反刍动物日粮组合效应发生机制的研究进展

在配置日粮配方时,营养学家们基于这样一个假设:饲料中各种营养物质之间无相互作用,配合日粮中总的营养物质等于单个饲料组份的加权和值。然而,越来越多的实践表明,动物的采食水平、日粮中蛋白质补充料、易降解纤维、易发酵碳水化合物和脂肪的添加,饲料间的不同搭配、加工调制和一些营养调控措施等均会改变日粮中单个饲料的消化率和利用率,以至配合日粮的表观消化率并不等于日粮中各饲料组份表观消化率的加权和值。这种不同饲料源的营养物质之间的整体互作效应就是所谓的日粮配合中的组合效应。1组合效应的概念组合效应指的是混合饲料中营养…     

功能大豆寡肽蛋白饲料品质的评价及其高效应用体系的建立

文章介绍了功能大豆寡肽蛋白饲料的营养特性,指出要结合配合饲料的加工工艺与动物消化道的生理特点对发酵豆粕的品质进行整体评定。同时,就使用功能大豆寡肽蛋白饲料为优质蛋白原料配制日粮,并建立以功能大豆寡肽蛋白饲料与日粮其它饲料间组合效应为基础的高效应用体系的必要性与现实意义进行了论述。     

影响组合效应的因素及其营养调控

卢德勋（2000）指出，日粮组合效应的实质是来自不同饲料的营养物质、非营养物质以及抗营养物质之间互作的整体效应，并且根据利用率或采食量等指标分为“正组合效应”、“负组合效应”和“零组合效应”三种类型。其中正组合效应可以提高粗饲料的消化率和采食量，如对低质饲草进行青绿饲料的催化性补饲时会产生正的组合效应，而负组合效应会降低有效代谢能，典型负组合效应如大量饲喂富含可溶性碳水化合物饲料，导致日粮纤维物质降解率下降。本文主要就影响饲料间组合效应的作用机理、影响因素及其调控技术等方面进行简要综述，以期为畜牧养殖业提供相应的理论参考。     

饲料间的组合效应及其在粗饲料科学搭配上的应用

1 饲料间组合效应的概念 动物的采食水平,日粮中蛋白质补充料、易降解纤维、易发酵碳水化合物和脂肪的添加,以及饲料间的不同搭配、加工调制和一些营养调控措施等均会改变日粮中单个饲料的消化率和利用率,以至配合日粮的表观消化率并不等于日粮中各单个饲料组分表观消化率的加权和值,饲料间的互作使得某一种饲料或日粮的采食量或利用率获得提高或降低。这种不同饲料源的营养物     

饲料间的组会效应及其在粗饲料科学搭配上的应用

1饲料间组合效应的概念 动物的采食水平,日粮中蛋白质补充料、易降解纤维、易发酵碳水化合物和脂肪的添加,以及饲料间的不同搭配、加工调制和一些营养调控措施等均会改变日粮中单个饲料的消化率和利用率,以至配合日粮的表观消化率并不等于日粮中各单个饲料组分表观消化率的加权和值,饲料间的互作使得某一种饲料或日粮的采食量或利用率获得提高或降低.     

饲料间组合效应及其在肉牛饲养中的应用

１饲料间组合效应的概念就消化率而言，当某一日粮的表观消化率不等于组成该日粮的各种饲料消化率的加权平均数时，就意味着产生了组合效应（Ｍｏｕｌｄ，１９８８）。组合效应可分为正（协同）和负（拮抗）组合效应两种。饲养水平是决定组合效应的重要因素之一。维持饲养...     

