4种常用饲料原料安全水分及等温吸附研究

试验旨在研究常用饲料原料的平衡水分吸附等温线，选择拟合效果最佳的方程，计算在不同环境温度下的绝对安全水分和相对安全水分。通过修正Halsey(MHAE)、修正Henderson(MHE)、修正Chung-Pfost(MCPE)、修正3参数GAB(MGAB)、修正Oswin(MOE)等5种农产品常用的吸附方程对4种饲料原料（大麦粉、次粉、麸皮、花生粕）平衡水分吸附等温线的拟合效果进行评价。结果发现，对大麦粉平衡水分吸附等温线，15℃时MHE方程拟合效果最好，25℃和35℃时MCPE方程拟合最好；对次粉平衡水分吸附等温线，15℃时MGAB方程拟合效果最好，25℃和35℃时MOE方程拟合效果最好；对麸皮平衡水分吸附等温线，MOE方程在15、25、35℃时拟合效果均为最好；对花生粕平衡水分吸附等温线，15℃时MOE方程拟合效果最好，25℃时MGAB方程拟合效果最好，35℃时MHAE方程拟合效果最好。选择拟合度最佳的方程，计算得出了4种饲料原料在不同环境温度下的绝对安全水分和相对安全水分，可为饲料贮存和防霉工作提供科学指导。     

饲料原料吸湿动力学模型研究

试验通过在不同温度(25、35、45℃和55℃)、湿度(32%、54%和74%)环境下,获得玉米、豆粕、菜粕、麦麸的吸湿曲线,并通过数据分析筛选出较优模型,发现饲料原料粉体吸湿动力学方程的适用度顺序为:双指数速率曲线模型一级速率曲线模型一元二次速率曲线模型零级速率曲线模型;拟合出饲料原料吸湿动力学模型方程的决定系数(R2)均在0.991 8以上,具有较好的拟合度。     

化学分析法评估饲料原料营养价值的稳定性初探

为初步探讨化学分析法测定生产常用原料营养价值的稳定程度,通过化学分析法多次测定不同饲料原料(豆粕、次粉、花生壳粉等)的水分、灰分和蛋白含量,利用统计学进行分析比较,结果发现:化学分析法测定洗米糠和玉米胚芽粕的水分,去皮豆粕和花生粕的粗灰分,豆粕和去皮豆粕的粗蛋白变异系数较小;而猪油和玉米麸的水分,花生壳粉和玉米皮的粗灰分,玉米胚芽粕和玉米麸的粗蛋白变异系数较大。试验表明:化学分析法测定洗米糠和玉米胚芽粕的水分,去皮豆粕和花生粕的粗灰分,豆粕和去皮豆粕的粗蛋白稳定性较高;而测定猪油和玉米麸的水分,花生壳粉和玉米皮的粗灰分,玉米胚芽粕和玉米麸的稳定性较低。     

湿态发酵豆粕不同添加比例和预处理工艺对颗粒饲料质量的影响

试验采用4×4双因素设计研究湿态发酵豆粕不同添加比例和预处理工艺及其交互作用对颗粒饲料质量的影响。试验选择典型肉鸡饲料配方,湿态发酵豆粕的添加比例为:4%、6%、8%和10%;预处理工艺分别为:A:直接添加;B:与玉米粉按3.7比例混合后添加;C:与玉米粉按3.7比例混合、粉碎后添加;D:与玉米粉按3.7比例混合、冷制粒、再粉碎后添加。结果表明:(1)随着湿态发酵豆粕添加比例的提高,制粒性能降低;随着预处理工艺变化(A～D),制粒性能提高。(2)随着湿态发酵豆粕添加比例的提高,混合粉料调质前、调质后、颗粒料水分极显著提高(P0.01);随着预处理工艺变化(A～D),混合粉料调质前水分、颗粒料水分极显著降低(P0.01),对混合粉料调质后水分影响不显著(P0.05);预处理工艺和湿态发酵豆粕添加比例双因素交互作用对混合粉料调质前、调质后水分有极显著影响(P0.01),对颗粒料水分无显著影响(P0.05)。(3)随着湿态发酵豆粕添加比例的提高,颗粒饲料硬度极显著降低(P0.01),颗粒饲料耐久性极显著升高(P0.01),成型率先升高再降低,添加量为8%时成型率最高(P0.01);随着预处理工艺变化,颗粒饲料硬度、成型率极显著升高(P0.01),对耐久性无显著影响(P0.05);双因素交互作用对成型率有极显著影响(P0.01),对硬度、颗粒饲料耐久性无显著影响(P0.05)。(4)随着储存时间的延长和湿态发酵豆粕添加比例的提高,霉菌总数有升高的趋势,湿态发酵豆粕添加4%、6%、8%、10%时,四种预处理工艺加工的颗粒饲料均能安全储存的时间分别为84、70、42、42 d。结论:通过改变预处理工艺,改善了制粒性能,提高了颗粒饲料质量,其中,DCBA;提高了湿态发酵豆粕添加比例,湿态发酵豆粕与玉米粉按3.7比例预混合、冷制粒、再粉碎预处理工艺下,湿态发酵豆粕添加比例可以提高到10%,同时延长了颗粒饲料的储存时间,储存时间长短关系为DBCA。     

