Largemouth bass feed added with Chinese gallnut tannic acid and ellagic acid

Abstract

The present invention discloses a feed for largemouth bass added with gallnut tannic acid and ellagic acid. In the feed for largemouth bass, calculated by weight percentage, the feed for largemouth bass contains: 50% fish meal, 28.4% soybean meal, 6.6% tapioca starch, 8% soybean oil, 0.5% compound multivitamins, 0.5% compound multiminerals, 3.33125% carboxymethyl cellulose, 0.5% choline chloride, 2% calcium dihydrogen phosphate, 0.15% gallnut tannic acid and 0.01875% ellagic acid. By adding 0.15% gallnut tannic acid + 0.01875% ellagic acid to the basic feed for largemouth bass, it has no effect on the body composition of largemouth bass, but can improve the intestinal morphology, thereby effectively reducing the feed coefficient and increasing the growth performance. It well solves the problem of slow growth in the large-scale cultivation of largemouth bass.

Description

Technical Field

[0001] The present invention relates to a feed for largemouth bass, in particular to a feed for largemouth bass added with gallnut tannic acid and ellagic acid. Background Art

[0002] The largemouth bass (Micropterus salmoides) is native to North America, belonging to the genus Micropterus of the order Perciformes, and is a typical carnivorous freshwater economic fish and one of the important freshwater aquaculture varieties in China. The largemouth bass has the characteristics of fast growth, cold tolerance, strong adaptability and disease resistance, delicious meat, and high economic benefits, so it is deeply loved by farmers and consumers.

[0003] In recent years, the aquaculture scale of largemouth bass has increased year by year. Due to its carnivorous nature, its growth and intestinal health problems under intensive aquaculture are very prominent, seriously restricting the development of the industry. Aquaculture conditions such as unbalanced feed nutrition, deteriorated aquaculture environment, hypoxia and high-temperature stress will all affect the growth and intestinal health of largemouth bass. The nutritional requirements and feed formulation technology of largemouth bass have been preliminarily studied. It has a relatively high protein requirement (45.0% - 51.6%), and the fish meal content in commercial feed is 40% - 50%. Summary of the Invention

[0004] The purpose of the present invention is to provide a feed for largemouth bass added with gallnut tannic acid and ellagic acid. By adding 0.15% gallnut tannic acid + 0.01875% ellagic acid to the basic feed for largemouth bass, it has no effect on the body composition of largemouth bass, but can improve the intestinal morphology, thereby effectively reducing the feed coefficient and increasing the growth performance.

[0005] The technical solution of the present invention: A feed for largemouth bass added with gallnut tannic acid and ellagic acid, in which, calculated by weight percentage, the feed for largemouth bass contains 0.15% of gallnut tannic acid and 0.01875% of ellagic acid.

[0006] In the aforementioned feed for largemouth bass added with gallnut tannic acid and ellagic acid, the feed for largemouth bass also contains 50% of fish meal, 28.4% of soybean meal, 6.6% of tapioca starch, 8% of soybean oil, 0.5% of compound multivitamins, 0.5% of compound multiminerals, 3.33125% of carboxymethyl cellulose, 0.5% of choline chloride, and 2% of calcium dihydrogen phosphate.

[0007] In the aforementioned feed for largemouth bass added with gallnut tannic acid and ellagic acid, the feed raw materials of the feed for largemouth bass are accurately weighed according to the ratio, then uniformly mixed, and then added with distilled water for conditioning and uniformly mixed, and processed into pellet feed with a diameter of 2.5 mm by a granulator, and dried in an oven at 65°C.

