Qualidade fermentativa da silagem da parte aérea e de raiz de mandioca em função da idade de colheita e tempos de armazenamento.

Abstract

Cassava root and shoot silage (M. esculenta Crantz) has shown great potential in ruminant feeding. However, the management applied at harvest, such as harvest age and storage time, can influence the fermentative characteristics and the final nutritional value of cassava silages. The objective was to evaluate the fermentative characteristics and the chemical composition of the silage of the shoot and root of cassava as a function of the age at harvest of the shoot and root and the storage time. In article 1, two experiments were carried out: in experiment 1, the shoot silage was evaluated and in experiment 2, the silage of its regrowth was evaluated. Experiment 1 evaluated shoot silages and experiment 2 evaluated its regrowth silage. Experiment 1 was carried out in a randomized block design arranged in a 6 × 3 factorial scheme, with six harvest ages of cassava shoots (6, 7, 8, 9, 10 and 11 months) and three silage storage periods (3, 30 and 90 days after ensiling), with four replications. Experiment 2 was carried out in a randomized block design arranged in a 4 × 2 factorial scheme, with four cassava shoot regrowth ages (6, 7, 8 and 9 months) and two silage storage periods (3 and 90 days). after ensiling), with four replications. In article 2, the experiment was carried out in a randomized block design arranged in a 4 × 3 factorial scheme, with four cassava root harvest ages (7, 9, 10 and 11 months) and three silage storage periods (3, 30 and 90 days after ensiling), with four replications. The fermentation profile, microbial populations, chemical composition and aerobic stability of silages were evaluated. For article 1, in experiment 1, there was an effect of the HA×ST interaction (P<0.05) on microbial populations, pH and chemical composition of shoot silages. It was observed that there was an effect of the HA×AS interaction (P<0.05) on the microbial populations, but there was not (P>0.05) for pH and temperature, with effect only of the AS (p<0.05). There was an effect of HA (P<0.05) on AS, Tmax, Htmax, AMP, PE, except PMS. For experiment 2, there was no effect of HA on microbial populations and pH (P>0.05), except for the enterobacteriaceae population (P<0.05). No effect of HA or ST on lactic acid bacteria populations was observed (P>0.05). There was an effect of ST for pH, with values of 3.5 and 3.7 for 3 and 90 days respectively (P<0.05). There was an effect of the HA×ST interaction only on the CP and NDF content of the silage (p<0.05). HA did not influence AS, Tmax, Htmax, AMP (P>0.05). In article 2, there was an effect of HA on microbial populations, pH and root chemical composition (P<0.05), except for the ENT population (P>0.05). There was an effect of the HA×ST interaction (P<0.05) on the pH, chemical composition and microbial populations of cassava root silages. Thus, harvest age and storage time influence the fermentative quality of shoot and root silages of cassava.