Formula feed that improves back fat thickness in pork pigs

Abstract

To provide a mixed feed capable of improving backfat thickness in pork pigs to a commercially valuable level, while preserving their high weight gain efficiency.SOLUTION: A mixed feed for pork pigs contains, in its total weight, 11.5 wt.% or less of crude protein, 3.0 wt.% or less of crude fat, 79.0 wt.% or more of total digestible nutrients, 2,650 kcal or more of net energy per kg of feed, and 0.60-0.90 wt.% of lysine.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a compound feed for fattening pork that improves the back fat thickness of pork. [Background technology]

[0002] Genetically improved breeding pigs (hereafter referred to as "prolific sows") are increasingly being introduced to pig farms in Japan. Compared to traditional domestic breeding pigs, prolific sows not only produce significantly more piglets per farrowing, but also significantly improve the piglets' own weight gain rates. However, piglets from prolific sows have significantly thinner backfat at shipping than traditional domestic pigs. This creates a major problem: a high proportion of pigs are judged "thin fat" during carcass grading by the Japan Meat Grading Association, resulting in a lower grade and lower carcass prices. If the backfat thickness of prolific sows can be improved while maintaining high weight gain using compound feed, it would significantly contribute to improving the productivity of pig farmers.

[0003] Patent Document 1 describes a pig feed additive containing 50% by weight or more of glycerides with a saturated fatty acid composition of C14-16:0. It is said that adding the additive to a 0.5% by weight compound feed improves body weight gain and feed conversion ratio, and increases backfat thickness. However, this invention targets piglets with thick backfat, with an average backfat thickness of 2.5 cm or more, rather than thin-fat piglets with a backfat thickness of 1.2 cm or less.

[0004] Non-Patent Document 1 found that adding rice and non-standard soybeans to commercially available feed increased backfat thickness, but worsening weight gain was observed in Test Group 3, where backfat thickness increased compared to the control group fed only commercial feed, and the author only states that rice and non-standard soybeans can be used without affecting weight gain or meat quality up to the proportions in Test Group 2, where there was no difference in backfat thickness.In Non-Patent Document 2, palm oil was added to the feed at a maximum of 7% by weight, increasing the energy content (total amount of digestible nutrients) in the feed by approximately 10% by weight compared to the control group, and although this resulted in improved weight gain, no increase in backfat thickness was observed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-6584 [Non-patent literature]

[0006] [Non-Patent Document 1] The effect of feeding feed rice and non-standard soybeans to fattening pigs on growth and meat quality, Hoshikawa et al., Yamagata Prefecture Agricultural Research Report No. 12, pp. 45-52, 2020. [Non-patent document 2] The effect of adding palm oil to a mixture of feed rice, barley, and tea processing residues on the feeding performance and meat quality of pigs in the late summer fattening stage, Wakiya et al., Journal of the Japanese Society of Swine Science, Vol. 51, pp. 207-212, 2014. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to solve the above-mentioned problems of the conventional technology and to provide a compound feed that can increase the back fat thickness, which has high commercial value, while maintaining the high weight gain performance of fattening pigs.

[0008] As mentioned above, piglets from prolific sows have significantly thinner backfat thickness at the time of shipping than traditional domestic pigs, and a large proportion of pigs are judged as "thin fat" during the carcass grading process by the Japan Meat Grading Association, resulting in a lower grade and a drop in carcass price, which is a major problem. In addition, as shown in Non-Patent Document 1, attempts to increase backfat thickness through feed are accompanied by a decrease in weight gain, which also poses a problem of reduced productivity. Furthermore, piglets from prolific sows respond poorly to feed to increase backfat thickness, and simply increasing the energy content of the feed has not solved the problem of thin fat. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have discovered that by keeping the crude fat content of compound feed for fattening swine low and increasing the energy content by using grains, using net energy as an indicator of energy content, and also keeping the crude protein content of the feed low and maintaining a constant level of amino acid content by using crystalline amino acids, it is possible to increase backfat thickness while maintaining weight gain performance even in piglets from prolific sows, and to reduce the decrease in grading grade due to thin fat, and have completed the present invention.

