Nutritional Value and Utilization Methods of Apple Pomace Feed

Nutritional Value and Processing Utilization of Apple Pomace FeedHe KeyongXue Quanhong, Lai Hangxian, Xin Jiankang(Northwest A&F University) China is one of the countries with the largest apple production in the world, of which about 20% is used for juice processing, producing about 1 million t of apple pomace annually. Apple pomace consists of peel, core and residual flesh, and contains various nutrients such as soluble sugars, vitamins, minerals and cellulose, making it a good succulent feed resource. Foreign countries have achieved remarkable economic benefits from using pomace as feed. For example, the United States, Canada and other countries have included apple pomace, grape pomace and citrus pomace as standard feed ingredients for pigs, chickens and cattle in their nationally issued feed composition tables. However, pomace in China has not yet been well utilized. At present, apart from a small amount of apple pomace being used as feed, the vast majority is discarded as waste. Since apple pomace has a moisture content as high as over 70%-80% and is rich in soluble nutrients, it creates suitable conditions for microbial growth and reproduction, so discarded apple pomace is highly prone to spoilage and foul odor. This not only causes a waste of resources but also pollutes the environment. Therefore, it is very necessary to research and develop the nutritional value and processing utilization of apple pomace feed, so as to turn waste into treasure and also resolve the contradiction of humans and livestock competing for grain.

1 Nutritional Composition of Apple Pomace and Feeding of Fresh Pomace
In apple pomace, peel and flesh account for 96.2%, seeds account for 3.1%, and stems account for 0.7%. Its nutritional composition and nutritional value are shown in Table 1.
Table 1 Nutritional composition and nutritional value of apple pomace Name
Dry matter
(％)
Crude protein
(％)
Crude fiber
(％)
Crude fat
(％)
Nitrogen-free extract (%)
Crude ash
(％)
Calcium
(％)
Phosphorus
(％)
Digestible energy (cattle) (MJ/kg)
Metabolizable energy (cattle) (MJ/kg)
Wet pomace
20.2
1.1
3.4
1.2
13.7
0.8
0.02
0.02
2.814
2.310
Dry pomace
89.0
4.4
14.8
4.8
62.8
2.3
0.11
0.10
14.424
9.366
Silage
21.4
1.7
4.4
1.3
12.9
1.1
0.02
0.02
2.94
2.394

As seen from Table 1, the crude protein content of apple pomace is relatively low, while the crude fat and nitrogen-free extract contents are relatively high. The metabolizable energy (cattle) value of dry pomace is close to that of corn (10.668 MJ/kg) and wheat bran (9.534 MJ/kg), and the metabolizable energy (cattle) values of fresh pomace and silage are close to that of corn silage (2.478 MJ/kg). In addition, it also contains relatively abundant macro-minerals and trace elements such as calcium, phosphorus, potassium, iron, manganese and sulfur, among which the iron content of dry pomace is 4.9 times that of corn; the contents of lysine, methionine and arginine are 1.7 times, 1.2 times and 2.75 times that of corn respectively, vitamin B2 is 3.5 times that of corn, and total sugars account for more than 15% of the nitrogen-free extract.
The pH of fresh apple pomace is 3.5-4.8, with relatively high acidity, so palatability is poor at the beginning of feeding. Before feeding fresh pomace, it is best to neutralize it with 0.5%-1.0% edible alkali, and the feeding amount should not be too large. It is appropriate to account for 1/3 of the daily ration of cattle, sheep and finishing pigs, and it is better to mix it with mixed (compound) feed for feeding. According to the experiment by Zhang Ling, Wang Cong, Huang Yingxiang et al. (2002), adding 10% fresh apple pomace to the diet for meat pigs had no adverse effect on the feed intake, daily weight gain and feed utilization of finishing pigs, and reduced feeding costs and improved economic benefits; in the diet of lactating cows, using 2 kg of mixed apple pomace to replace 1 kg of mixed concentrate, after a 30 d feeding experiment, the test group produced 19.17 kg of milk per day, while the control group produced 17.61 kg. The test group increased milk production by 8.86% compared with the control group, a significant difference (p<0.05); the milk-to-feed ratio of the test group was 2.65:1, and that of the control group was 2.16:1. For every 1 kg of feed consumed, the test group produced 0.49 kg more milk than the control group, increasing feed returns by 22.68%, a significant difference (p<0.05). Fresh apple pomace at 15% can also be used to replace concentrate for feeding beef cattle.

