Technical note: methods for detecting liquid enzyme additives added to animal feeds.

Methods for detecting and measuring the quantity of fibrolytic enzyme preparations added to feeds were investigated by enzymatic and tracer methods. Enzyme preparations added to corn silage, ryegrass silage, and a total mixed ration containing both silages and a concentrate could not be detected using their enzymatic activities. Glycosidase activities of solubles washed from the feed were more than an order of magnitude greater than glycosidases in the added enzymes. Carboxymethylcellulase and xylanase activity determinations, using reducing sugar release as the measurement, were subject to interference from reducing sugars present in the feed. A fluorescent tracer method, using fluorescein added at a rate of 1 g/L of feed enzymes, or 2 g/t of feed, was developed that enabled sensitive detection of liquid enzyme additions to feeds.     

柠檬成熟果实可溶性糖和有机酸积累特征分析

本研究利用GC-MS对3个柠檬品种和2个贵州地方特色宽皮柑橘(牛肉红朱橘和朱红橘)果肉中可溶性糖和有机酸含量进行了检测。研究结果表明,共检测到蔗糖、果糖、葡萄糖、木糖等10种可溶性糖,以及柠檬酸、苹果酸、奎宁酸、草酸等10种有机酸。柠檬、牛肉红朱橘、朱红橘可溶性糖和有机酸组分类似,差异主要在含量上。可溶性糖含量分析结果表明,果实中主要可溶性糖为蔗糖、果糖和葡萄糖,3种主要的可溶性糖在牛肉红朱橘和朱红橘中的平均含量均显著高于柠檬,分别是柠檬的4.51倍、2.18倍和1.68倍。有机酸含量分析结果表明,柠檬有机酸含量远高于牛肉红朱橘和朱红橘,3个柠檬柠檬酸和奎宁酸的平均含量分别是2个宽皮柑橘的12.18倍和10.05倍。以上分析结果表明,可溶性糖和有机酸含量反映了柑橘品种的种质特征,且与果实风味和口感一致。     

龙眼干果与鲜果的糖组分分析

利用高效液相色谱法 (HPLC) 分析了石硖、储良、东壁、青壳宝圆、冬宝9号、公妈本、九月乌、施冲浦、晚香等9个龙眼品种干果和鲜果的糖组分含量。结果表明,9个龙眼品种干果和鲜果中的可溶性糖主要有果糖、葡萄糖和蔗糖;鲜果中的果糖含量16.4 ~ 36.0 mg/g,葡萄糖含量14.9 ~ 33.7 mg/g,蔗糖含量87.5 ~ 161.7 mg/g,总糖含量135.7 ~ 193.0 mg/g,甜度值144.5 ~ 200.8;干果中的果糖含量84.5 ~ 160.7 mg/g、葡萄糖含量67.5 ~ 125.8 mg/g、蔗糖含量169.0 ~ 356.8 mg/g、总糖含量444.6 ~ 538.2 mg/g、甜度值497.2 ~ 590.7;龙眼干果和鲜果中均以蔗糖含量最高;与鲜果相比,干果中的果糖、葡萄糖占比提高,蔗糖占比降低。     

Recycled poultry bedding as cattle feed.

Since the 1950s, recycled poultry bedding has been used as an economical feedstuff for beef cattle. It has been extensively studied at several experiment stations around the world with regard to its safety and nutritional aspects. It will continue to be closely scrutinized as the public increases its awareness of agricultural issues. As this study was being prepared, the news media was "spotlighting" bovine spongiform encephalopathy. Currently, in the United States there is a ban on incorporation of mammalian-derived protein feeds into ruminant diets. This has led to a requirement of beef cattle producers signing affidavits indicating that they had met this obligation. Some poultry companies use ruminant meat and bone meal in broiler diets when least-cost formulation indicates that it is economically desirable. This then poses the question of whether feeding RPB to beef cattle should be permitted if the birds had been fed ruminant meat and bone meal. It also raises the question of whether cattle grazing pastures fertilized with RPB are exposed to ruminant meat and bone meal. Because of the importance of pasture fertilization as a waste disposal solution for the poultry industry, it seems that the issue will be quickly resolved by omitting the ruminant meat and bone meal from poultry diets should concerns increase. Use of RPB, like many byproduct feeds, requires a higher level of management expertise than traditional feeds. Despite the potential problems discussed in this study, an informed beef cattle producer can gain a financially competitive edge by using RPB. A simple processing method, deep-stacking under polyethylene sheeting, can produce a safe product that will provide a complete diet when blended with an energy source and supplemented with some long-stem fiber. The diets can be used for both brood cows and stocker calves for extended periods of time, and the practice of feeding RPB is safe for both cattle and consumers [45]. Economic parameters will influence the future use of RPB; however, the general public's perception and acceptance will ultimately determine its long-term use.     