饲料加工环节的原料损耗分析

饲料生产企业通过改进加工工艺,减少饲料加工过程中的原料损耗,利于降低生产成本。试验通过对36 824.6 kg陕西二级玉米进行接收与清理、粉碎工段损耗分析,以及对58 t A产品(配方组成:玉米粉61.00%,豆粕23.50%,鱼油2.20%,鱼粉3.50%,面粉7.60%,预混料2.20%)生产过程中的混合膨胀和成品工段进行损耗分析。结果显示:玉米接收与清理工段损耗为0.25%,粉碎工段损耗为2.21%,其中水分损耗为1.40%,其他损耗为0.81%;玉米与豆粕混合膨胀工段损耗为3.40%,其中水分损耗为1.90%,其他损耗为1.50%;从原料到成品的总损耗为3.46%。试验结果表明,饲料加工过程中产生的损耗主要为水分损耗,并且膨胀工段损耗大于粉碎工段损耗。     

不同原料对发酵参数的影响

试验采用3个菌种(乳酸菌、酵母菌、枯草芽孢杆菌)分别固态发酵相同水分的3种原料(玉米、豆粕、棉籽粕),以感官评价、原料pH变化和发酵后益生菌存留量作为评价指标,探讨不同饲料原料品质随发酵时间变化的规律,优化发酵饲料生产工艺。结果显示,不同饲料原料达到稳定pH所需的时间不同,相同发酵菌种达到pH稳定所需的时间为:玉米< 豆粕< 棉籽粕;玉米、豆粕和棉籽粕的种类对初始pH无影响;在pH达到稳定时,3种原料发酵后颜色和气味各呈现相应的特性,而黏度强度表现为:棉籽粕 >豆粕 >玉米;益生菌存留数量为:玉米 >豆粕 >棉籽粕。由此可知,玉米作为微生物发酵底物,发酵率高,益生菌存留量多,优于豆粕和棉籽粕。     

玉米、豆粕中胆碱生物学效价的研究

用肉仔鸡进行为期1周(8～14日龄)的生长反应试验 ,用标准曲线及斜率比法测定了玉米、豆粕中胆碱生物学效价。按单因子试验设计 ,用艾维因商品代8日龄肉仔鸡160只 ,随机分为10个处理组 ,每组4个重复、每个重复4只鸡。通过在玉米淀粉酪蛋白纯合饲粮中分别添加胆碱(由氯化胆碱提供)0、300、600和900mg/kg,作出生长反应曲线。用玉米分别占42.21 %、72.24 %的两个玉米半纯合饲粮和豆粕比例分别为16.50 %、24.83 %的两个豆粕半纯合饲粮饲喂肉仔鸡 ,测出玉米和豆粕中胆碱生物学效价分别为57.47 %和45.97 %。用两个玉米 +豆粕混合日粮作加性效应检验 ,证明玉米、豆粕中胆碱生物学效价可加性良好     

