Determination of in vitro digestibility in alfalfa hay (Medicago sativa L.) by adding exogenous xylanase enzymes

David Napoleón Vera Bravo, Kleber Fernando Mejía Chanaluisa, Félix Reinaldo Pastrán Calles, Jorge Luis Mendoza Mejía

Abstract

The objective of the work was to evaluate the Chemical Composition (CQ), Digestibility in vitro of the dry matter (DIVMS) of the alfalfa hay (Medicago sativa L.) simultaneously with the Production of gas in vitro (PGIV). The formulation of the problem states that: With the application of exogenous fibrolytic enzymes (xylanases) to the substrate and ruminal liquor, will the in vitro digestibility in alfalfa hay improve? It is justified by improving the digestibility in alfalfa hay, adding enzymes in the feed. The in vitro method consisted of an incubation of the food with ruminal fluid for 48h at 39ºC, where the (DIVMS) 24 and 48h and the in vitro gas production (PGIV) were simultaneously evaluated at 3, 6, 12, 24 and 48 hours of incubation at random, with four treatments and three repetitions, through the application of exogenous enzymes at three levels compared to a control, the following doses: 0 (control), 2000IU (T1), 4000IU (T2) and (T3) 8000 IU kg^-1 MS. The percentage of DIVMS was obtained at 24 and 48 hours using xylanases, a greater DIVMS was noted at 24 hours in T2: 38.87 % and a relationship in digestibility time up to 48 hours with 44.06 % with significant differences between treatments (P <0.05). The PG post-fermentation of the flasks, registered values in the different evaluated times where significant differences appear between the treatments. It is concluded that the addition of fibrolytic enzyme improved the quality of grass forage fermentation with low nutritional value and the application of xylanases resulted in a high quality hay, with the best effect on DGIV with a dose of 4000 IU kg^-1 MS (T2). The best incubation time on in vitro gas production reached a volume greater than 48h with 208.00 ml g^-1 MS (T2).