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1.
In the last decade an increasing occurrence of feed intoxications of Austrian domestic animals could be observed. According to specific cases and one experimental study using fattening pigs, the clinical symptoms laboratory findings of blood and feed samples are described. Based on the case history, the clinical symptoms of the incriminated animals and by exclusion of other diseases an etiologic correlation with the feed and the course of disease, a feed intoxication could be diagnosed. By corresponding microbiologic as well as mycotoxicologic positive results of the examined feedstuffs the diagnosis "mycotoxicosis" could be confirmed.  相似文献   

2.
本试验研究日粮硝酸盐的添加量对湖羊瘤胃还原硝态氮程度和对发酵参数及血液高铁血红蛋白的影响。试验选取6头湖羊,采用随机区组试验设计,每期分别饲喂含0%,1%,2%,3%,4%,5%硝酸钾的日粮。测定喂后0,0.5,1.0,1.5,2.0,4.0,6.0,8.0 h瘤胃液硝酸盐和亚硝酸盐含量及瘤胃发酵参数。晨饲后2.0 h通过颈静脉采血,测定高铁血红蛋白含量。结果表明,湖羊在采食1.0 h后硝酸盐含量达到最高(0.952.14 g/L),之后快速消失,亚硝酸盐含量在喂后1.5 h达到最高(0.936.22 μmol/L),之后降低。高铁血红蛋白的含量随硝酸盐添加量的增加而显著升高(P<0.01),最高达0.32%。添加硝酸盐显著提高瘤胃液pH值(P<0.01)和2.0 h的氨态氮含量(P<0.01)以及乙酸/丙酸,添加量高于3%会降低微生物蛋白和总挥发性脂肪酸的浓度,2%的硝酸盐添加量微生物蛋白和总挥发性脂肪酸的合成量最高,最有利于微生物发酵。  相似文献   

3.
Mycotoxins and reproduction in domestic livestock.   总被引:10,自引:0,他引:10  
Molds are parasitic plants that are ubiquitous in livestock feedstuffs. Even though molds themselves reduce the quality of grains, their synthesis of chemical substances termed mycotoxins causes the greatest monetary loss to the animal industry. Five major mycotoxins that impair growth and reproductive efficiency in North America are aflatoxins, zearalenone, deoxynivalenol, ochratoxin, and ergot. Aflatoxins are produced by Aspergillus flavus and Aspergillus parasiticus. Consumption of grains containing aflatoxins by swine affects reproduction indirectly by reducing feed intake and growth. In swine, aflatoxins impair liver and kidney function, delay blood clotting, increase susceptibility to bruising, and interfere with cellular humoral immune systems. Ruminants are comparatively resistant to aflatoxicosis, but presence of aflatoxins in milk of dairy cows is closely monitored for human safety. Depending on environmental conditions, Fusarium roseum can produce either zearalenone or deoxynivalenol. Days 7 to 10 postmating seem to be a critical period of gestation for zearalenone to exert its detrimental actions on early embryonic development. Presence of deoxynivalenol in swine feedstuffs decreases feed intake, causes feed refusal, and induces occasional vomiting. Several species of Penicillium and Aspergillus produce ochratoxin, a mycotoxin that causes necrosis of kidney tissue. Ergot alkaloids produced by Claviceps purpurea on wheat can cause reproductive problems and are associated with lactational failure in swine. Various methods have been developed to remove mycotoxins from infected feedstuffs. Chemical analyses in laboratories as well as diagnostic kits suitable for use at the elevator or farm can be used successfully to identify which mycotoxins are present in suspect feedstuffs.  相似文献   

4.
Fat-tailed sheep (FTS) is a group of breeds characterized by large (fatty) tails that it is commonly distributed in Africa, Middle East, Pakistan, and to a lesser extent in other countries. Awassi, a common FTS breed in many Mediterranean countries, is adaptive and suitable to live in harsh conditions of the arid and semiarid areas. One of the main constraints for sheep industry in those areas is the limited supply and variable quality and quantity of feedstuffs. Using several alternative feedstuffs (AF) has been a common practice to decrease production cost of Awassi sheep industry in those areas. The appropriate AF to be used is determined by several animal and feed factors. These AF includes, but not limited to, unconventional feedstuffs, agricultural byproducts, and agro-industrial byproducts. A good body of literature about the use of AF and the effects of such use on performance of Awassi sheep is available. Some of these AF have been shown to be safely used in Awassi diets with no detrimental effects on sheep performance or health and, thus, recommended to lower the production cost. Other AF has controversial effects and recommendations. This paper reviews the effects of using AF on performance of Awassi ewes and lambs. Effects on intake, nutrient digestibilities, growth rate, and carcass characteristics of lambs and on intake, nutrient digestibilities, body weight change, milk yield, and milk composition of ewes will be emphasized. Recommendations and limitations for using AF will also be briefly discussed.  相似文献   

