In the past two years, farmers have deeply felt the cost pressure brought about by rising feed prices. Under pressure, many farmers have withdrawn from the aquaculture industry. But the protagonist I'm going to talk about today is an exception. He is Mr. Chen, who turned the original "waste" - cassava residue into a "fragrant dumpling" in the chicken coop after ingenious fermentation of probiotics, which not only reduced the cost of feed, but also brought unexpected ecological benefits.
Mr. Chen originally raised free-range orchard chickens. In layman's terms, it means that chickens are raised in the orchard, but they are fed full feed. But since last year, he has found it difficult to sustain this method of farming due to rising feed prices.
Cassava residue, as a residue from cassava processing, was once considered useless waste. However, at this chicken farm, it has been transformed into a delicacy for the chickens. Through the introduction of probiotic fermentation technology, the nutrients in cassava residue have been effectively released, which not only improves the nutritional value of the feed, but also enhances the digestion and absorption capacity of the chickens.
Later, after many inquiries, Mr. Chen learned that there was a cassava processing factory not far from his farm. And that's where he completely changed his chicken business.
Cassava is one of the three major potato crops, the sixth largest food crop in the world, known as the "king of starch", and the food ration of nearly 600 million people in the world. It can be seen that the nutritional content of cassava can be comparable to our daily food.
Today, in addition to being the main raw material for starch, cassava is also used in a large number of feed productions. It can be said that cassava is actually a kind of feed for poultry and livestock.
The cassava processing plant near Mr. Chen's farm mainly produces starch, and the remaining large amount of cassava residue has been sold cheaply to nearby farmers. Or take it to feed the pigs, or feed the chickens, etc.
When he learned the news, he approached the owner of the processing plant and contracted all their cassava scraps to feed the chickens.
At first, Mr. Chen just pulled the cassava residue back and fed it directly to the chickens. Generally, he adds 30 catties of cassava pulp to a 100-pound chicken diet. Although this has saved a lot of costs, he still feels that it is not enough.
Later, he learned from the breeding technician of the official account of Yipinmiao, a professional poultry seedling supply platform, that if the cassava residue is fermented with microbial starter and then fed to chickens, the nutritional content will be greatly improved, and the proportion of alternative feed can also be greatly increased.
So he followed this method and fed the chickens with the cassava residue after simple fermentation, so that the proportion of cassava residue in the chickens' diet could be increased to more than 60%. The chickens not only eat happily, but their nutrition is no worse than that of all the feed.
It is by relying on this simple method that Mr. Chen has almost reduced the cost of raising chickens by 60%, and the quality of the chickens is better than the original full feed, and the price is also higher.
Now, when everyone is about to withdraw from the chicken industry, Mr. Chen will continue to expand the scale of breeding. Therefore, there are always more ways than difficulties, as long as you explore with your heart, you can be the champion.
What's more, chickens fed with fermented cassava residue feed grow robustly and have a much lower incidence of disease. This not only reduces the cost of medication in chicken farms, but also keeps chickens away from the risk of drug residues, providing consumers with healthier and safer food.
What's even more surprising is that the air from the chicken farm is almost non-pungent and the pungent smell that is common in traditional chicken farms. This is due to the beneficial flora produced by the fermentation of cassava residue, which effectively decomposes the malodorous substances in the chicken manure and greatly improves the breeding environment. In such an environment, the chickens are more comfortable to grow and the meat is more delicious.
The innovative practice of this chicken farm not only reduces production costs, but also improves the quality of chickens, achieving a win-win situation of economic and ecological benefits. The success of this model has also provided valuable experience for other agricultural fields and promoted the in-depth development of agricultural circular economy.
Fermented cassava residue is used as high-quality feed for pigs, chickens, ducks, cattle and sheep, and the nutrition is obviously improved and can be stored for a long time
Abstract:Cassava residue is the scrap material for the production of cassava starch and ethanol, and with the rapid development of cassava processing industry, the output of cassava processing waste is also increasing year by year, resulting in waste of resources and environmental pollution. Rich in and easily digestible carbohydrates and a variety of trace elements, minerals and amino acids, cassava pulp is a widely sourced and inexpensive energy feed, but its application in feed is limited due to the high crude fiber content and the presence of anti-nutritional factors. The microbial fermentation method can increase the protein content, improve palatability, and effectively reduce the content of anti-nutritional factors, thereby improving the nutritional quality and feed value. In this paper, the nutritional composition of fermented cassava residue and its application in livestock and poultry production were reviewed, in order to provide a reference for the rational development and utilization of fermented cassava residue.
