Pig feed

Abstract

To provide livestock feed which contains proper fiber which can yield meat having a strong flavor.SOLUTION: A livestock feed includes sugar cane starch lees blended therein.SELECTED DRAWING: None

Description

Technical Field

[0001] It relates to livestock feed containing fibrous substances in a particularly appropriate ratio.

Background Art

[0002] Conventionally, in raising livestock, by providing compound feed made in accordance with the formulation and amount according to the feeding standards, maintenance of a healthy state and normal growth have been achieved (for example, see Patent Document 1). For example, as the formulation of pig feed, those using corn, soybean meal, and bran as the main raw materials and adding various lacking nutrients are widely used. These main raw materials are inexpensive and can meet the nutrient requirements in the main nutrient items in the standards. Among these main raw materials, bran in particular contains a large amount of fibrous substances, suppresses excessive energy intake, and prevents obesity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors have clarified through research that among the fibrous substances contained in feed, highly digestible fiber in particular is involved in improving the intestinal environment of pigs, and that highly digestible fiber promotes the growth of microorganisms in the intestine, thereby improving the flavor of meat. In particular, sweet potato starch residue has a fibrous substance content similar to that of bran, but the proportion of highly digestible fiber in the fibrous substances is higher than that of bran, and the inventors have found that the meat quality can be improved by blending sweet potato starch residue into pig feed.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to provide livestock feed containing appropriate fibrous substances capable of obtaining meat with high flavor. [Means for solving the problem]

[0006] To solve the aforementioned problems, the livestock feed of the present invention is characterized by containing sweet potato starch residue. This characteristic allows livestock to habitually consume sufficient highly digestible fiber in their feed to promote microbial growth in the large intestine, thereby producing flavorful meat.

[0007] The aforementioned sweet potato starch residue is characterized by being included in the feed at a proportion of less than 30% by weight of the total feed. This characteristic has little impact on the overall nutrient requirements of the feed.

[0008] The aforementioned sweet potato starch residue is characterized by being blended with other fibrous feed ingredients in a proportion of less than 30% by weight of the total feed. This characteristic ensures a sufficient total fiber content while also containing ample highly digestible fiber, thereby effectively promoting microbial growth in the large intestine.

[0009] It is characterized by a high proportion of highly digestible fibers in the total fiber content being 20-40% by weight. This characteristic ensures a sufficient total fiber content while also containing ample highly digestible fiber, thereby effectively promoting microbial growth in the large intestine. [Modes for carrying out the invention]

[0010] The livestock feed according to the present invention will be described below based on examples. [Examples]

[0011] The livestock feed in this embodiment is a feed containing sweet potato starch residue, and it approximates the standard nutrient requirements.

[0012] Sweet potato starch residue is a food processing by-product discharged during the sweet potato starch manufacturing process, and is the residue left after extracting starch milk from sweet potatoes. Sweet potato starch residue consists of 43.5% by weight of starch and 49.7% by weight of dietary fiber, and is also rich in pectin.

[0013] (Demonstration test) A field test was conducted to verify the usefulness of feed containing sweet potato starch residue. In the field test, a test feed containing sweet potato starch residue and a control feed without sweet potato starch residue were prepared as a comparison.

[0014] As a control feed, a feed formulated to meet the nutrient requirements of late-stage fattening pigs was used, primarily consisting of corn, soybean meal, and wheat bran. Specifically, as shown in Table 1, the feed consisted of 66.69% by weight of dried corn, 14.92% by weight of soybean meal, 0.60% by weight of tricalcium phosphate, 0.70% by weight of calcium carbonate, 0.20% by weight of salt, and 0.11% by weight of premix. The nutrient requirements for each body weight are shown in Table 2.

[0015] [Table 1]

[0016] [Table 2]

[0017] As a test feed, a feed mainly consisting of corn, soybean meal, and sweet potato starch meal was used. In other words, sweet potato starch meal was used as a substitute for wheat bran, and as shown in Table 1, the feed was formulated with dried corn at 57.99% by weight, soybean meal at 21.97% by weight, sweet potato starch meal at 19.10% by weight, tricalcium phosphate at 0.63% by weight, salt at 0.20% by weight, and premix at 0.10% by weight.

