棉籽饼饲料中棉酚生殖毒性的研究进展

棉籽饼作为一种优质、廉价的动物饲料蛋白得到广泛的应用。但是,棉籽饼中含有的棉酚在一定程度上限制了其使用量。动物长期采食含有棉酚的饲料易引起生殖毒性。对棉酚的理化性质、限量使用及其对动物生殖毒性的研究现状进行了综述。     

Pathology and histopathology of gossypol toxicity in broiler chicks

Two experiments were conducted to determine the toxicity, pathology, and histopathology of purified gossypol in broiler chicks. Gossypol was added to broiler feed at 0, 100, 200, and 400 mg/kg of feed in Experiment 1 and at 0, 800, and 1600 mg/kg of feed in Experiment 2. Day-old broiler chicks were fed these diets from 1 to 21 days in Experiment 1 and from 1 to 23 days in Experiment 2. In Experiment 1, body weight and feed intake at 21 days were not significantly affected by dietary gossypol. However, chicks fed gossypol at 400 mg/kg of feed had poor feed conversion ratio compared with the other treatment. Feed conversion ratios were 1.493, 1.564, 1.471, and 1.60 for chicks fed gossypol at 0, 100, 200, and 400 mg/kg of feed, respectively (Experiment 1). Chicks fed 400 mg/kg gossypol also had mild perivascular lymphoid aggregate formations and bilary hyperplasia in the liver. In Experiment 2, gossypol at 1600 mg/kg resulted in 28.1% mortality. Gossypol at 800 and 1600 mg/kg feed resulted in significant decreases in body weight and feed intake of chicks. The average body weights of 23-day-old chicks in Experiment 2 were 676, 224, and 111 g for 0, 800, and 1600 mg/kg gossypol, respectively. Feed conversion ratios of chicks fed 800 and 1600 mg/kg gossypol were significantly higher than those of chicks fed control diets (1.383 vs. 1.564 vs. 1.745 for 0, 800, and 1600 mg/kg gossypol, respectively). Plasma iron and hematocrit values were significantly reduced by gossypol at 800 and 1600 mg/kg of feed. Enlarged gallbladder was the only gross pathology symptom associated with gossypol levels. Severe cases of perivascular lymphoid aggregate formation, biliary hyperplasia, and hepatic cholestasis were observed in chicks fed 800 and 1600 mg/kg of gossypol in feed. No gossypol-related changes were observed in kidney tissues of chicks. These results show that gossypol is toxic to broiler chicks at high levels. This study also shows that histopathologic changes in liver due to gossypol also occur at levels lower than the levels that affect body weight.     

棉籽饼粉脱毒饲料的制备及其应用效果初探

本试验通过制备棉籽饼粉脱毒饲料产品,采用感官鉴定法观察其物理性状,采用国标法测定其棉酚含量,采用凯氏定氮法测定其粗蛋白质含量,并通过肉鸭饲喂试验探讨其在肉鸭饲养过程中的应用效果.结果表明,脱毒后的棉籽饼粉中棉酚残存量不足10 mg/kg,与原始饼粕相比,粗蛋白质含量提高了4.35%,其颜色明显变浅,饼粕质地松软,硬度小,无硬块,无异臭,符合安全标准.经肉鸭饲喂试验发现,与对照组肉鸭相比,用制备的棉籽饼粉脱毒饲料代替常规饲料饲喂肉鸭其生长发育、器官发育、血液指标、饲料中营养成分利用情况均未发现异常,未发现棉酚中毒现象,说明脱毒后的棉籽饼粉饲料中棉酚含量符合饲用安全标准,达到脱毒目的.     

Review: Effect of Processing Whole Cottonseed on Nutrient Digestion,Performance of Lactating Dairy Cows,and Gossypol Bioavailability

Whole cottonseed (WCS) may be processed to reduce ruminal protein degradation and increase the flow of amino acids to the small intestine or to improve the handling characteristics involved with mechanized feed handling systems. Processes that have been studied include delinting, pelleting, roasting, extruding, and coating. The effect of processing on nutrient digestibility and animal performance varies among processing methods. Processing methods such as mechanical delinting and coating with gelatinized corn starch do not appear to alter nutrient digestibility or animal performance, but processing methods such as roasting or extrusion effectively decrease ruminal protein degradation and alter nutrient digestion. The response of lactating dairy cows to roasted or extruded cottonseed varies from trial to trial, but an analysis of data from several trials indicates that the milk yield response to roasted cottonseed in the diet is positive. Processing also affects gossypol form and bioavailability. Processing methods that do not rupture the seed and involve heating appear to increase the bioavailability of gossypol, whereas processes that rupture the seed before or during heating appear to reduce free gossypol concentrations effectively. Additional research is needed to define the effects of processing on nutrient digestion and gossypol form and bioavailability when cottonseed is fed for long periods.     

