Fermentation characteristics, aerobic stability and deterioration of silages from selected tropical maize hybrids.

Abstract

Maize is a crop that has the potential to revolutionize dairy production in the tropics, especially Africa, if well adopted and used as silage because of its good fermentation characteristics. Unfortunately, in Africa, it is preferred more as human food than animal feed, with only the poor-quality grains being incorporated into animal feed. In this study, six (6) tropical forage maize hybrids, developed at NaLIRRI, were selected and the fermentation characteristics (DM, pH, LA, AA, BA & NH₃-N) and aerobic stability & deterioration of their silages assessed. These included JPS-2022-13, JPS-2022-20, JPS-2022-41, JPS-2022-44, JPS-2022-48, and JPS-2022-84. The whole maize was harvested at the R3 stage of growth, chopped (2 cm), compacted in plastic containers (1 kg capacity), sealed and ensiled in the laboratory for 45 days. Data was analyzed in R software (R Core Team, 2024) using the tidyverse package (Wickham et al., 2019), where ANOVA was run and Tukey’s test was used to separate the means. Of the six fermentation characteristics that were analyzed, the silages performed well in 4 of them (DM, NH₃-N, AA & BA) but fell short in the remaining 2 (LA & pH), when compared to the ideal values. In terms of aerobic stability & deterioration, none of the hybrid silages performed to the expectations as none of them hit the 48-hour desired mark. However, JPS-2022-20 & JPS-2022-44 were the standouts in this aspect, achieving 30 & 28 hours of aerobic stability, respectively. The least aerobically stable silages were from JPS-2022-13, JPS-2022-48 and JPS-2022- 84 with 12 hours each. Effects of aerobic deterioration started to show from day 3 of aerobic exposure and by day 7, all the silages were completely spoilt, with a very unpleasant smell and completely dominated by molds. Therefore, it is recommended that use of additives like molasses while ensiling could improve on the fermentation characteristics of these silages and thus enhance their quality which in turn could improve their aerobic stability.