Phosphorus-free composite additive for promoting early skeletal development of broiler chickens and preparation method and application of phosphorus-free composite additive

Abstract

The invention discloses a non-phosphorus composite additive for promoting early skeletal development of broiler chickens as well as a preparation method and application of the non-phosphorus composite additive. The composite additive is prepared from the following raw materials in parts by weight: 40-60 parts of a heat-resistant phytase preparation, 0.1-0.3 part of a 25-hydroxyvitamin D3 preparation, 70-90 parts of a honeysuckle flower extract, 40-60 parts of coated sodium butyrate and 100-140 parts of rice hull powder. The preparation method comprises the following steps: weighing the heat-resistant phytase preparation, the 25-hydroxyvitamin D3 preparation, the honeysuckle flower extract, the coated sodium butyrate and the rice hull powder in parts by weight; the heat-resistant phytase preparation and the 25-hydroxyvitamin D3 preparation are preliminarily mixed, and then the honeysuckle flower extract, the coated sodium butyrate and the rice hull powder are added into a mixing machine to be mixed; and packaging the mixed materials into a packaging bag, and storing for later use. The composite additive prepared by the invention can comprehensively promote the bone health of the broiler chickens in the early growth stage on the premise of not depending on the addition of exogenous phosphorus.

Description

Technical Field

[0001] The invention belongs to the technical field of feed additives, and particularly relates to a phosphorus-free composite additive for promoting early bone development in broilers, a preparation method thereof, and an application thereof. Background Art

[0002] Research on promoting early bone development in broiler chickens (from hatching to three weeks of age) is crucial for improving growth performance and reducing disease incidence. Healthy bone development in early broiler chickens is a critical physiological link in ensuring breeding profitability, directly impacting their growth rate, disease resistance, and economic value after slaughter. Phosphorus, as a core component of bone hydroxyapatite, has long been considered a target for nutritional regulation.

[0003] In traditional farming systems, inorganic phosphates (such as calcium hydrogen phosphate and calcium dihydrogen phosphate) are typically added to feed to maintain calcium-phosphorus metabolic balance and promote bone matrix mineralization through exogenous supplementation. However, while this extensive inorganic phosphorus supplementation method can improve bone mineralization efficiency in the short term, it also exposes numerous problems. First, as a non-renewable resource, the scarcity and price fluctuations of phosphate rock exacerbate farming costs. Furthermore, broilers have a low absorption and utilization rate of inorganic phosphorus, resulting in significant resource waste. Unused phosphorus enters the environment through excretion. Due to its strong adsorption and slow degradation properties, it easily accumulates in soil and water, overcoming the self-purification capacity of ecosystems and causing environmental problems such as eutrophication. Second, excessive phosphorus intake leads to an imbalance in the calcium-phosphorus ratio, causing abnormally elevated parathyroid hormone (PTH), inhibiting osteoblast differentiation and activating osteoclast activity, ultimately increasing the incidence of bone diseases such as tibial dyschondroplasia (TD).

[0004] In recent years, the industry has tried a variety of technical improvement solutions to solve this problem: (1) Phytase replacement solution: By adding microbial phytase to decompose phytic acid phosphorus in feed, the dependence on inorganic phosphorus is reduced. However, in actual application, the high-temperature pelleting process of feed (75-90℃) easily leads to the denaturation of enzyme protein structure and a significant decrease in activity; in addition, the complex pH environment and digestive fluid components in the intestine also interfere with the stability of the enzymatic reaction, and the release effect of phytic acid phosphorus is difficult to guarantee. (2) Vitamin D3 fortification technology: Using 25-hydroxyvitamin D3 to enhance the expression of intestinal type IIb sodium phosphate transporter (NaPi-IIb) helps to improve the efficiency of phosphorus absorption, but its use alone is limited by the rigid constraints of the stoichiometric relationship of calcium and phosphorus deposition, and the overall phosphorus utilization rate is limited. In addition, there is a lack of effective regulation of the dynamic balance of "bone formation-bone resorption", making it difficult to achieve a comprehensive improvement in bone quality. (3) Low-phosphorus formula optimization: The total phosphorus demand is reduced through a precise model, but while reducing the phosphorus content, bone strength-related indicators (such as tibia fracture strength) also decrease, affecting the bone health and production performance of broilers.

