Feed additive for improving ovulation rate and litter size of sows, preparation method therefor, and use thereof

Abstract

Disclosed are a feed additive for improving the ovulation rate and litter size of sows, a preparation method therefor, and a use thereof. The feed additive is composed of three short-chain fatty acid salts, which are respectively sodium acetate, sodium propionate, and sodium butyrate. Sow feed contains the above feed additive, and the amount of the feed additive that is added is 0.1%-1% of the total weight of the basic daily diet of a sow. The feed additive of the present invention has a simple preparation process and low production costs and has the effect of significantly improving the ovulation rate and litter size of sows.

Description

Feed additive for increasing sow ovulation rate and litter size, and preparation method and application thereof Technical Field

[0001] The invention relates to a feed additive, in particular to a feed additive for improving the ovulation rate and litter size of sows, and a preparation method and application thereof. Background Art

[0002] Recent studies have demonstrated that short-chain fatty acids (SCFAs) are involved in the regulation of intestinal microbiota on reproductive performance in female animals (Jiang et al., 2019; Uryu et al., 2020; Zhuo et al., 2021; He et al., 2022). SCFAs are metabolites of indigestible polysaccharides anaerobic fermented by hindgut microbiota (van der Hee and Wells, 2021). SCFAs enter the capillaries from the intestinal lumen via transporters or free diffusion, and then enter peripheral tissues and organs via the portal vein, liver, heart, and peripheral blood (van der Hee and Wells, 2021). Domestic research has shown that increasing dietary fiber content (from 2.5% to 7.5%) over just one reproductive cycle significantly improved the reproductive performance decline of Meishan sows induced by long-term consumption of a high-energy, low-fiber diet (fiber content below 3%). This effect was associated with relieving stress in Meishan sows, increasing fecal short-chain fatty acid concentrations, and regulating reproductive hormones (Jiang et al., 2019). Similarly, Wu De's group reported that dietary fiber supplementation alleviated high-energy diet-induced ovarian granulosa cell apoptosis and follicular atresia in pigs via a "gut microbiota-short-chain fatty acid-melatonin-ovary" pathway (Zhuo et al., 2021). A group study conducted on 18 commercial pig farms demonstrated a significant positive correlation between fecal short-chain fatty acid concentrations and sow litter size (Uryu et al., 2020). These findings suggest that short-chain fatty acids, metabolites of the gut microbiota, may improve sow reproductive performance by improving follicular atresia, promoting follicular development, and ovulation.

[0003] Currently, there is a lack of research on the effects of adding short-chain fatty acid salts to the diet on sow follicle development, ovulation rate and litter performance.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a feed additive for improving the ovulation rate and litter size of sows, as well as its preparation method and application. Based on the characteristics that the Meishan sow, a local pig breed in my country, is famous for its excellent reproductive performance, its follicular development and ovulation rate are significantly better than those of sow breeds introduced from abroad, the present invention compares purebred Meishan sows with high and low litter sizes, combines fecal transplantation technology and multi-omics methods to screen and identify short-chain fatty acids (acetic acid, propionic acid and butyric acid), and at the same time, combines sodium acetate, sodium propionate and sodium butyrate in a ratio to obtain a feed additive that participates in regulating sow follicle development, maturation and ovulation.

[0006] To achieve the above purpose, the technical solution designed by the present invention is as follows:

[0007] The invention provides a feed additive for improving the ovulation rate and litter size of sows. The feed additive consists of three short-chain fatty acid salts, namely sodium acetate, sodium propionate and sodium butyrate.

[0008] Furthermore, the feed additive is composed of the following components in mass fractions:

[0009] Sodium acetate: 20-50 parts, sodium propionate: 20-40 parts, sodium butyrate: 10-30 parts.

[0010] Furthermore, the feed additive is composed of the following components in mass fractions:

[0011] Sodium acetate: 39.4 parts, sodium propionate: 33.3 parts, sodium butyrate: 27.3 parts.

[0012] The above-mentioned sodium acetate, sodium propionate and sodium butyrate are all food-grade chemicals. These short-chain fatty acids have not yet been reported to have the effect of increasing the ovulation rate and piglet size of sows.

[0013] The present invention also provides a use of the feed additive in improving the ovulation rate and litter size of sows.

[0014] The present invention also provides a use of the feed additive in preparing pig feed for improving the ovulation rate and litter size of sows.

[0015] The present invention also provides a sow feed for improving the ovulation rate and litter size of sows. The sow feed contains the above feed additive, and the addition amount of the feed additive is 0.1%-1% of the total weight of the sow's basic daily diet.

[0016] Furthermore, the added amount of the feed additive is 0.33% of the total weight of the sow's basic daily diet.

[0017] The present invention also provides a method for using the sow feed, which is characterized by comprising the following steps:

[0018] 1) adding the above feed additives to the basic diet and mixing them evenly to obtain a basic diet for sows, wherein the amount of the feed additives added is 0.1% to 1% of the total weight of the basic diet for sows;

[0019] 2) Add sow feed from 95 days of age to the first estrus. Stop feeding the sow feed after the first estrus and switch to the sow basic diet.

[0020] Furthermore, the added amount of the feed additive is 0.33% of the total weight of the sow's basic daily diet.