[0008] Advantages of the present invention: Compared with the prior art, in the technical solution of the present invention, gallic acid (GTA) and ellagic acid (EA) are added to the feed. Gallic acid is a general term for a class of high molecular weight water-soluble polyphenolic compounds, which are widely distributed in different tissues such as leaves, roots, fruits and epidermis of plants. Gallic acid (GTA) and ellagic acid (EA) in traditional Chinese medicines such as Chinese gallnut have the effects of antibacterial and bacteriostatic, antioxidant, anti-inflammatory and astringent anti-diarrhea, and are widely used in the fields of medicine, food and leather making. During the breeding process of Micropterus salmoides, gallic acid and ellagic acid can improve the growth performance by improving the intestinal tissue structure and optimizing the intestinal flora structure. When the dosages of gallic acid (GTA) and ellagic acid (EA) are limited to 0.15% and 0.01875%, in the same group of experiments, the feed conversion ratio is the lowest and the weight gain rate is the highest. Compared with the experimental group adding only Chinese gallnut tannic acid, when the addition amount of Chinese gallnut tannic acid is the same, the feed adding Chinese gallnut tannic acid and ellagic acid has better growth performance than the feed adding only Chinese gallnut tannic acid. It well solves the problem of slow growth in the large-scale breeding of Micropterus salmoides. Description of the Drawings

[0009] Figure 1 It is a schematic diagram of an intestinal section fed with Chinese gallnut tannic acid + ellagic acid;

[0010] Figure 1 In which:

[0011] A: Early stage of group F0; B: Early stage of group F1; C: Early stage of group F2; D: Early stage of group F3; E: Early stage of group F4;

[0012] F: Middle stage of group F0; G: Middle stage of group F1; H: Middle stage of group F2; I: Middle stage of group F3; J: Middle stage of group F4;

[0013] K: Late stage of group F0; L: Late stage of group F1; M: Late stage of group F2; N: Late stage of group F3; O: Late stage of group F4;

[0014] Figure 2 It is a schematic diagram of an intestinal section fed with Chinese gallnut tannic acid;

[0015] Figure 2 In which:

[0016] A: Early stage of group F0; B: Early stage of group F1; C: Early stage of group F2; D: Early stage of group F3; E: Early stage of group F4;

[0017] F: Middle stage of group F0; G: Middle stage of group F1; H: Middle stage of group F2; I: Middle stage of group F3; J: Middle stage of group F4. Detailed Embodiments

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0019] Embodiment of the present invention: A feed for largemouth bass added with gallotannic acid and ellagic acid. In this feed for largemouth bass, calculated by weight percentage, the feed for largemouth bass contains: 50% fish meal, 28.4% soybean meal, 6.6% tapioca starch, 8% soybean oil, 0.5% compound multivitamins, 0.5% compound multiminerals, 3.33125% carboxymethyl cellulose, 0.5% choline chloride, 2% calcium dihydrogen phosphate, 0.15% gallotannic acid, and 0.01875% ellagic acid.

[0020] The feed for largemouth bass is accurately weighed according to the ratio, then evenly mixed, and then distilled water is added for conditioning and mixed evenly. It is processed into pellet feed with a diameter of 2.5 mm by a granulator and dried in an oven at 65 °C.

[0021] In order to verify the influence of the feed in the embodiment of the present invention on largemouth bass, the following experiments were specifically conducted.

[0022] The experiment took largemouth bass as the research object, and different proportions of gallotannic acid and ellagic acid were added to its feed. Through this experiment, the addition ratios of gallotannic acid and ellagic acid that can effectively improve the growth performance of largemouth bass were sought, hoping to solve the problem of slow growth in large-scale farming of largemouth bass.

[0023] We conducted two groups of comparative experiments. The first group of experiments was to add only different proportions of gallotannic acid, and the second group of experiments was to add different proportions of gallotannic acid + ellagic acid.

[0024] 1. Experimental design

[0025] 1.1 Experimental feed

[0026] For the two comparative experiments, based on the nutritional requirements of largemouth bass juveniles, a basal feed was formulated. On the basis of the basal feed, different combinations of gallotannic acid and ellagic acid with proportions of 0, 0.05% GTA + 0.00625% EA, 0.10% GTA + 0.0125% EA, 0.15% GTA + 0.01875% EA, 0.20% GTA + 0.025 EA, 0.05% GTA, 0.10% GTA, 0.15% GTA, and 0.20% GTA were used to replace an equal amount of carboxymethyl cellulose to prepare 10 isonitrogenous and isoenergetic experimental feeds. Their compositions and nutritional compositions are shown in Tables 1 and 2. The feed raw materials were accurately weighed according to the ratio, then evenly mixed, and then distilled water was added for conditioning and mixed evenly. It was processed into pellet feed with a diameter of 2.5 mm by a granulator, dried in an oven at 65 °C, and then stored in a refrigerator at 4 °C for standby.

