Method for improving eggshell quality of laying hens in later egg laying period by adding lactobacillus salivarius into feed

Abstract

The invention discloses a method for improving egg shell quality in the later egg laying period of laying hens by adding intestinal probiotics into feed, and belongs to the technical field of healthy poultry breeding. According to the method, specifically enriched lactobacillus salivarius is screened based on correlation analysis of intestinal flora and eggshell quality. The strain is added into basic ration of laying hens in the later egg laying period according to a certain proportion (preferably 150 mg / kg feed) in the form of bacterial powder with the viable count not lower than 1 * 10 < 9 > CFU / g, and the laying hens are continuously fed for at least 8 weeks. According to the method, the laying rate and the average daily egg weight of the laying hens in the later laying period can be remarkably increased, the eggshell thickness and strength are effectively improved, and the egg breaking rate is reduced. The strain screening method provided by the invention is scientific, clear in application effect, safe and free of residues, and an effective green solution is provided for solving the problem that the eggshell quality is reduced in the later egg laying period of laying hens.

Description

Technical Field

[0001] This invention relates to the field of poultry health farming technology, specifically to a method for significantly improving the laying performance and eggshell quality of laying hens in the late laying period by adding a specific intestinal probiotic—Lactobacillus salivarius—to the basal diet. Background Technology

[0002] In the later stages of egg production (usually after 480 days of age), laying hens commonly face declining production performance and deteriorating eggshell quality, mainly manifested as reduced egg production rate, thinner eggshells, and decreased eggshell strength, resulting in serious economic losses. Traditionally, this problem has been alleviated by supplementing calcium sources, vitamin D3, or using some feed additives, but the effects are limited or there are problems such as residues and high costs.

[0003] In recent years, the regulatory role of gut microbiota on host health and nutrient metabolism has received widespread attention. Probiotics, as a safe and green feed additive, have been used to maintain gut health and improve immunity. However, their specific regulatory effects and mechanisms on the later stages of egg production in laying hens, especially on the intricate physiological process of eggshell calcification, remain unclear. There is a lack of targeted and stable strains and application protocols.

[0004] While there are reports of using probiotics to improve egg production performance in existing technologies, strain screening often lacks direct evidence of a correlation with target traits (such as eggshell quality), leading to unstable and untargeted application effects. Therefore, developing a probiotic based on scientific screening with a clear efficacy in improving eggshell quality and its precise application method is of great significance for the sustainable development of the egg-laying hen industry. This invention innovatively proposes using "intestinal microbial community characteristics that can improve eggshell quality" as a screening blueprint to reverse-engineer key functional strains, which can then be applied to the targeted regulation of eggshell quality. Summary of the Invention

[0005] To address the industry challenges of declining eggshell quality and increased egg breakage rate in the later stages of egg production, this paper proposes a probiotic application method that is highly effective, safe, and residue-free, and based on the correlation between host gut microbiota and eggshell quality.

[0006] The core ingredient: Lactobacillus salivarius powder, with a live bacteria count of not less than 1×10⁻⁶. 9 CFU / g; The mechanism of action: Regulating gut microbiota structure: Specifically increases the relative abundance of beneficial bacteria such as Lactobacillus salivarius in the gut, inhibits the growth of harmful bacteria, and improves the balance of gut microbiota.

[0007] Producing beneficial metabolites: The strain's metabolism produces short-chain fatty acids (such as acetic acid and propionic acid), which lower intestinal pH and promote the dissolution and absorption of calcium salts.

[0008] Activate calcium metabolism genes: Through the "microbiota-metabolite" signaling, the expression of key functional genes such as calcium-binding protein (CaBP-d28k) in the duodenum and uterine shell gland tissue is upregulated, thereby systematically enhancing the efficiency of intestinal calcium absorption and uterine calcium deposition.

[0009] Improving eggshell quality: Ultimately achieving a significant increase in eggshell strength and thickness, such as... Figure 3 As shown, the breakage rate was effectively reduced.

[0010] Implementation steps: Screening of *Lactobacillus salivarius* strains: Intestinal contents were collected from laying hens fed a compound plant extract (containing genistein and oregano oil) that significantly improved eggshell quality. The gut microbiota structure was analyzed using 16S rRNA gene high-throughput sequencing. Bioinformatics analysis (e.g., LEfSe analysis) and statistical tests (e.g., Kruskal-Wallis H test) were performed, as shown in the attached figure. Figure 1 As shown, in the group with the best eggshell quality, the relative abundance of Lactobacillus salivarius showed a trend of specific enrichment.

[0011] Animals and grouping: Laying hens in the late laying period were selected and randomly divided into a control group and three experimental groups with low, medium and high levels.

[0012] Feeding management: Mix the bacterial powder thoroughly with the basal diet and feed normally every day for 8 weeks.

[0013] Effect verification: The production performance and egg quality indicators of each group were statistically analyzed and compared. Detailed Implementation

[0014] The invention will now be described in detail with reference to the accompanying drawings and embodiments. These descriptions are intended to explain the invention and not to limit it.