Cottonseed meal (gossypol) toxicosis in a swine herd

Cottonseed meal (CSM) that contained a high concentration of free gossypol was inadvertently used as a protein supplement, without appropriate iron supplementation, for a swine herd in Illinois. Fifty percent of 300 grower and finishing swine died, and an additional 20% became ill during a 4- to 6-week period. Clinical signs included respiratory distress and abdominal distention. At necropsy, the hearts were diffusely pale, flaccid, and rounded because of dilatation of all 4 chambers, the livers were large and congested, and hydropericardium, hydrothorax, and ascites were evident. Histologic changes consisted of diffuse myocardial fiber atropy with perinuclear vacuolation, and multifocal myocardial and skeletal muscle necrosis. Changes in the liver included marked centrilobular congestion, loss of hepatocytes, and fatty degeneration. Differential diagnoses included monensin, selenium, and gossypol toxicoses, and vitamin E/selenium deficiency. Analyzed feed samples did not contain monensin. Feed selenium concentrations ranged from 428 to 1,513 micrograms/kg, and iron concentrations from 160 to 180 mg/kg. Cottonseed meal (3 to 10%) was detected by feed microscopy. A sample of the 40% protein supplement contained 19% CSM and 1,300 mg of free gossypol/kg, whereas feed samples contained 200 to 400 mg of free gossypol/kg. The history, clinical signs, pathologic findings, and feed analyses were compatible with a diagnosis of gossypol toxicosis. Cottonseed meal, a high-protein supplement used widely in southern United States, may contain gossypol (a polyphenolic binaphthalene pigment), which in its free form is especially toxic to simple-stomached animals. If CSM is used, supplementation with ferrous sulfate is recommended at a 1:1 weight ratio with free gossypol, up to 400 mg of FeSO4/kg.     

育肥牛棉酚中毒的诊断与治疗

棉酚中毒是由于长期、过量饲喂含游离棉酚超标的棉副产品,引起的以出血性胃肠炎、血红蛋白尿以及雄性生殖毒性和母畜流产为主要特征的中毒病。新疆是我国的棉花主产区,棉花加工过程中产生了大量的棉籽饼、棉籽粕、棉壳等副产品,这些副产品是优质的动物饲料来源,具有产量多、来源广、价格便宜、适口性好的特点,广泛应用于肉牛和肉羊的育肥。本文通过对育肥牛棉酚中毒的诊断与治疗,重点阐述棉酚中毒的发病机理、治疗手段与预防措施,以期为棉酚中毒的预防治疗及有效脱毒合理饲喂提供一定的参考。     

固体联合发酵对棉粕发酵产物富肽蛋白产量及脱毒效果的影响

利用枯草芽孢菌（Bacillus subtilis NDX6）和植物乳杆菌（Lactobacillus plantarum BLLP）对棉粕、豆粕不同比例混合样品进行有氧和无氧联合发酵试验,并用纯棉粕进行联合发酵生长曲线研究,探讨固体联合发酵对棉粕发酵产物中富肽蛋白含量及脱毒效果的影响.结果表明,6个配方中纯棉粕发酵降解有毒物质游离棉酚含量最高约81％,游离氨基酸及小肽的含量提高约6.5倍（P＜0.05）,饲料pH由原来的6.20以上降低到5.12以下,有益菌活菌数提高约10倍;纯棉籽粕有氧发酵时间为38 h,无氧发酵时间60～66 h,游离氨基酸含量提高约7.54倍,游离棉酚降低约89％.用棉粕固体联合发酵可以脱毒,降解蛋白提高饲料吸收利用率.     