反刍动物日粮组合效应研究进展

动物的采食水平,日粮中补充料的添加使用,饲粮原料的不同搭配组合和不同比例混合,以及加工调制方法和营养调控措施的不同均会影响动物对日粮中单个饲料的采食与利用,使得日粮的表观消化率并不等于通过"可加性"原则计算的表观消化率的期望值,即发生饲料间的组合效应,又叫"非加性"效应。文章通过对组合效应的研究背景,概念,衡量指标,研究方法,产生机制以及组合效应在生产实践中的应用进行综合论述,为日粮的高效安全配制提供理论指导。     

含次生代谢物饲料组合效应评定方法的比较研究

文章综述了植物次生代谢物的概念、功能及其营养与抗营养作用,并就反刍动物含次生代谢物饲料组合效应的研究方法进行了比较研究,指出瓶子产气法较注射器产气法更适合于在发展中国家开展此类研究,同时提出了具体的设计方法。并特别指出,在用体外产气技术筛选出具代表性的组合后,再结合动物饲养试验,能较全面、准确地评定含次生代谢物饲料的组合效应及其营养代谢机理。     

反刍动物含次生代谢物饲料的组合效应

文章综述了反刍动物含次生代谢物饲料的组合效应,并对该类饲料的组合效应进行了分类,指出了其与常规饲料组合效应的异同及今后值得重点思考的几个问题。同时还就此类饲料组合效应的研究方法进行了比较,指出应在体外产气技术的基础上结合动物饲养试验来进行含次生代谢物饲料的组合效应及其营养代谢机理。     

反刍动物木本饲料的组合效应

本文综述了反刍动物木本饲料的组合效应,并对该类饲料(多含次生代谢物)的组合效应进行了分类,指出了其与常规饲料组合效应的异同及今后值得重点研究的几个问题。同时还就此类饲料组合效应的研究方法进行了比较,指出应在体外产气技术的基础上结合动物饲养试验来进行木本饲料的组合效应及其营养代谢机理的研究。     

2019年肉牛饲料与营养评价的国外研究进展

文章旨在了解饲料与营养对肉牛生产性能、消化性能、瘤胃发酵以及甲烷(CH₄)排放的影响。文章综述了2019年国外的相关文献报道,主要从精饲料、粗饲料及饲养营养综合评价3个方面进行综述。精饲料集中于各种蛋白质饲料和能量饲料的研究。粗饲料研究侧重于粗饲料品种和加工方式对不同生理阶段肉牛生产性能、消化性能和CH₄产生的影响。饲料营养综合评价主要侧重于犊牛期研究,并对育肥期和放牧期肉牛的饲料营养进行评价,以根据肉牛的生理阶段特点,选择适宜的饲料原料,并合理搭配和调制日粮以改善瘤胃菌群结构,充分提高养分利用率。     

猪饲料中能量利用和能量评价体系的研究进展

养猪需要能量用于维持和生产，饲料应根据其能量需求提供准确的可用能量。考虑到总能在消化和代谢过程中的损失，猪饲料中可用能量被定义为消化能、代谢能或净能。在这些能量值中，净能系统被认为提供了最接近动物可利用能量的含量和日粮能量值，因为其考虑了饲料消化利用和代谢的热量增量。但日粮净能值和部分营养素是动态变化的，因此，没有一个净能系统能准确预测饲料中真正可用的能量。饲料消化能或代谢能值对预测净能值很重要，但取决于猪的生长阶段。由于营养物质消化能力的不同，尤其是纤维消化能力，净能值还受环境和猪不同生长阶段营养利用率的影响。因此，在推进饲料能量评价时应考虑动物、环境和饲料特性之间的相互作用。本文综述了猪饲料中不同能量利用和能量评价体系的应用结果。 [关键词]猪；饲料；能量；评价体系     

Crop beta-glucanase activity limits the effectiveness of a recombinant cellulase used to supplement a barley-based feed for free-range broilers

