Application and Regulatory Mechanisms of Cereal Diets Treated with Lactic Acid in Ruminants北大核心CSCD

近年来,反刍动物集约化养殖中为追求快速高产,常饲喂高精料饲粮,但随之也带来一系列的危害。乳酸处理谷物饲粮通过改性淀粉,可调控反刍动物瘤胃发酵,增加其瘤胃消化抗性,使更多淀粉进入小肠消化,增加饲粮效率,并在缓解瘤胃酸中毒方面有积极的意义。本文主要分析了乳酸处理谷物饲粮对反刍动物瘤胃pH、胃肠道微生物、生产性能、饲粮中磷消化率、机体代谢组和炎性反应的影响及其潜在调控机制,为有效利用乳酸处理谷物饲粮、促进反刍动物健康养殖提供理论依据。     

亚急性瘤胃酸中毒对反刍动物瘤胃生理功能及物质吸收转运的影响

畜牧业集约化养殖越来越普遍。为提高反刍动物生产性能,饲喂大量能量饲料,进而引发亚急性瘤胃酸中毒(SARA),导致动物采食量下降、畜产品产出降低以及动物发生炎症反应。近年研究表明,SARA会改变瘤胃生理状态,而瘤胃健康对反刍动物饲养至关重要。本文综述了反刍动物SARA状态下瘤胃生理生化过程变化,结合瘤胃发酵模式变化和瘤胃微生物的改变,重点阐述了SARA引起的瘤胃上皮细胞形态结构变化、屏障功能改变、瘤胃上皮细胞中物质转运及相关载体表达及其引发的瘤胃上皮细胞炎症通路,为更好指导反刍动物饲养及为瘤胃营养生理生化研究提供参考。     

单宁对反刍动物生产性能、瘤胃发酵及微生物区系影响的研究进展

单宁是一类广泛存在于植物中的多酚化合物,因其涩味降低反刍动物采食量,故通常被归类为饲料中的抗营养因子。近年来,研究发现单宁可与蛋白质结合,抑制蛋白质被瘤胃过度降解,增加了蛋白质在后肠道的消化吸收,提高了反刍动物对氮元素（N）的利用率。此外,研究表明单宁在调控瘤胃发酵和抑制甲烷排放方面表现出积极作用。本文主要综述了单宁对反刍动物生产性能、瘤胃发酵和微生物区系的影响,旨在为其应用于反刍动物健康养殖提供合理的理论参考依据。     

Using the unique degradation ratio system (DRS) as an alternative method for feed evaluation and diet formulation: A review

Recently obtained information on applications of the unique degradation ratio system (DRS) as an alternative method for feed evaluation and diet formulation is reviewed, in relation to optimum rumen fermentation and nutrient utilization and availability. The DRS ratio values show the balance between potentially microbial protein synthesis from rumen degradable crude protein and that potentially from the energy extracted during anaerobic fermentation in the rumen. In modeling feed evaluation and diet formulation, the degradation ratios can be used in assisting to detect effects of feed processing and optimize the composition of ruminant diets. Unfortunately, few researchers provide such crucial ratio data when they studied rumen degradation characteristics of a feed or diet mainly due to lack of knowledge of the DRS system. The emphasis of this article is on: (i) systematic introduction of the DRS system; and (ii) prediction the optimal rumen fermentation using the DRS system. The information described in this article may give better insight into the principal, computation and applications of the DRS system for feed and diet evaluation. A focus of the article is on evaluation of the DRS system as an alternative new approach to establishment of a feed evaluation system that more accurately accounts for feed digestive processes in the ruminant on a quantitative basis.     

奶牛低淀粉型日粮研究进展

低淀粉型日粮的应用不仅可以满足高产奶牛生产阶段的能量需要,而且可以保证奶牛瘤胃健康,避免瘤胃酸中毒。常用低淀粉型饲料有优质牧草、中性洗涤可溶性纤维源饲料以及可溶性糖三大部分。饲喂低淀粉型日粮可以有效缓解挥发性脂肪酸的产生,避免瘤胃pH降低,并促进了奶牛的采食以及养分消化,提高乳品质。本文从低淀粉型日粮的实现手段,以及瘤胃发酵参数和生产性能方面阐述低淀粉型日粮在奶牛生产中的必要性,确立今后的研究重点应该在各种原料替代谷物原料的最适比例及组合效应方面,从而完善奶牛低淀粉型日粮配制技术。     