两种不同发酵工艺的棉籽粕营养价值的研究

利用现代固态发酵原理,研究两种不同发酵工艺对棉粕脱毒效果及其营养价值的影响。工艺一是使用本实验室保存的两株菌直接进行固态发酵,工艺二是在工艺一的基础上添加酶解液进行固态发酵。试验结果表明(以干物质计),棉籽粕发酵和发酵酶解产品中游离棉酚分别降低到197.68 mg/kg和202.35 mg/kg,粗蛋白质分别提高到59.64%和60.88%,小肽含量分别提高到19.41%和23.59%。来航蛋公鸡强饲代谢试验结果表明,发酵和发酵酶解棉籽粕的能量和营养物质消化率均高于未发酵棉粕。肉鸡饲养试验结果表明,发酵棉粕按50%、75%和发酵酶解棉粕按75%的比例替代基础日粮中的豆粕,不影响肉鸡的日采食量。国标二级高游离棉酚棉籽粕经过固态发酵处理后,外观蓬松变软,气味芳香,其营养价值得到显著改善。蛋公鸡的营养物质及能量消化率得到显著提高,同时益生菌及生物酶活性增加,在肉仔鸡日粮中的应用不影响日采食量。     

Gossypol detoxification in the rumen and Helicoverpa armigera larvae: A review

Gossypol, a phenolic compound found in the cotton plant, is widely distributed in cottonseed by-products. Although ruminant animals are believed to be more tolerant of gossypol toxicity than monogastric animals due to rumen microbial fermentation, the actual mechanisms of detoxification remain unclear. In contrast, the metabolic detoxification of gossypol by Helicoverpa armigera (Lepidoptera: Noctuidae) larvae has achieved great advances. The present review discusses the clinical signs of gossypol in ruminant animals, as well as summarizing advances in the study of gossypol detoxification in the rumen. It also examines the regulatory roles of several key enzymes in gossypol detoxification and transformation known in H. armigera. With the rapid development of modern molecular biotechnology and -omics technology strategies, evidence increasingly indicates that research into the biological degradation of gossypol in H. armigera larvae and some microbes, in terms of these key enzymes, could provide scientific insights that would underpin future work on microbial gossypol detoxification in the rumen, with the ultimate aim of further alleviating gossypol toxicity in ruminant animals.     

Dioxins: risk management by agriculture and feed industry--options and limits

Dioxins represent a group of undesired substances that may contaminate feedstuffs. Due to their persistency in the environment it can be expected that feed contamination by dioxins will occur in the future, too. Therefore efforts in agriculture and in the feed industry have to be focussed on measures that minimize the dioxin contamination of feedstuffs, especially under the aspects of food safety. Several dioxin scandals in the past have contributed to a higher awareness in feed production as well as on the side of food consumers and administration resulting in changes of feed legislation (implementation of maximum levels of dioxins in feed and food). Some of the dioxin scandals enlarged the knowledge concerning the potential ways dioxins entering the food chain (for example dioxin contamination during the drying process of grass meal, recycling of contaminated oils, use of contaminated kaolinit a.s.o.). In difference to those accidents in feed producing agriculture there is a main influence of potential soil contamination on the dioxin contents in feedstuffs (like roughage). Producing roughage (green fodder, silage, hay) on areas with grass land by grazing animals can result in corresponding consumption of soil that contaminates the green fodder. Intending a lowest feed contamination by dioxins implies that the soil contamination is known. Depending on the rate of soil contamination farmers should decide on the kind of feed production and on the techniques of harvesting the fodder. For example it is possible to produce maize (whole plant in high cut technique) without higher dioxin contents in maize silage, on the other hand it can not be recommended to use contaminated fields for growing beets or by grazing ruminants, pigs or poultry (outdoor systems). In general during the harvesting process technical measures have to be chosen that reduce/minimize the soil contamination because the dioxin concentration in the soil of exposed areas is much more higher than the dioxin concentration within the feedstuffs. The high costs of dioxin analyses limit an implementation of a monitoring program including samples of soil and feedstuffs of each feed producing unit or individual farms. Therefore it is necessary to focus the monitoring efforts on areas and samples that let expect a higher risk of dioxin contamination. New screening tests should be developed and implemented that allow a higher frequency and density of control measures concerning dioxin. In the case of suspicious findings only those samples could be analysed by the classic chemical procedure (time consuming, high costs). Especially in cases of food contamination (for example detected in monitoring programs of the food industry) it is necessary to find out the way and cause, not neglecting the potential role of the contaminated soil. Last but not least it is recommended to inform the public continuously about levels of dioxins that are actually found in food as well as in feed (and soils), especially on behalf of the consumers confidence in food and feed control and its related administration. Continuous information will increase the consumers understanding that there is (and will be for further years) a background contamination of feed and food in general (that decreased markedly in the last decades), and that cases of detected higher dioxin levels are exceptional findings that result immediately in efforts of the food and feed industry to obstruct the way that enabled an entering to the food chain.     