[0015] (1) Experimental design: 224 late-laying Jingfen No. 6 laying hens were randomly divided into groups (n=56): Control group: basal diet; Experimental group 1: Lactobacillus salivarius (100 mg / kg); Experimental group 2: Lactobacillus salivarius (150 mg / kg); Experimental group 3: Lactobacillus salivarius (200 mg / kg); Sample collection ① Record the number of eggs laid, egg weight, and broken / soft eggs daily, and calculate the egg production rate, average egg weight, average daily egg production weight, and broken egg rate; ② At the end of the 4th and 8th weeks of the trial feeding period, three egg samples close to the average egg weight of each replicate were selected, and 12 egg samples were collected for each treatment to test the egg quality.

[0016] Test indicators and methods ①Production performance: Production performance includes egg production rate, average egg weight, average daily egg weight, and broken egg rate, calculated using the following formulas: Egg production rate = Number of eggs laid per repeat / Number of laying hens × 100%; Average egg weight = total egg weight / total number of eggs; Average daily egg weight = Average egg weight × Egg production rate; Broken egg rate = number of broken eggs / total number of eggs laid × 100%.

[0017] ② Egg quality: The egg quality testing methods are as follows: Egg weight, Haugh unit, and yolk color are measured using a multi-functional egg quality analyzer; eggshell thickness is measured using vernier calipers, specifically by removing the inner shell membrane from the blunt end, equatorial portion, and pointed end of the eggshell, and the thickness is measured separately, with the average value taken; the longitudinal and transverse diameters of the egg are also measured, and the egg shape index is calculated as: egg shape index = maximum longitudinal diameter / maximum transverse diameter; the egg white and yolk are separated, and the yolk weight is measured; the eggshell strength is measured using an eggshell strength tester. Attached Figure Description

[0018] Figure 1 Screening diagram of Lactobacillus salivarius strains; Figure 2 The effects of Lactobacillus salivarius on the laying performance of hens in the late laying period; Figure 3 The effect of Lactobacillus salivarius on the quality of eggs in the later stages of egg production.

[0019] This invention significantly improves the laying performance and eggshell quality of laying hens in the later stages of egg production by adding specific intestinal probiotics to the basal diet, providing an effective and green solution to the problem of declining eggshell quality in the later stages of egg production.

Claims

1. A method for improving eggshell quality in late-laying hens by adding Lactobacillus salivarius to feed, characterized in that: Includes the following steps: a) Screening for Lactobacillus salivarius in the gut that is associated with improved eggshell quality; b) Add the bacterial powder of the strain to the basic daily diet of laying hens in the late laying period for feeding; c) Continue feeding for at least 8 weeks to significantly improve eggshell strength and thickness.

2. The method according to claim 1, characterized in that... The screening criteria were as follows: Intestinal contents were collected from laying hens fed a compound plant extract (containing genistein and oregano oil) that significantly improved eggshell quality, and the intestinal flora structure was analyzed using 16S rRNA gene high-throughput sequencing. Bioinformatics analysis and statistical tests revealed that the relative abundance of *Lactobacillus salivarius* showed a specific enrichment trend in the group with the best eggshell quality.

3. The method according to claim 1, characterized in that: The Lactobacillus salivarius powder has a viable count of not less than 1×10⁻⁶. 9 CFU / g.

4. The method according to claim 1, characterized in that... The feeding program was as follows: 224 Jingfen No. 6 laying hens at 105 weeks of age in the late laying stage were randomly divided into 4 groups (n=56): the control group (NC) was fed a basal diet; by feed weight, experimental group 1 (LS1) was supplemented with 100 mg / kg Lactobacillus salivarius in the basal diet; experimental group 2 (LS2) was supplemented with 150 mg / kg Lactobacillus salivarius in the basal diet; and experimental group 3 (LS3) was supplemented with 200 mg / kg Lactobacillus salivarius in the basal diet.

5. The method according to claim 4, characterized in that: During the feeding period, the number of eggs laid, egg weight, and broken / soft eggs were recorded daily, and the egg production rate, average egg weight, average daily egg weight, and broken egg rate were calculated. At the end of the 4th and 8th weeks of the trial feeding period, three egg samples close to the average egg weight of each replicate were selected, and 12 egg samples were collected for each treatment to test the egg quality.

6. The method according to claim 5, characterized in that: The egg production rate of the three Lactobacillus salivarius-added groups (LS1, LS2, LS3) was significantly higher than that of the control group (NC) (P < 0.05); the average daily egg weight of the LS2 and LS3 groups was significantly higher than that of the NC group (P < 0.05).

7. The method according to claim 5, characterized in that: At 4 weeks, the eggshell thickness of the LS1 and LS2 groups was significantly increased (P < 0.05); at 8 weeks, the eggshell strength of the LS2 group was significantly higher than that of the other groups (P < 0.05).

8. The application as described in claim 1, characterized in that: Adding Lactobacillus salivarius to the diet of laying hens in the later stages of egg production can significantly improve production performance and egg quality; the optimal dosage of the bacterial powder is 150 mg / kg.

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