[0027] Table 1 Composition and nutrient levels of experimental diets with different proportions of GTA (dry matter basis)

[0028]

[0029] Table 2 Composition and nutrient levels of experimental diets with different proportions of GTA + EA (dry matter basis)

[0030]

[0031] 1.2 Experimental fish and aquaculture management

[0032] In the first group of experiments, largemouth bass were temporarily cultured in a disinfected temporary culture pond and acclimated with the basal diet for 1 week. After temporary culture, 450 healthy largemouth bass with the same body size and a body weight of (10.23 ± 0.05) g were selected and randomly divided into 5 groups, with 3 replicates in each group and 30 fish in each replicate. They were stocked in circular culture tanks with a diameter of 3 m and a depth of 0.6 m, and fed experimental diets with gallotannic acid addition levels of 0 (F0 as the control group), 0.05% (F1 group), 0.10% (F2 group), 0.15% (F3 group), and 0.20 (F4 group), respectively.

[0033] In the second group of experiments, largemouth bass were temporarily cultured in a disinfected temporary culture pond and acclimated with the basal diet for 2 weeks. After temporary culture, 450 healthy largemouth bass with the same body size and a body weight of (10.23 ± 0.05) g were selected and randomly divided into 5 groups, with 3 replicates in each group and 30 fish in each replicate. They were stocked in circular culture tanks with a diameter of 3 m and a depth of 0.6 m, and fed experimental diets with 0 (F0 group), 0.05% GTA + 0.00625% EA (F1 group), 0.10% GTA + 0.0125% EA (F2 group), 0.15% GTA + 0.01875% EA (F3 group), 0.20% GTA + 0.025 EA (F4 group), respectively.

[0034] In both groups of experiments, feeding was carried out 2 times a day at 09:00 and 17:00 respectively. During the aquaculture experiment, aeration was continuously carried out for 24 h, the dissolved oxygen concentration was ≥ 6.5 mg / L, the water temperature was (20.5 ± 1.0) °C, the pH was 7.5 ± 0.2, and the ammonia nitrogen concentration was ≤ 0.3 mg / L. The aquaculture cycle was 90 d.

[0035] 1.3 Sample collection

[0036] After the aquaculture experiment ended, samples were collected. Feeding was stopped 24 h before sample collection. Three juvenile largemouth bass were randomly caught from each aquaculture tank to measure growth data such as body length and body weight. Then, the intestines of three fish were randomly taken from each tank and preserved in 4% paraformaldehyde for tissue sectioning. Another three fish from each aquaculture tank were used for the determination of whole fish nutritional components and stored in a -20 °C refrigerator for future testing.

[0037] The experimental data were statistically analyzed using SPSS software. When the one-way analysis of variance (ANOVA) reached a significant level (P < 0.05), Duncan's test was used for multiple comparisons. The data were expressed in the form of mean ± standard error.

[0038] 2. Experimental results

[0039] 2.1 Growth performance

[0040] In the first group of experiments, as shown in Table 3, the addition of gallotannic acid to the feed had no significant effect on the hepatosomatic index and survival rate of largemouth bass (P > 0.05). As the addition amount of gallotannic acid in the feed increased, the FBW, WGR, and SGR of the F2 and F3 groups were significantly higher than those of the other groups (P < 0.05), while the feed conversion ratio of the F2 and F3 groups was significantly lower than that of the other groups (P < 0.05).

