In vitro ruminal fermentation kinetic of diets containing forage cactus with urea and different starch sources

• Main Authors: Yann dos Santos Luz, Mauro Pereira de Figueiredo, Fábio Martins Oliveira, Fernando Salgado Bernardino, Eduardo de Jesus Novaes, João Paulo Santos Roseira
• Format: Article
• Language: English
• Published: Universidade Estadual de Londrina 2014-06-01
• Series: Semina: Ciências Agrárias
• Online Access: http://www.uel.br/revistas/uel/index.php/semagrarias/editor/submission/13289

The study was conducted to evaluate fermentation kinetic of diets based on cactus forage enriched with urea and Tifton 85 hay, containing different starch sources, using semi-automated in vitro gas production technique. Treatments were disposed in a randomized block design, with four replications, where concentrates were formulated as follows: cassava roots (FSMa), semi flint corn grains (FSMiSD), dent corn grains (FSMiD) and wheat bran (FTMa). All diets were formulated to obtain 15% of crude protein. Gas pressure were measured 2, 4, 6, 8, 10, 12, 15, 18, 21, 24, 30, 36, 48, 72 and 96 h after inoculation. For fast phase maximum gas volume (Vf1), both treatments containing corn did not differ (P>0.05). FTMa differed (P<0.05) from diets composed with corn, as main starch source. Specific degradation rate of fast fraction (Kd1) was higher (P<0.05) on FSMa and FTMa diets, compared with corn diets. Colonization time (L) showed lower values (P<0.05) for FTMa diet. The lowest total gas production was observed on FTMa and the highest for FSMiD, varying from 225.49 to 268.31 mL/g, respectively. Cassava roots as starch source contributes to a faster fermentation, compared to both corns, allowing a better synchronization with faster degradation nitrogen sources.