[0010] In other words, by not only increasing the energy content of the feed but also decreasing its crude protein content, it became possible to improve pigs' feed intake and dramatically increase their daily energy intake. In doing so, by using net energy rather than the conventional total digestible nutrient content as the energy content of the feed, it became possible to more accurately evaluate and control the energy content in the feed and the pigs' daily energy intake. In addition, it was discovered that decreasing the crude protein content of the feed not only contributes to an increase in net energy in the feed, but is also effective in increasing feed intake. A decrease in crude protein also leads to a decrease in pig growth performance, but by using crystalline amino acids to maintain a constant level of amino acid content in the feed, it is possible to prevent a decrease in growth performance.Even in piglets from prolific sows, where it was difficult to increase backfat thickness, it was possible to increase backfat thickness while maintaining growth performance, thereby improving quality at the time of shipment.

[0011] That is, the embodiments of the present invention are as follows. [1] A compound feed for fattening pork intended for thin-fat pigs with a back fat thickness of 1.2 cm or less, containing a crude protein content of 11.5% by weight or less, a crude fat content of 3.0% by weight or less, a total digestible nutrient content of 79.0% by weight or more, a net energy content of 2,650 kcal or more per kg of feed, and lysine in the range of 0.60 to 0.90% by weight in the total feed. [2] Formula feed for fattening pork pigs as described in [1], in which the total proportion of grains in the total feed is 80% by weight or more. [Effects of the Invention]

[0012] The compound feed for fattening swine of the present invention can increase backfat thickness and reduce the proportion of pigs that are judged to be thin-fat at the time of shipping. Although the feed has a low crude protein content, it retains sufficient amino acids, making it possible to maintain previous weight gain figures. As a result, the grade and price of carcasses can be improved without reducing pig productivity, contributing to improved profits for pig farms. DETAILED DESCRIPTION OF THE INVENTION

[0013] The compound feed for fattening swine of the present invention is a feed containing 80% by weight or more of grains such as corn, polished rice, brown rice, wheat, wheat flour, barley, rye, milo, breadcrumbs, sweet potato, etc. Other grain ingredients may or may not be added.

[0014] The crude protein content of the feed is 11.5% by weight or less, preferably 11.0% by weight or less, more preferably 10.5% by weight or less, even more preferably 10.0% by weight or less, and most preferably 9.5% by weight or less. The protein source, such as vegetable oil cakes, animal feed, or cornstarch, is not particularly limited, and raw materials commonly used in compound feed for fattening swine may be used. Specific examples include, but are not limited to, soybean oil cake, rapeseed oil cake, corn gluten meal, corn jam meal, fish meal, pork / chicken meal, chicken meal, pig blood meal, and corn distiller's grain solubles.

[0015] The lysine content in the feed is 0.60 to 0.90% by weight, preferably 0.65 to 0.80% by weight. If the lysine content exceeds 0.90% by weight, fat adhesion is suppressed, and the effects of the present invention cannot be obtained. The lysine used here is not particularly limited, and raw materials commonly used in compound feed for fattening swine may be used. When crystalline lysine is used, either L-lysine hydrochloride or L-lysine sulfate may be used, as long as it is approved as a feed additive. The lysine in the present invention is a value that includes not only the crystalline lysine in the feed but also all lysine contained in other raw materials.

[0016] The crude fat content in the feed is 3.0% by weight or less, preferably 2.5% by weight or less, more preferably 2% by weight or less, even more preferably 1.5% by weight or less, and most preferably 1.0% by weight or less. Although fats and oils may be added, it is desirable to add no fats and oils to achieve a grain content of 80% by weight or more and a crude fat content of 3.0% by weight or less. The crude fat content in the present invention is a value that includes not only fats and oils in the feed but also all fats contained in other raw materials.

[0017] The energy content of the feed is 79.0% by weight or more of the total digestible nutrients, preferably 80.0% by weight or more, more preferably 81.0% by weight or more, and most preferably 82.0% by weight or more. The total digestible nutrients is the value calculated by adding up the digestible protein, digestible carbohydrates, and digestible crude fat for each ingredient used in the feed x 2.25, and the total digestible nutrients in the feed is this total value.

