Sampling Techniques for Feed Analysis PDF

Sampling techniques for feed analysis CU: Animal Nutrition Margarida Cardoso Duarte, PhD www.egasmoniz.com/pt www.egasmoniz.com/pt Samples for chemical analysis should be representative, if not, -...

Sampling techniques for feed analysis CU: Animal Nutrition Margarida Cardoso Duarte, PhD www.egasmoniz.com/pt www.egasmoniz.com/pt Samples for chemical analysis should be representative, if not, - the analytical value obtained will Master Degree in Veterinary Medicine be not significant. www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques For teaching purposes only! COMMISSION REGULATION (EC) No 152/ 2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed -- Medicine Veterinary Medicine ANNEX I in Veterinary METHODS OF SAMPLING ANNEX II Degree in Master Degree GENERAL PROVISIONS ON METHODS OF ANALYSIS FOR FEED Master www.egasmoniz.com/pt www.egasmoniz.com/pt Feed sample types For teaching purposes only!  bulk feed, packaged feed, in containers  solid, liquid, semi-liquid  feed blocks and mineral licks (alimentos em blocos e pedras minerais para lamber) --  forage and other roughage (forragem e outros alimentos grosseiros) Medicine Veterinary Medicine in Veterinary (Explained and Healthy Salt Types) – Family Life Share Why Do Cows Lick Salt? Degree in Master Degree Master Fresh hay on a summer afternoon | Smithsonian Photo Contest | Smithsonian Magazine www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques - definitions For teaching purposes only! Sampled portion/ lot (lote): A quantity of product constituting a unit, and having characteristics presumed to be uniform (e.g. same production day, produced in sequential order and with the same raw materials…). Incremental sample (amostra elementar): A quantity taken from one point in the sampled portion. -- Aggregate sample (amostra global): An aggregate/ sum of incremental samples taken from the same Medicine Veterinary Medicine sampled portion. in Veterinary Reduced sample (amostra reduzida): part of the aggregate sample, L obtained from it through a representative reduction process. A Degree in B Final sample (amostra final): part of the reduced sample or of the Master Degree homogenized aggregate sample (not less than 500 g or 500 ml). Master www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques – quantitative requirements For teaching purposes only! The size of the lot must be such that each of its constituent parts can be sampled. Different quantitative requirements for:  Control of substances or products uniformly distributed throughout the feed; --  e.g. minimum nr of incremental samples for bulk lots < 2.5 ton (= 7) or < 2500 liters (= 4). solids liquids Medicine Veterinary Medicine  Control of undesirable substances or products likely to be distributed non uniformly throughout the feed. For instance: in Veterinary  aflatoxins;  Degree in rye ergot (Claviceps purpurea – parasitic fungus that atacks rye; hallucinogenic); Master Degree  castor-oil plant (or Ricinus communis, the seed contains the toxin ricin);  plant material from Crotalaria gender (Fabaceae family) (toxic plant if ingested: e.g., Master hepatic encephalopathy in horses). www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques (cont.) For teaching purposes only! A correct sampling implies:  Be composed of several incremental samples (= aggregate sample) in the required amount taking into account the variability of the feed/ raw material. --  Should be collected randomly from different parts of the feed/ raw material (particularly important in roughage feed (forragem)) Medicine Veterinary Medicine  In the case of pastures (grazing), it should be avoided over-trampled areas or areas that are not in Veterinary representative (e.g. under trees). Degree in Master Degree Master Adapted from “Chemical analysis” class. Ribeiro T. (2022) www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques (cont.) For teaching purposes only! Examples: Pastures: collect in different spots and randomly if the area > 1 m2 Hay/Straw: collect different samples (incremental) from several bales and ensure all parts of the plant are included (stem, leaves, ear - caule, folhas, espiga) -- Silages (ensilados): collect samples from different parts of the silo (and ships) Medicine Veterinary Medicine (dynamic sampling is possible only during silo discharge). Avoid air exposed areas. in Veterinary Grains and compound feed: using probes to collect from different locations Degree in Master Degree Master Adapted from “Chemical analysis” class. Ribeiro T. (2022) www.egasmoniz.com/pt www.egasmoniz.com/pt Sampling techniques (cont.) For teaching purposes only!  Samples should be collected into clean bags/ flasks, closed and with removal of air as much as possible;  Samples must be sent to the lab as soon as possible (e.g. dried (if fresh forages – -- prone to putrefy) or freezed (silages – prone to fermentation)); Medicine Veterinary Medicine  Samples must be identified: description of feed/ raw material, collecting location, date… Master Degree Master in Veterinary Degree in Adapted from “Chemical analysis” class. Ribeiro T. (2022) www.egasmoniz.com/pt www.egasmoniz.com/pt Samples preparation for analysis in the laboratory For teaching purposes only! - Samples for lab:  weight amount (depending on analytical methodology)  homogeneous  representative of the “final sample” -- - If moisture content of sample may change during preparation: moisture content before and after preparation must be determined (to avoid quantification errors) – e.g. pre-drying of Medicine Veterinary Medicine pastures and forages for further grinding; in Veterinary - Grinding, mixing and/or sieving - shall be carried out as quickly as possible with minimal exposure of the sample to the air and light; Degree in Master Degree - Storage of samples: appropriate temperature - to avoid sample composition deterioration; Master stored in brown glass containers – if intended analysis of vitamins or substances which are particularly sensitive to light. Adapted from “Chemical analysis” class. Ribeiro T. (2022)