Cassava (Manihot esculenta crantz), also known as cassava and sweet potato, is known as the "king of starch" and is one of the three major potato crops, with a total annual output of more than 10 million tons. Cassava residues (CR), as a by-product of cassava extraction of starch or ethanol, can reach millions of tons in the country every year, it is mainly composed of cassava rind and broken cell wall tissue, containing a large amount of cellulose, starch and a small amount of fat and protein, is a kind of energy feed resources with great development potential. However, the nutrition of cassava residue is unbalanced, palatability is poor, and it contains certain cyanogenic glycosides, and long-term feeding will affect the growth and health of livestock and poultry, which greatly limits its application in livestock and poultry diet. For a long time, a large amount of cassava residue has been directly buried or discarded, which is not only a waste of feed resources, but also aggravates environmental pollution. In recent years, more and more attention has been paid to the development and utilization of unconventional feed resources, and cassava residue has gradually become one of the research hotspots as a new green feed raw material. At present, the application of microbial fermentation technology to treat cassava pulp is one of the main methods to improve its nutritional value and eliminate anti-nutritional factors. Through microbial fermentation, the cellulose, hemicellulose and lignin in cassava residue can be effectively degraded, the toxicity is also reduced, and digestive enzymes and probiotics can also be produced, which improves the nutritional value and palatability of cassava residue. Therefore, adding an appropriate amount of fermented cassava residue to livestock and poultry diet can not only improve the resource utilization rate of cassava residue but also alleviate the shortage of feed resources. It can also improve the performance of livestock and poultry production and improve the economic benefits of breeding.
The method of fermenting cassava residue is very simple, 1 package of starter "99 multi-functional feed starter agent" containing compound enzyme preparations (500g, the market price is about 25 yuan, and the amount of use is appropriately increased in the low temperature season), 1 ton of wet cassava residue (or 0.5 tons of dry cassava residue), 100 kg of starch-containing feed (the proportion is about 10% of the cassava residue, the more the better, such as corn, rice, sweet potato, starch), add 2 kg of salt, add more than 50 kg of soybean meal (rapeseed meal, cotton meal, peanut meal, Tea meals, etc. are fine, the more the better) The effect is better. The water content is adjusted to about 60%, sealed and fermented for more than 7 days (more than 15 days in the low temperature season), and it can be used when there is a strong sweet wine aroma. After fermentation, it can be stored in a sealed state for about 1 year.
A large number of applications are to use cement ponds to ferment cassava residue↑, add corn flour + starter mixture to sprinkle layer by layer, and finally cover and seal with a double-layer film
Reference usage and precautions:
1. Fermented cassava residue feed can not be all substituted for full price feed, according to the proportion of 15%-30% of the feed mixed with livestock and poultry feed, follow the principle of less and then more, late pregnancy, lactating sows are recommended 10%. Domestic animals such as cattle and sheep can be added to 20%-50%.
2. If the fermented cassava residue is to be stored for a long time, it should be strictly sealed and compacted to exclude air as much as possible.
1 Effect of fermentation on the nutritional value of cassava residue
Fermented cassava residue refers to the use of cassava residue as the main raw material, the use of microbiological fermentation technology to reduce the content of crude fiber and anti-nutritional factors in cassava residue, in the fermentation process to produce a large number of digestive enzymes, proteins, peptides, amino acids, organic acids, vitamins, trace elements and other nutrients and hormones to form the formation of feed raw materials.