[0005] Therefore, in the face of multiple challenges in resources, environment and health caused by phosphorus dependence in the current broiler farming system, the development of a non-phosphorus-dependent bone development regulation technology has become a key path to promote the transformation and upgrading of the industry, and is also an important direction for future feed additive research and development. Summary of the Invention

[0006] In light of this, the present invention provides a phosphorus-free composite additive for promoting early bone development in broilers, as well as its preparation method and application. The composite additive's formulation is based on a "multi-target synergistic regulation" mechanism. Without the addition of exogenous phosphorus, it effectively promotes healthy early bone development in broilers through the scientific combination of multiple functional ingredients and complementary mechanisms. This fundamentally addresses the issues of traditional breeding systems, such as high phosphorus dependence and limited functionality.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The invention discloses a phosphorus-free composite additive for promoting early bone development of broilers. The phosphorus-free composite additive is prepared from the following raw materials in parts by weight: 40-60 parts of a heat-resistant phytase preparation, 0.1-0.3 parts of a 25-hydroxyvitamin D3 preparation, 70-90 parts of a honeysuckle extract, 40-60 parts of coated sodium butyrate, and 100-140 parts of rice husk powder.

[0009] Preferably, the activity of the heat-resistant phytase preparation is 20,000 IU / g, and the concentration of the 25-hydroxyvitamin D3 preparation is 1.25%.

[0010] The present invention also provides a method for preparing the above-mentioned phosphorus-free composite additive, comprising the following steps:

[0011] S1. Weigh the raw materials according to the following weight parts: 40-60 parts of heat-resistant phytase preparation, 0.1-0.3 parts of 25-hydroxyvitamin D3 preparation, 70-90 parts of honeysuckle extract, 40-60 parts of coated sodium butyrate, 150-250 parts of rice husk powder, and set aside;

[0012] S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 are preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder are sequentially added to the mixer and stirred continuously until uniformly mixed;

[0013] S3. The materials mixed in step S2 are divided into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive.

[0014] The invention also discloses the application of the phosphorus-free composite additive in feed for broiler chickens in the early growth stage.

[0015] Preferably, the broiler early growth feed is prepared from the following raw materials in parts by weight: 50-70 parts of corn, 30-50 parts of soybean meal, 2-3 parts of soybean oil, 1-3 parts of soybean protein concentrate, 2-3 parts of stone powder, 0.05-0.2 parts of L-lysine hydrochloride, 0.1-0.2 parts of DL-methionine, 0.1-0.3 parts of choline chloride, 0.2-0.4 parts of salt, 0.005-0.02 parts of complex vitamin premix, and 0.005-0.02 parts of complex trace elements.

[0016] Preferably, the amount of the phosphorus-free composite additive added to each kilogram of feed is 2500-3500 mg.

[0017] Preferably, the addition amount of each component of the phosphorus-free composite additive in the feed is: heat-resistant phytase 400-600 mg / kg, 25-hydroxyvitamin D3 1-3 mg / kg, honeysuckle extract 700-900 mg / kg, coated sodium butyrate 400-600 mg / kg, and rice husk powder 1000-1400 mg / kg.

[0018] Preferably, the amount of the phosphorus-free composite additive added to each kilogram of feed is 3000 mg, and the added amount of each component of the phosphorus-free composite additive in the feed is: heat-resistant phytase 500 mg / kg, 25-hydroxyvitamin D3 2 mg / kg, honeysuckle extract 800 mg / kg, coated sodium butyrate 500 mg / kg, and rice husk powder 1198 mg / kg.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention proposes a phosphorus-free composite additive for promoting early bone development in broilers. The core of this additive is to improve the efficiency of broilers in utilizing phosphorus and other key minerals through a multi-target synergistic regulatory mechanism, without relying on exogenous phosphorus addition, thereby achieving comprehensive promotion of bone health. The additive consists of a heat-resistant phytase preparation, a 25-hydroxyvitamin D3 preparation, a honeysuckle extract, coated sodium butyrate, and rice husk powder. These ingredients address the key physiological links of broiler bone development from different perspectives, constructing a multi-level, multifunctional, and mechanism-complementary nutritional regulatory network. The details are as follows:

[0021] (1) Heat-resistant phytase preparations, as basic phosphorus-releasing units, can maintain structural stability and biological activity during the high-temperature pelleting process of feed. After entering the digestive tract, they can efficiently hydrolyze phytic acid molecules and release mineral elements such as phosphorus, calcium, and magnesium that were originally bound. This significantly improves the utilization rate of phytic phosphorus in feed, provides an effective source of phosphorus for broilers, and alleviates the problem of mineral nutrition deficiency caused by the lack of exogenous phosphorus addition. At the same time, this phosphorus release process is not affected by drastic changes in intestinal pH, has high stability and adaptability, and is an important technical path to replace traditional phosphates.

