The influence of wilting on the quality of Leucaena leucocephala silage

Abstract Text: An experiment was conducted in the northwest of Venezuela in order to evaluate the ensiling properties of Leucaena leucocephala using laboratory silos. Factors studied were wilting for 0 and 3 h and ensiling time of 0, 7, 14, 21, and 35 days.The silos were kept in the room set at 25ºC  and samples  were taken from three silos at each sampling time for chemical analyses. Data were analyzed as a randomized design with a 2x5 factorial of wilting and ensiling time, respectively, with three replications. Means were compared by Tukey test. Response variables were:  DM, cellulose (C), pH , total nitrogen (TN), ammonia (NH₃) and NH₃/TN. Increasing ensiling time of high moisture Leucaena resulted in losses of DM  in the silage, unwilted silage contained 52.3% DM at the end of ensiling time while wilting silage showed 59.9% of DM. Ensiling Leucaena from 0  to 35 days resulted in decreased (P<0.05) C content in 9.5%   for high moisture silage in contrast to  6.5% for wilted. This could have been due to the cumulative activity of plant cell respiration and some facultative bacteria in the fresh ensiled forage. The pH increased (P<0.05) while TN, NH₃ and NH₃/TN decreased (P<0.05) with reduced moisture content of ensiled Leucaena.The concentrations of fermentation end-product decreased with wilting, showing that low moisture restricted fermentation. The reduction in TN content in wilted silage was expected due to breakdown of true protein during sun-drying and ensiling process. Wilting resulted in  decreased (P<0.05)  NH₃ and  NH₃/TN when compared to high moisture silage.  Concentrations of NH₃ and NH₃/TN in high moisture silage were 35.3 and 24.6% greater, respectively than wilted silage. However, levels of NH₃ were less than 80-100 g/kg TN which is commonly used to represent well fermented silage. All silages in the current experiment achieved satisfactory preservation.

Keywords: Leucaena leucocephala, wilting, silage, quality