5.
Unground feedstuffs like cereals and roughage which are conspicuous by high proportions of finer particles and dust have to be estimated as risky environmental factors due to the accumulation of microorganisms (moulds, bacteria and lipopolysaccharides) and mites in the fines frequently. The dusty fraction in feed samples should be separated by sensorial inspection of feedstuffs (for example by sieves) and has to be looked at (using pocket lens) critically to find out lacks in the hygienic quality of feedstuffs. Dusty qualities of roughage contain high counts of moulds frequently, therefore a mycological investigation is to be recommended for these samples. The feedstuffs may influence the quantity and quality of air dust within the stable as the starch content (similar to the fed diet) indicates. Likewise corresponding LPS contents were measured in feeds and airborne dust of pig stables. Due to the high counts of microorganisms in the dusty fraction of cereals an intensive cleaning procedure for cereals has to be recommended for minimizing the load of germs; a reduced risk for deterioration can be expected. The residues of cleaning processes (combined mechanic/pneumatic procedures) of cereals should not be reutilized in the production of compound feeds by feed manufacturers, the nutritive value is relatively low anyway due to the high ash- and fiber-contents. Potential risks of dusty feedstuffs to animals' health and the influences of mites, moulds and lipopolysaccharides on the development of gastrointestinal and respiratoric disturbances are discussed. Experimental investigations are needed to elucidate the role of inhaled dust--and its content of lipopolysaccharides especially--in the development of respiratory diseases in veterinary medicine.  相似文献   

6.
Within 8 weeks 22 of 400 sheep died with symptoms of Cu intoxication. In the liver of 2 dead sheep Cu contents of 491 and 830 mg/kg dry matter were found. The concentration of copper in the concentrate and other feedstuffs (grass, hay, straw, kale, dried sugar beet pulp) could not explain the development of Cu-toxicosis. The mineral-vitamin-supplement contained 86.7 mg Cu/kg. Obviously the Cu intoxication of previously Cu loaded sheep was provoked by offering the mineral supplement ad libitum (with intervals of 3-4 days), the intake of this mixture reached values up to 400 g/animal and day. By renunciation of mineral supplements in the same flock 7 months later lambs died due to Cu deficiency (Cu content in the liver: 13-14 mg/kg dry matter).  相似文献   

7.
Accurate determination of the moisture (water) content in individual feed ingredients and mixed feeds is critical throughout the feed industry. Most analytical methods used to determine apparent water content of feedstuffs are empirical, estimating water by evaporation and loss of weight on drying (oven drying methods). These methods differ greatly in effectiveness, resulting in bias. Bias associated with measuring the water content of feedstuffs is a concern not only because of the lack of confidence in the moisture value itself, but also because moisture determinations affect accurate quantification and expression of other nutrient values. Methods for determining moisture in feeds have frequently been borrowed from the cereal, forage, or other applications without validating the extension of the method. Methods such as Karl Fischer titration measure water by direct comparison to a calibration standard for water and can be used as reference methods for the evaluation of empirical methods. The objective of this paper is to review methods for determining moisture, review comparisons among moisture methods for various feedstuffs, make recommendations for a reference method, and make general recommendations toward improving the results of moisture testing. The need to evaluate and improve moisture methods and standardize practices in laboratories is evident from this study. It also is evident that the methods appropriate for a specific feed ingredient or feed should not be extended to all feeds without proper validation to the new matrices. Part of the validation for empirical methods should be comparison to Karl Fischer or other the direct methods. It also is recommended that the results obtained using oven methods not be termed "moisture;" rather, they should be termed "loss on drying," and the drying conditions should become part of the term.  相似文献   

8.
Brine shrimp larvae was tested as a possible simple biological screening system to identify specimens of animal feedstuffs that should be examined further by chemical analytical procedures for mycotoxins. All extracts of the control, nonmouldy feedstuffs increased larval mortality, this being most marked in the case of silage. Chemical and biological testing of diagnostic specimens indicated that the bioassay identified two of four chemically positive specimens and 59 of 135 chemically negative specimens and 59 identified larvicidal compounds present in normal feedstuffs gave a high percentage (56%) of false-positive bioassay results when compared to the results of chemical analyses for three mycotoxins. The use of brine shrimp larvae did not materially reduce the necessity of conducting chemical analyses for mycotoxins.  相似文献   

