Laboratory for Animal Feed Analysis conducts physical and chemical tests as well as microbiological and mycotoxicological chemical tests of animal feed. The Laboratory analyses finished animal feed mixtures, vitamin and mineral pre-mixtures, animal feeding stuffs of vegetal, animal and mineral origin, fats used in animal nutrition and biological samples. Based on the tests, the nutritional and microbiological quality of finished animal feed mixtures and premixes used in animal nutrition is evaluated due to their significant impact on the animal growth and health during their breeding and farming and on the quality of final product used in human nutrition. The Laboratory also produces, by linear optimisation program, recipes of poultry feeding mixtures for clients’ needs, and deals with the technology of poultry breeding and nutrition in the intensive poultry production. In agreement with or at request by clients, the Laboratory conducts analysis by the method specified or delivered by the client unless issued as a Croatian standard. In the latter case, in agreement with the client, the Laboratory first introduces and elaborates the method. Highly selected poultry breeds in the intensive production, in addition to the optimal ones, and the application of specific immunoprophylaxis measures must consume the food of good quality that will ensure animal productivity with minimum consumption. Due to such major importance of nutrition in achieving good production results of poultry farming, the Laboratory for the Animal Feed Analysis of the Poultry Centrehas been active from its very foundation in the field of chemical analysis of animal feed and the introduction of experts into the poultry feeding technology and production of feeding mixtures. Since 1969, the Laboratory for Animal Feed Analysis has been testing the animal feeds and feed mixtures for poultry. The analyses have been focused on the basic nutritional composition, calcium, phosphorous, microelements (sodium, manganese, potassium, copper, zinc and iron), vitamin A and E (Carr-Price method and Emmerie-Engel colorimetric method). In 1974, the Laboratory purchased an atomic absorption spectrophotometer for determination of microelements in feed and a calorimetric bomb for determination of gross energy of feeding stuffs and animal feed mixtures. Detection of presence and determination of quantity of anticoccidials (amprol, ethopabate, sulphaquinoxaline, pyrimethamine, clorpindol, robenidine, nicarbazin), which are introduced into pre-mixtures and finished animal feed mixtures, has been in application since 1975. Only ten years after the introduction of high-pressure liquid chromatography, the most modern technique in analytical chemistry, a high-pressure liquid chromatograph (HPLC) was purchased. Contents of vitamins A and E in pre-mixtures and finished animal feed mixtures since 1977 have been determined by means of HPLC. Requests by manufacturers of anticoccidials for fast control of their addition into vitamin and mineral pre-mixtures and animal feed mixtures have led to the need for the expansion of HPLC operation. Determination of amino acid methionine and BHT added to vitamin and mineral pre-mixtures has been applied since 1981/1982. As the production requires fast resolution of feeding related problems, in 1983 an infraalyzer 400 with a computer was purchased. Results of analyses of mixtures by the device are visible in several seconds, saving the time and chemicals and creating no waste substances that would contaminate the environment. Since 1984, linear optimization program has been used for practical needs, which helps to crate in short time the recipe of mixtures by nutritional substances for an optimally balanced animal meal. Because of health problems in the poultry farming which pointed out to the presence of pesticide tetramethylthyuram disulphide (TMTD), the HPLC method for its analysis was introduced. Since 1985, the analysis of mycotoxins – ochratoxin A, zeranol and zearalenone has been part of the routine. For detection of mycotoxins in animal feed and feeding stuff mixtures, the cooperation of mycologists is required as they will evaluate the samples on the basis of presence of specific moulds and select those that will be subject to the mycological test, although the presence of characteristic moulds does not always have to be a definite indicator of the presence of mycotoxins and vice versa. According to the mycological analysis, the sample does not have to be suspect of the presence of mycotoxins, which does not mean that mycotoxins are not present in the animal feed. To avoid problems in the digestion of raw starch in young animals and carnivores, starch in their feeding stuffs should be subject to additional heat processing by various techniques (superheated steam, micronization, toasting, flaking, etc.). These procedures are aimed to increase the digestibility of the cereals as food i.e. their usability. By determination of starch gelatinisation level in cereals and animal feed – expressed as hydrolized starch in the percentage of total quantity in a sample corrected by reduced sugar and natural colour, the successful heat treatment of cereals may be evaluated. Generally accepted addition of fats to feed mixture is attributed to the fact that its addition to feed mixture has significant advantages (energy density with the lowest cost per energy unit, containing unsaturated fatty