脂肪酸钙在反刍动物饲料中的应用

本文综述了脂肪酸钙的营养特性及其在反刍动物饲料中的应用效果,旨在为其在反刍动物日粮中的合理应用提供理论依据。     

糖蜜在反刍动物营养中的应用

糖蜜是甘蔗、甜菜等榨糖后的一种副产品.近年来,糖蜜已经成为了反刍动物饲养中一种必不可少的辅助性饲料.本文主要综述了糖蜜的营养特性及其在反刍动物营养中的作用,为其在反刍动物饲料中的研究、开发和应用提供理论依据.     

体外法在反刍动物饲粮营养价值评定上的应用

体外评定技术是利用离体方法评定反刍动物饲粮营养价值的一系列方法与技术。目前常用的体外评定技术包括瘤胃微生物消化法、酶法、尼龙袋法和体外产气法等。本文针对上述几种方法的特点及优缺点进行了评述,并详细介绍了体外产气技术,比较了注射器式和压力传感器式两个体外产气系统。     

The intravenous bile Acid loading test in the goat: determination of a procedural protocol and reference values

An intravenous bile acid loading test was performed on 16 goats using various dosages and sampling protocols. A recently developed enzymatic bile acid assay provided an economical and technologically simple method for bile acid analysis. Intravenous injection of bile salts into goats was well tolerated. Clearance times were rapid. A protocol for performance of the test was suggested and a practical reference range for T 1/2 clearance of 4+/-1 minute was determined. Further investigations of this test in the assessment of liver function in the ruminant appear warranted.     

科尔沁沙地播种时期对不同紫花苜蓿品种抗寒性的影响

为探讨科尔沁沙地苜蓿根颈抗寒保护物质对播种时期的生理响应。选择3个紫花苜蓿品种(骑士T、公农1号、擎天柱),在内蒙古自治区赤峰市阿鲁科尔沁旗草业核心区,于2017年7月1日开始,每隔5 d播种一期,播种至8月15日。2017年10月11日、11月11日取样测定紫花苜蓿根颈中可溶性糖、可溶性蛋白、游离氨基酸、淀粉含量,翌年春季调查越冬率,对苜蓿根颈中的抗寒保护物质含量变化及其与越冬率的相关性进行探究。结果表明,随着播种时期的推迟,苜蓿根颈的可溶性糖、可溶性蛋白、淀粉、游离氨基酸均呈递减趋势,苜蓿越冬率与11月11日取样测定苜蓿根颈中的可溶性糖、可溶性蛋白、游离氨基酸均呈极显著正相关关系;苜蓿越冬率与10月11日取样测定苜蓿根颈中的可溶性糖含量呈显著正相关关系,与可溶性蛋白和游离氨基酸呈极显著正相关关系;公农1号苜蓿品种在11月11日测定的根颈的可溶性糖含量及淀粉含量显著高于骑士T和擎天柱,且与越冬率变化一致。研究认为,播种时期是影响科尔沁沙地苜蓿越冬的重要因素之一,苜蓿根颈中可溶性糖、可溶性蛋白、游离氨基酸是抗寒保护物质。为确保安全越冬科尔沁沙地种植苜蓿最佳的播种时期为7月1日-7月16日,适宜该地区种植的品种为公农1号。     

高寒草场主要牧草对黄帚橐吾水浸液化感胁迫的生理响应

用不同浓度的黄帚橐吾叶水浸液处理高寒草场4种常见牧草中华羊茅、大雀麦、垂穗披碱草和早熟禾后,测定了受体植物叶片内超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性,及丙二醛、可溶性糖和脯氨酸的含量以及相对电导率等生理指标,旨在探讨受试植物对黄帚橐吾化感作用的生理响应。结果显示,游离脯氨酸的变化在所有处理中均达到显著或极显著差异,且明显的依赖浓度,可能与降低渗透势,保证组织在化感物质胁迫引起水势下降时细胞膨压得以维持有关。其余指标变化不同,反应出不同受体植物对相同化感胁迫的生理响应是不同的。     