2 Processing and Feeding of Apple Pomace
Because fresh apple pomace has high moisture and high acidity, its proportion in the diet should not be large when fed fresh, and it is not easy to store; at the same time, pomace production is obviously seasonal. To make full use of the feed resource of pomace, relying only on feeding fresh pomace is very limited in its utilization, so processing treatment is also necessary. Although it is still at the research and development stage, some good results and benefits have already been achieved.
2.1 Silage
Silage can reduce some problems that cannot be overcome in the feeding of fresh apple pomace. The silage method for apple pomace is the same as that for other feeds, but because of its high moisture content, its moisture must be reduced when ensiled alone. It can also be mixed and ensiled with corn (with or without cobs), wild green grass, bran and chopped hay. The proportion should be calculated according to the moisture content of the raw materials used so as to be suitable for silage. However, the pomace must be fresh, pollution-free pomace processed within 1-2 d (other raw materials for mixed silage must also be of guaranteed quality), and should be ensiled as it is transported. During ensiling, if an appropriate amount of urea and microecological preparations specially used for silage can be added, the protein content and silage quality can be improved.
According to the experiment by Zhang Weipeng, Xu Changjun, Shen Meiqing (2002) on lactating cows: group 1 cows were fed 20 kg of mixed silage of apple pomace and corn stalks at a ratio of 1:3 and 7 kg of concentrate per head per day; group 2 cows were fed 20 kg of corn stalk silage and 7 kg of concentrate; group 3 cows were fed 5.5 kg of dry corn stalks and 8 kg of concentrate. After a 60 d feeding experiment, group 1 cows produced on average 1.2 kg more milk per head per day than group 2 cows, and 2.2 kg more than group 3 cows. Also, according to Zhang Mingqi, Zhang Xiangning, Zhang Shouqing (2001), using apple pomace silage to replace 40% of corn silage for feeding lactating cows increased milk production by 10.8% compared with the control group, an extremely significant difference (p<0.01).
2.2 Drying
After drying, apple pomace can be crushed into dry powder as needed. It not only has good palatability, is easy to store, convenient for packaging and long-distance transportation, but can also be used as a raw material for compound feed and pellet feed for various livestock and poultry. Drying can use natural sun drying and artificial drying. Natural drying requires several consecutive sunny days to dry it, keeping the moisture at about 10%, and about 2 t can be dried from every 10 t. Natural drying does not require special equipment; a drying yard with a cement surface or brick surface is enough, so the investment is small and the cost is low; but there must be several consecutive days of good sunshine, and encountering cloudy and rainy days during drying can easily cause mildew and deterioration. Artificial drying requires mechanical equipment and consumes energy, and the cost is high, but the drying effect is good, the quality is high, the nutrient loss is small, and it is not affected by weather. Therefore, drying should be adapted to local conditions. The two can also be combined, that is, first use good weather for natural sun drying, and when the moisture has been reduced to a certain extent, then use artificial drying, which will reduce costs.
Dry apple pomace powder can be used as a raw material for compound (mixed) feed and can replace part of corn and wheat bran. According to the feeding levels and feed conditions of livestock and poultry in China, the recommended proportions of dry apple pomace powder in compound feed are: 3%-7% for piglets, 10%-25% for finishing pigs, 2%-4% for chicks, 5%-10% for growing chickens, 3%-5% for laying hens, and 10%-25% for cattle and sheep concentrate supplements. In addition, part of the dry apple pomace can also be added to the forage of cattle and sheep.
When using dry apple pomace powder to make compound feed, the amount can be increased from less to more, gradually increasing to the recommended proportion, so that livestock and poultry have an adaptation process. Through experiments, using dry apple pomace powder to replace part of the concentrated feed for pigs achieved an average daily weight gain of 550 g, and the feed consumed per kg of weight gain was 0.6 kg less than that of the control group; adding 1.5%-3.0% dry apple pomace powder to the diet of chicks can increase their weight gain by 25%-27%.
2.3 Silage First, Then Natural Drying
According to the experiment by Yang Fuyou, Qi Zhouyue, Li Caifeng et al. (2000), fresh apple pomace is first ensiled during the peak production season, and by June, July and August of the following year, taking advantage of the high summer temperatures, the ensiled pomace is then sun-dried. At this time, natural drying only takes 2-3 d, and there is no need to gather it into piles at night, saving labor and time, and the drying effect is also good with high quality. In this way, it not only solves the difficult problem of treating fresh pomace for juice factories, but also finds work for the arrangement of labor during the off-season in summer for juice factories; at the same time, it also solves the contradiction that fresh pomace is difficult to store and transport over long distances, increasing economic benefits for juice factories. Such a juice factory is not only a juice production plant, but also a feed raw material production plant for silage-dried pomace.
