Near Infrared Reflectance Spectroscopy for the Determination of Free Gossypol in Cottonseed Meal

Gossypol is a toxic polyphenolic compound produced by the pigment glands of the cotton plant. The free gossypol content of cottonseed meal (CSM) is commonly determined by the American Oil Chemists’ Society (AOCS) wet chemistry method. The AOCS method, however, is laboratory-intensive, time-consuming, and therefore, not practical for quick field analyses. To determine if the free gossypol content of CSM could be predicted by near infrared reflectance spectroscopy (NIRS), CSM samples were collected from all over the world. All CSM samples were ground and a portion of each analyzed for free gossypol by the AOCS procedure (reference data) and by NIRS (reflectance data). Both reflectance and reference data were combined in a calibration. The coefficient of determination (r²) and standard error of prediction (SEP) were used to assess the calibration accuracy. The r² was 0.728, and the SEP was 0.034 for the initial calibration that included samples from all over the world. However, the r² and SEP improved to 0.921 and 0.014, respectively, if the calibration was made using CSM samples only from the United States. These results indicate that a general prediction equation can be developed to predict the free gossypol content of CSM by NIRS. From a practical standpoint, NIRS technology provides a method for quickly assessing whether a particular batch of CSM has a free gossypol content low enough to be suitable for use in poultry diets.     

游离棉酚水平对海兰蛋鸡生产性能的影响

选用43周龄海兰褐壳蛋鸡120羽,随机分成4组,每组3个重复,每个重复10羽鸡分别饲喂游离棉酚(FG)含量为0mg/kg、20mg/kg、70mg/kg、120mg/kg的试验日粮.试验结果表明:(1)日粮游离棉酚水平对产蛋率影响不显著(P＞0.05),(2)日粮游离棉酚水平对蛋重影响不显著(P＞0.05).(3)当FG达到120mg/kg时,蛋鸡的日采食量比对照组显著降低(P＜0.05),下降了1.4g;日粮中FG含量达到70mg/kg时蛋鸡的日采食量略有下降.     

日粮添加棉酚对哈萨克羊水代谢影响的研究

试验选用5只2岁、体重约40 kg的健康雄性哈萨克羊,单笼饲养。试验共4期(每期18 d,共72 d),第1期不添加棉酚,第2、3、4期在混合精料中分别添加984、1353、1722 mg/d棉酚。结果表明,随着棉酚添加量的增加,试验羊的饮水量、排尿量、麦秸采食量、排粪量及粪中含水量无明显变化(P>0.05);抗利尿激素、肾素、皮质酮水平无显著变化(P>0.05),促肾上腺皮质激素、醛固酮水平在前3期呈下降的趋势,第4期与第3期相比显著上升(P<0.05);血清中Na⁺水平在2、3期明显下降(P<0.05),第4期恢复到第1期水平,血清中Cl^-水平呈下降趋势,Ca²⁺水平也呈下降趋势,在4期试验中K⁺、无机磷、Mg²⁺含量无明显变化(P>0.05);尿中Na⁺、无机磷含量无变化(P>0.05),Cl^-含量前3期上升,第4期恢复到第1期水平,K⁺、Mg²⁺、Ca²⁺含量第4期较前3期均显著下降(P<0.05)。     

Lowering seed gossypol content in glanded cotton (Gossypium hirsutum L.) lines

Cottonseed is a rich source of high quality protein, but its value as an animal feed is limited by gossypol, a toxic polyphenolic compound contained in glands located throughout the plant. This compound helps protect the plant from pests. Totally glandless varieties have been developed, but not adopted as these plants are left vulnerable to pests. This study describes a breeding strategy to decrease the levels of gossypol in the seed while maintaining a high enough concentration of toxin in vegetative plant parts to offer protection from pests. Preliminary studies indicated that crosses between varieties with different gland densities and distributions produced a range of glanding patterns. By selecting within the resulting progeny, we have identified F₇ generation progeny that have <0.30% total gossypol in the seed, while still possessing glands at critical locations on the vegetative plant parts. These new lines will be a valuable source of germplasm for developing low seed gossypol varieties. Seed from these varieties would provide a new source of inexpensive protein for animal feeding rations.     

棉酚降解酶对棉籽粕酶解脱毒的条件参数优化

【目的】优化棉酚降解酶对棉籽粕酶解脱毒的条件参数。【方法】采用4因子4水平的正交试验设计,以游离棉酚的含量为指标筛选出棉籽粕的最佳酶解条件参数。【结果】棉酚降解酶对棉籽粕酶解脱毒的最佳条件参数为温度35℃、时间1.5 h、添加量3%、底物水分35%。【结论】筛选出的酶解脱毒参数具有显著的效果,在最优酶解参数条件下,通过试验验证,棉籽粕中游离棉酚的含量由341.02 mg/kg降至37.01 mg/kg,游离棉酚脱毒率可达89.15%,可以应用于对棉籽粕游离棉酚的酶解脱毒。     