2004年第4期读者评刊结果

一、时效性最好 1.正确认识肉狗养殖市场 2.禽流感重挫大豆与豆粕市场 3.羊业市场前景依然看好 4.发展养羊业不容忽视的问题 5.中国预混合饲料市场广阔 6.国内玉米市场行情北稳南跌 二、实用性最好 1.因地制宜选兔种 2.正确认识肉狗养殖市场 3.禽流感重挫大豆与豆粕市场 4.羊业市场前景依然看好 5.玉米糟饲喂肉牛技术 6.农户养奶牛有7种养法不科学 三、可靠性最好 1.正确认识肉狗养殖市场 2.禽流感重挫大豆与豆粕市场 3.羊业市场前景依然看好 4.2003年12月份全国畜产品价格 5.农业部出台措施确保水畜…     

精补料豆粕添加量对西杂肉牛育肥性能和成本的影响

选择48头体重相近[(220.42±30.86)kg]的8~10月龄西门塔尔杂交肉牛随机分为4个试验组,饲喂添加从0%到18%豆粕的4组等蛋白、等能量的玉米干酒精糟+玉米精补料,探讨4组不同豆粕添加量的精补料饲喂杂交肉牛的育肥性能和成本。133 d育肥试验的结果表明,饲喂0%和5%豆粕精补料的杂交肉牛增重和料重比均优于饲喂18%豆粕精补料的杂交肉牛;单位增重成本均低于18%豆粕精补料,分别降低了13.01%和10.59%;饲喂0%和5%豆粕精补料的各项试验指标最好,饲喂13%豆粕精补料的较差,饲喂18%豆粕精补料的最差(P0.05、P0.01)。显著性差异来自线性效应。由此,随着提高精补料豆粕添加量,西杂肉牛没有改善总增重和日增重、料重比及体增重成本,精补料蛋白质品质对肉牛育肥性能作用甚微;通过比较肉牛育肥效果和成本,玉米干酒精糟(DDGS)是豆粕最佳替代蛋白饲料。     

样品水分含量分布状态对傅立叶近红外预测模型的影响

试验旨在研究样品水分含量呈正态分布与匀态分布对傅立叶近红外所建模型预测效果的影响。试验以豆粕水分含量的分布形态为研究对象,采用单因子试验设计,设3个不同σ值的正态分布样品校正集和1个匀态分布样品校正集,分别建立预测豆粕水分含量的模型。结果表明:3个正态分布所建预测模型的RMSECV低于匀态分布所建模型,当用4个模型预测水分含量范围在9%~14%,平均值为11.47%的样品集时,3个正态模型预测结果分别为12.23%、11.41%、11.48%,而匀态模型为11.47%,显然优于正态模型。正态模型预测中间水分含量的准确性较高,优于匀态模型,而匀态模型预测两端高、低水分的样品的准确性优于正态模型。     

仿生消化法测定猪饲料原料还原糖释放量的重复性和可加性研究

本试验旨在建立单胃动物仿生消化系统模拟猪饲料原料消化后还原糖释放量的测定方法,为饲料养分生物学效价的评估提供参考。还原糖释放量与上样量的线性关系研究以玉米-豆粕混合物(75%玉米+25%豆粕)为研究对象,上样量设0.2、0.4、0.6、0.8和1.0 g 5个处理,每个处理4个重复,每个重复1根消化管;方法的重复性检验以玉米-豆粕混合物、大麦、花生粕和米糠为研究对象,每个样品设3个批次,每个批次4个重复;方法的可加性检验设19个处理,其中处理1~7分别为玉米、大麦、高粱、大豆粕、花生粕、棉籽粕和米糠,处理8~19为2种或2种以上饲料原料按不同比例组合制备的12种混合饲料,每个处理4个重复,每个重复1根消化管,在仿生消化系统中模拟猪消化后测定各处理的还原糖释放量。结果表明:上样量在0.2~0.8 g时,还原糖总释放量与上样量呈显著的线性关系(R2=0.999 2),还原糖相对释放量在559.56~582.70 mg/g DM变化,变异系数为1.66%,而上样量为1.0 g时,还原糖相对释放量比上样量为0.2~0.8 g时的平均值下降5.37%;3个批次的大麦、花生粕、米糠和玉米-豆粕混合物的还原糖释放量的批内变异系数、批间变异系数和总变异系数均不大于1.68%,批间最大相对偏差分别为0.68%、1.50%、1.39%和0.29%;12种混合饲料还原糖释放量的实测值显著高于计算值(P0.05),而还原糖释放量的计算值与实测值的线性回归模型与y=x相重合(截距P=0.480 5;斜率P=0.514 1)。由此得出,当上样量在0.2~0.8 g时,上样量与还原糖释放量呈显著线性关系;仿生消化法测定猪饲料原料还原糖释放量的重复性和可加性满足定量分析的基本要求。     