[0018] The energy content of the feed is 2,650 kcal or more per kg of feed in net energy terms, and may be, for example, 2,700 kcal or more, 2,750 kcal or more, or 2,800 kcal or more. Net energy refers to the energy used for body maintenance and growth, obtained by subtracting the energy excreted in feces, urine, and heat production from the total energy contained in the feed ingredients (the energy generated when burned). The net energy of each feed ingredient in the present invention is based on the value for NE growing pig (kcal) in the INRAE-CIRAD-AFZ Feed tables provided by INRA in France, and the net energy in the feed is the total value.

[0019] The breed of pig is not particularly limited, and includes Landrace, Large Yorkshire, Duroc, Middle Yorkshire, Berkshire, and crossbreeds thereof. Particularly preferred examples include meat pigs produced from high-performing sows (prolific sows) recently introduced from overseas.

[0020] The feed of the present invention is fed during the fattening period of pork pigs (from when the body weight is approximately 70 kg until shipping). [Example]

[0021] The effects of the present invention will be shown below with reference to examples, but the present invention is not limited to these.

[0022] Demonstration experiment 1 (1) Test Contents The growth and shipping performance of piglets born to prolific sows imported from overseas was examined. A commercially available compound feed for fattening swine was used, and the animals were given free access to it. A total of 63 pigs were used in the test, with 12 replicates (4-6 pigs per replicate). The growth performance of piglets from a body weight of approximately 70 kg to 115 kg and the carcass grading specifications issued at the time of shipping were examined. In addition, even if the back fat thickness is 1.2 cm or more, the carcass grading may be downgraded as it is judged to have a "thin belly," and even if the back fat thickness is 1.2 cm or less, if there is a downgrading factor of "heavy weight," the "thin back" may not be listed in the carcass grading specification, so the number of downgraded heads and the number of head with a back fat thickness of 1.2 cm or less do not necessarily match.

[0023] (2) Test results The raw material composition and nutritional value of the test diets are shown in Tables 1 and 2. The test results are shown in Tables 3 and 4. Growth performance during the test period was 1,064g / day gain, 3,087g / day feed intake, and a feed conversion ratio of 2.89. Furthermore, carcass grading specifications issued at the time of shipment showed that the overall average backfat thickness was 1.32cm, with 1.41cm for castrated males and 1.27cm for females. Approximately half of the 63 piglets (29 pigs) were downgraded due to thin fat (thin back and thin belly). Thirty of the 63 piglets had backfat thicknesses of 1.2cm or less, below the "high" grade range. This study confirmed that piglets born to prolific sows have high weight gain, but low backfat thickness and low carcass grade due to thin fat are a major problem. In addition, since slight differences were observed in the average back fat thickness between castrated males and females, in the following demonstration experiments, the ratio of castrated males to females in the test and control groups was made as uniform as possible.

[0024] [Table 1]

[0025] [Table 2]

[0026] [Table 3]

[0027] [Table 4]

[0028] Demonstration experiment 2 (1) Test Contents In contrast to the control group, which was fed a diet similar to a commercially available compound feed for fattening swine, the test group was fed a diet with roughly the same net energy, crude protein, and lysine contents, a crude fat content of 3% or less by weight, and a grain content of 80% or more by weight. Feed was available ad libitum. A total of 24 piglets from prolific sows were used in the study, with 12 piglets divided into two groups of six each. Growth performance from body weights of approximately 65kg to 110kg was compared, as well as the number of pigs judged to be backfat thick and thin-fat on the carcass grading specifications issued at the time of shipment.

[0029] (2) Test results The raw material composition and nutritional value of the test diets are shown in Tables 5 and 6. The test results are shown in Tables 7 and 8. During the test period, there was almost no difference in growth performance between the test group and the control group in terms of weight gain, feed intake, and daily net energy intake. Furthermore, a comparison was made of the number of animals with backfat thickness and lean fat determined in the carcass grading specifications for 9 of the 12 animals in each group. The test group had slightly lower backfat thickness and a higher number of animals determined to be lean. These results suggest that simply increasing the grain content of the diet to 80% by weight or more and the crude fat content to 3% by weight or less will be insufficient to improve backfat thickness or lean fat percentage.