反刍动物日粮物理有效中性洗涤纤维的研究进展

饲料纤维在反刍动物日粮中不仅具有化学成分的重要性,且纤维的物理性状(颗粒大小)还能够影响咀嚼活动、瘤胃发酵、乳脂肪含量及机体健康状况。作者就表征纤维的化学和物理性状的指标——物理有效中性洗涤纤维的定义、内涵、计算方法及对反刍动物进食行为、瘤胃发酵、营养物质消化率和泌乳性能等方面的营养调控功能进行了综述。     

蒸汽压片玉米在奶牛生产中的应用研究进展

玉米是奶牛舍饲的主要能量饲料来源之一,而蒸汽压片技术是一项目前较为成熟的日粮加工技术,主要通过机械的湿热加工方法改变原料物理形态和营养物质的化学结构,广泛应用于反刍动物日粮中。蒸汽压片处理工艺中的蒸汽压力、温度和处理时间会影响压片产品的容重和淀粉糊化度,进而影响其饲喂效果。研究发现,经蒸汽压片处理的玉米可有效提高其淀粉消化率,加快瘤胃内的发酵速度,改变瘤胃发酵模式,促进瘤胃微生物蛋白合成,有利于维持瘤胃pH及瘤胃内环境的稳定。也有研究表明,蒸汽压片玉米饲喂奶牛后,对其采食量没有明显影响,但可以提高产奶量,改善乳成分,从而提高奶牛的产奶性能。作者对蒸汽压片玉米技术及其在奶牛生产中的应用研究进展进行综述,以期为蒸汽压片玉米在中国奶牛生产中的合理使用提供参考。     

不同离子型表面活性剂对反刍动物瘤胃发酵调控的研究进展

表面活性剂是一种新型的反刍动物饲料添加剂,根据表面活性剂的分子结构,可将其分为阴离子型、阳离子型、两性离子型和非离子型表面活性剂,其作用机理是通过改变瘤胃微生物种群数量进而增加瘤胃内源性酶的分泌量、分泌酶活性或促进酶与底物之间的相互作用,改变瘤胃发酵模式,提高瘤胃微生物对粗饲料的降解能力,进而提高反刍动物生产性能。作者主要综述了表面活性剂的分类及几种常见的表面活性剂对反刍动物瘤胃发酵调控的影响,其中包括非离子型（吐温、烷基多糖苷、茶皂素）、两性离子型（甜菜碱、大豆磷脂）和阴离子型（十二烷基苯磺酸钠、磺基丁二酸钠二辛酯）;介绍了日粮中添加不同离子型表面活性剂对反刍动物瘤胃微生物种群数量、内源酶活、发酵产物等影响,为新型表面活性剂的开发和表面活性剂在反刍动物日粮中的合理应用提供参考依据。     

植物提取物调控反刍动物瘤胃发酵的研究进展

植物提取物中的挥发油、皂苷、生物碱、萜类等化学物质具有抗菌、促生长、提高免疫力和抗氧化等功能。近年来研究发现,植物提取物还可以调控反刍动物瘤胃发酵模式,提高氮存留,减少甲烷排放的功能,因此,植物提取物作为调控反刍动物瘤胃发酵的一种重要添加剂得到了广泛的研究与应用。目前国内外的学者已经在有效植物品种的筛选和植物提取物作用机理、剂量效应等方面的研究取得了较大进展。文中就目前植物提取物对反刍动物瘤胃发酵调控的最新研究进展作一综述,为我国开展植物提取物作为反刍动物瘤胃发酵调控添加剂的研究提供参考。     

幼龄反刍动物纤维营养需要与影响因素

幼龄反刍动物饲粮的纤维性碳水化合物(FC)来源与组成对调控其生长发育和瘤胃功能建立有重要作用,其来源各异,粒度不同,对正处于生长期的幼龄反刍动物的采食和消化、瘤胃液p H及瘤胃发育等生理参数的影响存在差异。本文综述了近年来关于幼龄反刍动物饲粮中性洗涤纤维(NDF)来源和粒度的研究,分别从生产性能、瘤胃发酵和瘤胃发育3个方面总结了二者对幼龄反刍动物的影响,并对相关机制进行了探讨。     