乳酸菌固态混合发酵研究

以玉米粉、豆粕、麦麸为基质,以保加利亚乳杆菌、嗜酸乳杆菌、嗜热链球菌为发酵菌种,采用固态发酵技术,以活菌数为指标,通过单因素和L9(34)正交试验确定了三种菌混合发酵的最佳条件,并对其发酵产物的常规营养成分进行分析测定。结果表明:固态基质中玉米粉:豆粕:麦麸=1:1:1、培养基初始含水量80%p、H值6.3、接种量为10%、三种菌接种比例为1:1:1、发酵温度40℃时的发酵效果最好。在此条件下,保加利亚乳杆菌数为3.0×109 CFU/g,嗜酸乳杆菌数为4.6×109 CFU/g,嗜热链球菌数为5.8×109 CFU/g,发酵产物粗蛋白质、粗脂肪和氨基酸态氮含量分别是发酵前的1.16、1.12和6.94倍。为开发一种新型生物饲料打下基础。     

Nutritional value of quality protein maize for starter and finisher swine.

Growth trials with starter (n = 120, 6.8 kg initially, 28 d of age, Exp. 1) and finisher (n = 70, 59 kg initially, Exp. 2) pigs were conducted to compare quality protein maize (QPM, .40% lysine) and normal corn (.31% lysine) in simple corn-based diets containing the same levels of soybean meal. In Exp. 1, pig performance was similar (P greater than .10) on all diets, regardless of the level of soybean meal, suggesting that QPM and normal corn have similar feeding value in lysine-adequate (.99 to 1.11%) diets. In Exp. 2, less soybean meal was needed in QPM than in normal corn diets to maximize performance; increasing soybean meal from 10.8 to 13.8% improved rate (P less than .05) and efficiency (P less than .01) of gain of pigs fed normal corn diets but had no effect on performance of pigs fed QPM diets. A QPM-based diet containing 6% soybean meal and supplemental lysine and tryptophan failed to maximize feed efficiency, but growth rate was equal to that obtained on the normal corn diet with 13.8% soybean meal. The apparent fecal digestibility of GE and ileal digestibility of N were similar for QPM and normal corn, but apparent ileal digestibility of most essential amino acids was slightly higher for QPM (Exp. 3). Experiment 4 compared apparent digestibilities of QPM, conventional opaque-2 corn and two high-protein corns. Digestibilities differed (P less than .05) among the corns, but the absolute differences were small and were likely due to differences in amino acid content of the corns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sites of digestion in beef steers fed bermudagrass hay and supplemented with high-nitrogen feeds alone or mixed with tallow

Five crossbred beef steers (329 kg) were used in a 5 x 5 Latin square experiment with 14-d periods to determine the effects of supplementation with high-nitrogen (N) feeds alone or mixed with tallow on sites of digestion with a basal diet of bermudagrass hay. Hay was 1.93% nitrogen, 75% neutral detergent fibre and fed at 1.83% of body weight (dry matter; DM). Supplements were basal (B; 105 g DM): 81.8% dried molasses product (DMP) and 18.2% calcium carbonate (CC); soybean meal (S; 942 g DM): 88.0% soybean meal, 9.8% DMP and 2.2% CC; S mixed with 9.8% tallow (SF; 1041 g DM); corn gluten and blood meals (CB; 662 g DM): 62.5% corn gluten meal, 20.8% blood meal, 13.6% DMP and 3.0% CC; CB mixed with 13.2% tallow (CBF; 757 g DM). Total N intake was 117, 185, 187, 174 and 172 g/d, and duodenal N flow was 121, 148, 143, 162 and 169 g/d for B, S, SF, CB and CBF, respectively, being lower for B than for other treatments and higher for supplements with the corn gluten and blood meal mix than for soybean meal (P less than 0.05). Duodenal microbial N flow was 39, 51, 49, 38 and 45 g/d for B, S, SF, CB and CBF, respectively, being greater (P less than 0.05) for supplements with soybean meal than with corn gluten and blood meals. Duodenal flow of feed N was greater (P less than 0.05) with than without high-N feeds and for supplemental corn gluten and blood meals than for soybean meal (78, 90, 86, 117 and 116 g/d for B, S, SF, CB and CBF, respectively). In conclusion, mixing of tallow and high-N feeds did not affect the extent of ruminal N disappearance, and soybean meal supplementation increased duodenal N flow less than did supplementation with corn gluten and blood meals. Increased duodenal N flow with soybean meal was associated with about equal elevations of ruminal outflow of microbial and feed N, whereas the corn gluten-blood meal mix affected the intestinal protein supply by increasing ruminal escape of feed protein.     