[0022] (2) On the basis of the above, 25-hydroxyvitamin D3 preparations, as the core factor for enhancing phosphorus absorption and regulating bone metabolism, can directly activate the expression of type IIb sodium phosphate transporter (NaPi-IIb) in intestinal epithelial cells, significantly improving the efficiency of phosphorus transmembrane transport, and thus enhancing the body's ability to absorb limited phosphorus sources; moreover, this active form of vitamin D also participates in multiple key links of bone metabolism such as osteoblast differentiation, osteocalcin synthesis and PTH secretion regulation, and can effectively promote the deposition of calcium and phosphorus in bones, maintain the dynamic balance between bone formation and bone absorption, and prevent the occurrence of diseases such as hyperparathyroidism and tibial dyschondroplasia (TD) caused by low phosphorus status.

[0023] (3) In addition, honeysuckle extract, with its rich polyphenol active ingredients such as chlorogenic acid and flavonoids, has good antioxidant, anti-inflammatory and immunomodulatory functions, which helps to improve the integrity of the intestinal mucosal barrier, reduce the interference of inflammatory factors on nutrient absorption, and maintain the body's homeostasis. Encapsulated sodium butyrate, through its sustained-release properties, gradually releases butyric acid molecules in the posterior part of the intestine, exerting the typical physiological functions of short-chain fatty acids, including regulating the intestinal pH environment, promoting the colonization of beneficial bacteria, enhancing the renewal rate of intestinal epithelial cells, and maintaining the intestinal mucosal barrier function, thereby improving the overall nutrient absorption efficiency. Rice husk powder, as a natural plant fiber source, plays the role of physical filler and sustained-release carrier in the formula, optimizing processing performance and product stability. In addition, its rich lignin and hemicellulose components can regulate intestinal peristalsis, promote digestive juice secretion, improve intestinal motility, and prevent digestive disorders such as constipation or diarrhea. At the same time, as a functional dietary fiber, rice husk powder can also assist in regulating intestinal microecology and provide a good microenvironmental support for the absorption and metabolism of other active ingredients.

[0024] In summary, the phosphorus-free composite additive provided by the present invention, through the scientific combination and functional integration of five major components, has constructed an integrated nutritional regulation system with "feed phosphorus release - mineral absorption enhancement - intestinal health maintenance - bone metabolism regulation - immune homeostasis support" as the main line. Each component not only plays a specific function, but also forms a comprehensive intervention path with strong system, wide adaptability and stable effect through mutual cooperation and mechanism complementation. It successfully achieves the effective promotion of early bone development of broilers without adding any exogenous phosphorus, breaking through the high dependence on phosphorus in traditional breeding models, and has significant resource conservation, environmental friendliness and production application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The phosphorus-free composite additive prepared by the present invention;

[0026] Figure 2 Effects of the phosphorus-free composite additive prepared by the present invention on the behavioral state and health status of broiler chickens;

[0027] Figure 3 Effects of the phosphorus-free composite additive prepared by the present invention on the growth performance of broiler chickens;

[0028] Figure 4 Effects of the phosphorus-free composite additive prepared by the present invention on early tibia parameters of broiler chickens;

[0029] Figure 5 The invention discloses the effect of the phosphorus-free composite additive prepared by the present invention on the femoral parameters of broiler chickens in the early stage. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0032] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0033] The invention discloses a phosphorus-free composite additive for promoting early bone development of broilers. The phosphorus-free composite additive is prepared from the following raw materials in parts by weight: 40-60 parts of a heat-resistant phytase preparation, 0.1-0.3 parts of a 25-hydroxyvitamin D3 preparation, 70-90 parts of a honeysuckle extract, 40-60 parts of coated sodium butyrate, and 100-140 parts of rice husk powder.

[0034] The activity of the heat-resistant phytase preparation is 20,000 IU / g, and the concentration of the 25-hydroxyvitamin D3 preparation is 1.25%.

[0035] The present invention also provides a method for preparing the above-mentioned phosphorus-free composite additive, comprising the following steps:

[0036] S1. Weigh the raw materials according to the following weight parts: 40-60 parts of heat-resistant phytase preparation, 0.1-0.3 parts of 25-hydroxyvitamin D3 preparation, 70-90 parts of honeysuckle extract, 40-60 parts of coated sodium butyrate, 100-140 parts of rice husk powder, and set aside;

[0037] S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 are preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder are sequentially added to the mixer and stirred continuously until uniformly mixed;

[0038] S3. The mixed materials in step S2 are packed into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive, such as Figure 1 shown.

