A meta-analysis examining lactic acid bacteria inoculants for maize silage: Effects on fermentation, aerobic stability, nutritive value and livestock production

A database containing 140 articles published in journals (731 treatment means evaluated) was used to examine the effect of different lactic acid bacteria (LAB) on fermentation, chemical composition and aerobic stability of maize (corn) silage. Compared with the control, dry matter (DM) loss increased by 8% and 50% (p < .01) due to inoculation of maize silage with either homolactic LAB ((ho)LAB) or heterolactic LAB ((he)LAB). In vitro DM digestibility of maize silage increased only with (ho)LAB inoculation (+2.22%; p < .01). The (he)LAB inoculation increased (p < .01) the aerobic stability of maize silage by 71.3 hr. To investigate the effect of silage inoculation on livestock production, a second database comprising 35 articles [99 treatment means evaluated based on results from 648 cattle (429 beef cattle and 219 dairy cows) and 298 sheep] was used. Inoculation of maize silage with either (ho)LAB or (he)LAB did not affect milk yield (p > .05), but their combination ((mix)LAB) depressed milk yield (-2.5 kg/day; p < .01). Inoculation with (ho)LAB increased DM intake in sheep (+0.15 kg/day; p = .02), but decreased it in beef cattle (-0.26 kg/day; p = .01) without affecting average daily gain for both sheep and beef cattle (p >= .06). In conclusion, fermentative loss increased regardless of the bacterial inoculant used, while aerobic stability increased mainly by using (he)LAB. Benefits from (ho)LAB inoculation on animal performance were noted only for feed intake in sheep, while productive performances of dairy cows and beef cattle were not improved.