9.
The egg production industry is facing various problems that need to be solved. For amino acid nutrition to achieve scientific and economical feeding of laying hens, it is necessary to elucidate the content, digestibility, or availability of nutrients of feedstuffs and feeds and the requirement of amino acids for laying hens. In addition, improvement to quality of eggs and meat of spent hens, methods of management and development of new feedstuffs are essential. For sustainable animal production, decrease in excreta and animal welfare should be studied. The real‐time determination of content and digestibility of amino acids in feedstuffs are essential for formation of feeds. Recent advances in the near infrared reflectance analysis will be able to determine the content, digestibility and availability of nutrients in feedstuffs and feeds, if we have a supplemental amount of conventional analysis to define the calibration population. The amino acid requirements are affected by various factors. Therefore the method to quickly and exactly determine amino acid requirements in response to various factors is necessary. By using plasma free amino acid concentration as a criterion, it is possible to determine amino acid requirements in various conditions of laying hens within a short experimental period, repeatedly using the same animals. Because the amino acid requirements differ among individual animals, it should be expressed as grams per hen per day. Practically, it is impossible to formulate various feeds for individual hens. The various expressions have been developed and these expressions have advantages and disadvantages. The nitrogen excretion of laying hens is easily reduced by reducing dietary nitrogen levels and restricting the feed intake. The availability of amino acid may be improved by feeding management, and supplementing enzyme, but the quality of eggs and meat of spent hens and welfare of laying hens are not affected by amino acid nutrition.  相似文献   

10.
The following list is presented as a summary of guidelines that may be helpful in the investigation of a nutritional disorder. 1. Identify the perceived herd or flock problem. The client's complaint usually reflects an appearance of clinical signs or a depression in production parameters. The practitioner should also identify subclinical manifestations and other concurrent problems. 2. Identify the affected population or subpopulation. Groups should be identified according to breed, sex, age, reproductive status, growth phase, and lactation status. It is critical to identify the affected population, as a diet can be adequate for one population and deficient or excessive for another. For example, 24-month-old Angus heifers in the first 60 days of lactation would have greater risk of protein-energy malnutrition than would 5-year-old Angus cows in their second trimester of gestation if both were fed a marginal hay ration. 3. Identify the nutritional requirements for the affected population. The National Research Council publications serve as a guideline in determining nutrient requirements. 4. Identify factors that influence nutrient requirements and feed intake. Environmental factors, such as ambient temperature, can affect both nutrient requirements and feed intake of the population. Housing conditions, such as muddy lots, can increase maintenance requirements. 5. Sample and evaluate the feedstuffs. Nutrient(s) must be bioavailable--that is, they must be in a form that can be ingested, digested, and absorbed by the animal. 6. Sample and evaluate water sources for quantity and quality. 7. Evaluate feed bunk management practices. 8. Examine the herd. Both affected and normal populations should be examined. 9. Evaluate and submit to a laboratory any animal samples that may relate to the disorder. 10. Assemble the data and develop a hypothesis to support a diagnosis. 11. Provide a written account of all recommendations for the producer.  相似文献   

11.
Challenges with fats and fatty acid methods   总被引:5,自引:0,他引:5  
  相似文献   

12.
Measurements of the digestibility and availability of amino acids in feedstuffs should predict the ability of feedstuffs to supply amino acids to pigs in forms suitable for protein synthesis. Some of the methods available for such measurements are discussed; further work is needed to establish their reliability for predicting production responses to feedstuffs. At present the nitrogen balance technique appears to be the most useful, though indirect, method of evaluating feedstuffs as sources of amino acids.  相似文献   

13.
A nine-year-old Labrador retriever dog was admitted to the emergency unit of the Hebrew University Veterinary Teaching Hospital with acute-onset tremors and coma. It had recently ingested a large quantity of phenobarbital and had a high serum phenobarbital concentration. On this basis, a diagnosis of acute phenobarbital intoxication was made. Significant leucopenia, thrombocytopenia and mild anaemia developed on the third day after admission. The leucopenia resolved on day 6 and the thrombocytopenia on day 13. The red blood cell count remained low for the next month. The dog was discharged on day 13 at which time it was ambulatory but weak. It was completely recovered clinically eight days later. In summary, high levels of serum phenobarbital as a result of acute intoxication induced pancytopenia, which improved when the serum phenobarbital level was normalised.  相似文献   

14.
Dependent on the species, feedstuffs and plants differ considerably in their iodine content. Among the I-poorest feedstuffs there are grain concentrates, extracted soybean and rapeseed oil meals, mixed feed (without I-containing mineral mixture) and grasses. The I content of the plants decreases with proceeding growth. The I intake of ruminants via vegetable feed and drinking water is affected by the distance of the site from the seaside and the geological origin of the soil material. Ruminants get considerably less iodine via feedstuffs and water in the southern territory of the GDR than in the central and northern areas. Therefore, mineral mixtures for cattle and sheep are supplemented with 18 mg KIO3 per kg mixture in the southern districts. The I analysis of 205 charges of mineral mixtures revealed only a mean I content of 7 (3.8-11.3) mg per kg mixture.  相似文献   