[0039] The invention also discloses the application of the phosphorus-free composite additive in feed for broiler chickens in the early growth stage.

[0040] Among them, the above-mentioned broiler early growth feed is made from the following raw materials in parts by weight: 50-70 parts of corn, 30-50 parts of soybean meal, 2-3 parts of soybean oil, 1-3 parts of soybean protein concentrate, 2-3 parts of stone powder, 0.05-0.2 parts of L-lysine hydrochloride, 0.1-0.2 parts of DL-methionine, 0.1-0.3 parts of choline chloride, 0.2-0.4 parts of table salt, 0.005-0.02 parts of complex vitamin premix, and 0.005-0.02 parts of complex trace elements.

[0041] The amount of the phosphorus-free compound additive added to each kilogram of feed is 2500-3500 mg.

[0042] Among them, the addition amounts of each component of the phosphorus-free composite additive in the above feed are: heat-resistant phytase 400-600 mg / kg, 25-hydroxyvitamin D3 1-3 mg / kg, honeysuckle extract 700-900 mg / kg, coated sodium butyrate 400-600 mg / kg, and rice husk powder 1000-1400 mg / kg.

[0043] Most preferably, the amount of the phosphorus-free composite additive added to each kilogram of feed is 3000 mg, and the amount of each component of the phosphorus-free composite additive added to the feed is: heat-resistant phytase 500 mg / kg, 25-hydroxyvitamin D3 2 mg / kg, honeysuckle extract 800 mg / kg, coated sodium butyrate 500 mg / kg, and rice husk powder 1198 mg / kg.

[0044] The technical solution of the present invention is further described below with reference to specific embodiments:

[0045] Example 1

[0046] The preparation method of the phosphorus-free composite additive for promoting early bone development in broiler chickens in this embodiment comprises the following specific steps:

[0047] S1. Weigh the following raw materials in parts by weight: 50 g of heat-resistant phytase preparation, 0.2 g of 25-hydroxyvitamin D3 preparation (1.25%), 80 g of honeysuckle extract, 50 g of coated sodium butyrate, and 119.8 g of rice husk powder, set aside;

[0048] S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 were preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder were added to the mixer in sequence, and stirred at a speed of 40 rpm for 20 minutes until uniformly mixed;

[0049] S3. The materials mixed in step S2 are divided into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive.

[0050] Example 2

[0051] The preparation method of the phosphorus-free composite additive for promoting early bone development in broiler chickens in this embodiment comprises the following specific steps:

[0052] S1. Weigh the raw materials according to the following weight parts: 40g heat-resistant phytase preparation, 0.1g 25-hydroxyvitamin D3 preparation, 70g honeysuckle extract, 40g coated sodium butyrate, 100g rice husk powder, set aside;

[0053] S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 were preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder were added to the mixer in sequence, and stirred at a speed of 30 rpm for 10 minutes until uniformly mixed;

[0054] S3. The materials mixed in step S2 are divided into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive.

[0055] Example 3

[0056] The preparation method of the phosphorus-free composite additive for promoting early bone development in broiler chickens in this embodiment comprises the following specific steps:

[0057] S1. Weigh the raw materials according to the following weight parts: 60g of heat-resistant phytase preparation, 0.3g of 25-hydroxyvitamin D3 preparation, 90g of honeysuckle extract, 60g of coated sodium butyrate, 139.7g of rice husk powder, and set aside;

[0058] S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 were preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder were added to the mixer in sequence, and stirred at a speed of 60 rpm for 20 minutes until uniformly mixed;

[0059] S3. The materials mixed in step S2 are divided into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive.

[0060] Effect Example 1

[0061] The phosphorus-free composite additive prepared in the above Example 1 is applied to this effect example, and its application effect is as follows.

[0062] 1. Materials

[0063] (1) Experimental animals: 210 Arbor Acres (AA) broiler chickens (1 day old, weighing 44.95 ± 0.09 g) were purchased from Shandong Rizhao Jiayi Animal Husbandry Co., Ltd.

[0064] (2) Sources of raw materials: heat-resistant phytase (activity 20,000 IU / g, Shandong Longkote Enzyme Preparation Co., Ltd.), 25-hydroxyvitamin D3 (concentration 1.25%, Shandong Haineng Bioengineering Co., Ltd.), coated sodium butyrate (Hangzhou Kangdequan Feed Co., Ltd.), honeysuckle extract (Changsha Shanghe Biotechnology Co., Ltd.) and rice husk powder (Mianyang Zaiweibao Technology Co., Ltd.).

