Quality Of Animal Products Research Articles

Xylooligosaccharides as prebiotics from agricultural by-products: Production and applications

The growing demands of novel food products for well-being and age related issues coupled with increasing health care expenditure has attracted global attention on prebiotics. During the end of twentieth century, a great concern was expressed for transfer of antibiotic resistance genes from animal to human through food chains leading to the concept of “preventive medication”. Xylooligosaccharides (XOS) is the only nutraceutical that can be produced from lignocellulosic biomass. Production of XOS from agricultural residues offers great scope to the nutraceutical industries as the raw material is cheap and abundantly available. The major advantages of XOS consumption, apart from selective growth stimulation of beneficial gut microflora, include reduction of blood glucose and cholesterol, reduced pro-carcinogenic enzymes in gastrointestinal tract, enhanced mineral absorption from large intestine and immune-stimulation. The sweet taste of XOS enables it to be used as an artificial sweetener. Owing to the ban on antibiotics as a feed supplement in livestock, the XOS could be future alternatives to guard gastrointestinal tract from the onslaught of pathogenic microflora. This will sustain the productivity and improve the quality of animal products to fulfil the demands of value added livestock products. Therefore, XOS could be the future sought after molecules in preventive medicine.

A Research on Community-based Livestock of Qinghai-Tibet Plateau

This essay analyses the opportunities and challenges in the development of Qinghai-Tibet Plateau grassland animal husbandry, and proposes the concept of Qinghai-Tibet Plateau Community-Based Animal Husbandry and new ideas for development. It covers the up-to-date outcomes of the following five foci of the project’s research and demonstration: 1) adaptative natural rangeland utilization technology and model; 2)local forage species based ecologically safe forage production chronology and model; 3)local animal heritage breeds protection and utilization technology and model; 4) local specialized animal products quality improvement technology and production model; 5)the strategy of local capacity building and participatory community action demonstration.

TMR 원료로 이용하는 농식품 부산물 사료 이용 활성화 방안에 관한 연구

본 연구는 농식품 부산물을 TMR 원료로 이용하여 사료비 절감 효과와 축산물 품질향상에 도움이 될 수 있도록 그 이용을 활성화하기 위한 농식품 부산물 발생현황조사 및 분석, TMR 이용 현황 및 문제점 조사, 사료이용 시 문제점 및 법률과 제도적 대안을 제시코자 수행하였으며 그 결과는 다음과 같다. 첫째, 폐기물관리법에서 관리되고 있는 유기성폐기물은 폐식용유 10,488톤, 동식물성잔재물 832,493톤, 동물사체 5,740톤, 동물성잔재물 1,171,892톤, 식물성잔재물 2,172,415톤, 왕겨와 미강 12,905톤 등 총 4,205,931톤이었으며 TMR 원료로 이용할 수 있는 식물성 잔재물과 왕겨 그리고 미강이 전체의 51.7%를 차지하였으며 발생지 별로는 전국 상위 10개 지자체에서 76~100% 발생되고 있어 이의 체계적 수급관리시스템이 필요하였다. 둘째, TMR 원료로 사용되는 10대 주요 농식품 부산물은 콩비지, 미강, 깻묵, 맥주박, 주정박, 맥강, 장유박, 감귤박, 버섯부산물 및 기타 식품부산물(빵, 국수, 과자 등)이었다. 셋째, 농가가 농식품 부산물을 이용하는데 가장 큰 애로사항은 농식품 부산물이 폐기물관리법에 의해 폐기물로 관리되고 있어 이를 사용하기 위해서는 재활용신고나 재활용시설설치 등 법률적 의무가 있어 사료이용 활성화를 위해 폐기물 지위 종료제와 같은 제도 개선과 전국적으로 10여 개의 공적 유통센터 설립이 필요한 것으로 사료되었다. This study was conducted to survey and analyze the quantity of various organic wastes and to vitalize the utilization of agri-food by-products as raw materials for Total mixed ration (TMR), to improve feed cost savings and the quality of animal products. On-the-spot obstacles for animal farmers, along with legal and institutional alternatives are presented. The results are as follows. First, organic wastes in Korea are managed by the Allbaro system created in the Wastes Control Act, which processes 10,488 tons of cooking oil waste, 832,493 tons of animal and plant residues, 5,740 tons of animal carcasses, 1,171,892 tons of animal residues, and 2,172,415 tons of plant residues including 12,905 tons of rice hull and bran, for a total of 4,205,931 tons. Raw materials for TMR, namely rice hulls and bran as well as plant residues, accounted for 51.7% of the total national organic waste. The top 10 municipalities process 76~100% of all organic wastes and a supply management system is needed for the waste. Second, the 10 major agri-food by-products used as raw materials for TMR are bean curd by-product, rice bran, oil-cake, brewers dried grain, Distiller's Dried Grains with Solubles (DDGS), barley bran, soy sauce by-product, citrus fruit by-product, mushroom by-product and other food by-product (bread, noodles, snacks, etc.). Third, the biggest difficulties in using agri-food by-products are legal obstacles. Because agri-food by-products are regulated as industrial wastes by the Waste Control Act, animal farmers that wish to use them have legal reporting obligations including the installation of recycling facilities. To enable the use of agri-food by-products as raw materials for TMR, waste management system improvements such as 'the end of waste status' and the establishment of more than 10 public distribution centers nationwide are deemed essential.