1.1 Improve nutritional value
Natural cassava residue contains a lot of carbohydrates, rich mineral elements and amino acids, but the crude fiber and moisture content are too high, and the protein content is low, which is difficult to meet the nutritional needs of animals as feed. According to the source of large-scale production, cassava residue is mainly divided into two categories: cassava starch residues (CSR) and cassava brewing residues (CBR). Due to the different production processes (cassava often adds a lot of yeast and various enzymes at various stages of ethanol production to completely destroy the cassava cell wall), the nutrient content of the two types of cassava residue is quite different. Compared to CSR, CBR has a higher content of crude protein, crude ash, neutral detergent fiber, acid detergent fiber, copper, iron, manganese, zinc, etc., as well as most amino acids, while the nitrogen-free extract content is lower. The nutritional content of cassava residue is shown in Table 1, and the amino acid composition and content of cassava residue are shown in Table 2.
To improve the nutritional value of cassava pulp, especially CSR, the first step is to increase its protein content. A large number of studies showed that the crude protein content in cassava residue increased significantly after microbial treatment, as shown in Table 3. Song et al. compared the crude protein content of five kinds of white rot mushrooms after treatment of cassava residue, and the results showed that Coriolus versicolor and Pleurotus ostreatus increased the crude protein content by 111.7% and 107.9%. This may be due to the fact that during the fermentation process, microorganisms use the substrate for microbial synthesis and produce CO2 through respiration, resulting in the loss of substrate dry matter and the increase of crude protein relative content. At the same time, a large number of bacterial proteins and microbial metabolites accumulated during the fermentation process also significantly increased the nitrogen content. The rapid growth of microorganisms has a greater demand for nitrogen sources, so Guan Junjun et al. added 7% urea (a commonly used inorganic nitrogen source) in the fermentation process of cassava residue, which increased the protein content of cassava residue after fermentation by 5.72 times.
Microorganisms use the organic matter in cassava residue to grow and multiply, produce a large number of cellulase, protease and other digestive enzymes, and convert the solid insoluble substances (cellulose, hemicellulose, etc.) in cassava residue into liquid soluble sugars, so that simple sugars, disaccharides, polypeptides and amino acids and other easily digestible small molecules are released, and at the same time, a part of organic acids, alcohols, aldehydes, esters and other substances are generated, which not only increases the sour aroma of raw materials, improves palatability, but also further improves the nutritional quality and utilization rate of cassava residue. It is worth mentioning that white rot fungus not only has the characteristics of degrading cellulose and hemicellulose, but also has become the only class of microorganisms in nature that can independently degrade lignin because of its extracellular lignin-degrading enzyme system. The results showed that the lignin of cassava pulp treated with Coriolus versicolor, a white rot fungus, was degraded by nearly half. In addition, cassava pulp exhibited prebiotic potential during in vitro fermentation, which was able to modulate the gut microbiota composition and microbial metabolites of subjects by promoting the growth of Bifidobacterium and Roseburia. Traditional cassava residue is mostly fermented by a single strain, mainly lactobacilli or yeasts and molds in fungi. Among them, molds (such as Aspergillus niger, Aspergillus oryzae, Trichoderma) are widely used in solid-state fermentation, which is due to the high osmotic pressure of the mold itself, and its activity is not easily affected by the high osmotic pressure of the solid matrix. More and more studies have shown that the mixed fermentation effect of some strains with different biological characteristics and mutual benefit and symbiosis is often better than that of single strain fermentation, which is likely to be the result of the complementary advantages and synergistic promotion of fermentation of these microorganisms, which is mainly manifested in the higher increase of protein content and the greater decrease of crude fiber content of cassava residue after multi-strain mixed fermentation. In short, the quality and effectiveness of the microorganism treated cassava residue feed have been significantly improved. Therefore, compared with natural cassava residue, the suitable amount of fermented cassava residue in livestock and poultry production has also been greatly increased.