[0065] (3) Preparation of basic feed (without adding calcium hydrogen phosphate): Preparation plan for every 100 kg of feed:

[0066] Accurately weigh 56.92 kg of corn, 35 kg of soybean meal, 2.83 kg of soybean oil, 1.97 kg of concentrated soy protein, 2.5 kg of stone powder, 0.09 kg of L-lysine hydrochloride, 0.15 kg of DL-methionine, 0.2 kg of choline chloride, 0.3 kg of table salt, 0.03 kg of multivitamin premix, and 0.01 kg of multi-trace element premix for poultry. The poultry multivitamin premix provides the following per kilogram of feed: vitamin D3 25μg, retinol 2.4mg, vitamin E13mg, vitamin K 0.5mg, thiamine 2mg, riboflavin 8mg, pyridoxine 3.5mg, pantothenic acid 10mg, niacin 35mg, cobalamin 0.01mg, folic acid 0.55mg, biotin 0.18mg; the poultry multi-trace element premix provides the following per kilogram of feed: iron 100mg, zinc 60mg, manganese 40mg, copper 6mg, selenium 0.30mg, iodine 0.15mg.

[0067] Add 1 / 2 of the corn, soybean meal, and soybean protein concentrate into the mixer in sequence, pre-mix the stone powder, L-lysine hydrochloride, DL-methionine, choline chloride, and salt until uniform, and then add them into the mixer, then add the poultry multivitamin premix and the poultry multi-trace element premix into the mixer in sequence, then add the soybean oil into the mixer, and finally add the remaining corn into the mixer; start the mixer, set the speed to 1400 r / min, and the mixing time to 5 minutes. After the mixing is completed, the materials are collected and set aside to obtain the basic feed in this effect example.

[0068] (4) Preparation of feed containing calcium hydrogen phosphate: The preparation plan for every 100 kg of feed is as follows: accurately weigh 56.92 kg of corn, 32.5 kg of soybean meal, 2.78 kg of soybean oil, 3.66 kg of soybean protein concentrate, 1.36 kg of stone powder, 1.94 kg of calcium hydrogen phosphate, 0.15 kg of L-lysine hydrochloride, 0.15 kg of DL-methionine, 0.2 kg of choline chloride, 0.3 kg of salt, 0.03 kg of poultry multivitamin premix, and 0.01 kg of poultry multitrace element premix. The poultry multivitamin premix provides the following per kilogram of feed: vitamin D3 25μg, retinol 2.4mg, vitamin E13mg, vitamin K 0.5mg, thiamine 2mg, riboflavin 8mg, pyridoxine 3.5mg, pantothenic acid 10mg, niacin 35mg, cobalamin 0.01mg, folic acid 0.55mg, biotin 0.18mg; the poultry multi-trace element premix provides the following per kilogram of feed: iron 100mg, zinc 60mg, manganese 40mg, copper 6mg, selenium 0.30mg, iodine 0.15mg.

[0069] Add 1 / 2 of the corn, soybean meal, and soybean protein concentrate into a mixer in sequence; pre-mix stone powder, calcium hydrogen phosphate, L-lysine hydrochloride, DL-methionine, choline chloride, and salt until uniform; then add the mixture into the mixer; then add the poultry multivitamin premix and the poultry multitrace element premix into the mixer in sequence; then add soybean oil into the mixer; and finally add the remaining corn into the mixer; start the mixer, set the speed to 1400 r / min, and the mixing time to 5 minutes. After the mixing is completed, the materials are connected and set aside to obtain the calcium hydrogen phosphate feed in this effect example.

[0070] (5) Preparation of feed containing phosphorus-free composite additive (prepared in Example 1): The formulation scheme for every 100 kg of feed is as follows: accurately weigh 56.92 kg of corn, 35 kg of soybean meal, 2.83 kg of soybean oil, 1.97 kg of soybean protein concentrate, 2.5 kg of stone powder, 0.09 kg of L-lysine hydrochloride, 0.15 kg of DL-methionine, 0.2 kg of choline chloride, 0.3 kg of salt, 0.03 kg of poultry composite vitamin premix, and 0.01 kg of poultry composite trace element premix.

[0071] This effect example is calculated based on the ratio of 3000 mg of phosphorus-free composite additive per kilogram of feed. 100 kg of feed requires 300 g of the composite additive prepared in Example 1 of the present invention (50 g of heat-resistant phytase preparation, 0.2 g of 25-hydroxyvitamin D3 preparation (concentration of 1.25%), 80 g of honeysuckle extract, 50 g of coated sodium butyrate, and 119.8 g of rice husk powder).

