利用体外培养法建立饲料营养成分与瘤胃丙酸产量的回归模型

根据美国康乃尔净碳水化合物和蛋白质体系 (CNCPS) ,分析测定了 4类 2 4种饲料的营养成分 ,利用体外批次培养技术测定了它们在体外培养一定时间后的丙酸产量 ,并由此建立了饲料中产丙酸的营养成分和瘤胃丙酸产量的回归方程     

奶牛饲料体外产气评定预测模型及其改进

奶牛的生产性能很大程度上受制于饲料的营养价值。饲料营养价值评定需要测定其化学成分及消化特性，包括体内法（in vivo）、半体内法（in sire）和体外法（in vitro）。由于采用体内产气法可以测定发酵产物，考虑了饲料可溶但不发酵的部分，避免了消化道流量、指示剂、微生物指示剂和动物个体差异而导致的误差，同时具有估测动态发酵的优势，以其省时，省力，费用较低，成为评价反刍动物饲料营养价值的常用方法。饲料营养成分对体外评定法中体外消化率（IVTD）、产气量及挥发性脂肪酸产量的估测存在一定影响。     

拔节期弱光胁迫对扬麦15麦秸营养成分和体外发酵的影响

本试验旨在研究拔节期弱光胁迫对扬麦15麦秸营养成分和体外发酵的影响。试验以弱筋小麦扬麦15为材料,在拔节期进行3个遮阴水平(0、50%、66%)和3个遮阴时间(2、4、8 d)的处理,小麦成熟收割时取麦秸进行营养成分分析并评定其体外降解率。结果表明:1)与0组相比,遮阴50%组和66%组显著降低了麦秸粗蛋白质含量(P0.05),遮阴时间以及遮阴水平与遮阴时间交互作用对麦秸营养成分的影响均不显著(P0.05)。2)与0组相比,遮阴50%组和66%组显著降低麦秸干物质和中性洗涤纤维体外降解率(P0.05),遮阴时间以及遮阴水平与遮阴时间交互作用对营养物质体外降解率的影响均不显著(P0.05)。遮阴水平与遮阴时间的增加均降低了麦秸体外发酵产气量。遮阴时间的增加显著降低了总挥发性脂肪酸的产量(P0.05),遮阴水平与遮阴时间的增加均显著降低了乙酸产量(P0.05),且影响有交互作用(P0.05),但对丙酸、丁酸产量和乙酸/丙酸无显著影响(P0.05)。结果提示,拔节期遮阴处理降低了麦秸粗蛋白质含量、干物质和中性洗涤纤维体外降解率、产气量、总挥发性脂肪酸与乙酸产量,但对乙酸/丙酸没有影响;遮阴效果随时间与水平增加而增加。     

体外法研究不同磷添加水平对奶牛瘤胃内pH 和挥发性脂肪酸的影响

采用体外法研究无机磷添加浓度对瘤胃发酵的影响。无机磷在培养液中设0、30、60、90、120、150、200、250、300、350 mg/L 10个水平。体外培养发酵48 h后终止培养,测定培养液的pH、总挥发性脂肪酸(VFA)。结果表明,不同无机磷添加水平对乙酸、丙酸、丁酸和总VFA产量影响显著(P＜0.05),无机磷添加水平为200 mg/L时,乙酸、丙酸、丁酸及总VFA产量最高,随后下降。瘤胃培养液pH随无机磷添加水平的增加而显著降低(P＜0.05),无机磷添加水平为200 mg/L时达到最小值5.65,随后又上升。在本试验条件下,添加无机磷明显促进瘤胃微生物对饲料养分的发酵,适宜添加水平为200 mg/L。     

鸡饲料代谢能生物学评价与内源能估测方法的选择

饲料经家禽的消化道经过物理、化学和微生物消化后,经泄殖腔将代谢产物排出体外;经消化道吸收的饲料营养成分,在家禽体内代谢后其代谢产物以尿的形式经泄殖腔排出体外。家禽粪和尿都是经过泄殖腔排出体外这一生理特点决定了测定家禽的代谢能比测定消化能要容易。     

