An improved enzymatic method by adding gammanase to determine digestibility and predict energy value of compund feeds and raw materials for cattle

Johan De Boever, BG Cottyn, José Vanacker, CV Boucque

    Onderzoeksoutput: Bijdrage aan tijdschriftA1: Web of Science-artikelpeer review


    Because the current pepsin-cellulase method of De Boever et al. (1986) (Animal Feed Science and Technology, 1986, 14: 203-214) underestimates the digestibility of palm kernel cake, the procedure was adapted by using a cellulase mixture and adding gammanase. In a comparative test on 28 currently used raw materials, the modified method not only increased the digestibility of palm kernel cake (+13.7% units), but also that of soya bean hulls (+4.7, whereas the other feeds were little affected. Further, new equations to predict metabolizable energy (ME) and net energy lactation (NEL) were derived for normal (n=61; ME 9.3-13.9; NEL 5.4-8.5 MJ kg(-1) DM) as well as for fibre rich (n=37; ME 3.8-12.7; NEL 1.9-7.6 MJ kg(-1) DM) compound feeds and raw materials. For normal concentrates, best multiple linear regressions based on the new enzymatic method (EN), the original pepsin-cellulase digestibility (CE) and on rumen fluid digestibility (RF) had similar residual standard deviations (RSD) of about 0.25 and 0.20 MJ kg(-1) DM for ME and NEL, respectively. For fibre-rich concentrates, the RSDs of RF equations were lower (ME 0.28; NEL 0.20 MJ kg(-1) DM) than those of EN equations (ME 0.43; NEL 0.28 MJ kg(-1) DM) and CE equations (ME 0.50; NEL 0.32 MJ kg(-1) DM). However, when validated, EN equations appeared more accurate than CE and RF equations and the use of tabular values; the ME of 28 mixed feeds was predicted with errors of 2.7 2.8 3.7% and 3.3 respectively, whereas for 16 raw materials the errors amounted to 3.3 3.6 5.0% and 4.3 respectively. Prediction errors with NEL equations were 0.5-1.1% higher.
    Oorspronkelijke taalOngedefinieerd/onbekend
    TijdschriftAnimal Feed Science and Technology
    Pagina's (van-tot)1-18
    Aantal pagina’s18
    PublicatiestatusGepubliceerd - 1-mei-1994

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