15.
The objective of this study was to determine the effect of dietary nitrate on methane emission and rumen fermentation parameters in Nellore × Guzera (Bos indicus) beef cattle fed a sugarcane based diet. The experiment was conducted with 16 steers weighing 283 ± 49 kg (mean ± SD), 6 rumen cannulated and 10 intact steers, in a cross-over design. The animals were blocked according to BW and presence or absence of rumen cannula and randomly allocated to either the nitrate diet (22 g nitrate/kg DM) or the control diet made isonitrogenous by the addition of urea. The diets consisted of freshly chopped sugarcane and concentrate (60:40 on DM basis), fed as a mixed ration. A 16-d adaptation period was used to allow the rumen microbes to adapt to dietary nitrate. Methane emission was measured using the sulfur hexafluoride tracer technique. Dry matter intake (P = 0.09) tended to be less when nitrate was present in the diet compared with the control, 6.60 and 7.05 kg/d DMI, respectively. The daily methane production was reduced (P < 0.01) by 32% when steers were fed the nitrate diet (85 g/d) compared with the urea diet (125 g/d). Methane emission per kilogram DMI was 27% less (P < 0.01) on the nitrate diet (13.3 g methane/kg DMI) than on the control diet (18.2 g methane/kg DMI). Methane losses as a fraction of gross energy intake (GEI) were less (P < 0.01) on the nitrate diet (4.2% of GEI) than on the control diet (5.9% of GEI). Nitrate mitigated enteric methane production by 87% of the theoretical potential. The rumen fluid ammonia-nitrogen (NH(3)-N()) concentration was significantly greater (P < 0.05) for the nitrate diet. The total concentration of VFA was not affected (P = 0.61) by nitrate in the diet, while the proportion of acetic acid tended to be greater (P = 0.09), propionic acid less (P = 0.06) and acetate/propionate ratio tended to be greater (P = 0.06) for the nitrate diet. Dietary nitrate reduced enteric methane emission in beef cattle fed sugarcane based diet.  相似文献   

16.
At 30-to-60-day-old lambs reared without mothers 23 different feed mixtures were tested in N-balance experiments. The following results were achieved: The concentration of digestible crude protein and energy as well as the relation between them (PEQ) have no significant influence on the lambs' nitrogen retention. The energy intake and the intake of digestible crude protein have an intensive, significant influence on nitrogen retention. Rising energy and N-intake within the limits on which the investigation is based increased nitrogen retention. Of the protein feedstuffs tested, a 6 ... 7% higher nitrogen retention was realised from soybean oil meal as the sole source of proteins with 35% retained nitrogen related to the nitrogen intake in comparison to the combinations soybean oil meal/dried skim milk resp. fish meal. Increasing dried yeast portions (greater than 5%--20%) in the feed mixture diminished nitrogen retention. On the basis of the existing results the following recommendations for the use of the tested protein feedstuffs in rearing feed for lambs can be formulated: Soybean oil meal can be used as the sole source of protein in rearing lambs. The use of up to 5% dried yeast in the rearing feed as protein source and for vitaminisation is possible; 20% however diminish nitrogen retention. Because of the positive effect on feed intake it appears suitable to use fishmeal in the rearing feed for lambs.  相似文献   

17.
Calculation of dietary intake for beef cattle using the equation outlined by the NRC (1984) is confounded by the need to know the net energy for maintenance content of the diet (NEmkg). Intake cannot be calculated until NEmkg is specified, but intake must be indicated before performance can be predicted. To calculate NEmkg, dietary intake must be known or estimated, or it can be calculated using a complicated quartic equation. This quartic equation, when solved, gives the percentages of selected feedstuffs necessary to balance a diet. Placing the resulting percentages of feedstuffs necessary back into the generalized net energy equation solves for NEmkg. The quartic equation may be simplified by inserting imaginary nutrient values that optimize the equation for simplicity. It remains a quartic equation, but the coefficients for the first three factors of the equation are fixed, with only the unary X term and the coefficient containing variables. A modified version of Newton's method of approximating roots of equations estimates the percentage of feed necessary and when incorporated into the generalized net energy equation solves for NEmkg. The final reduced form results in simplified equations for NEmkg for each of the classes of beef cattle that are easily solved by the hand-held calculator.  相似文献   

18.
Although there is considerable information about the utilisation of energy by poultry, there is still uncertainty about the values that should be used to describe the energetic value of feedstuffs. A standardised method of feed evaluation is required to overcome the difficulties and a proposal for such a method is outlined in this paper. The three main characteristics of the proposal are: (a) that the system should be based on the biological determination of metabolisable energy; (b) that adjustments should be made for variations in chemical composition of feedstuffs described by a generic term, and (c) that adjustment should be made for the utilisation of metabolisable energy in different circumstances to yield one or more net energy systems.  相似文献   

19.
20.
利用芳香族化合物估测反刍动物采食量的潜力   总被引:6,自引:8,他引:6  
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.  相似文献   

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