In Vitro Methods for Measuring the Dry Matter Digestibility of Ruminant Feedstuffs: Comparison of Methods and Inoculum Source

Abstract

We conducted this study to evaluate the new in vitro system, DAISY", to determine dry matter (DM) digestibility in ruminant feedstuffs. Results from the DAISY" were compared to those obtained by the traditional Tilly and Terry method. The traditional method buffer was used for both methods. We also compared two sources of rumen inoculum from sheep and dairy cows. Seventeen different feeds were tested, grouped into roughage, concentrate, and CP supplements. The experiment was replicated on two different occasions for all feeds and the two sources of inoculum. The source of inoculum and the time at which it was collected had no effect on the in vitro DM digestibility of the feedstuffs in either of the methods. The DAISY" DM digestibility value compared well with the traditional method values for the roughage group; however, for some feedstuffs in the concentrate and CP supplement groups, the DAISY" values were significantly higher than the traditional method values. Regression analysis of the feeds that resulted in similar values with the two methods revealed that the DAISY" method can be used to predict in vitro digestibility with relatively small variation.

Comparação de métodos in vitro para a quantificação da digestibilidade da matéria seca e da fibra em detergente neutro de forragens e concentrados

“…2), todas as avaliações conduzidas em incubadoras produziram resultados superiores ao observado com o método de Tilley e Terry (1963). Esse comportamento corrobora outros autores (Mabjeesh et al, 2000;Santos et al, 2000;Lopes et al, 2010;Duque et al, 2011), os quais, em média, obtiveram maiores estimativas de digestibilidade com o uso de incubadoras em Arq. Bras.…”

“…Recentemente, disponibilizou-se no mercado o fermentador artificial de rúmen denominado Daisy II (Ankom Technology Co., Macedon, NY, EUA), com a vantagem de possibilitar a análise de várias amostras simultaneamente, reduzindose, assim, o labor empregado nas análises (Holden, 1999;Mabjeesh et al, 2000;Adesogan, 2002) (Holden, 1999;Mabjeesh et al, 2000;Santos et al, 2000). Entretanto, estudos contrastando os resultados produzidos pelo fermentador TE-150 em relação ao tradicional Tilley e Terry (1963) …”

Effect of the dietary level of cull pinto beans (Phaseolus vulgaris) on ruminal fermentation, kinetics, and digestibility of hair lambs

“…Feed, orts, and fecal samples were ground in a Wiley mill through a 1-mm screen and analyzed for CP (method 976.05;AOAC, 2003). Acid detergent fiber (ADF) and NDF were determined sequentially according to Van Soest et al (1991) (Mabjeesh et al, 2000). After incubation, bags were washed four times with cold water for 5 min and then dried (60 ºC) for 24 h. Concentration of ADF was determined in the bag residue to calculate the percentage of indigestible ADF (Penning and Johnson, 1983).…”

Utilização de fezes (eqüina ou bovina) em substituição ao líquido ruminal como fonte de inóculo para determinação da digestibilidade in vitro de alimentos para ruminantes

“…O FAF apresentou uma DIVMS de 72,09%, 65,58% e 60,76% para os inóculos LR, FB e FE a qual foi maior que a de 58% e 53,6% observado por Mabjeesh et al (2000) ao utilizar as respectivas técnicas Tilley e Terry (1963) Assis (1997), Mandebvu et al (1999) e Gonçalves (2001), porquanto os mesmos chegaram a números inferiores, sendo esses, 62,87%, 61% e 59%.…”

“…Trata-se, pois, de um método que se possibilita comparar espécies ou cortes realizados em diferentes períodos de crescimento de um grande número de espécies forrageiras (Silva, 1990;Holden, 1999;Mabjeesh et al, 2000;Santos et al, 2000).…”