[0072] Add 1 / 2 of the corn, soybean meal, and soybean protein concentrate to the mixer in sequence, pre-mix stone powder, calcium hydrogen phosphate, L-lysine hydrochloride, DL-methionine, choline chloride, and salt until uniform, and then add them to the mixer, then add the poultry composite vitamin premix, poultry composite trace element premix, and composite additive (prepared in Example) to the mixer in sequence, then add soybean oil to the mixer, and finally add the remaining corn to the mixer; start the mixer, set the speed to 1400 r / min, and the mixing time to 5 min. After mixing is completed, connect the materials for use, and obtain the feed containing the phosphorus-free composite additive in this effect example.

[0073] 2. Animal Grouping and Treatment

[0074] Two hundred and ten healthy, one-day-old Arbor Acres (AA) broiler chicks of similar weight were selected and randomly divided into three treatment groups, each with five replicates and 14 birds per replicate. The experimental period was from 1 to 21 days of age. During the experimental period, the broilers in each group were uniformly managed and had free access to food and water. The treatment groups were set up according to the type of diet they were fed as follows: a blank group (fed a basal diet without calcium hydrogen phosphate), a control group (basal diet supplemented with calcium hydrogen phosphate), and a test group (basal diet supplemented with the composite additive prepared in Example 1). The diet formula and nutritional levels of each group are shown in Table 1. The nutritional requirements of broilers refer to the U.S. NRC (1994) and China NY / T 33-2004 "Chicken Feeding Standards". The calcium content of feed was determined according to GB / T 6436-2018 "Determination of calcium in feeds", and the total phosphorus content was determined according to GB / T 6437-2018 "Determination of total phosphorus in feeds - Spectrophotometric method". The calcium and total phosphorus contents in the feed are measured values, and the rest are calculated values.

[0075] Table 1

[0076]

[0077]

[0078] During the experiment, each group was caged, with each cage measuring 140 cm long × 70 cm wide × 35 cm high. The environmental control was as shown in Table 2 below:

[0079] Table 2

[0080]

[0081]

[0082] During the experiment, the behavior and health status of broiler chickens were observed and recorded. Figure 2As shown, the results showed that the broilers in the blank group showed obvious symptoms of abnormal bone development, including inability to stand, difficulty in movement, and squatting on the ground in a split posture, suggesting a serious tendency to tibial cartilage dysplasia; the broilers in the control group and the experimental group were in good overall mental state, moved freely, and had no obvious leg disease symptoms, indicating that both the control group and the experimental group can effectively maintain the healthy bone development of broilers in the early stage.

[0083] 3. Data Analysis

[0084] Data Analysis: Experimental data were initially organized using Excel 2019 and then statistically analyzed using the LSD procedure in SAS 9.4 (SAS Institute Inc., Cary, NC, USA). Results are expressed as mean (mean) and standard error (SEM); P < 0.05 was considered significant. The following figures were generated using GraphPad Prism 8.3 (GraphPad Software Inc., San Diego, California, USA).

[0085] 4. Test results

[0086] 4.1 Effect of the Phosphorus-Free Composite Additive Prepared by the Present Invention on the Growth Performance of Broilers

[0087] During the experiment, the feed intake of broiler chickens in the blank group, control group, and experimental group was recorded, and the broiler chicks were weighed on an empty stomach (12 hours fasting) at 1 day and 21 days of age to accurately assess their weight gain. The number and weight of broiler chickens that died during the experiment were recorded, and the weight gain, feed-to-weight ratio, and mortality rate of broiler chickens during the experiment were counted and calculated. Figure 3 As shown, where:

[0088] (1) Body weight gain (g) = 21-day-old broiler weight - 1-day-old broiler weight;

[0089] (2)

[0090] (3)

[0091] from Figure 3It can be seen that compared with the control group, the body weight, body weight gain and feed intake of the broilers in the blank group were significantly reduced (P<0.05), while the feed-to-weight ratio and mortality rate were significantly increased (P<0.05), indicating that feeding the basal feed without supplementing an effective phosphorus source has a significant adverse effect on the early growth performance of broilers. This shows that phosphorus plays a key role in the early rapid growth period of broilers, and its deficiency will directly inhibit growth potential and increase health risks. Compared with the blank group, the growth performance of the broilers in the experimental group was significantly improved, and their body weight, body weight gain and feed intake were significantly increased (P<0.05), and the feed-to-weight ratio and mortality rate also decreased significantly (P<0.05), indicating that the composite additive prepared in Example 1 of the present invention can effectively alleviate the adverse effects of the low-phosphorus diet in the blank group without adding any exogenous phosphorus, and significantly improve the growth performance of broilers. In addition, the body weight, weight gain, mortality, feed intake and feed-to-weight ratio of the broilers in the experimental group have recovered to levels close to those of the control group, indicating that the compound additive has a good application effect in promoting early bone development of broilers, maintaining normal metabolic function and improving survival rate, achieving the goal of healthy broiler farming without exogenous phosphorus addition.