不同饲料原料的体外发酵性能及产甲烷潜力

优化日粮配方是减少反刍动物甲烷产生的最有效途径。本研究利用体外瘤胃液发酵技术,对14种饲料原料(糠麸、植物蛋白和谷物)体外发酵性能相关性及产甲烷潜力进行评估。根据各成分的产甲烷量将饲料配方分为高产、中产和低产类型,然后进行体外发酵,以确定实际产甲烷量及其对消化率的影响。结果:3类原料中总可消化养分水平最高的分别是棕榈粕、玉米DDGS和小麦。糠麸原料pH与除乙酸与丙酸比值外的所有参数均呈负相关,而乙酸与丙酸比值与除pH、CO2外的所有参数均呈负相关,植物蛋白原料pH和乙酸与丙酸比值呈正相关,而这两个参数与其他参数呈负相关,而谷物原料为基质进行体外发酵时,pH与乙酸与丙酸比值为正相关,而与其他参数表现为负相关。当以玉米皮、棉粕和大麦作为基质孵育72 h后,甲烷产量最低,而以本地麸皮、豆粕和玉米为基质时,甲烷产量最高。结论:低产甲烷饲料配方可以降低甲烷产量,但提高了非纤维碳水化物、总可消化养分和挥发性脂肪酸产量。     

丙酸贮存饲料可产生生长促进作用

利用丙酸贮存饲料的主要作用是能抗真菌、细菌和发酵菌。因此可以防止饲料腐败变质。同时在动物肠道中的丙酸仍然有抗微生物的作用。对用丙酸贮存的饲料所取得的饲养效果,作如下几点说明: 1.饲料中细菌含量减少,从而也减少了肠道有害微生物及其所造成的麻烦。 2.保证饲料中营养成分不被破环和无中毒现象     

巍山县肉牛常用饲料营养价值评定

对巍山县19种肉牛常用精、粗饲料的营养价值进行综合评定,测定了常规营养成分、范氏纤维成分、体外消化率、瘤胃降解率及能量价值。结果表明:不同饲料之间的营养成分、体外消化率、瘤胃降解率和有效能含量存在较大差异,优质粗饲料较秸秆饲料高,优质牧草较野生牧草高,而肉牛浓缩料和肉牛精料补充料比玉米面和牧草提供较大比例的过瘤胃蛋白。     

利用丙酸贮存饲料的经济效益

<正> 利用丙酸贮存饲料具有抗真菌、细菌和酵母菌的主要功能,并能防止饲料腐烂变质。试验表明:丙酸进入畜禽消化道中起抗微生物的效用。使用丙酸贮存饲料具有下列效果: ——减少饲料中的细菌和消化道中有害的微生物,并能减少畜禽的应激反映。——贮存饲料中的营养成分不会变质,不会产生霉菌毒素。这样,饲料就有较高的营养价值,并且更     

粗饲料丙酸产量与CNCPS组分相关性研究

试验通过测定7种粗饲料的丙酸产量和CNCPS(康奈尔净碳水化合物-蛋白质系统)组分,旨在研究二者的相关性。结果表明:培养36 h苜蓿与羊草、青贮玉米与专用青贮玉米的VFA总量差异显著(P0.05)。应用丙酸产量与CNCPS组分关系模型预测不同时间点的丙酸产量的误差小于8.7%,表明丙酸产量与CNCPS组分之间存在相应关系。     

The effect of citronellylseneciate on the utilization of feed in sheep

The influence of citronellylseneciate on the digestibility of nutrients and energy, as well as on the level of some rumen and blood metabolites, was studied in feed rations for rams. Citronellylseneciate was not found to have a significant influence on the digestibility of nutrients and energy and nitrogen balance in feed ration. Neither did citronellylseneciate influence the production of total volatile fatty acids and the molar percent of acetic, propionic and n-butyric acids. The addition of citronellylseneciate to feed ration resulted in a decrease in the pH value in rumen and in a non-significant increase in ammonia in rumen and urea in blood. The hematological profile showed increased levels of phosphorus and glutamate-oxalate transferase.     