食用棉籽蛋白液——液—固三相萃取法脱酚试验研究

棉籽蛋白是很好的植物蛋白和饲用蛋白源,但其中含有有毒成分棉酚,需要经过脱毒处理才能利用。研究液—液—固三相萃取法脱除棉籽饼粕中游离棉酚(FGP)的效果,以期为食用棉籽蛋白的开发提供参考。     

诱变选育棉籽粕高效脱毒菌株

以橄榄假丝酵母(Candida oleophila)、克雷克酵母(Kloeckera lindneri)、红酵母(Rhodothece glutinis)为出发菌株,采用物理诱变剂紫外线和化学诱变剂硫酸二乙酯(DES)对其进行单一诱变及复合诱变处理,选育出棉酚降解率较高的菌株,并确定单一诱变和复合诱变的最佳诱变条件.结果表明:出发菌株经紫外线和硫酸二乙酯诱变处理后再进行有利突变株的筛选,通过初筛、复筛,获得6株棉酚降解率较高的突变株(GJ-Z-25、GJ-D-25、GJ-Z-25-D-25、GJ-Z-20-D-20、HJ-D-20、HJ-Z-20-D-20),棉酚降解率分别高达90.69%、91.40%、93.78%、89.64%、90.78%和89.56%,比诱变前分别提高了50.00%、51.20%、55.14%、48.29%、26.33%和24.63%;橄榄假丝酵母的复合诱变效果好于单一诱变,最佳诱变条件是紫外线照射25 s,DES处理25 min;红酵母的DES诱变效果好于复合诱变,最佳诱变条件是DES处理20 min.通过本实验获得了高浓度棉酚耐受菌株,棉酚的降解率极显著提高,从而使棉粕营养价值显著提高.     

响应面法与基于神经网络的遗传算法在优化棉粕固态发酵中外源添加物用量上的应用

采用响应面法和基于神经网络的遗传算法,对提高棉粕固态发酵中游离棉酚降解的外源添加物水平(尿素添加量、碳酸钠添加量、菜粕添加量等因素)进行优化,并对这2种方法的优化效果进行比较.结果表明:采用响应面法优化,当尿素、碳酸钠和菜粕的添加量分别为0.97%、2.47%和24.32%时,预测的游离棉酚最大降解率为77.71%,实际降解率为79.10%;3因素中,添加碳酸钠对棉酚降解的影响最显著;而采用神经网络协同遗传算法优化,当尿素、碳酸钠和菜粕的添加量分别为0.98%、2.45%和23.66%时,预测值和实际值分别为81.36%和80.09%;采用神经网络模拟结合遗传算法的优化方法拟合度为99.91%,高于响应面法的91.91%,且均方差(RMSE)较低,为0.13,表明在棉粕固态发酵优化中,采用基于神经网络的遗传算法比响应面法具有更好的结果拟合度和准确性.     

棉籽蛋白的溶剂法脱毒工艺研究

棉籽中含有丰富的蛋白质,同时含有对畜禽有害的游离棉酚,因此研究适宜的脱毒方法脱除棉籽中的游离棉酚具有重大的现实意义.利用有机溶剂对棉籽中棉酚进行脱除工艺研究,考察不同的脱酚溶剂、温度、时间、脱酚次数和溶剂比对棉籽脱酚的影响.经过实验得最佳工艺条件是选择95;乙醇作为脱酚溶剂,脱酚温度为50℃,溶剂比为1∶3(g/mL),脱酚次数为4次,脱酚时间为3 h.在此条件下,可使脱酚棉籽蛋白中游离棉酚残留量＜400 mg/kg.     

Effects of fermented cottonseed meal on the growth performance,gastrointestinal microflora population and small intestinal morphology in broiler chickens

1. This experiment was conducted to evaluate the effects of replacing dietary cottonseed meal (CSM) or fermented cottonseed meal (FCSM) for soya bean meal (SBM) on growth performance, carcass characteristics, gastrointestinal microbial populations, and intestinal morphology of broiler chickens.

2. CSM was fermented with Bacillus subtilis, Aspergillus niger and A. oryzae for 7 d. A total of 300 one-d-old male Ross 308 broiler chickens were used in a 42-d experiment in which the birds were randomly allotted to one of 5 dietary treatments (containing 0%, 10% and 20% CSM or FCSM) in a completely randomised design. Birds were reared on litter floor and had free access to feed and water during the experiment.

3. Results indicated that the fermentation process significantly reduced crude fibre and free gossypol, while it increased crude protein content and lactic acid bacteria (LAB) count in CSM.

4. The use of FCSM instead of CSM significantly improved growth performance of broilers. The abdominal fat yield in treatments containing FCSM was significantly lower than in the other treatments. The increase in the population of LAB in the crop and decrease in the population of coliforms in the ileum of birds fed on diets containing FCSM were more significant than in other birds. Villi in the duodenum and jejunum of the birds fed on diets containing FCSM were significantly higher than for the other experimental groups.

5. The positive effects of diets containing FCSM on growth performance and intestinal health of broiler chickens showed that this processed source of protein can serve as an appropriate alternative for SBM in diets for broiler chickens.