1. The supplementation of diets rich in soluble polysaccharides with microbial cellulases and hemicellulases decreases digesta viscosity and promotes broiler performance. 2. In contrast, recent experiments suggest that polysaccharidases are ineffective for improving the nutritive value of pasture biomass used by free-range broilers. However, the feasibility of using cellulases and hemicellulases to improve the utilisation of cereal-based feeds by pastured poultry remains to be established. 3. A study was undertaken to investigate the capacity of a recombinant cellulase from Clostridium thermocellum to improve the nutritive value of a barley-based feed for free-range pastured broilers of the RedBro Cou Nu x RedBro M genotype. 4. The results show that supplementation of a barley-based diet with a recombinant beta-glucanase had no effect on the performance of free-range broilers, foraging in legume-based diets from d 28 to 56. In addition, the results confirm that the lack of effect of the recombinant enzyme in improving the nutritive value of the barley-based feed does not result from enzyme proteolysis or inhibition in the gastrointestinal tract. 5. Significantly, beta-glucanase activity was identified in the crop of non-supplemented animals. The data suggest that endogenous cellulases originated both from the barley-based feed and from the crop microflora. 6. The results presented here suggest that in older birds of slow-growing genotypes associated with free-range production systems, previously unknown sources of beta-glucanases, such as the feed and microbial symbiotic microflora, can affect the effectiveness of exogenous enzymes added to the feed.     

反刍动物日粮正组合效应的调控及优化配制

本文阐述了日粮组合效应的概念、衡量指标、影响因素及发生机制，并指出通过了解反刍动物日粮不同营养素产生的组合效应，调控饲料互作使之向正组合效应转化，可以科学的利用正组合效应，合理的配制日粮，提高反刍动物饲料的利用率和生产性能。     

Solid state fermented potato pulp can be used as poultry feed

1.?Potato pulp is the industrial waste produced during starch extraction from potatoes. Its discharge has become an environmental pollution problem and a decisive cost factor due to stricter environmental legislation and associated expense in the potato starch industry.

2.?To date, little information has been provided regarding the nutritive value and any possible toxic effects of potato pulp for poultry feed.

3.?In the present paper, a model was developed to assess potato pulp for use as a new poultry feed, which will help starch factories to decrease waste discharge.

4.?First, a solid-state fermentation technique to change potato pulp to poultry feed is briefly described; then, the major nutrient compositions of this feed are analysed; lastly, related toxicological effects are studied and the safety of the feed assessed.

5.?The results indicated that no unintended effects were found on layer quails during a 30-d feeding study, and the new feed initially showed its safety for poultry in our assessment procedure. However, additional work on limiting nutrients analysis, appetite depressant effects, and egg-laying in a large-scale experiment is required to further establish the findings.     

木本饲料青贮及利用研究进展

木本饲料是一种新型的非常规饲料,富含多种氨基酸、维生素和有机物,营养价值丰富,且大部分木本饲料植物粗蛋白质含量较高,可作为优良的蛋白质饲料资源,有效利用能够缓解蛋白质资源匮乏对畜牧业发展的严重制约。但由于抗营养因子的存在,未经处理的木本饲料直接饲喂牲畜适口性较差、消化利用率不高,而通过青贮处理能有效地减少饲料营养物质的损失、提高适口性、改善其营养成分、提升饲喂效果,现已成为一种重要的处理方式。作者基于国内外对木本饲料青贮的相关研究,围绕不同木本饲料营养价值的评定、青贮原料选取、青贮添加剂（化学添加剂、乳酸菌添加剂、酶制剂和营养型添加剂）对青贮发酵的影响、木本饲料与不同原料（禾本科牧草、不同的木本饲料、农业副产品等）混合青贮技术及其对发酵的影响、木本饲料成功青贮后营养成分特征及木本青贮饲料在各项饲喂试验中对不同动物的饲喂效果等方面的研究进展进行系统地综述,并针对木本饲料的研究现状及资源重要性对其未来发展提出建议和展望,以期为木本青贮饲料的后续开发和实际生产应用提供参考。     

长颈鹿饲养管理和日粮养分估算

介绍了长颈鹿的一些生物学特征：分类、生理特性、天敌和食性。根据太原动物园多年饲养经验,长颈鹿日粮包含精料、蔬菜、水果、树叶、稀饭、补充营养等。估算了长颈鹿精料（颗粒料）营养成分和所有日粮营养成分。长颈鹿所有日粮养分含量估算结果如下：能量3.20MJ/kg,粗蛋白质13.69%,粗脂肪3.83%,粗纤维8.95%,碳水化合物34.31%,灰分4.31%,钙1.53%,总磷0.12%。提出了饲养管理中的一些建议：日常饲喂中要禁止饲喂发霉变质饲料,要留意拣出草料中的绳索、塑料袋、金属等异物,防止对动物造成不必要的损伤。根据季节、气候调整日粮,西瓜、黄瓜、绿豆只在夏季提供。长颈鹿属反刍动物,日常饲喂要以树叶为主,槐树叶营养丰富,是优良的长颈鹿饲料。大葱可能对长颈鹿有特殊作用。     