瘤胃中乳酸的代谢及其调控机制

有关瘤胃酸中毒发生机制研究表明,瘤胃乳酸的累积可能对酸中毒诱导起重要作用,而高精料日粮下瘤胃乳酸累积主要取决于瘤胃乳酸产生菌和乳酸利用菌间的平衡程度。本文综述了瘤胃微生物对乳酸的代谢机制,包括主要乳酸产生菌[溶纤维丁酸弧菌(Butyrivibrio fibrisolvens)、牛链球菌(Streptococcus bovis)、乳酸杆菌(Lactobacillus)]和主要乳酸利用菌[反刍兽新月单胞菌(Selenomonus ruminantium)、埃氏巨型球菌(Megasphaera elsdenii)],并简要概述了酸中毒的调控方法,旨在为反刍动物瘤胃酸中毒的乳酸中毒机制深入解析提供参考。     

Comparative aspects of plant tannins on digestive physiology,nutrition and microbial community changes in sheep and goats: A review

Comparative aspects of plant tannins on digestive physiology, nutrition and microbial community in sheep and goats are discussed in the context of differences due to feed intake, digestibility, utilization of nutrients and microbial community. The purpose of this review was to present an overview of the potential benefits of tannin‐containing diets for sheep and goats and specie differences in their response to tannins. It is well established that moderate level of tannins in the diet (3%–4% tannins DM) can precipitate with soluble proteins and increase protein supply to the sheep, but comparative aspects of tannin‐containing diets in sheep and goats on animal performance, digestive physiology, rumen microbial changes and potential benefits to sustainable animal production by those compounds have received little attention. In addition, developing plant‐based tannin‐containing diets for control of rumen microbiota and rumen fermentation (e.g., methane gas) would be expected to have a greater impact on the ruminant health, productivity and emission of greenhouse gasses. The positive impacts of the plant tannin compounds mainly depend on their influence on the gut microbiome diversity and ability to generate fermentation end products (short‐chain fatty acids) that have diverse biological roles. Diets which contain optimal levels of tannins have potential benefits for sustainability of small ruminant production systems. However, there is a need for an improved understanding of the utilization of tannin‐containing forages to improve their management. This implies investigations of animal responses to tannin‐containing forages or browse species and, in particular, a better understanding of the interactions that can arise between sheep and goats on digestion, DMD, rumen fermentation and microbial community changes. This knowledge could help to improve current feeding systems in terms of efficiency of feed use and environmental impacts (reduce methane gas production) and thus contribute to the development of a sustainable sheep and goat production.     

2010年国际反刍动物营养研究进展——Ⅱ.碳水化合物营养

碳水化合物在优化反刍动物瘤胃发酵,提高饲料利用效率,进而提高动物的生产性能等方面具有极其重要的作用。作者从碳水化合物的需要量的生理机制,农副产品应用及其对反刍动物生产性能、繁殖性能和产品品质影响等方面对反刍动物碳水化合物营养研究进行了综述。     

Effects of wood kraft pulp feeding on feed digestibility and rumen fermentation of Japanese Black steer in the middle fattening stage

We investigated the effects of wood kraft pulp (KP) feeding on feed digestibility and rumen fermentation of Japanese Black (JB) steer in the middle fattening stage. The feeding experiment was carried out a replicated 3 × 3 Latin square design using six JB steers (16.2 ± 0.8 months of age). Steers were fed rice straw and three concentrated feeds: commercial formula feed (control), formula feed containing 7.5% KP on a dry matter (DM) basis (7.5% KP), and formula feed containing 15% KP on a DM basis (15% KP). Feed digestibility and rumen fermentation parameters were recorded for 3 days during the measurement period, after an adaptation phase of 11 days. There was no significant difference in DM intake per day among diets. A slightly higher digestibility of neutral detergent fiber was observed in steers fed 15% KP, compared with those fed other diets (P = 0.059). The butyric acid ratio in rumen fluid was higher in steers fed KP diets than in steers fed control (P = 0.083). The average ruminal pH was unaffected by KP diets. This study suggests that replacing 15% of concentrated feed with KP has little effect on feed digestibility and rumen fermentation in JB fattening steer.     