钼的毒性与反刍动物钼中毒

本文综述了微量元素钼对反刍动物毒性的研究结果,如:钼的化学特性、钼在饲料与反刍动物体内的含量与分布、钼的生物学作用、钼在反刍动物体内的吸收、代谢及与其它元素间的互作等。最后阐述了反刍动物钼营养需要量、饲料中钼的最大允许量及反刍动物钼中毒的防治。     

饲料中牛、羊源性成分现场可视化检测方法的建立

根据牛、羊线粒体中物种特异性序列设计引物,应用可视化环状等温扩增技术（visual loop-mediate isothermal amplification,vLAMP）对牛、羊源性成分进行快速扩增及可视化判断,同时建立牛、羊源成分人工污染的饲料模型,考察vLAMP检测方法的灵敏度。结果表明,牛源性引物和羊源性引物仅分别对牛、羊源性成分产生特异性扩增,灵敏度高达0.001%。本试验所建立的牛、羊源性成分现场可视化筛查方法具有较高的特异性与灵敏度,操作简单、快速,可用于饲料中牛、羊源性成分污染和食品掺伪的现场可视化检测。     

过瘤胃氨基酸在反刍动物饲料中的应用

本文综述了过瘤胃赖氨酸及蛋氨酸在反刍动物饲料中的应用,旨为过瘤胃氨基酸在反刍动物生产中的合理使用提供理论依据。     

利用芳香族化合物估测反刍动物采食量的潜力

综述了芳香族化合物的发现过程、反刍动物饲草料、瘤胃和尿液中芳香族化合物的主要类型及存在形式.马尿酸是最早从家畜排泄物中发现的芳香族化合物.反刍动物的尿液中排出的苯甲酸几乎完全来源于日粮中的前体物.饲料日粮中芳香族化合物是酚酸、简单酚、香豆素、棉子酚、酚的生物碱、类黄酮、单宁酸和木质素.羟基肉桂酸和安息香酸是维管束植物中广泛存在的一类酚类化合物,其在禾本科牧草中的含量远高于豆科牧草,但禾谷类籽实中的含量却很低.瘤胃液和尿液中的芳香族代谢物主要是无酚的芳香酸、酚酸和苯酚,环己烷羧酸是惟一发现的脂环族酸.饲喂不同的日粮饲草料,反刍家畜以马尿酸形式排出的氮量大约占尿氮总量的6%,变化范围为1%～38%.测定尿中芳香族化合物特别是马尿酸对预测反刍家畜的采食量具有重要潜力和作用.     

Effective rumen degradation of dry matter, crude protein and neutral detergent fibre in forage determined by near infrared reflectance spectroscopy

The objective of the present study was to examine if near infrared reflectance spectroscopy (NIRS) could be used to predict degradation parameters and effective degradation from scans of original forage samples. Degradability of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) of 61 samples of perennial ryegrass (Lolium perenne L.) and orchardgrass (Dactylis glomerata L.) was tested by using the in situ technique. The grass samples were harvested at three different stages, early vegetative growth, early reproductive growth and late reproductive growth. Degradability was described in terms of immediately rumen soluble fraction (a fraction, for DM and CP only as NDF does not contain a soluble fraction), the degradable but not soluble faction (b fraction) and the rate of degradation of the b fraction (c value). Overall effective degradability of DM, CP and NDF was also calculated. Near infrared reflectance spectroscopy was examined for its ability to predict degradation parameters and to make a direct prediction of effective degradation from scans of the original samples of perennial ryegrass and orchardgrass. Prediction of effective degradation of the different feed fractions showed different accuracy. The coefficients of determination (R(2)) from regressions of predicted vs. measured effective degradation, using a cross-validation method, were 0.92 for DM, 0.78 for CP and 0.61 for NDF. The attempt to predict the degradation parameters (a, b and c) by NIRS was less successful as the coefficients of determination for the degradation parameters were low. Concentrations of CP and NDF in the original samples were predicted by using NIRS and the validated R(2) value was 0.98 for CP and 0.92 for NDF. It is concluded that using NIRS predictions from scans of original samples is a promising method to obtain values for the effective degradation of DM, CP and NDF in ruminant feeds, but that larger calibration sets are necessary for obtaining improved accuracy.     