Influence of antibiotics used as feed additives on the immune effect of erysipelas live vaccine in swine

To investigate the influence of antibiotics used as feed additives on the immune response to erysipelas live vaccine, the pig inoculation test was applied. Avilamycin, oxytetracycline quaternary salt, enramycin, virginiamycin and tylosin phosphate were selected as test antibiotics. Five experimental feeds containing each antibiotic at the highest concentration permitted for feed additives in Japan, and the basal diet lacking antibiotics were examined. Twenty-nine pigs were divided into six groups. At first all the groups were fed with the antibiotic-free basal diet for 7 days, and then each group received the experimental feeds. On the 14th day after feeding with test feeds all the pigs, except for one control pig in each group, were immunized with the vaccine and all the pigs were then challenge-exposed to a virulent strain of Erysipelothrix rhusiopathiae 14 days after vaccination. The clinical response was observed every day for 14 days. In all the groups, most of the vaccinated pigs did not develop any clinical signs of acute erysipelas after the challenge exposure, whereas non-vaccinated control pigs died or showed severe generalized erythema with profound depression and anorexia. No differences in the protection against the challenge exposure were observed among the groups. Therefore, the present results suggest that these selected antibiotics would not interfere with the immune effect of the vaccine if given at the usual concentrations used for feed additives.     

Optimal beef cattle diets formulated by nonlinear programming

A beef diet model based on National Research Council recommendations is significantly nonlinear for feed ingredients, daily gain and weight of cattle. Solving a diet model has been difficult, but advances in nonlinear programming now allow solutions that are quick and easy. This study developed a nonlinear programming method for optimally planning a feeding program by choosing feeds, daily gains and selling weight. Two types of diets are important for this purpose:optimal-return diets and least-cost-gain diets. For a given weight of cattle, an optimal-return diet chooses feeds and daily gain to maximize returns above feed costs. A least-cost-gain diet chooses feeds and daily gain to minimize feed plus yardage costs per kilogram of gain. In an optimal feeding program, a sequence of optimal-return diets is fed to increasing weights of cattle. Feed costs plus yardage per kilogram of gain rise to equal the actual selling price at the optimal selling weight, and the cattle are sold. Cattle feeders and researchers with access to a microcomputer can maximize net returns from a feeding program.     

Predicting intake and digestibility using mathematical models of ruminal function

Intake and digestibility of feeds by ruminants are influenced by characteristics of the feed, animal and feeding situation. Integration of these characteristics in mathematical models is critical to future progress in forage evaluation and optimal formulation of diets for ruminants. The physiological and physical theories of intake regulation can be described by simple mathematical equations. These equations indicate that intake is a linear function of animal characteristics, such as body weight and production level, and a reciprocal function of feed characteristics, such as fill effect and energy content. Theoretical equations were developed to predict intake when the neutral detergent fiber and energy content of the diet and the energy requirements of the animal are known. The theoretical model also can be used to predict the maximum intake that will maintain a given level of animal production by solving the physiological and physical intake equations at their intersection. Psychogenic intake regulation, which is related to the animal's behavioral response to factors not related to physiological or physical characteristics, can be described mathematically as a multiplier. Digestibility can be predicted by summing the contents of ideal nutritive entities in feeds, which have true digestibilities near 100%, subtracting their associated endogenous losses and adding the variable digestible fiber content. Steady-state models indicate fractional rates of digestion and passage can be used to define ideal nutritive entities and predict digestibility over a range of kinetic characteristics. The steady-state solutions are particularly useful in understanding and predicting the depression in digestibility associated with changes in rates of passage at high levels of feed intake.