饲草料中的天然有毒有害物质及其对羊的危害

抗营养因子广泛存在于植物界,这些有毒有害物质进入动物体内后,其可能转化为具有更大活性和毒性的物质,引起畜禽产品质量和产量下降,起到致病作用,甚至引起死亡。主要对饲草料中硝酸盐及亚硝酸盐、苷类物质、棉酚等抗营养因子的危害作一介绍。     

Soybean hulls, wheat middlings, and corn gluten feed as supplements for cattle on forage-based diets.

Soybean hulls, wheat midds, and corn gluten feed are viable alternative supplements for forage-fed cattle. All three result from the processing of major Unites States agricultural crops, so large supplies are available. Their value is better for ruminant animals than for monogastrics because they contain digestible fiber components. These byproducts are widely available throughout the Unites States and will generally be more economical than traditional feed grains or commercial feeds when used appropriately as supplements to forage-based diets. Knowledge about the composition of base forage must be used in planning supplementation strategies because base forages vary in protein and mineral content [9]. Soybean hulls alone may be a good selection in situations in which forages are adequate or high in protein. In situations where forage is marginal or deficient in protein, wheat midds, corn gluten feed, or a mix of soybean hulls and corn gluten feed might be most desirable. All three feeds can be variable in nutrient composition, so they should be analyzed to ensure a balanced nutrient level in diets. Soybean hulls are especially variable in crude protein content and should always be analyzed when forages are marginal or deficient in protein. Despite the fact that published energy levels are substantially lower, research has shown that soybean hulls and wheat midds have a value comparable to corn and soybean meal in forage-based diets. Corn gluten feed has also been comparable to corn and soybean meal in most reports but is closer in value to its published energy levels. In general, results with soybean hulls have been surprisingly good and consistent, whereas responses to wheat midds and corn gluten feed supplementation have been more variable and sometimes disappointing. Feeding rates for soybean hulls can range from low to extremely high depending on forage availability and desired performance. Wheat midds should be limited in most situations to 50% of the expected dry matter intake because of their rapidly digested starch content. Corn gluten feed should be limited to approximately 50% of expected dry matter intake because of its high sulfur content. Several research groups are currently evaluating self-feeding programs for these byproducts, and while the potential for health and production problems exist, results have been encouraging in most cases. Self-feeding would reduce the labor costs of hand feeding and could provide backgrounders with a program to expand cattle numbers on a limited land base.     

A Prospective Study of Radiation Therapy for the Treatment of Grade 2 Mast Cell Tumors in 32 Dogs

Surgery, chemotherapy, and irradiation have been used singly or in combination to treat dogs with cutaneous grade-2 mast cell tumors (MCT). However, optimal treatment has not been established. At The Animal Medical Center, 32 dogs with grade 2, stage 0 MCT received cobalt radiation treatment to a dose of 54 Gy; 94% had a disease-free interval of 1 year. The 2–,3–,4–, and 5–year disease-free intervals were 86%. Survival rates were 100% for 1 year and 96% for 2 to 5 years, with only 1 death caused by MCT. Primary site was not a prognostic factor for survival in this study. Minimal toxicity was observed and was limited to acute cutaneous reactions. Late-term reactions to radiation therapy were mild and considered acceptable in all cases. No deaths occurred due to treatment, and no dog was eliminated from the study because of radiation therapy toxicity. Radiation therapy appears to be an effective treatment for dogs with grade 2, stage 0 MCT.     

Calcium, phosphorus, and magnesium homeostasis in ruminants

Significant advances have been made in the last 30 years in the understanding of Ca, PO4, and Mg homeostasis in ruminants. Despite these advances, the primary cellular or molecular lesions responsible for failure of homeostasis have yet to be identified. Suggested causes, such as primary hormone deficiencies, have been eliminated, and we now believe that aging and nutrition can reduce the ability of intestine, bone, and kidney to respond rapidly to the hormone signals responsible for homeostasis during rapid increases in demand for these minerals. Further research is required before these lesions can be identified and new knowledge applied to the development of economical, effective programs that prevent milk fever and hypomagnesemic tetany. Until then, diseases such as milk fever will continue to affect 8 to 9 per cent of our dairy cows, and dairy farmers will continue to spend millions of dollars a year for treatment of the primary disease and the many secondary problems that result from these diseases.     