仿生消化系统测定玉米和大豆粕酶水解物能值影响因素的研究

本试验旨在通过探讨饲料样品的粉碎粒度、未水解残渣的清洗次数和透析袋处理后的存放时间对仿生消化法中玉米、大豆粕干物质消化率和酶水解物能值的影响,为确立基于仿生消化系统（ＳＤＳ １）测定饲料酶水解物能值的操作规程提供参考。试验采用单因素完全随机设计,共设１１个处理,每个处理５个重复,每个重复１根消化管。其中处理１～３、４～７、８～１１分别考察饲料样品的粉碎粒度、未消化残渣的清洗次数、透析袋处理后的存放时间对玉米和大豆粕干物质消化率及酶水解物能值的影响。结果表明：１）粉碎粒度对玉米、大豆粕的干物质消化率和酶水解物能值都有显著性影响（Ｐ＜０．０５）。当玉米的粉碎粒度从 ４０目减少到 １００目时,其干物质消化率和酶水解物能值依次增加,而且变化幅度较大的粒度范围出现在 ４０～６０目。而大豆粕的粉碎粒度从４０目减少到１００目时,尽管６０目样品的干物质消化率与酶水解物能值最高,但与其他 ２个粉碎粒度样品的干物质消化率相差在 ０．７０％以内。２）未消化残渣的清洗次数对玉米、大豆粕的干物质消化率与酶水解物能值均有显著性影响（Ｐ＜０．０５）。随着清洗次数的增加,玉米、大豆粕的干物质消化率和酶水解物能值逐步趋于稳定。在清洗 ６次后,玉米、大豆粕的干物质消化率与酶水解物能值的变异已趋于 ＳＤＳ １的测定误差的允许范围之内。３）透析袋处理后的存放时间对玉米、大豆粕的干物质消化率和酶水解物能值也有显著性影响（Ｐ＜０．０５）,但在 ４个存放时间的处理水平内,玉米、大豆粕的干物质消化率、酶水解物能值的变化都在０．９４％和 ０．３７ＭＪ／ｋｇ以内,处于 ＳＤＳ １测定误差的允许范围内。综合上述结果,ＳＤＳ １测定饲料酶水解物能值时,样品的粉碎粒度应为 ６０目、未消化残渣的清洗次数为 ６次。透析袋前处理后 ４℃下存放 ９０ｄ内均可用于对玉米、大豆粕干物质消化率和酶水解物能值的测定。     

Litter Moisture and Footpad Dermatitis as Affected by Diets Formulated on an All-Vegetable Basis or Having the Inclusion of Poultry By-Product

Chicken feet (paws) are valuable products in the Asian market. Foot dermatitis, mostly caused by litter condition, can affect the foot skin tissue leading to downgrades and reduced market value. In this study, a diet having animal by-products was compared with 2 all-vegetable diets formulated with corn, soybean meal, and toasted soybean with or without corn gluten meal. A total of 1,200 birds were placed in 24 pens with new pine shavings as litter. Each treatment had 8 replications. Birds were fed the experimental diets up to 40 d of age. Starting at 21 d of age, 10 birds per replication were labeled and submitted to weekly evaluations of foot dermatitis. Litter samples were also collected weekly to determine percentage of moisture. In general, litter moisture and incidence and severity of foot dermatitis increased as broilers aged. Inclusion of corn gluten meal consistently reduced the incidence and severity of footpad dermatitis, which occurred in parallel with the reduction in litter moisture. Litter moisture from birds fed a diet with the inclusion of poultry by-product was similar to that obtained with corn gluten meal; however, benefits from reductions in foot dermatitis were not seen. It is concluded that feed formulation can affect litter moisture and the incidence and severity of foot dermatitis. Birds fed all-vegetable diets based exclusively on corn and soybean meal have an increased potential to develop footpad dermatitis as well as to produce excreta with greater percentages of moisture when compared with those fed diets with inclusions of poultry by-product or corn gluten meal.     