[0092] 4.2 Effect of the phosphorus-free composite additive prepared by the present invention on early tibial parameters of broiler chickens

[0093] When the broilers grew to 21 days of age, one broiler in good health was randomly selected from each of the five replicates in each treatment group. The selected broilers were humanely slaughtered according to standard slaughtering procedures, and the tibia was quickly removed to avoid tissue damage. The removed tibia was first cleaned with physiological saline to remove attached muscles and other soft tissues, and then the surface moisture was absorbed with filter paper. Various indicators were measured to analyze the development of the broiler tibia, such as Figure 4 shown.

[0094] from Figure 4(A) It can be seen that there are obvious differences in the appearance of the broiler tibias of the control group, blank group and test group. The tibia of the control group is complete in appearance, uniform in color and presents a healthy light yellow or white color. The surface of the tibia is smooth, and the length and diameter are large, showing high bone density and good mineral deposition, indicating that its bone development is in good condition; the tibia of the blank group appears shorter and thinner, with darker or uneven color, rough and irregular tibia surface, and even small cracks or other defects can be seen. The length and diameter of the tibia are significantly smaller than those of the control group, reflecting that the low-phosphorus diet has a significant negative impact on bone growth, suggesting that bone development is hindered or there is a risk of pathology; the appearance of the tibia of the test group is close to that of the control group, with uniform color and no significant discoloration. The surface of the tibia is relatively smooth. Although the length and diameter of the tibia are slightly smaller than those of the control group, it is significantly better than that of the blank group. This shows that the composite additive prepared by the present invention can effectively alleviate the adverse effects of low-phosphorus diet on broiler bone development and promote bone health without adding exogenous phosphorus.

[0095] from Figure 4 As can be seen in (B), compared with the control group, the tibia weight, length, diameter, ash weight, ash content, calcium content and phosphorus content of the broiler chickens in the blank group were significantly reduced (P<0.05), indicating that feeding the basal feed without supplementing an effective phosphorus source had a significant negative impact on the early bone development of broiler chickens, specifically manifested in a significant reduction in tibia weight, size and mineral deposition, further demonstrating the importance of phosphorus to the early bone health of broiler chickens. Compared with the blank group, the tibia weight, length, ash weight, ash content, calcium content and phosphorus content of the broiler chickens in the test group were significantly increased (P<0.05), indicating that the composite additive prepared in Example 1 of the present invention can effectively alleviate the adverse effects of low-phosphorus diets and promote the normal development of broiler bones without adding any exogenous phosphorus. In addition, compared with the control group, the tibia diameter and calcium content of the broiler chickens in the experimental group reached the level of the control group (P>0.05), and their tibia weight, length, ash weight, ash content and phosphorus content were also close to the level of the control group, indicating that although the experimental group did not add an additional phosphorus source, the bone development of the broiler chickens was significantly improved by using the composite additive, almost returning to the standard of the positive control group, further illustrating that the composite additive of the present invention can promote the normal development of broiler bones without adding any exogenous phosphorus.

[0096] 4.3 Effect of the phosphorus-free composite additive prepared by the present invention on early femoral parameters of broiler chickens

[0097] When the broilers grew to 21 days of age, one broiler in good health was randomly selected from each of the five replicates in each treatment group. The selected broilers were humanely slaughtered according to standard slaughtering procedures, and the femur was quickly removed to avoid tissue damage. The removed femur was first cleaned with physiological saline to remove attached muscles and other soft tissues, and then the surface moisture was absorbed with filter paper. Various indicators were measured to analyze the development of the broiler femur, such as Figure 5 shown.

[0098] from Figure 5 As can be seen in (A), there are obvious differences in the appearance of the broiler femurs of the control group, blank group and test group. The overall color of the femur of the control group is uniform, light yellow, with a smooth surface, complete and strong shape, indicating good bone health; Blank group: The femur is darker in color, and some bones have obvious dark spots or irregular areas on the surface, and the shape is relatively small, indicating that there may be bone dysplasia or lesions, which is consistent with the above-mentioned decline in growth performance and increased health risks; Test group: The color and shape of the femur are close to those of the control group, the surface is relatively smooth, and there are no obvious dark spots, indicating that the composite additive of the present invention has improved the effect of low-phosphorus diet on bones to a certain extent and promoted the normal development of bones.