Comparative effects of fumonisins on sphingolipid metabolism and toxicity in ducks and turkeys

Fumonisins (FBs) are mycotoxins that are found worldwide in maize and maize products. Their main toxic effects have been well characterized in poultry, but differences between species have been demonstrated. Ducks appeared very sensitive to toxicity, whereas turkeys are more resistant. At the same time, alterations of sphingolipid metabolism, with an increase of the concentration of the free sphinganine (Sa) in serum and liver, have been demonstrated in the two species, but the link between the toxicity of FBs and Sa accumulation remains difficult to interpret. The aim of the present work was to compare the effects of FBs (10 mg FB1 + FB2/kg body weight) on sphingolipid metabolism in ducks and turkeys. Growth, feed consumption, and serum biochemistry were also investigated to evaluate toxicity. The main results showed that FBs increased Sa concentrations in liver and serum in ducks and turkeys, but these accumulations were not directly correlated with toxicity. Sa accumulation was higher in the livers of turkeys than in ducks, whereas Sa levels were higher in the sera of ducks than in turkeys. Hepatic toxicity was more pronounced in ducks than in turkeys and accompanied a decrease of body weight and an increase of serum biochemistry in ducks but not in turkeys. So, although FBs increase Sa concentration in the livers of both species, this effect is not directly proportional to toxicity. The mechanisms of FB toxicity and/or the mechanisms of protection of ducks and turkeys to the Sa accumulation within the liver remain to be established.     

Monensin toxicity in cattle

Monensin has been tested to determine its toxicity and safety in cattle. Single dose acute toxicity and signs associated with toxicity were determined by oral gavage, 7-d oral gavage and feeding experiments with high concentrations of monensin in feed. Oral feeding studies indicated a near complete anorexia resulting from intake of sublethal amounts of monensin. In these cases, cattle recovered from the insulting dose and resumed growth and feed intake. In long-term chronic feedlot, pasture supplement, and reproduction safety studies conducted with monensin administered in the feed, the high concentrations caused cattle to show signs of mild monensin intoxication. Mortality resulted from feeding groups of cattle large quantities of monensin in small quantities of feed. Furthermore, these studies have demonstrated no detrimental effects upon reproduction. Collectively, these studies indicate that the greatest risk of intoxication occurs when cattle first receive a feed containing monensin. Mixing errors and misuse situations under actual use conditions have resulted in cases of cattle mortality. In most cases the mortality was predictable based upon the exposure in controlled studies.     

The effect of feeding whole cottonseed on the fertility of bulls

SUMMARY 23 bulls were fed whole cotton seed (WCS) for 9 months, which resulted in the ingestion of 7.6 to 19.8 g free gossypol per head daily, or 20.4 to 50.8 mg per kg body weight daily. This level of free gossypol ingestion exceeded that of previous studies of a shorter duration in which gossypol was deemed to have affected bull fertility. There was no significant difference between treated and untreated bulls for total spermatozoal abnormalities, secondary spermatozoal abnormalities, scrotal circumference, scrotal circumference per kg body weight, percentage passing the Society for Theriogenology examination for breeding soundness, and mean breeding soundness examination score. There was a higher proportion of primary spermatozoal abnormalities in untreated than in WCS-fed bulls (P = 0.05). Of the bulls that were prepuberal at the onset of the trial (n = 9), the mean age of onset of puberty was not significantly different in the WCS group than in the untreated group, but it approached significance (P = 0.05). There was no significant difference in the scrotal circumference at the onset of puberty between the two groups. Analysis of the bulls' drinking water showed they could have ingested sufficient minerals in the water to bind with the free gossypol ingested, thereby detoxifying it. This may also explain why the results of previous trials have been so variable.     