[0018] The sweet potato starch residue used was produced from sweet potatoes grown in Kagoshima Prefecture and dried for 48 hours or more using a low-temperature air dryer at 60°C before preparation. The test feed was designed such that the contents of TDN (total digestible nutrients), CP (crude protein), and OCW (total fiber) were equal to those of the control feed. When designing the feed, the values of protein, crude fat, crude fiber, crude ash, calcium, and phosphorus contents, OCW (total fiber), and Oa (highly digestible fiber) of the sweet potato starch residue were used as the pre-analyzed values. The TDN content, which is the reference total digestible nutrients, was based on the values in the Japanese Standard Feed Composition Table (2009 edition). Since the sweet potato starch residue used in the test feed had been dehydrated by lime treatment, its Ca content was high, and calcium carbonate was not added to the test feed.

[0019] Eight castrated male pigs of the LWD crossbreed were used as the experimental animals for the demonstration test. From the two litters, individuals with similar weights were selected, and four pigs were placed in each of the control group (59.4 ± 7.21 kg) and the test group (58.8 ± 12.2 kg) to make the average weights equal. The test pigs were individually housed, fed ad libitum, and provided with free drinking water in a pigsty with a concrete floor covered with sawdust. The test pigs were given a one-week acclimation period starting from the time when their average weight reached approximately 60 kg, and then the fattening test was initiated. The feed supply time was set at once a day (9:00 am) for both the control group and the test group. The supply amount was increased according to the feed intake. The test pigs were shipped at a weight of approximately 110 kg.

[0020] The physicochemical analysis of the meat after shipment was conducted according to the Manual of Physicochemical Analysis and Sensory Evaluation of Meat (Livestock Improvement Center, Incorporated Administrative Agency, 2010). The fatty acid composition and fat melting point of the subcutaneous inner layer fat were measured. The fatty acid composition and fat melting point of the subcutaneous inner layer fat were measured using the longissimus dorsi muscle between the 9th - 10th thoracic vertebrae and the 13th - 14th thoracic vertebrae of the right semi-round side of the carcass. For the fatty acid composition of the subcutaneous inner layer fat, the extracted fat was treated with a fatty acid methyl esterification kit and measured using gas chromatography. The fat melting point was measured by the rising melting point method.

[0021] In addition, indole and skatole in adipose tissue were measured using subcutaneous inner layer fat between the 9th - 10th thoracic vertebrae and the 13th - 14th thoracic vertebrae of the right semi - round branch meat. 1.0 g of minced adipose tissue was precisely weighed into a homogenizer, and then 3 ml of internal standard solution was added. The internal standard solution was prepared by diluting 3.3 g / L of 2 - methylindole 100 - fold with methanol. The homogenizer containing the ground sample was centrifuged at 238×g for 5 minutes at 4°C, and the supernatant was filtered through a 0.45 μm filter. Then it was stored at - 25°C overnight and further centrifuged at 8000×g for 10 minutes at 4°C. The obtained supernatant was used for analysis.

[0022] (Results and Discussion) Table 3 shows the general components, OCW, and Oa content of the test feed in weight percentage. Comparing the test feed with the control feed, the Oa content is higher (about 60 weight percentage points more), and the proportion of highly digestible fiber Oa in the total fiber OCW is also higher, about 70 weight percentage points. Specifically, the Oa content of the test feed is 5.4 weight percentage, OCW is 16.7 weight percentage, and the proportion of highly digestible fiber Oa in the total fiber OCW is 32.2 weight percentage.

[0023] [Table 3]

[0024] Table 4 shows the fatty acid composition of subcutaneous inner layer fat. In the test group, it was found that the proportion of 18:1 (oleic acid) in the fatty acid composition of subcutaneous inner layer fat tended to increase.

[0025] [Table 4]

[0026] Table 5 shows indole and skatole in the subcutaneous inner layer of fat. No significant difference was observed in the skatole content between the two groups. Although no significant difference was observed in the indole content either, since the P - value is 0.14, it is considered that there is a certain effect on its reduction.

[0027] [Table 5]

[0028] It should be noted that skatole content of 0.10 μg / g or higher may cause an unpleasant odor, and it has been reported that some consumers can distinguish even 0.05 μg / g levels. Therefore, it can be said that the skatole content in both groups was not at a concentration that would produce an unpleasant odor.

[0029] (Measurement of total nitrogen (TN) content and volatile basic nitrogen (VBN) content in feces) Furthermore, to investigate the effects of non-starch polysaccharide feeding on intestinal fermentation, the dry matter content, total nitrogen (TN) content, and volatile basic nitrogen (VBN) content of feces were measured. Fecal samples were collected directly from the pigs' anuses within one week prior to shipment and frozen until analysis. Fecal samples air-dried at 60°C were subjected to measurement of moisture content and nitrogen content. Fecal nitrogen content was measured using the oxygen circulation combustion method with a Shimadzu NC-220F.