The effect of Rumensin on the metabolic profile of rumen fluid in feedlot cattle

The effects were studied of sodium monensinate dosed 125 mg on the metabolic profile of rumen fluid. The experiment was conducted under current farming conditions in a pavilion cattle fattening house. The experiment, which lasted 367 days, comprised 985 bulls of the Bohemian Spotted breed. The feed ration was based on silage with an additive of dried poultry litter and concentrates. The additive was administered in concentrate mixture, 125 mg per head/day. After the start of the experiment want of appetite to sodium monensinate was observed. The animals took approximately four weeks to adapt completely to the additive. The following characteristics were investigated to study the metabolic profile of rumen fluid: actual acidity, total titration acidity, ammonia, total nitrogen, lactic acid, total volatile fatty acids, per cent acetic acid, per cent propionic acid, molar ratio acetic acid: propionic acid, per cent iso- and n-butyric acid, absolute number of infusoria and energy net yield of volatile fatty acids. Increased levels of the clinico-biochemical parameters of the metabolic profile of rumen fluid were found in lactic acid, propionic acid and energy net yield of volatile fatty acids. The per cent of propionic acid increased at some samplings by up to 116%. A drop was recorded in total nitrogen, per cent acetic acid, per cent butyric acid, molar ratio C2 : C3 and total number of infusoria. The decrease in the per cent of acetic acid ranged around 16% and the drop in butyric acid level amounted at some samplings up to 78%. No response to the additive was observed in the other characteristics of the metabolic profile of rumen fluid.     

Rumen digestive physiology and microbial ecology

The rumen is a dynamic, continuous fermentation compartment that provides a suitable environment for a variety of species of anaerobic bacteria, protozoa, and fungi. These microorganisms have a complex series of interactions with the feeds supplied to the host, with some using particulate matter as both sources of nutrients and sites of sequestration to avoid being washed from the rumen by the rapid flow of fluids. Because of the ability to use soluble nutrients and to reproduce rapidly, other microbes associate primarily with the liquid phase of the rumen contents. Due to the metabolic activity of all microbial populations, feeds are converted to microbial matter and fermentation end products, which serve as nutrients for the ruminant. Optimum feed utilization by ruminants is dependent on achieving maximum rumen fermentation and flow of microbial protein to the duodenum. At this time, it is clear that the major nutrients required by the microbial populations include both fibrous and nonfibrous sources of carbohydrates and nitrogen in the form of ammonia, amino acids, and peptides. In spite of five decades of research, the exact quantities and sources of these nutrients that will result in optimum rumen fermentation rates and microbial yields are only partially known.     

苜蓿+玉米间作系统饲料生产潜力的评定

本试验目的在于探讨不同苜蓿+玉米间作模式下营养物质生产能力及其瘤胃可降解养分产量的差异,从而对玉米+苜蓿间作系统饲料生产能力作出合理的评定。试验设苜蓿、玉米行数比分别为2∶2,3∶2,4∶2,5∶2四个间作处理,每处理3个重复,其所占间作面积比分别为33％∶67％,43％∶57％,50%∶50%,55%∶45%,玉米、苜蓿单作为对照组。通过测定各处理干物质产量、营养物质产量、养分瘤胃降解率,从而可以对不同间作模式下可降解营养物质产量及总可降解养分产量等指标进行比较,对不同间作系统饲料生产能力进行综合评定。结果表明,苜蓿+玉米间作系统与玉米和苜蓿单作系统相比,提高了单位间作面积总干物质产量、营养物质的产量,营养物质瘤胃降解率和瘤胃可降解养分产量,具有更高的饲料生产潜力,是一种可行的饲料生产模式,本试验条件下5∶2间作模式表现出最佳的生产优势。     