1. 2 Reduces the effect of anti-nutritional factors
Cassava and its by-products contain a variety of anti-nutritional factors such as cyanide, phytic acid, tannins, nitrates and saponins, which seriously affect the absorption and utilization of nutrients, can significantly inhibit the growth and development of livestock and poultry, and excessive intake can also cause organ damage and even death. Among these anti-nutritional factors, cyanide is the most important factor limiting the development and application of cassava and its by-products as a feed resource. Cassava residue contains two kinds of cyanogenic glycosides, linolenic glycoside and leprozoside (or ethyllinolenic glycoside), which will form hydrogen cyanide (HCN) under the action of linnic bitterinase or weak acid conditions, and the cyanide ion (CN—) can inhibit the activity of a variety of enzymes in cells, especially cytochrome oxidase is the most sensitive to cyanide. CN—By binding to Fe3+ of oxidized cytochrome oxidase, it prevents its reduction to Fe2+, inhibits mitochondrial respiratory chain transmission, hinders normal respiration of cells, and causes tissue cells to be unable to use oxygen in the blood and cause asphyxia. However, the results of A. Welk et al. showed that low-dose HCN can be converted into thiocyanate ions (SCN—) in animals, and through the antioxidant enzyme system to produce thiocyanate ions (OSCN—), which can stimulate the animal immune system and help improve the body's immunity. The detoxification methods of cassava and its by-products include traditional methods such as immersion, drying, cooking, frying, baking, solvent extraction, and a combination of methods, but these detoxification methods have problems such as nutrient loss, high cost, or solvent residue. In recent years, more and more studies have shown that the use of microbial fermentation of cassava residue can not only improve the nutrient content, but more importantly, effectively reduce the toxicity of anti-nutritional factors, as shown in Table 4. In order to explore the effects of combined fermentation of different strains on the content of various anti-nutritional factors in cassava residue, S.O. Aro et al. used Aspergillus flavus, Lactobacillus delberginius and Lactobacillus roduli to ferment cassava residue, and the phytate content decreased from 9.89 mg/kg to 2.75 mg/kg. The oxalate content was reduced from 270.10 mg/kg to 56.32 mg/kg by mixed fermentation of Aspergillus fumigatus, Lactobacillus delbergini and Lactobacillus rodula. By mixed fermentation of Aspergillus niger, Lactobacillus delbergini and Lactobacillus rodinus, the tannin content was reduced from 0.09% to 0.04%. By mixed fermentation of Saccharomyces cerevisiae, Lactobacillus delbergini and Lactobacillus corynei, the cyanide content was reduced from 17.88 mg/kg to 9. 40 mg/kg。 G. Oboh et al. used Aspergillus niger to ferment cassava products, and the cyanide content decreased by 51. 37～71.92%。 Song Lili et al. found that the cyanide content of cariocarcina was reduced by nearly 80% after fermentation of cassava residue. C.E. Okpako et al. used Aspergillus niger and Lactobacillus rhamnosus for mixed fermentation, and the detoxification rate of cassava residue was as high as 81.78%. The above results show that the cyanide content in cassava residue can be effectively reduced by microbial fermentation, which is far lower than the standard of ≤ 100mg/kg of cyanide in cassava and its processed products stipulated in the Feed Hygiene Standard (GB13078-2017) of the mainland. Table 4 summarizes the cyanide content in fermented cassava residue studied by previous researchers, generally speaking, the addition ratio of fermented cassava residue in compound feed is 5%~20%, and the maximum allowable amount of cyanide in compound feed for chicks is 10mg/kg, and that of other compound feed is 50mg/kg, which suggests that the cyanide content in fermented cassava residue is no longer the main factor affecting its utilization.
On the other hand, cassava residue is not only difficult to digest and utilize because it contains more crude fiber, but also affects the digestion and absorption of other nutrients in the diet, showing obvious anti-nutritional effects. Yang Haiming et al. added different proportions of cassava residue to the diet of 10-week-old geese, and found that with the increase of the proportion of cassava residue, the apparent metabolic rate of feed nutrients such as dry matter, crude protein and energy showed a downward trend. The results of Zhang Gang et al. showed that adding cellulase to the diet containing 10% cassava residue could degrade part of the cellulose, thereby effectively reducing the anti-nutritional effect of cellulose, which was manifested in the improvement of the apparent digestibility of dry matter, crude protein and energy in the diet, which significantly promoted the growth of pigs. At present, a large number of research results show that after microbial fermentation, the digestibility of various nutrients is improved with the decrease of crude fiber content in cassava residue, which shows that the antinutritional effect caused by high crude fiber content in cassava residue is significantly weakened by microbial treatment. In conclusion, microbial treatment is an effective way to safely reduce the antinutrients in cassava pulp.