Detection of Coxiella burnetii in placenta and abortion samples from British ruminants using real-time PCR

A real-time PCR was developed to detect Coxiella burnetii (the cause of Q fever) in ruminant placentas and aborted fetuses. Primer and probe sets previously developed for human tissue studies were used to target the insertion sequence IS1111 gene for C burnetii. The assay was highly sensitive, with a limit of detection of 10 copies of template, theoretically equating to a single bacterium, and did not cross-react with a panel of other bacteria. To determine sensitivity on field samples submitted for the diagnosis of abortion, results using the IS1111 PCR assay were compared with a com1 PCR assay. When applied to ruminant abortion material, including placental cotyledons and fetal samples, the IS1111 and com1 assays yielded positive results in 23 (25 per cent) of 93 and 19 (20 per cent) of 93 samples, respectively. One infected goat herd was monitored for 31 months: 57 (92 per cent) of 62 placental cotyledon samples from aborting and non-aborting goats, and 10 (30 per cent) of 33 fetal samples were positive by the IS1111 PCR assay.     

我国北方地区奶牛常用饲料蛋白质组分及其降解规律的研究

本试验研究以NRC(2001)奶牛营养需要(第7版)采用的对粗蛋白质组分的分析方法为基础,对奶牛养殖中常用的部分饲料原料进行取样分析,利用尼龙袋法测定出这些常用饲料原料的各种蛋白质组分(A、B、C)和B组分的降解速率。结果表明,粗饲料的粗蛋白质中A组分和C组分的比例较高,A组分变异较大;B组分的比例相对较小,在瘤胃中的降解速率较低。精料的粗蛋白质中B组分的含量较高,而C组分的含量较低。因而,精料是反刍动物瘤胃降解蛋白质(RDP)和瘤胃非降解蛋白质(RUP)的主要来源。     

Effect of dietary amino acids on in vitro rumen bacterial protein synthesis in buffaloes.

The effect of different ratios of urea to amino acid N at a fixed concentration of soluble sugars as energy source and varying levels of soluble sugars at optimum urea cell suspension was obtained from the rumen fluid of buffalo (Bubalus bubalis) calves fed on a growth ration. Under glucose fermentation, the bacterial protein content of the incubation mixture (I. M.) was increased to 3.91, 6.31 and 5.08 times the control value (urea alone) when 25, 50 and 75% of urea-N was replaced with amino acid N, respectively. With cellobiose, the corresponding increase was 4.06, 5.29 and 5.63 times. At 50% urea-N replacement with amino acid N (a ratio for maximum protein synthesis), the bacterial content was maximum when 1 g glucose or cellobiose per 100 ml of I. M. was added. Per cent incorporation of radioactivity from amino acids into bacterial protein was maximum at 25% amino acid N level with both the soluble sugar sources. The total amino acids incorporated into bacterial protein were, however, more at 50% than at 25% amino acid N level.     

Nutrient Value Evaluation of Different Type Feeds by in vitro Gas Production Method

The experiment was conducted to evaluate nutrient value of ruminant feeds by in vitro gas production method.The volume of gas production(GP) at 2, 6, 12 and 24 h, in vitro fermentation parameters and nutrient degradation rate of three energy feeds(corn, corn bran and wheat bran) and three roughages(alfalfa meal, alfalfa hay and corn silage) were measured, and gas production kinetic parameters among different feeds and the relationship between fermentation kinetics and nutritent composition were analyzed.The results showed that the GP₂₄, theoretical gas production(A) and B of corn was the highest among energy feeds, but there was no significant differences of B among different energy feeds(P>0.05).The DMD of corn, the NDFD of corn bran and the CPD of wheat bran were the highest;There were no significant differences in GP₂₄ among roughages.The GP₂₄, A, DMD, CPD of alfalfa meal were the highest, while there was no significant differences of B among roughages(P>0.05).Correlation analyses indicated that the theoretical maximum gas production and the accumulative gas production were extremely significant negatively related to CP, NDF, ADF and Ash(P<0.01).Therefore, the experiment revealed that significant differences were observed in in vitro gas producetion kinetic parameters among different feeds, which could supply scientific basis for diet formulation in dairy practice.     

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.