畜禽饲料配方设计中数学模型的应用

 在约束条件为原料组份及比例（x_n）、原料营养素含量（a_ij）、原料价格（c_n）及能量、粗蛋白、部分限制性氨基酸及矿物元素等主要营养参数指标（b_m）条件下,用数学建模的方法建立了畜禽饲料配方设计的数学模型, 并在满足畜禽营养标准的前提下,获得成本最低(z)的畜禽饲料优化配方。另外,通过对开产期至高峰期（产蛋率＞85%）饲料配方设计的实证,推荐了一个科学、简便、实用的畜禽饲料优化配方EXCEL求解方法。     

Nutrient supply of health and sick fluid fed calves]

In the department for calves being fed with fluid feed of a specialised enterprise for calf rearing the daily intake of fluid feed (skim milk improved with milk substitute), concentrated feed and hay of a total of 341 female animals and the daily intake of energy and protein was calculated thereof. The average consumption of nutrients of the 206 healthy calves was compared with some international and national norms for the demand of nutrients. The comparison with some international values of demand and the results of the partial correlation analysis between energy and protein intake and live weight increase showed that the applied nutrition regime (particularly the kind of fluid feed) has resulted in an excessive supply of the calves with proteins and an insufficient supply with energy. This could not be realised from the GDR nutrients norm for the raising of calves published in 1976. Based on theoretical considerations and some recent findings of the science of nutrition we derived values of the protein and energy demand of our own. Subsequently an attempt is made to assess the supply with nutrients for sick calves.     

日粮中添加丙烯酸对绵羊消化代谢的影响

选取25只身体健康,体重32kg左右的8月龄中国美利奴(新疆型)细毛公羊,日粮精粗比为25∶75,采用分组试验设计,分别是对照组、添喂丙酸8,12mmol/(d·只)组和添喂丙烯酸8,12mmol/(d·只)组,研究丙烯酸对绵羊消化代谢和体增重的影响。结果表明,与对照组和添喂丙酸组相比,添喂丙烯酸组绵羊干物质采食量没有显著差异(P>0.05);添喂丙烯酸组与对照组相比,半纤维素消化率提高5.15%~9.70%,纤维素消化率提高3.64%~5.73%,但差异不显著(P>0.05);8mmol丙烯酸组钙、磷的消化率分别高于8mmol丙酸组2.86%和8.39%,但差异不显著(P>0.05);添喂8,12mmol/(d·只)丙烯酸组绵羊的尿氮排出量(g/d)分别低于对照组12%和18%,而N保留率与对照组相比分别提高5.35%和3.91%,但均没有显著差异(P>0.05)。添喂丙烯酸组绵羊的体增重和饲料利用率与对照组和丙酸组相比没有显著差异(P>0.05)。本研究表明,添喂丙烯酸对绵羊的采食量、干物质、有机物、粗蛋白、纤维素、半纤维素的消化量(率)均无显著影响(P>0.05),对绵羊氮、钙、磷的代谢无显著影响(P>0.05)。     

Excessive oral administration of iron to sheep. 1. Digestibility of rations, results of fattening and carcass yields]

4 digestibility trials (4 male sheep per group) and 2 growth trials were carried out with 24 (V 1) and 32 (V 2) fattening lambs to investigate the effect of abundant oral Fe doses on the digestibility of crude nutrients in a ration of barley + dried green feed and on the results of fattening and carcass yields. Fe supplementation (less than 1400 mg per sheep/day) did not significantly change the digestibility coefficients of crude nutrients. Increasing Fe levels in the concentrates decreased the rates of liveweight increase and food consumption in both growth trials. Well-established statistical evidence was provided for the decline in absolute carcass yields resulting from the lower weight of the lambs at the end of the fattening period after Fe supplementation.