[0041] In the second group of experiments, as shown in Table 4, in this experiment, the final body weight, weight gain rate, and specific growth rate showed a trend of first increasing and then decreasing, and the final body weight, weight gain rate, and specific growth rate of the F2, F3, and F4 groups were significantly higher than those of the F0 and F1 groups (P < 0.05). The feed conversion ratio of the F3 group was significantly lower than that of the other groups (P < 0.05). There were no significant changes in the hepatosomatic index and condition factor of each group (P > 0.05).

[0042] By comparing Tables 3 and 4, it can be found that in the two groups of experiments, for the same groups with similar initial body weights, the groups with the addition of gallotannic acid + ellagic acid were generally higher than those with only gallotannic acid added. This means that the growth rate of largemouth bass fed with feed containing gallotannic acid + ellagic acid was generally higher than that of those fed with feed containing only gallotannic acid.

[0043] Table 3 Effects of gallotannic acid on the growth performance of largemouth bass

[0044]

[0045] Table 4 Effects of gallotannic acid + ellagic acid on the growth performance of largemouth bass

[0046]

[0047] 2.2 Intestinal sections

[0048] It can be seen from Figure 1 Figure 1 that in the second group of experiments, compared with the control group, the number of intestinal villi in each experimental group increased significantly, and the arrangement was more compact and orderly.

[0049] It can be seen from Figure 2 Figure 2 that in the first group of experiments, the F0 group had fewer intestinal villi and a sparse arrangement. Compared with the F0 group, the intestinal villi in each experimental group increased, with a good morphology and a compact arrangement. In the foregut tissue, the crypt depths of the F1 and F2 groups were significantly lower than that of the F0 group (P<0.05).

[0050] 2.3 Body composition determination

[0051] Table 5 Effects of gallotannic acid on the body composition of Micropterus salmoides

[0052]

[0053] For data in the same row, no letter or the same letter superscript indicates no significant difference (P>0.05), and different lowercase letters indicate significant differences (P<0.05).

[0054] Table 6 Effects of gallotannic acid + ellagic acid on the body composition of Micropterus salmoides

[0055]

[0056] As can be seen from Table 5, adding gallotannic acid to the feed had no significant effect on the crude fat, moisture, crude ash, crude protein and crude fat contents of the liver of Micropterus salmoides (P>0.05), but compared with the F1 group, the crude fat content of the liver in each group decreased.

[0057] As can be seen from Table 6, the results showed that adding gallotannic acid and ellagic acid to the feed had no significant effect on the body composition of Micropterus salmoides (P>0.05).

[0058] Through the above experimental comparison, it can be found that adding 0.15% GTA + 0.01875% EA to the basic feed of Micropterus salmoides had no effect on the body composition of Micropterus salmoides, but could improve the intestinal morphology, thus effectively reducing the feed coefficient and increasing the growth performance. In the same group of experiments, its feed coefficient was the lowest and the weight gain rate was the highest. Compared with the experimental group adding only gallotannic acid, when the addition amount of gallotannic acid was the same, the feed adding gallotannic acid and ellagic acid had better growth performance than the feed adding only gallotannic acid.

Claims

1. Largemouth bass feed added with gallnut tannic acid and ellagic acid, characterized in that: In this largemouth bass feed, calculated by weight percentage, it contains 0.15% of gallnut tannic acid and 0.01875% of ellagic acid.

2. The Micropterus salmoides feed added with gallotannin and ellagic acid according to claim 1, characterized in that: This largemouth bass feed also contains 50% fish meal, 28.4% soybean meal, 6.6% tapioca starch, 8% soybean oil, 0.5% compound multivitamins, 0.5% compound multiminerals, 3.33125% carboxymethyl cellulose, 0.5% choline chloride, and 2% calcium dihydrogen phosphate.

3. The Micropterus salmoides feed added with gallotannin and ellagic acid according to claim 1, characterized in that: This largemouth bass feed accurately weighs the feed raw materials according to the ratio, then mixes them evenly, adds distilled water for conditioning, mixes evenly, and processes them into pellet feeds with a diameter of 2.5 mm using a granulator, and then dries them in an oven at 65°C.

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