The trend of risk assessment technologies of animal Environmental Risk Substances

Numerous types of Environmental Risk Substances (ERSs) are produced, causing exposure not only in the industry, but also in daily life in modern society. ERSs are pernicious to animals as well as to human beings, since some of them remain for long periods of time or become condensed in organisms during the ecological cycles via environmental pollution. In recent times, the quality and distribution process of animal products have been in the spotlight, and the way of thinking regarding healthy lifestyle has been changing. Thus, this calls attention to the analysis of ERSs which may impede the safety of animal products to allow the distribution of healthy products. This review covers the trends and directions on the development of biomarkers that can precisely diagnose ERS-exposed animals at the molecular level, and the new paradigm of prompt and accurate environmental risk assessment using cells and genes.

Age-Related Changes in Egg Quality of Hy-Line Brown Hens

The present study was conducted to monitor age-related changes in egg quality during the entire production cycle of laying hens. Thirty eggs were sampled from the commercial farm on a weekly basis for egg analysis. In order to increase in confidence in sampling, farm personnel were educated to collect the eggs from the pre-determined cages during the whole period and all layers were subjected to an identical farm management and fed a commercial layer diet. In total, 1,470 eggs were sampled and transported to the laboratory of Korea Institute for Animal Products Quality Evaluation. The parameters for egg quality included egg weight, eggshell color, eggshell breaking strength, eggshell thickness, Haugh unit and yolk color. It was shown that egg weight increased as the hen aged. Eggshell breaking strength gradually decreased, but eggshell thickness was randomly scattered without showing any age-related trends during the laying period. The intensity of eggshell color kept relatively constant while yolk color increased with age. Finally, Haugh unit as an indicator of freshness of eggs was consistently decreased as the hens aged. In this study, we noticed that eggshell breaking strength and egg weight were negatively correlated (r= - 0.500, p 0.50), but marginally and positively correlated with egg weight (r = 0.248, p = 0.082). It is concluded that among the various egg quality parameters analyzed, egg weight, eggshell breaking strength or Haugh unit reduced as the hens aged. Further study is needed to include various parameters of egg quality such as chemical or nutritional composition which will provide more insight into the age-mediated changes in egg quality.

Haematological and physiological responses of Piemontese beef cattle to different housing conditions

Public concern for animal welfare has progressively grown over the recent years. In this context, stress has a great economical impact on growth of animals and quality of animal products. The development and validation of methods to assess animal stress, particularly at the farm level, are desirable to evaluate animal production systems. Piemontese breed is traditionally tie-stall housed in the fattening period. Hence, the objective of this study was to characterise a profile of physiological and haematological changes of Piemontese beef cattle under different management conditions (tie-stall and loose housing). Our results suggest that the housing system is an important factor in animal welfare. Indeed, the values of the total protein, lysozyme, cortisol, serum and faecal corticosterone concentration and GR-α gene expression indicate that the tie-stall housing is more stressful than the loose system. All the alterations highlighted in this study considered together may be effective biomarkers of stress and disease susceptibility.

Drivers for animal welfare policies in Africa.