[0030] VBN is mostly ammonia and is known to correlate with indole and skatole concentrations in feces. In the validation study, TN and VBN content were measured and evaluated as an effect on fiber fermentation in the intestines. Furthermore, the difference between TN and VBN was used as an indicator of the bacterial protein content synthesized by intestinal fermentation.

[0031] Table 6 shows the effects of feeding sweet potato starch residue on the nitrogen content and VBN (volatile basic nitrogen) in the feces of castrated boars. No difference was observed in the VBN content in the feces between the two groups. In the experimental group, TN (total nitrogen) and TN-VBN in the feces increased significantly. Sweet potato starch residue contains more non-starch polysaccharides than wheat bran. Similar to sweet potato starch residue, studies in which fattening pigs were fed a low-CP feed containing 10% by weight of apple juice pulp, beet pulp, and sweet potato shochu lees, which also contain more non-starch polysaccharides than wheat bran, have reported an increase in nitrogen excretion in the feces, which is consistent with the results of this study.

[0032] [Table 6]

[0033] Non-starch polysaccharides such as pectin are fermentable carbohydrates that are not broken down in the small intestine but enter the large intestine, where they are broken down by intestinal bacteria. Feeding non-starch polysaccharides activates the microbiome in the large intestine, promoting microbial protein synthesis. In this process, urea secreted from the blood into the large intestine is used for protein synthesis, which is known to increase nitrogen excreted in feces and decrease nitrogen excreted in urine.

[0034] In addition, the higher Oa content in the test feed compared to the control feed significantly contributed to the promotion of intestinal fermentation, which is thought to have improved the gut microbiota. Furthermore, since the total amount of fiber (OCW) in the test feed was formulated to be similar to that of the control feed, there was no decrease in dry matter intake due to an excessive amount of OCW.

[0035] Furthermore, the increase in TN while the VBN level in the feces remained unchanged suggests that sweet potato starch residue, which is rich in non-starch polysaccharides such as pectin, promoted the growth of microorganisms in the intestines of fattening pigs. The reduction in indole content in subcutaneous endothelial fat in this study is thought to be related to the fact that sweet potato starch residue promoted the growth of intestinal microorganisms, and that nitrogen compounds in the intestines were utilized for microbial protein synthesis.

[0036] (Sensory evaluation) Consumer-type sensory evaluation was conducted in accordance with the guidelines for sensory evaluation of meat and the manual for physicochemical analysis and sensory evaluation of meat. For sensory evaluation, the longissimus thoracis muscle from the 10th to 15th thoracic vertebrae of the left half-carcass and the longissimus thoracis muscle from the 5th to 9th and 14th to 15th thoracic vertebrae of the right half-carcass were used. Each sample was stored at -25°C until sensory evaluation and thawed at 5°C for 24 hours. Then, the longissimus thoracis muscle was sliced ​​to a thickness of 0.5 cm and a width of 2.5 cm, trimmed to 1 cm of fat and 4 cm of lean meat, and used for evaluation.

[0037] The cooking method used was the grilling method, where the meat was exposed to 0.5 wt% saline solution and heated at 230°C for 30 seconds on each side. A two-point preference method was used for evaluation, and random numbers were assigned to the samples from each group. When providing samples to the panel, the group from which the food was given was not disclosed. The panel consisted of 41 people in total: 13 men and 28 women aged 10 to 50.

[0038] The questionnaire consisted of seven items: "Which did you find appealing when smelling it before eating?", "Which did you find tender when chewing it thoroughly?", "Which did you find juicy?", "Which did you find to have a strong umami flavor?", "Which did you find to have easily melting fat?", "Which did you find delicious overall?", and "Which did you want to purchase?". For each question, the panelists were asked to select one option from either "a random number for the control group" or "a random number for the test group".

[0039] Table 7 shows the sensory evaluation. From these results, a significantly larger number of panelists chose the pork from the test group compared to the control group for the four questions: "Which one smelled good before eating?", "Which one had a strong umami flavor?", "Which one was generally delicious?", and "Which one would you like to purchase?".

[0040] [Table 7]

[0041] This suggests that feeding sweet potato starch meal to pigs makes it possible to produce pork with a good aroma that consumers prefer. The question that showed the biggest difference was "Which pork did you find to have a good aroma before eating it?" Regarding the correlation between fatty acid composition and the "aroma" of pork, a significant positive correlation was found for palmitic acid, palmitoleic acid, and oleic acid. It is thought that the influence of the high oleic acid content and low indole content in the pork of the test group on the preference for "aroma" is related to the fact that the pork of the test group tended to have a high oleic acid content and a low indole content.