2.4 Apple Pomace Bioactive Feed
Because apple pomace has a relatively high nitrogen-free extract content, by adding a suitable nitrogen source, it can be converted into single-cell protein feed through microbial fermentation, improving the nutritional value of apple pomace. Zhang Yuzhen et al. isolated yeast from apple pomace by the double-layer plate method, and studied the effects of different fermentation temperatures, culture media, pH values, nitrogen sources and medium moisture content on the protein composition of the microbial cells. They considered that the optimal culture temperature was 35°C, the suitable pH value for growth was 6.0-6.5, urea was a relatively ideal nitrogen source medium, and a moisture content of about 55% was suitable for yeast growth. Ji Baoping et al. considered that the suitable medium for apple pomace fermentation was wheat bran, and that combination with soybean cake, rapeseed cake, cottonseed cake, brewer's grains, etc. was relatively suitable; the addition amounts of uric acid and ammonium sulfate as inorganic nitrogen sources were 1.5% uric acid and 2.0% ammonium sulfate. The excellent strain combinations used for fermentation production were Geotrichum candidum + Trichoderma koningii and Geotrichum candidum + Rhizopus oryzae. The crude protein content of the fermentation product increased from 20.10% to 29.30%, an increase of 45.77%. Xu Kangzhen et al. used laser mixed-strain fermentation of apple pomace to produce feed protein, with a suitable fermentation temperature of 30-34°C, an inoculation ratio of 4:1, and an inoculation amount of 10%.
According to our research, using Aspergillus niger and yeast fermentation can increase the protein content of the fermentation product. The crude protein and pure protein contents of the inoculated treatment were 50.0-65.0 g/kg and 33.5-54.4 g/kg respectively, which were increased by 15.2%-49.8% and 5.7%-71.6% compared with the control (uninoculated) 43.4 g/kg and 31.7 g/kg. The effect was even better after adding the inorganic nitrogen ammonium sulfate. The pure protein content in the inoculated fermentation product was 41.2-98.7 g/kg, an increase of 17.4%-181.2% compared with the sterile control.
Cao Min, Diao Qiyu et al. studied the use of apple pomace as a substrate to make fermented feed to replace sugar beet pulp or other feeds for feeding dairy cows. Test groups 1 and 2 produced 1.89 kg and 1.91 kg more milk per day than the control, and the milk fat percentage, milk protein percentage and total milk solids were all improved. The annual profit increase per cow was 1,498 yuan and 1,196 yuan more than the control. At the same time, during the experimental period, the disease incidence of cattle in the experimental groups was significantly lower than that in the control group (26 head-days vs. 131 head-days).
China is a country with a serious shortage of feed protein, and has long relied on imported protein feeds such as fishmeal from abroad to meet domestic needs. According to the utilization efficiency of pomace feed, apple pomace microbial feed will certainly become the development direction of pomace feed utilization, and it will certainly be of great significance to the development of China's feed industry. At present, many researchers are sparing no effort in carrying out development and research work.
(References omitted)
　

[This post was last edited by shifuming2007 on 2008-2-15 23:14]
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Where is apple pomace sold? What is the price?
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How is it used in poultry feed and pig feed?
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I have been looking for it for a long time, and finally here it is. Thank you for the good material.
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Apple pomace really has a good effect in cattle feed, but now it is also not easy to purchase. Generally in Xi'an, Shandong and other places, it is a seasonal raw material. Some can have 7 protein.
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Is the digestible energy of apple pomace really this high? Is the sugar content very high? What kind of sugar is it mainly?
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How is it added to pig and chicken feed, and what is the effect?
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Downloaded, thank you.........
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It cannot be added too much, the color is too dark.
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It looks just like garbage to me, and there may be pesticide residues! Best to boycott it!
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The development of unconventional raw materials is a use of waste, turning waste into treasure. Support!!!
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It belongs to turning waste into treasure, but I just do not know what the price is like?
If food processing enterprises strictly control quality, the possibility of pesticide residues will be reduced.