[0030] [Table 5]

[0031] [Table 6]

[0032] [Table 7]

[0033] [Table 8]

[0034] Demonstration experiment 3 (1) Test Contents The control group received a swine fattening formula feed primarily composed of corn and soybean oil meal, while the test group received the same diet, but with a crude protein content 3% lower than the control group (11.5% by weight or less) and lysine supplemented with crystalline amino acids. The net energy content of the diet was slightly higher in the test group. Feed was available ad libitum. A total of 32 piglets from prolific sows were used in the study, with 16 piglets divided into three groups of 5-6 piglets each. Growth performance from weights of approximately 70 kg to 115 kg (until shipment) was compared with the values ​​on the carcass grading sheet issued at shipment. Growth performance from weights of approximately 70 kg to 115 kg was compared with the backfat thickness and number of pigs with thin fat determined on the carcass grading sheet issued at shipment.

[0035] (2) Test results The raw material composition and nutritional value of the test diets are shown in Tables 9 and 10. The test results are shown in Tables 11 and 12. Growth performance during the test period showed higher body weight gain, feed intake, and daily net energy intake in the test group compared to the control group. Furthermore, the backfat thickness and lean fat percentage in the carcass grading specifications at the time of shipping showed slightly higher backfat thickness in the test group. However, the proportion of animals rated as lean fat was higher in the test group. These results suggest that reducing the crude protein content in the diet increases feed intake, which in turn increases body weight gain and daily net energy intake, potentially improving backfat thickness, although not enough to affect the lean fat rating.

[0036] [Table 9]

[0037] [Table 10]

[0038] [Table 11]

[0039] [Table 12]

[0040] Demonstration experiment 4 (1) Test Contents A total of 18 piglets from prolific sows were fed a diet that contained over 90% grain by weight and had significantly reduced crude protein and lysine compared to commercially available compound feed for fattening swine, to see if it would improve backfat thickness and the number of pigs judged to be thin. The test was conducted twice, with 7 and 11 pigs, and the growth performance from a weight of approximately 70 kg and the carcass grading statement issued by the shipping destination when the pigs were shipped at an average weight of around 115 kg were checked.

[0041] (2) Test results The raw material composition and nutritional value of the test feed are shown in Tables 13 and 14. The test results are shown in Tables 15 and 16. Weight gain during the test period was lower than in Demonstration Test 3, confirming that reducing lysine to the level of this test would result in a decline in weight gain. Furthermore, the animals were shipped at an average weight of approximately 115 kg. The backfat thickness and grading criteria in the issued carcass grading specifications showed an average backfat thickness of 1.32 cm, with half of the animals (9 animals) being rated as thin-fat. These results confirm that reducing lysine while simultaneously reducing crude protein in the feed would only worsen weight gain and would not lead to improvements in backfat thickness or carcass grade.

[0042] [Table 13]

[0043] [Table 14]

[0044] [Table 15]

[0045] [Table 16]

[0046] Demonstration experiment 5 (1) Test Contents In contrast to the control group, which received a swine fattening formula feed primarily composed of corn and soybean oil meal, the test group received the same diet, with grain content of 80% by weight or more, crude fat content of 3% by weight or less, total digestible nutrients of 79.0% by weight or more, net energy content of 2,650 kcal / kg or more, crude protein content of 11.5% by weight or less, and lysine supplemented with crystalline amino acids. Feed was available ad libitum. A total of 26 piglets from prolific sows were used in the study, with 13 piglets divided into two groups of 6-7 pigs each. Growth performance from a body weight of approximately 70 kg was compared with the number of pigs with backfat thickness and thin fat determined on the carcass grading specifications issued at the time of shipment.