acids necessary in animal nutrition, improving the food taste and food conversion, etc.). In the recent twenty years, a number of research was conducted for identification and determination of indicators required for optimal recipes and guidelines based on which the quality of fat may be evaluated, as the reduction of the quality of fat in the food is reflected in the reduced growth in monogastric animals. In that regard, the indicator of optimum quality of fats as food additives is among other ways evaluated by determination of: free fatty acids, impurities, unsaponifiable matter, oxidised fatty acids, iodine number, peroxide number, fatty acid composition, etc. Evaluation of the regularity of heat treatment process of a soy grain is done by determination of activities of urease, solubility of proteins in water compared to total proteins and trypsin inhibitors, etc. Laboratory for Animal Feed Analysis is equipped for determination of humidity, ashes, fats, fibres and proteins; for determination of macro and micro-elements by atomic absorption spectrophotometry method; for spectrophotometric methods, for chromatographic methods; microbiological – mycotoxicological methods. The analyses are conducted by reference methods such as recommended by ISO standards and accepted as Croatian standards or published in AOAC methods. Based on a decision by the Ministry of Agriculture and Forestry (Official Gazette NN no.:44/1999), the Croatian Veterinary Institute, Poultry Centre is a licensed and reference laboratory for testing of quality of animal feed for physical, chemical, microbiological and toxicological tests. Laboratory for Mycology and Mycotoxicology was established in 1972. The establishing of the Laboratory was stimulated primarily by the poultry farming industry, due to an increased awareness of the fact that animal feed directly or indirectly impacts the occurrence of poultry diseases. At its very beginning, the Laboratory controlled the microbiological safety of animal feed, conducted the identification of moulds and bacteria from animal feed and from organs of dead poultry, and later also detection of anticoccidials in animal feed mixtures and analyses of animal feed on the presence of mycotoxins by methods of thin-layer chromatography. In 1985, the Laboratory introduced methods for the analysis of fungicides and high-pressure chromatography methods for mycotoxins. In late 2000, procedures and methods of microbiological and mycotoxicological tests of feed samples were harmonized according to ISO standards and AOAC analytical methods. Animal feed is a source of nutritional and biologically active substances, which by their quality and quantity must fulfil the requirements of contemporary poultry lines. However, animal feed is often contaminated with moulds at certain point of production, processing, transport or storage. In addition to chemical decomposition of carbohydrates, proteins and other essential substances, moulds often release also secondary products of their metabolism that we call mycotoxins. Currently, 25% of all cereals are contaminated with mycotoxins. Consequences of contaminated animal feed are reflected in losses in its nutritional value and organoleptic properties, and the effect of mycotoxins directly affects the health and production results of poultry. Current operations of the Laboratory for Mycology and Mycotoxicology include the following tests: control of microbiological safety of raw materials and animal feed; isolation and identification of moulds and bacteria from animal feed; diagnostic of diseases caused by pathogenic moulds; control of mycotoxicological safety of raw materials and animal feed by means of TLC and HLPC methods for detection of mycotoxins (T-2, DAS, zearalenone and derivatives, ochratoxin and DON); determination of anticoccidials in mixtures and premixes. Laboratory for Technology of the Poultry Centre was particularly active in the beginnings of creation, spreading and organisation of intensive poultry farming in our country as the Department experts made the preliminary technological documents for almost all farms and facilities involved in the poultry breeding. Besides, permanent control of the implementation of technology and application of new technological achievements in the production required permanent field visits of experts and at certain points that was the most numerous department of the Centre for Poultry Farming. As our poultry farming has been modernised in all its segments, its needs in terms of professional and scientific upgrade changed and the scope and profile of operations of our experts adapted. It was a start of the more intensive control of ambient factors in the production and of specific technological segments which due to their bad condition could have a negative impact on the health and productivity of poultry. Thus, besides the creation of preliminary technical documents for the construction of poultry farming plants, control of ambient and technology of production, our experts by their professional and scientific work engaged in the poultry health care protection in the production which is currently a major part of their activities. The evaluation of the production success is also within the scope of their operations, just as is determination of negative factors which may place risk on it in all its categories and segments.
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