 1, characterized in that, The neutral detergent fiber (NDF) content of cottonseed meal was determined according to the method specified in standard GB / T 20806 "Determination of Neutral Detergent Fiber (NDF) in Feed".

4. The method for predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition according to claim 1, characterized in that, The free gossypol content (FG value) of cottonseed meal was determined according to the method specified in standard GB / T 13086 "Determination of Free Gossypol in Feed".

5. The method for predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition according to claim 1, characterized in that, The coefficient of determination R of the mathematical model 2 It is 0.

940.

6. The application of the method for predicting the net phosphorus utilization rate of cottonseed meal by broilers based on chemical composition according to any one of claims 1-5, characterized in that, Application in the formulation of broiler feed.

7. A method for preparing broiler feed, characterized in that, Includes the following steps: Step 1. Calculate the SMA value of net phosphorus utilization in cottonseed meal using the method described in any one of claims 1-5. Step 2. Input the SMA value as the effective phosphorus conversion factor for cottonseed meal into the feed formulation system; Step 3. Based on the conversion factor, dynamically calculate the effective phosphorus level of the cottonseed meal formulation and adjust the raw material combination in real time to meet the phosphorus requirements of broiler chickens.

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