Livestock in Africa represent on average 30% of the agricultural gross domestic product (GDP) and about 10% of the national GDP. Up to 300 million people depend on livestock for their income and livelihood. Accordingly, livestock are considered to be important for the African continent. Despite this, little or no provision for animal welfare is made in the laws and regulations of most African countries. However, the World Organisation for Animal Health (OIE) Performance of Veterinary Services (PVS) Tool includes animal welfare as a critical competency in Veterinary Services, and most African countries have now conducted PVS appraisals. The development of a Regional Animal Welfare Strategy in Africa is also important because it will provide opportunities for full engagement by all relevant parties. Key elements in this process should include collaboration and coordination in information dissemination to all stakeholders, who should include all those in the value chain. The roles played by the OIE Member Delegates and Focal Points, and non-governmental organisations (NGOs), in driving animal welfare policy in most African countries are notable. Without a level of understanding of animal welfare that is sufficient to support clear animal welfare policy development and implementation, problems may appear in the near future which could jeopardise the attainment of increased animal productivity and product quality. This may have negative implications for economic growth and for national and international trade.

The effect of production system and management practices on the quality of meat products from ruminant livestock

Demands for products of animal origin are increasing worldwide owing to the significant growth in the human population and changes in the health, wealth and life expectancy of people. The agricultural sector has the scientific knowledge, expertise and technology to respond to these challenges, but consumers are concerned about the methods used to meet these new challenges. They are also concerned about the environmental impact of modern technologies and intensification of production systems. Various combinations of pasture-based and intensive systems are employed to raise ruminant livestock, depending on resources and climate. The quality of animal products from production systems differs, but there are advantages and disadvantages for each. In South Africa, cattle and sheep are generally fattened for short periods to ensure efficient production and to meet market requirements. This is more easily achieved by feeding different proportions of concentrate diets, with or without feed additives and growth promotants that are approved for use in food-producing animals. Hormonal growth implants are strictly regulated for use in animal production systems. Production systems affect both the extrinsic and intrinsic aspects of carcass and meat quality of livestock. Extrinsic aspects that are affected include weight gain, age at slaughter and carcass weight. Concentrate feeding generally yields a more consistent carcass composition than pasture-fed animals, which addresses the necessity for more consistent meat quality. Intrinsic aspects of animal products that are affected include carcass composition and conformation, carcass fat content and colour, meat composition, colour, tenderness and flavour. Beef and lamb from pastures are darker, and carcass fat contains more yellow pigments, which may affect a consumer’s choice to purchase. The typical pasture flavour in meat is because of the presence of branched-chain fatty acids, 3-methylindole and other oxidation products, and off-flavours are often detected. In many countries, the meat flavour of intensively fed livestock is preferred to pasture-fed animals, but certain consumers prefer the more intense pasture flavour. Pasture feeding has beneficial effects on n-3 fatty acids, notably eicosapentaenoic acid (EPA, C20:5n-3) and docasahexaenoic acid (DHA, C22:6n-3). Beef and lamb from pasture-fed animals are generally less tender, but shelf life is better, owing to the presence of antioxidants such as vitamin E.Keywords: Hormonal growth implants, feed additives, antimicrobial implants, carcass quality, meat quality

Antioxidant dynamics in the live animal and implications for ruminant health and product (meat/milk) quality: role of vitamin E and selenium

The global population is predicted to grow to over 9 billion by the middle of 21st century, with 70% of people living in urban areas, and food demand is projected to grow by 70% by 2050. Climate change presents a series of challenges for global animal agriculture. As a result of thermal challenges associated with climate variability, availability of quality pasture, animal behaviour, physiological and immunological functions are potentially impacted. Oxidative status plays an important role in the regulation and maintenance of several physiological and immunological functions of the body. Ruminants are exposed to several environmental and metabolic challenges that can trigger oxidative stress. In this scenario, it is possible for an increase in free radical production and a depletion of antioxidant reserves, resulting in damage to lipids, proteins and DNA. Since oxidative stress can affect animal health and the quality of their products (meat/milk), antioxidant supplementation of ruminant diets represents a useful tool to sustain redox homeostasis when the ruminants are exposed to oxidative stress. This paper will examine the roles that oxidative stress plays in some physiological functions, and it will discuss the implications of antioxidant supplementation on ruminant health and production. Physiological levels of dietary antioxidants underpin efficient energy utilisation, optimal antioxidant potential, and balanced mitochondrial function to enhance protein deposition without impacting animal health. The research conducted over the last decade has improved the understanding of physiological functions of antioxidants, with selenium and vitamin E receiving particular attention. There is evidence that the functions of selenium and vitamin E extend beyond the classical antioxidant properties to immunomodulation especially when administered at higher doses than recommended. Improving the oxidative status of ruminants will play an important role in delivering high-quality milk and meat products to consumers. Considering the growing awareness among consumers of the benefits of antioxidant-rich food, there is a great opportunity for the livestock industries to focus on producing antioxidant-enriched milk and meat products or functional foods. Therefore, the premise of this paper is to review the recent developments in understanding antioxidant dynamics in ruminants and their role in reducing the impact of environmental stress and metabolic diseases. In addition, the paper will explore the putative implications that antioxidant supplementation has on the quality animal products and how the improved understanding can be best utilised to achieve efficient and sustainable animal production systems to ensure quality animal products for human consumption.