[0021] Beneficial effects of the present invention:

[0022] 1) The preparation process of the feed additive of the present invention is simple, and it only requires mixing sodium acetate, sodium propionate and sodium butyrate in a certain proportion;

[0023] 2) The feed additive of the present invention has low production cost, stable chemical properties, is easy to use, and can be directly added to complete feed as a premix component;

[0024] 3) The feed additive of the present invention is safe and healthy, has no side effects on the health of sows, and has the effect of significantly increasing the ovulation rate and litter size of sows. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 shows the effects of FMT on follicular development and intestinal flora function in Meishan sows;

[0026] In the figure, A is the ovarian morphology (H&E staining), B is the density statistical results of follicles at all levels, C is the intestinal flora functional analysis, and D is the SCFAs concentration in the colon contents.

[0027] Figure 2 shows the effect of dietary supplementation of short-chain fatty acids (SCFAs) on follicular development in sows;

[0028] In the figure, the control group (Ctrl) consists of sows fed a basal diet, and the experimental group (SCFAs) consists of sows fed a basal diet supplemented with 3.3% SCFAs.

[0029] A is the design diagram of animal experiment.

[0030] B is the ovarian morphology (H&E staining),

[0031] C is the statistical result of the density of follicles at different levels.

[0032] Figure 3 shows the effect of adding short-chain fatty acids (SCFAs) to the diet on the litter size of sows;

[0033] In the figure, the control group (Ctrl) consists of sows fed a basal diet, and the experimental group (SCFAs) consists of sows fed a basal diet supplemented with 0.33% SCFAs feed additive. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to specific embodiments so that those skilled in the art can understand.

[0035] Example 1

[0036] To investigate the role of intestinal microbiota in the high ovulation rate of Meishan sows, fecal microbiota transplantation (FMT) was performed using fecal microbiota from similarly aged Meishan sows housed under the same conditions. The results showed that FMT promoted a shift in the intestinal microbiota composition of the recipient Meishan sows toward that of the donor, promoted follicular maturation and reduced follicular atresia, enhanced the carbohydrate metabolism capacity of the intestinal microbiota, and increased the concentration of SCFAs in the colonic contents (Figure 1). Literature review and analysis of SCFA concentrations in colonic contents suggest that SCFAs may mediate the promoting effect of FMT on follicular maturation in sows.

[0037] To this end, we further used commercial Landrace × Large White (Landrace × Large White) sows as research subjects, and added 0.33% feed additives to the basal diet of sows from 95 days of age to the first estrus. We found that this could significantly increase the number of mature follicles (Figure 2), ovulation rate (Figure 2) and piglet size (Figure 3) of the sows.

[0038] The preparation method of the above feed additive is as follows:

[0039] The feed additive is obtained by mixing various raw materials in proportion, wherein the feed additive is composed of the following components in mass fractions:

[0040] Sodium acetate: 39.4 parts, sodium propionate: 33.3 parts, sodium butyrate: 27.3 parts.

[0041] Example 2

[0042] The method for preparing feed additive 2 in Example 2 is basically the same as that in Example 1, except that:

[0043] Feed additive 2 is composed of the following components in mass fractions:

[0044] Sodium acetate: 40 parts, sodium propionate: 40 parts, sodium butyrate: 20 parts.

[0045] Example 3

[0046] The method for preparing feed additive 3 in this embodiment 3 is basically the same as the method for preparing feed additive 3 in embodiment 1, except that:

[0047] Feed additive 3 is composed of the following components in mass fractions:

[0048] Sodium acetate: 35 parts, sodium propionate: 35 parts, sodium butyrate: 30 parts.

[0049] Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on this embodiment without inventiveness, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A feed additive for increasing the ovulation rate and litter size of sows, characterized in that: The feed additive consists of three short-chain fatty acid salts, namely sodium acetate, sodium propionate and sodium butyrate.

2. The feed additive for improving the ovulation rate and litter size of sows according to claim 1; characterized in that: The feed additive is composed of the following components by mass fraction: composition: Sodium acetate: 20-50 parts, sodium propionate: 20-40 parts, sodium butyrate: 10-30 parts.

3. The feed additive for improving the ovulation rate and litter size of sows according to claim 2; characterized in that: The feed additive is composed of the following components by mass fraction: composition: Sodium acetate: 39.4 parts, sodium propionate: 33.3 parts, sodium butyrate: 27.3 parts.

4. Use of the feed additive according to claim 1 in improving the ovulation rate and litter size of sows.

5. Use of the feed additive according to claim 1 in preparing pig feed for improving the ovulation rate and litter size of sows.

6. A sow feed for improving the ovulation rate and litter size of sows, characterized in that: The sow feed contains the feed additive according to claim 1, and the added amount of the feed additive is 0.1%-1% of the total weight of the sow's basic daily diet.

7. The sow feed according to claim 6, characterized in that: The added amount of the feed additive is 0.33% of the total weight of the sow's basic daily diet.

8. A method for using the sow feed according to claim 6, characterized in that: The following steps are involved: 1) adding the feed additive according to claim 1 to the basic diet, mixing evenly to obtain a basic diet for sows, wherein the amount of the feed additive added is 0.1%-1% of the total weight of the basic diet for sows; 2) Add sow feed from 95 days of age to the first estrus. Stop feeding the sow feed after the first estrus and replace it with the basic sow diet.

9. The method for using the sow feed according to claim 8, characterized in that: The added amount of the feed additive is 0.33% of the total weight of the sow's basic daily diet.

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