反刍动物瘤胃发酵调控措施

本文论述了通过改变日粮、添加离子载体、饲用微生物及利用基因工程技术等手段对瘤胃发酵进行调控的作用瘤胃发酵调控的机理,探讨瘤胃调控目前面临的问题和对未来的展望,以便更好地调节瘤胃发酵使反刍动物达到稳定高效的生产目标。     

ASAS Centennial Paper: animal science teaching: a century of excellence

Teaching has a long and varied history in the life of departments of animal science and the American Society of Animal Science. Some of the earliest reports from meetings of the society have strong indication that planning the curriculum was a prominent feature of the meetings. Teaching symposia were also included almost from the beginning. The society went through a lengthy period from the 1940s through most of the 1960s when teaching was not a prominent focus, but a symposium in 1968 appeared to be a catalyst for change, and, since that date, teaching has again been an important part of the meetings. In recent years, outstanding symposia and contributed papers have made the teaching section a vibrant entry. Departments of animal science have changed considerably since the early days in which "men taught boys" and the primary goal was to produce farmers. More female students, more urban students, interest in a wide variety of animals, and greatly diversified career goals have been emerging during the last few decades. Departments of animal science and the American Society of Animal Science are positioning to be able to respond to change and face the challenge of providing excellence in teaching during the next century.     

Effects of tea saponins on rumen microbiota,rumen fermentation,methane production and growth performance—a review

Reducing methane emission from ruminant animals has implications not only for global environmental protection but also for efficient animal production. Tea saponins (TS) extracted from seeds, leaves or roots of tea plant are pentacyclic triterpenes. They have a lasting antiprotozoal effect, but little effect on the methanogen population in sheep. There was no significant correlation between the protozoa counts and methanogens. The TS decreased methanogen activity. It seems that TS influenced the activity of the methanogens indirectly via the depressed ciliate protozoal population. The TS addition decreased fungal population in the medium containing rumen liquor in in vitro fermentation, but no such effect was observed in the rumen liquor of sheep fed TS. Tea saponins had a minor effect on the pattern of rumen fermentation and hence on nutrient digestion. When added at 3 g/day in diets, TS could improve daily weight gain and feed efficiency in goats. No positive associative effect existed between TS and disodium fumarate or soybean oil on methane suppression. Inclusion of TS in diets may be an effective way for improving feed efficiency in ruminants.     

高精料饲粮条件下反刍动物瘤胃适应机制的解析

饲喂高能、高淀粉饲粮是集约化生产中提高反刍动物生产性能的常用策略,但高精料饲粮易引起一系列的营养代谢疾病,其中以瘤胃酸中毒最为常见。反刍动物瘤胃不仅具有消化、吸收营养物质的功能,瘤胃上皮亦是重要的免疫屏障,故瘤胃健康对反刍动物至关重要。本文主要从反刍动物采食高精料饲粮时其瘤胃组织形态、瘤胃上皮适应分子机制和瘤胃微生物区系3个方面的变化进行阐述,以期为高精料饲粮条件下瘤胃适应机制的研究提供参考。     

Effect of increased concentrate allotment before evening grazing on herbage intake,nitrogen utilization and rumen fermentation in dairy cows grazed on perennial ryegrass pasture

Two experiments were conducted to elucidate the effect of increased concentrate allotment before evening grazing on herbage intake, nitrogen utilization and rumen fermentation in dairy cows. In experiment 1, nine lactating cows were grazed in the morning and evening sessions (2.5 h each). The cows were allocated to treatments of three concentrate allotment levels before the evening grazing session by altering proportions to daily total offered; 25%, 50% and 75%. Daily herbage dry matter intake quadratically decreased with increasing the concentrate allotment levels (P < 0.05). Nitrogen utilization was similar among treatments. To investigate diurnal changes in rumen fermentation, a second experiment was conducted where six ruminally cannulated non‐lactating dairy cows grazed in the morning and evening sessions (3 h each) were subjected to the same treatments as experiment 1. Total volatile fatty acid concentration in the rumen linearly increased with increasing the concentrate allotment levels throughout the pre‐evening grazing session to the post‐morning grazing session (P < 0.01). The results indicate that dairy cows reduce daily herbage intake but do not alter nitrogen utilization with increasing concentrate allotment before evening grazing. © 2016 Japanese Society of Animal Science     

有机酸对反刍动物营养的应用研究

有机酸可改变反刍动物瘤胃发酵类型、改进其生产性能。作为一种新型的“绿色”活性添加剂，其在反刍动物生产上具有广阔的应用前景。