THE POSSIBILITY OF LEGUMES PRODUCTION

Primary receptacles improve profitability legumes are limiting demonstrations and acts of plant diseases and pests. Pathogens are 25-50% lower yield of soybean, chickpea, beans, peas. Pests focally up to 87% of viable seeds sown reduce the number of plants per 1 ha. Only effective protection against disease and estimates of crop production can increase the average profitability of legume crops by 15-30%. Livestock is very important, but in the Southern Urals requires real support for its production with a positive balance (in the calculations with a deviation of 5%). The most important resource in our opinion may be a reduction in price of fodder. Thus, legumes are sought for animal protein. Soybeans, chickpeas, beans, peas universal culture and the possibility of their use in the food balance for a healthy diet of ordinary people engaged in recreational and other sports niche expands further improve the profitability of their production. Regulation of the balance of the distribution of food and feed produced grain legumes allows fine regulation of the cost of fodder for a particular type of livestock activities. Phytosanitary capabilities, the balance of influence of legumes on arable land, also requires a fine regulation of these processes. Obtaining long-term public support for this production is unlikely in the WTO because actual search for ways to improve the profitability of production of agricultural technologies. In our view, a comprehensive approach taking into account the capacity of local markets for crop production. Such activity can act as a guaranteed quality of agro-technology and animal products from local resources specific zonal conditions of production.

Soil, pasture and animal product quality

The management of pasture, through the use of appropriate stocking rates and grazing systems, influences the feeding behaviour of the animals. The impact of animal behaviour on vegetation can be of great importance for the sustainability of pastures and mantaining their biodiversity. Indeed, a different response in terms of quality of animal products is mediated by the ability of animals to concentrate or transform grass components, according to the characteristics of the soil. The herbage ingested by animals provides them with compounds with aromatic characteristics, such as terpenes, and with functional properties beneficial for human health, such as carotenoids, vitamins, polyphenols and polyunsatured fatty acids. The combination of different ecological conditions on different soils through specific management practices determines the differentiation of several pasture vegetation types, a unique patrimony of great value in terms of biodiversity and capability to sustain local production, also important because of their own high added value. This review deals with pasture management aimed at conserving the soil and reducing gas emissions, and takes into consideration the quality of animal products as a result of such management.

Fattening heifers on continuous pasture in mountainous regions - implications for productivity and meat quality

Economical and ecological issues as well as consumer demand for sustainably produced agricultural food rise the trends to fatten beef cattle on pasture during the grazing season. However, particularly for mountainous regions, implications of turning beef cattle on pasture remain unclear concerning animal performance and product quality. Therefore, the present study was conducted to compare short grass grazing with a semi-intensive indoor fattening system in the Alps. Charolais × Simmental heifers of about 300 kg live weight were either fattened on continuous pasture (3–6 mm sward height) and finished in barn (Pasture group) or solely raised in barn on a grass silage-based diet with 2 kg concentrates (Indoor group). Animals were slaughtered at 550 kg live weight. Results showed that continuous pasture with a finishing period in barn allowed as good growth and carcass performance as fattening in barn. Over the whole experiment, average daily gain was 993 g/day in the Pasture group and 1026 g/day in the Indoor group. During the growing period, daily gain was numerically lower in the Pasture group than in the Indoor group (767 g and 936 g, respectively). Carcass fatness of pasture fed animals was lower but within the desirable threshold. Water holding capacity, meat colour, and shear force, an indicator for beef tenderness, were unaffected by feeding practices, but fat colour was more yellow in the Pasture group. Furthermore, meat from animals fattened on pasture had lower intramuscular fat contents and enhanced proportions of nutritionally valuable omega-3 fatty acids and conjugated linoleic acids.  

Perceived Access and Actual Intake of Healthy Diets Among Households in Vulnerable Salvadoran Communities

This study aimed to examine the dietary intake of Salvadoran households according to perceived access to healthy meals (PAHD), and to identify household characteristics associated with diet quality and PAHD. Secondary data analysis with a sample of 139 Salvadoran households from resource-poor communities in El Salvador. Chi-square tests and ANOVA were used to assess differences in dietary intake across households classified according to PAHD. High-PAHD households had higher women's education, household food security levels, overall diet quality, and variety, and higher intakes of animal products, fats, cholesterol, vitamin C, and sodium (P< .05). Diet quality was not associated with the household characteristics studied. Overall diet quality was associated with higher levels of PAHD, but some differences in intakes were not as expected, such as higher intakes in foods and nutrients associated with low-quality diets, among high PAHD households.