体外产气法评价油菜秆与玉米、豆粕的组合效应

本研究旨在探讨不同比例的油菜秆与玉米、豆粕组合对体外瘤胃发酵及其组合效应的影响。采用体外发酵法研究油菜秆与玉米(0%, 15%, 30%)、豆粕(0%, 15%, 30%)组合的体外发酵参数及其组合效应值的变化,探索优化组合效果。结果表明,随着玉米比例的增加,乙酸、丙酸、丁酸和挥发性脂肪酸生成量相应增加,乙丙比下降。当油菜秆∶玉米∶豆粕为40∶30∶30时,培养液pH,氨态氮(NH₃-N)浓度和乙丙比均极显著下降(P<0.01);48 h产气量、潜在产气量、产气速率、乙酸、丙酸、总挥发性脂肪酸(VFA)浓度和有机物消化率(OMD)均极显著提高(P<0.01)。以48 h产气量、NH₃-N、挥发性脂肪酸浓度和OMD的组合效应值以及综合组合效应值(AEs)为衡量指标,油菜秆∶玉米∶豆粕为55∶30∶15组合的正组合效应最大(P<0.01)。综上所述,在本试验条件下,油菜秆∶玉米∶豆粕为55∶30∶15组合的能氮比例较为合理,瘤胃发酵效率最高,为最优组合,可提高油菜杆的利用效率。     

蜡样芽孢杆菌与粪肠球菌协同发酵豆粕工艺条件优化

试验研究了不同发酵条件对发酵豆粕品质的影响,采用单因素优化,逐级递进法,对豆粕发酵条件进行了优化。以豆粕为原料,以益生蜡样芽孢杆菌和粪肠球菌作为发酵菌种进行固态发酵试验研究,主要考察其对发酵产物酸溶蛋白和总有机酸的影响。结果表明,豆粕固体发酵最优工艺条件为:发酵菌种比2:1(蜡样芽孢杆菌菌液:粪肠球菌菌液=2:1)、发酵初始含水量45%,发酵时间54 h、好氧与厌氧时间比2:1,在此发酵条件下酸溶蛋白达到14.95%、总有机酸2.47%、抗原蛋白降解率在90%以上。     

Influence of Process Parameters on Nutritional Components of Fermented Soybean Meal

To study the optimal condition of fermented soybean meal production, several factors were selected to study the effects of different strains inoculation quantity, fermentation temperature, moisture content, fermentation time and accessories on soybean meal fermentation.The results showed that when Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus addition proportions were 3‰, 2‰, 1‰, respectively, proteinase supplementation was 2‰, strains activation time was 0.5 h, initial moisture content was 38%, fermentation temperature kept at 30 to 42 ℃, physical and chemical indexes of fermented soybean meal were optimal, the contents of small peptide and lactic acid could reach more than 20% and 3.5%, respectively, and at the same time, quality of fermented soybean meal was very stable.     

发酵工艺参数对发酵豆粕营养成分的影响

为探讨发酵豆粕生产的最适条件,本研究测定不同的菌种接种量、发酵温度、水分、发酵时间、辅料等几种因子对豆粕发酵效果的影响。结果显示枯草芽孢杆菌、酿酒酵母菌、乳酸菌的添加比例分别为3‰、2‰、1‰,蛋白酶添加量为2‰,菌种活化时间为0.5 h,发酵的初始水分为38%,温度保持在30~42 ℃时,发酵豆粕的理化指标最优,其中小肽含量可达20%以上,乳酸含量可达3.5%以上,并且质量稳定。