EXERCISE 9

first consideration in feed quality control

involves examination of raw materials / feed ingredients with naked eye (color, odor, texture, dampness, presence of adulterant, presence of mold, and insect infestation)

study of appearance of feed samples and/or adulterant under the stereomicroscope

substances / impurities of cheaper value and low quality that are intentionally added to feeds to change its physical/chemical characs; add bulk or weight

(adulterant) used to increase feed weight

(adulterant) has high gross content but low digestible energy content due to high amount of cellulose

is indigestible to monogastric animals due to absence of endogenous cellulase

(adulterant) also contain high amount of cellulose (same with saw dust)

(adulterant) contains high amount of cellulose and lignin which is also indigestible to monogastric animals

(chemical evaluation) most extensively used method for determination of nutritive value of feeds (moisture, ether extract, crude fiber, crude protein, ash, and NFE)

(proximate analysis) determined by weighing finely ground sample before and after drying it to constant weight at 105C (overnight); all substances that volatize at this temp represent _____ content of sample

apparatus for proximate analysis of moisture

(proximate analysis) sum of all ether-soluble materials; this residue is fat and fatty acid esters, but includes all ether-soluble substances (waxes, essential oils and pigments)

apparatus for ether extract (crude fat)

(proximate analysis) rough measure of portion of carbs that is poorly utilized by monogastric animals; measured as loss in ignition at 550C for 4 hours; composed mainly of cellulose, hemicellulose, and lignin

apparatus used to get crude fiber

(proximate analysis) computed as total nitrogen content of sample multiplied by 6.25. formula is %N*6.25.

process for CP that involves sample digestion, distillation, and titration

apparatus used for crude protein

(proximate analysis) estimate of inorganic content of feed sample; involves igniting sample in furnace that burns all OM to CO2 and H20; residue remaining after combustion represents it

apparatus used for ash (mineral content)

(proximate analysis) represents sun of remaining undetermined portions of feed and is meant to represent more digestible portions; only one determined by calculation; formula is = 100 - (moisture+ash+crude protein+crude fat+crude fiber)

(microbial evaluation / microbiological assay) used to determine presence of salmonella spp. and mycotoxin-producing fungi (aspergillus and fusarium in feeds)

(microbial evaluation / microbiological assay) most widespread and best known of all mycotoxins