S.L. 437.55 Art. 6as a separate the suitable structure). one for the (at least 5 g) for the origin of the samples part of the systematically of animal are screened for 6.2. sediment At least 5 g funnel or - If a sufficient time shall be The sediment - If an minutes before The total The weighing consists of fractions.

Procedure Pelleted feeds may be pre-sieved if both fractions are analysed sample. At least 50 g of the sample shall be treated (ground with care using grinding equipment (5.2) if necessary in order to achieve an appropriate From the ground material two representative portions shall be taken, sieve fraction (at least 5 g) (6.1) and one for the concentrated sediment (6.2). Colouring with staining reagents (6.3) can additionally be applied identification.

In order to indicate the nature of the animal proteins and the particles, a decision support system such as Aries can be used and reference can be documented. 6.1. Identification of constituents of animal origin in the sieve fractions At least 5 g of the sample is sieved through the sieve (5.3) in two fractions. The sieve fraction(s) with the large particles (or a representative fraction) is applied as a thin layer to a suitable support and screened under the stereomicroscope (5.5) at various magnifications for constituents origin. Slides made with the sieve fraction(s) with the fine particles systematically under the compound microscope (5.6) at various magnifications constituents of animal origin. FOR THE OFFICIAL CONTROL OF FEEDINGSTUFFS

Identification of constituents of animal origin from the concentrated

(accurate to 0,01 g) of the sample shall be transferred into a separation conical bottomed settling beaker and treated with at least 50 ml of tetrachloroethylene (4.3.1). The mixture shall be shaken or stirred repeatedly.

closed separation funnel is used the sediment shall be left to stand for a (at least three minutes) before the sediment is separated off. Shaking repeated and the sediment shall be left to stand again at least three minutes. shall be separated off again. open beaker is used, the sediment shall be left to stand for at least five the sediment is separated off. sediment shall be dried and subsequently weighed (accurate to 0,001 g). is only necessary in case an estimation is required. If the sediment many large particles it may be sieved through a sieve (5.3) in two dried sediment shall be examined for bone constituents under the stereomicroscope (5.5) and the compound microscope (5.6).

embedding agents and staining reagents microscopic identification of the constituents of animal origin can be the use of special embedding agents and staining reagents.

hydrate (4.1.1): By carefully heating, cell structures can be seen more starch grains gelatinise and unwanted cell contents are removed.

Either sodiumhydroxide or potassiumhydroxide clears the material of assisting the detection of muscle fibres, hairs and other keratin structures.

and glycerol (4.1.3): Bone constituents can be well identified in this agent because most lacunae remain filled with air and appear as black 5-15 µm. Iodine/potassium iodide solution (4.4.1): Used for the detection of starch (blue-and protein (yellow-orange colour). Solutions may be diluted if solution (4.4.2): Red/pink colouring of bones, fish bones and scales. the sediment (see section 6.2), the total sediment shall be transferred tube and rinsed twice with approximately 5 ml alcohol (4.2.1) (each shall be used, the solvent shall be let settle about one minute and Before using this staining reagent, the sediment shall be bleached by 1 ml sodium hypochlorite solution (4.5.1). The reaction shall be continue for 10 minutes. The tube shall be filled with water, the sediment settle two to three minutes, and the water and the suspended particles off. The sediment shall be rinsed twice more with about 10 ml of shall be used, let settle, and the water poured off each time). Two to drops (depending on the amount of residue) of the alizarine red solution The mixture shall be shaken and the reaction shall be let occur a few coloured sediment shall be rinsed twice with approximately 5 ml followed by one rinse with acetone (4.2.2) (each time a vortex shall solvent shall be let settle about one minute and poured off). The then ready to be dried. reagent (4.4.3): By carefully heating, cystin-containing constituents (hair, become black-brown. FOR THE OFFICIAL CONTROL OF FEEDINGSTUFFS [

6.4. Examination in feed possibly containing fishmeal At least one slide shall be examined from the fine sieve fraction and fraction of the sediment under the compound microscope (see sections Where the label indicates that the ingredients include fishmeal, or of fishmeal is suspected or detected in the initial examination, at least slides of the fine sieve fraction from the original sample, and the fraction shall be examined.