[0099] from Figure 5 As can be seen in (B), compared with the control group, the femur weight, length, diameter, ash weight, ash content, calcium content, and phosphorus content of the blank group broilers were significantly reduced (P < 0.05), indicating that in the absence of an effective phosphorus source, broiler bone development was significantly inhibited, mineral deposition was reduced, and bone structural integrity was impaired. Compared with the blank group, the femur development of the broilers in the experimental group was significantly improved, and their femur weight, length, ash weight, ash content, calcium content, and phosphorus content were significantly increased (P < 0.05), indicating that the composite additive prepared in Example 1 of the present invention can effectively promote healthy bone development without the addition of exogenous phosphorus, and exert a good nutritional regulatory effect. Moreover, the femur diameter of the broilers in the experimental group has returned to the level of the control group, with no significant difference (P>0.05); although there are still significant differences in femur weight, length, ash weight, ash content, calcium content and phosphorus content compared with the control group (P<0.05), the overall trend has clearly approached that of the control group; this shows that the composite additive prepared by the present invention can effectively alleviate the problem of skeletal dysplasia under low-phosphorus feed conditions, and has good application prospects and promotion value.

[0100] The above is a detailed introduction to the phosphorus-free composite additive disclosed in the present invention for promoting early bone development in broilers, its preparation method and application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A phosphorus-free composite additive for promoting early bone development in broiler chickens, characterized in that: The phosphorus-free composite additive is prepared from the following raw materials in parts by weight: 40-60 parts of heat-resistant phytase preparation, 0.1-0.3 parts of 25-hydroxyvitamin D3 preparation, 70-90 parts of honeysuckle extract, 40-60 parts of coated sodium butyrate, and 100-140 parts of rice husk powder.

2. A phosphorus-free composite additive for promoting early bone development in broilers according to claim 1, characterized in that: The activity of the heat-resistant phytase preparation is 20,000 IU / g, and the concentration of the 25-hydroxyvitamin D3 preparation is 1.25%.

3. The method for preparing the phosphorus-free composite additive according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Weigh the raw materials according to the following weight parts: 40-60 parts of heat-resistant phytase preparation, 0.1-0.3 parts of 25-hydroxyvitamin D3 preparation, 70-90 parts of honeysuckle extract, 40-60 parts of coated sodium butyrate, 150-250 parts of rice husk powder, and set aside; S2. The heat-resistant phytase preparation and 25-hydroxyvitamin D3 preparation in step S1 are preliminarily mixed, and then the honeysuckle extract, coated sodium butyrate and rice husk powder are sequentially added to the mixer and stirred continuously until uniformly mixed; S3. The materials mixed in step S2 are divided into well-sealed bags or containers and stored in a cool, dry place away from light to obtain a phosphorus-free composite additive.

4. Use of the phosphorus-free composite additive according to claim 1 in feed for broiler chickens in the early growth stage.

5. The use according to claim 4, characterized in that The broiler chicken early growth feed is prepared from the following raw materials in parts by weight: 50-70 parts of corn, 30-50 parts of soybean meal, 2-3 parts of soybean oil, 1-3 parts of soybean protein concentrate, 2-3 parts of stone powder, 0.05-0.2 parts of L-lysine hydrochloride, 0.1-0.2 parts of DL-methionine, 0.1-0.3 parts of choline chloride, 0.2-0.4 parts of salt, 0.005-0.02 parts of complex vitamin premix, and 0.005-0.02 parts of complex trace element premix.

6. The use according to claim 5, characterized in that The amount of the phosphorus-free composite additive added to each kilogram of feed is 2500-3500 mg.

7. The use according to claim 6, characterized in that The added amounts of the components of the phosphorus-free composite additive in the feed are: 400-600 mg / kg of heat-resistant phytase, 1-3 mg / kg of 25-hydroxyvitamin D3, 700-900 mg / kg of honeysuckle extract, 400-600 mg / kg of coated sodium butyrate, and 1000-1400 mg / kg of rice husk powder.

8. The use according to claim 7, characterized in that The amount of the phosphorus-free composite additive added to each kilogram of feed is 3000 mg, and the added amount of each component of the phosphorus-free composite additive in the feed is: 500 mg / kg of heat-resistant phytase, 2 mg / kg of 25-hydroxyvitamin D3, 800 mg / kg of honeysuckle extract, 500 mg / kg of coated sodium butyrate, and 1198 mg / kg of rice husk powder.

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