[0042] Furthermore, as shown in Figure 6, the feeding of sweet potato starch meal significantly increased the nitrogen content in the feces, suggesting an increase in the synthesis of bacterial proteins in the intestines. This indicates that the gut microbiota may also be changing, potentially affecting the aroma of the pork through changes in intestinal metabolites. In addition, as shown in Table 3, the test feed had a high content of highly digestible fiber Oa, which likely improved the gut microbiota of the pigs in the test group and reduced putrefactive substances in the large intestine. The high content of highly digestible fiber Oa is also thought to have an effect on the desirable "aroma" of the pork.

[0043] Thus, feeding sweet potato starch meal to fattening pigs tended to increase the oleic acid content in the subcutaneous inner layer of fat. Furthermore, due to its high content of highly digestible fiber Oa, it promoted fiber fermentation in the intestines of fattening pigs, significantly increasing the nitrogen content in feces and showing a certain effect in reducing the indole content in the subcutaneous inner layer of fat. In addition, in sensory evaluations targeting general consumers, a significantly larger number of panelists chose pork fed with sweet potato starch meal. These results suggest that sweet potato starch meal is a feed ingredient that can produce pork with good taste, particularly in terms of aroma, which is preferred by consumers.

[0044] Sweet potato starch residue is a food processing by-product produced during the manufacturing process of sweet potato starch. Approximately 20,000 tons are produced annually, and it has a low unit price. Furthermore, it is difficult to say that appropriate uses have been established, and the fact that efforts are being made to find effective uses for it means that the hurdles to procuring it in large quantities are low. In other words, since sweet potato starch residue is produced as a by-product of processing, just like wheat bran, it can be used as a substitute for wheat bran. Moreover, it is possible to produce pork with a better taste that consumers prefer compared to control feed that contains wheat bran instead of sweet potato starch residue.

[0045] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0046] For example, the test feed in the above example is formulated with 57.99% by weight of dried corn, 21.97% by weight of soybean meal, 19.10% by weight of sweet potato starch meal, 0.63% by weight of tricalcium phosphate, 0.20% by weight of salt, and 0.11% by weight of premix. However, this is just one example, and the selection of raw materials other than sweet potato starch meal and their ratios are not limited as long as the standards for nutrient requirements are met.

[0047] For example, it is preferable that the corn content is adjusted to between 50-65% by weight and soybean meal to between 15-25% by weight to meet the nutrient requirements, and that the Oa content is 3.5-10% by weight of the total feed, the OCW content is 10-20% by weight, and the proportion of highly digestible fiber Oa in the total OCW is 20-40% by weight, as this tends to be strongly preferred by consumers in sensory evaluations. Similarly, it is preferable that major grains other than bran and sweet potato starch meal, such as corn and soybean meal, be included in the total feed at 60-85% by weight. Furthermore, the proportion of corn can be reduced to about 20% by weight by including barley or milo. Moreover, in feeds where the amino acid balance is adjusted with feed amino acids to reduce protein content, the soybean meal content may be as low as 5% by weight.

[0048] Furthermore, while the proportion of sweet potato starch meal in the total feed is not limited to 19.10% by weight, exceeding 25% by weight can result in excessive fiber, causing the levels of some nutrients to fall below or above the nutrient requirements, potentially leading to adverse effects on fattening. Therefore, a percentage of less than 25% by weight is preferable.

[0049] Furthermore, in the test feed described above, the formula was modified so that the bran in the control feed was completely replaced with sweet potato starch meal in order to demonstrate the effect of sweet potato starch meal. However, the formula is not limited to this, and sweet potato starch meal may be used in combination with fibrous feed ingredients that have a relatively high fiber content, such as bran.

[0050] Furthermore, when using fibrous feed ingredients with a relatively high fiber content, such as wheat bran, in combination with sweet potato starch meal, it is preferable that the total amount of these ingredients is less than 30% by weight of the total sweet potato starch meal in the feed.

Claims

1. A pig feed that does not contain bran, and is characterized by containing corn, soybean meal, and sweet potato starch meal, wherein the sweet potato starch meal is included in a proportion of less than 30% by weight of the total feed, and the proportion of highly digestible fiber in the total fiber is 20 to 40% by weight.

2. The pig feed according to Claim 1, wherein the corn, soybean meal, and sweet potato starch meal are blended in a proportion of 90% by weight or more of the total feed.

3. The pig feed according to claim 1 or 2, characterized in that the corn and soybean meal are blended in a proportion of 60 to 85% by weight of the total feed, and the sweet potato starch meal is blended in a proportion of less than 25% by weight of the total feed.

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