2 Application of fermented cassava residue in livestock and poultry production
2. 1 hog
Adding an appropriate amount of fermented cassava residue to pig feed can improve economic benefits without affecting production performance, and also has the effect of improving the health of the body, and fermented cassava residue has broad market development prospects in pig breeding industry. Liu Chuandu put the fermented cassava residue into full price feed feed three different stages of pigs, pigs are normal feeding, no anorexia, although there is no obvious impact on daily weight gain and feed conversion rate, but the piglets in the late stage, the early fattening period and the late fattening period of the diet cost is reduced by 62.7 yuan/t, 170.1 yuan/t and 89.3 yuan/t respectively, the economic benefits are significant. The proportion of natural cassava residue in pig diet is small, and the amount of natural cassava residue in the diet of growing and fattening pigs can be significantly increased after microbial fermentation. However, based on the dual considerations of growth performance and economic benefits, the addition amount of fermented cassava residue in the diet of fattening pigs should not exceed 10%. For pig breeds that are tolerant to crude diet, such as special wild boar, the addition ratio of fermented cassava residue can be increased to 20%, and the daily weight gain and economic benefits are the best, and this breeding model is worth promoting to production practice. Ou Zhaolin explored the feasibility of using local cassava residue as a feed source in the breeding process of Longlin black pigs, and the results showed that replacing corn in the diet with the same amount of 6% fermented cassava residue had no adverse effects on the growth performance, blood glucose level, blood lipid level, carcass traits and meat quality of pigs. Wang Zhiwen et al. showed that the constipation of lactating sows was improved to a certain extent by replacing the bran with 4% fermented cassava residue and feeding lactating sows. The sour smell and taste of cassava residue after fermentation can significantly increase the feed intake of sows, and the lactation during lactation can also be correspondingly increased. At the same time, the composition of the intestinal flora of the sow was further optimized, which helped to alleviate oxidative stress and improve the composition of colostrum and normal milk, which in turn increased the daily gain and litter weight gain of weaned piglets by 7.1% and 9.6%, respectively.
2. 2 Ruminants
There are relatively many studies on the application of fermented cassava residue in ruminant production, which can promote rumen metabolism of ruminants, improve feed utilization, improve production performance and reduce feed cost.
2. 2. 1 sheep
The results of Gao Junfeng's study showed that adding different proportions of fermented cassava residue to the diet of black goats in Guangxi could improve the growth performance of black goats, and the feeding effect was the best when adding 20%, which was mainly manifested in the significant improvement of the apparent digestibility of nutrients and the enhancement of rumen metabolism process in black goats. Wang Qiang's research results showed that the best fattening effect was achieved when 20% corn was fed to Hu sheep with fermented cassava residue. Fan Yixuan et al. also obtained the results that are basically consistent with the above, and the replacement of corn with 20% fermented cassava residue has no effect on the slaughter performance and blood biochemical indexes of Hu sheep, and can also improve the feed intake and daily weight gain of Hu sheep, so as to obtain the greatest economic benefits. It is worth mentioning that 40% fermented cassava residue can significantly reduce the content of saturated fatty acids in mutton, which has a certain effect on improving the quality of Hu mutton. However, with the further increase of the addition ratio, the feed intake of the lake sheep decreased, and when the substitution ratio reached 60%, it could cause severe diarrhea in the lake sheep. Zhou Luli et al. fed Hainan black goats with fresh cassava residue, dried cassava stems and leaves and fresh royal grass, and the average daily weight gain and dry matter intake of black goats increased, while the apparent digestibility of crude fat, crude protein, neutral detergent fiber and acid detergent fiber was significantly improved, which showed that it was feasible to use fermented cassava pulp as a feed source for sheep.