[0047] (2) Test results The raw material composition and nutritional value of the test diets are shown in Tables 17 and 18. The test results are shown in Tables 19 and 20. During the test period, the test group showed slightly higher body weight gain and higher feed intake than the control group. As a result, the test group showed significantly higher net daily energy intake. Furthermore, the backfat thickness reported on the carcass grading sheet issued at the time of shipment was approximately 0.5 cm higher on average in the test group than in the control group, a statistically significant difference. Furthermore, no pigs in the test group were judged to be too thin. These results confirm that the test diet conditions can improve backfat thickness while maintaining body weight gain, thereby reducing the risk of carcass grade degradation due to thin fat, even in pigs produced by prolific sows with high body weight gain and thin backfat.

[0048] [Table 17]

[0049] [Table 18]

[0050] [Table 19]

[0051] [Table 20]

[0052] Demonstration experiment 6 (1) Test Contents In Demonstration Experiment 5, it was confirmed that by feeding piglets from prolific sows a compound feed for fattening pork with a diet containing 80% by weight or more of grain, a crude fat content of 3% by weight or less, a total digestible nutrient content of 79.0% by weight or more, a net energy content of 2,650 kcal / kg or more, and a crude protein content of 11.5% by weight or less, it was possible to improve backfat thickness while maintaining weight gain and reduce the decline in carcass grade due to thin fat. In additional tests, for the purpose of confirming reproducibility, it was confirmed whether the same results as in Demonstration Experiment 5 could be obtained if the formulation design was within the scope of the claims. The negative control group was fed a standard swine fattening formula feed primarily composed of corn and soybean meal, while the positive control and test groups were fed a swine fattening formula feed that met the following requirements: grain content of 80% by weight or more, crude fat content of 3% by weight or less, total digestible nutrients of 79.0% by weight or more, net energy content of 2,650 kcal / kg or more, and crude protein content of 11.5% by weight or less. A total of 69 piglets from prolific sows were used in the test, with 19-20 piglets divided into three groups of 6-7 piglets each. Growth performance from a body weight of approximately 70 kg was compared with the number of pigs with backfat thickness and thin fat determined on the carcass grading specifications issued at the time of shipment. (2) Test results The raw material composition and nutritional value of the test diets are shown in Tables 1 and 2. The test results are shown in Tables 3 and 4. During the test period, the positive control and test groups demonstrated higher body weight gain and feed intake than the negative control groups. As a result, the positive control and test groups demonstrated significantly higher daily net energy intake. Furthermore, backfat thickness, as measured by the carcass grading specifications issued at the time of shipment, was approximately 0.24–0.28 cm higher on average in the positive control and test groups compared with the negative control groups. Statistically significant differences were also confirmed between the negative control and positive control groups and between the negative control and test groups. Furthermore, fewer pigs in the positive control and test groups were judged to be low in fat compared with the negative control group. These results confirm that the positive control and test groups' dietary conditions can improve backfat thickness while maintaining body weight gain, even in pigs produced by prolific sows with high body weight gain and low backfat, and reduce the risk of carcass grade degradation due to low fat. This demonstrates the reproducibility of Experiment 5.

[0053] [Table 21]

[0054] [Table 22]

[0055] [Table 23]

[0056] [Table 24]

[0057] <Summary> By feeding pigs a diet with the following characteristics during the meat pig stage, it is possible to increase backfat thickness while maintaining weight gain, and reduce the decline in carcass grade due to thin fat. The proportion of grain ingredients in the compound feed must be 80% by weight or more. The crude fat content of the compound feed must be 3% by weight or less, the total digestible nutrients must be 79.0% by weight or more, and the net energy content must be 2,650 kcal / kg or more. The crude protein content of the compound feed must be 11.5% by weight or less, and the lysine content must be 0.60-0.90% by weight.

Claims

1. A compound feed for fattening pork intended for thin-fat pigs with a back fat thickness of 1.2 cm or less, containing a crude protein content of 11.5% by weight or less, a crude fat content of 3.0% by weight or less, a total digestible nutrient content of 79.0% by weight or more, a net energy content of 2,650 kcal or more per kg of feed, and lysine in the range of 0.60 to 0.90% by weight in the total feed.

2. 2. The compound feed for fattening swine according to claim 1, wherein the total proportion of grains in the total feed is 80% by weight or more.

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