平菇菌糠饲料的营养价值与安全性评估分析

试验依据国家饲料卫生标准(GB13078—2001)中的检测方法对平菇不同生长阶段培养基的基质组分进行了检测和安全性评定。通过对平菇不同生长阶段培养基(以棉籽壳和玉米芯为主)基质组分的检测及对基质饲料价值的评定,结果发现,第4潮菌糠用作饲料营养价值较高且生产成本较低。此时粗蛋白质含量为10.10%,较初始培养基提高了59.31%,而粗纤维含量降低了29.57%,木质素、纤维素和半纤维素的降解率分别提高到63.62%、46.60%和77.06%;并依据国家饲料卫生标准要求对第4潮菌糠中的游离棉酚、黄曲霉毒素B₁和重金属含量等指标进行了检测,其中游离棉酚的含量仅为67.90 mg/kg,未测出黄曲霉毒素B₁的含量(＜10 μg/kg),铅、氟、铬、镉、汞的含量均符合国家饲料安全标准。因此,用第4潮菌糠制备反刍动物粗饲料可满足要求,切实可行。     

REVIEW: Factors Affecting Decisions on When to Calve Beef Females

The decision of when to calve beef females is critical to production efficiency and profitability in a cow and calf enterprise. Calf production and associated costs are affected by calving season because environmental conditions, stage of production, and season of the year interact to affect nutritional status and reproductive performance. Cow and calf producers typically choose to commence calving and breeding at times of the year when weather is least stressful and forage conditions are optimal. Choosing to do so can reduce the amount of supplemental feed needed to ensure acceptable pregnancy rates, resulting in reduced annual feed costs. However, the time of year when forage conditions are optimal varies across the United States because of not only environmental (ambient temperature, rainfall, day length) differences among latitudes and longitudes but also differences in soil types and topographies. Consequently, forage species and their growth characteristics differ among regions. Given such differences, feeding strategies and feed costs vary among regions. Additionally, summer heat stress, particularly in southern states, has negative consequences on reproductive performance in both the female and male and will reduce calf performance. Such a wide array of production environments, productivity levels, and associated costs will cause profitability to vary among regions of the United States, making it impossible to identify a universally acceptable date to commence calving and breeding. Consequently, the decision of when to calve beef females should be based on site-specific conditions.     

Study on Application of Candida utilis CU-3 in Cotton Straw Feed Fermentation

This experiment was conducted to study the effects of cotton straw fermentated by Candida utilis CU-3,in order to obtain a compound preparation with high efficiency to improve the quality of cotton straw feed.The gossypol tolerance of the strain was tested through the plate tolerance with gossypol acetate as the sole carbon source,and the optimal detoxification conditions of CU-3 were optimized by the solid fermentation.CU-3 mixed fermentation with other preparations were applied to the realistic production,the chemical substances such as crude protein,crude fiber and crude fat in the cotton straw were detected to verify the fermentation effect.The results showed that CU-3 could be grown in 1 000 mg/kg gossypol acetate medium,which was the sole carbon source.The increase of fermentation time and inoculation amount,the detoxification rate of CU-3 on cotton straw increased significantly (P<0.05),and the detoxification rate was the best when the water content was 60% in single-factor cotton straw solid fermentation.The variance analysis of response surface model showed that the equation regression was significant (P<0.01),the maximum degradation rate was 70%,when the conditions were 60% water content of cotton straw,10% inoculation amount and 30 days fermentation time.CU-3 mixed with other preparations,the sensory evaluation scores were all excellent,cotton straw had golden color,clear structure and mellow smell.The free gossypol content of cotton straw was significantly reduced (P<0.05),the minimum content of free gossypol was 62.00 mg/kg.The crude protein content was significantly increased (P<0.05),the highest reached 9.41%.The crude fat content was up to 14.50 g/kg.The crude fiber content was significantly reduced (P<0.05).The cadmium,lead and chromium contents of each treatment group reached the standard.The best compound preparation was CU-3 with 2% corn flour.The application effect tests were carried out in the three farms of 142 Regiment,Manas and Beiwucha.The pH of the cotton straw were between 5.05 and 5.20 after fermentation,the detoxification rates were all above 70% and the highest reached 78.5%,the crude protein contents were 7.97%,8.24% and 9.89%,the crude fiber content were 35.4%,34.5% and 31.2%,respectively,the crude fat content was up to 10%.In this experiment,CU-3 and its compound preparation could effectively improve the detoxification efficiency and feed quality of cotton straw under optimized fermentation conditions,and provide experimental basis for the application of cotton straw feed in Xinjiang.