2. 2. 2 Cows
Huang et al. explored the appropriate substitution ratio of fermented cassava residue as buffalo roughage, and the results showed that replacing 25% elephant grass or 25%~50% corn straw with fermented cassava residue had no significant effect on in vitro fermentation characteristics and methane yield. P. Ruanggote et al. studied the effect of fermented tapioca starch residue on the breeding effect of local beef cattle and Angus crossbred cattle in Thailand, and found that although the digestibility of nutrients decreased, the growth performance and carcass traits of cattle were not adversely affected. Recently, S. Sommai et al. showed that adding 300g of fermented cassava residue to the diet of each local Thai beef cow per day significantly promoted rumen fermentation capacity, improved rumen microbiota composition, improved nutrient digestibility, and reduced methane production. In order to further study the effect of fermented cassava residue on dairy cows, A. Cherdthong et al. added 20% fermented cassava ethanol residue to the concentrate of dairy calves, and fed concentrate according to 1% of the cow's body weight, and found that neither the feed conversion rate, rumen fermentation capacity nor rumen microbial composition were affected. It can be seen that based on environmental protection and waste resource utilization, fermented cassava ethanol residue is a green and safe raw material for cattle feed. However, S. Yimmongkol believed that fermented tapioca starch residue should not be used in large quantities in cattle diets due to its high water content and low crude protein content, which would reduce the nutrient intake and production performance of cattle.
2. 3 Poultry
The addition of fermented cassava residue to poultry diet has the effect of regulating hormone levels and improving nutritional status, and can also effectively reduce breeding costs and improve breeding environment. Yu Xiangchun et al. found that adding 15% fermented cassava residue powder to Wenchang chicken diet had a good weight gain effect and economic benefits. Jiang Jiansheng et al. showed that the substitution of fermented cassava residue for part of the full feed had no significant effect on the production performance of Cherry Valley ducks, but with the increase of cassava residue substitution, the emission reduction effect and economic benefits of H2S and NH3 in the production environment increased more obviously, and the profit could increase by 1.18~2.18 yuan/bird. The results of Lei L. et al. showed that replacing some conventional feed raw materials such as corn, soybean meal and wheat bran with 5% fermented cassava ethanol residue had a certain effect on the slaughter rate of Cherry Valley ducks, and did not affect the growth performance and meat quality. However, with the increase of the substitution ratio of fermented cassava residue in the diet, the digestibility of nutrients will be reduced, so it is suggested that the substitution ratio of fermented cassava residue in the diet of meat ducks should not exceed 15%. Qiao Xingfang et al. compared the effects of cassava residue on the metabolic hormones of growing geese before and after fermentation, and the results showed that compared with natural cassava residue, adding 20% fermented cassava residue could increase the hormone level of geese by improving the nutritional status of the body, so that it could achieve the same blood hormone level as that after regular diet feeding geese.
3 Summary
As a new type of green biological feed, fermented cassava residue is rich in protein, digestive enzymes, amino acids, organic acids, vitamins, trace elements and other nutrients that are beneficial to animal growth, while the content of crude fiber and cyanide is reduced to significantly reduce its anti-nutritional effect, which is conducive to improving the digestion and absorption function and growth performance of the animal body, and has a very broad development prospect. In addition, starting from the harmlessness and resource utilization of cassava residue, the application of cassava residue after microbial fermentation in livestock and poultry production can not only reduce the environmental pollution caused by agricultural waste, but also produce economic benefits through resource utilization, which meets the requirements of national energy conservation and emission reduction and circular economy and other related industrial policies, and is also an effective way to solve the problem of human and livestock competing for food, with greater economic and social benefits. However, the effective screening of fermentation bacteria, the survival rate of strains, the effect of different strains combined, the optimization of fermentation process and product stability still need to be actively discussed and studied, and the use of residue feed in the process of livestock and poultry breeding has not yet formed a unified industry standard, which greatly limits the application and development of cassava residue in the feed industry. Therefore, in the future, it is necessary to systematically carry out animal experiments, through comprehensive research on different livestock and poultry and different physiological stages, fully investigate and demonstrate the application ratio, addition method and feeding effect of fermented cassava residue in production, and explore and construct scientific and reasonable supporting feeding technology to guide production practice.
In the future, with the continuous progress of science and technology and the concept of environmental protection, I believe that more innovative practices like this will emerge to jointly paint a new picture of green and sustainable agriculture.