Genómica en la producción animal

El mejoramiento genético evalúa y utiliza la variación genética para mantener y mejorar cualitativa y cuantitativamente la producción animal. La identificación de animales con altos méritos genéticos se dificulta por el hecho que la mayoría de las características de importancia económica, por ser de naturaleza cuantitativa, son controladas por varios genes los cuales interactúan con el medio ambiente. El objetivo de este documento fue realizar una revisión sobre la aplicación de la genómica en la producción animal para diferentes características tanto las asociadas a la producción de leche como carne y la disponibilidad actual de herramientas de genética molecular y genómica que permiten predecir con mayor precisión los valores genéticos de los animales desde su nacimiento, disminuyendo el intervalo entre generaciones y aumentando la intensidad de selección.

도축검사 후 지방성 병변과 축산물 품질 연관성 조사

Abstract The survey was conducted to investigate the relation between slaughter inspection results and the quality of cattle carcasses by inquiring animal products grading service results of Korea Institute for Animal Products Quality Evaluation (KAPE) about partial-disposed cattle carcasses after dismantling inspection. Of the 13,586 slaughtered cattle, 1,343 (9.9%) cattle heads were partially disposed from January to August, 2012 at slaughterhouses in Gwangju area, Korea. Of the 1,343 partial disposed cattle, 613 (45.6%) cattle carcasses were graded into above Grade 1. Among partially disposed 1,171 Hanwoo heads, 613 (52.3%) cattle carcasses were graded into above Grade 1. However, none of dairy and beef cattle carcasses were graded into above Grade 1 out of 163 and 9 partial disposals, respectively. Of the 221 partial disposals by enteric fat necrosis, 139 carcasses were graded into above Grade 1, and the ratio; 62.9% ( P =0.001), was higher than that (50.3%) of total cattle carcass grade which is above Grade 1. From these results, it is suggested that quality of cattle carcasses which is mainly determined by marbling might be related to the fatty lesions such as fatty liver and enteric fat necrosis.

An Evaluation of Microbial Health Risks to Livestock Fed with Wastewater‐Irrigated Forage Crops

This paper presents the results of five experiments in which animal health risks associated with the consumption of crops irrigated with domestic wastewater were evaluated. Forage maize and Tanner grass were irrigated with treated wastewater and used in goats and calves feeding trials. The irrigated crops presented high levels of surface contamination with E. coli (10(4) -10(7) 25 g(-1) ) and salmonellae (up to 1.6 × 10(4) 25 g(-1)), but none of the animals showed signs of infection or of disease. Further, the microbiological quality of animal products always complied with the Brazilian and European Union standards for food safety. It is suggested that the WHO guideline values for restricted irrigation (≤ 10(4) E. coli 100 ml(-1) and ≤ 1 helminth egg l(-1)), which were developed to protect the health of agricultural field workers, would be equally protective of the health of both animals fed with wastewater-irrigated crops and humans consuming products from such animals.

Paratuberculose em ruminantes no Brasil

A paratuberculose ou doença de Johne é uma enterite granulomatosa causada por Mycobacterium avium subsp. paratuberculosis (Map) e comumente afeta ruminantes domésticos, no entanto, pode infectar várias espécies de mamíferos. Está presente nos cinco continentes e é considerada endêmica em algumas regiões pela Organização Internacional de Epizootias (OIE). Pertence à lista de enfermidades notificáveis, que compreende as doenças transmissíveis de importância sócio-econômica e/ou em saúde-pública, cujo controle é necessário para o comércio internacional de animais e alimentos de origem animal. A importância da doença de Johne não se restringe somente aos prejuízos econômicos causados à indústria animal, mas também na possível participação do Map na íleocolite granulomatosa que afeta seres humanos, conhecida como doença de Crohn. No Brasil, a paratuberculose já foi descrita em diversas espécies de ruminantes e em vários estados. Embora os relatos naturais da enfermidade sejam pontuais, acredita-se na possibilidade da transmissão interespecífica e na disseminação do agente através da compra e venda de animais infectados. O objetivo deste artigo foi reunir as informações disponíveis referentes aos aspectos epidemiológicos, clínico-patológicos e laboratoriais da paratuberculose em bovinos, bubalinos, caprinos e ovinos no Brasil, e salientar a necessidade de implementação de medidas de controle sanitário da enfermidade no país, o que possibilitaria a melhoria da qualidade e valorização dos produtos de origem animal no mercado internacional.

Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora.

In recent years, there has been a growing appreciation on the relevance of gastrointestinal microflora in both ruminants and non-ruminants owing to revelation of their role in several physiological functions including digestion, nutrient utilization, pathogen exclusion, gastrointestinal development, immunity system, gut gene expression and quality of animal products. The ban imposed on the use of antibiotics and hormones in feed has compelled animal researchers in finding an alternative which could overcome the issues of conventional feed additives. Though the concept of prebiotic was evolved keeping in mind the gastrointestinal flora of human beings, presently animal researchers are exploring the efficiency of prebiotic (inulin) for modulating the gut ecosystem of both ruminants and non-ruminants. It was revealed that prebiotic inulin is found to exhibit desirable changes in the gut of non-ruminants like poultry, swine, rabbit etc for augmenting gut health and improvement of product quality. Similarly, in ruminants the prebiotic reduces rumen ammonia nitrogen, methane production, increase microbial protein synthesis and live weight gains in calves. Unlike other feed additives, prebiotic exhibits its effect in multipronged ways for overall increase in the performances of the animals. In coming days, it is expected that prebiotics could be the part of diets in both ruminants and non-ruminants for enabling modulation of gut microflora vis a vis animals productivity in ecological ways.

Estimation of relative economic weights of hanwoo carcass traits based on carcass market price.

The objective of this study was to estimate economic weights of Hanwoo carcass traits that can be used to build economic selection indexes for selection of seedstocks. Data from carcass measures for determining beef yield and quality grades were collected and provided by the Korean Institute for Animal Products Quality Evaluation (KAPE). Out of 1,556,971 records, 476,430 records collected from 13 abattoirs from 2008 to 2010 after deletion of outlying observations were used to estimate relative economic weights of bid price per kg carcass weight on cold carcass weight (CW), eye muscle area (EMA), backfat thickness (BF) and marbling score (MS) and the phenotypic relationships among component traits. Price of carcass tended to increase linearly as yield grades or quality grades, in marginal or in combination, increased. Partial regression coefficients for MS, EMA, BF, and for CW in original scales were +948.5 won/score, +27.3 won/cm2, −95.2 won/mm and +7.3 won/kg when all three sex categories were taken into account. Among four grade determining traits, relative economic weight of MS was the greatest. Variations in partial regression coefficients by sex categories were great but the trends in relative weights for each carcass measures were similar. Relative economic weights of four traits in integer values when standardized measures were fit into covariance model were +4:+1:−1:+1 for MS:EMA:BF:CW. Further research is required to account for the cost of production per unit carcass weight or per unit production under different economic situations.

Poisonous Plants and Plant Toxins that are Likely to Contaminate Hay and Other Prepared Feeds in the Western United States

L ivestock poisoning by toxic plants is a relatively common problem in pastures and rangelands and it is estimated to annually cost the livestock 1 industry more than $ 200 million. However, these estimates are for grazing animals and the total cost is prob- ably much greater because many animals are poisoned by contaminated feeds. Many poisonous plants are accessible to grazing livestock, but they are generally avoided and are not eaten, or they are eaten at doses that they do not produce detectable disease. In such cases toxic plants may not be more than a problem of displacing desirable nutritious plants. However, this is not always the case, especially when toxic plants contaminate prepared feeds. Poisonous plants incorporated in preserved forages, such as hay and silage, are much more likely to be eaten. This may occur because of increased competition from herd mates or by increased feeding pressure as prepared feeds are most often used in winter when alternative food sources are exhausted. Alternatively, the plants may become more palatable as they are diluted with palatable feed or the previously distasteful plant components are altered during forage preparation or storage. In addition, normally safe forages, under certain conditions, can produce and accumulate toxins. Identifying these toxic contaminates and understanding when forages may be toxic is critical in reducing poisoning and ensuring quality animal products. Our objectives of this review are to present basic principles of identifying contaminated feeds and sampling forages, introduce several common forages that under certain conditions can be toxic, present a brief description of plants that we have found contaminating feed in the western United States, and review how to treat or avoid such poisonings. DOI: 10.2458/azu_rangelands_v34i2_s tegelmeier