Meta-analysis of effects of inoculation with homofermentative and facultative heterofermentative lactic acid bacteria on silage fermentation, aerobic stability, and the performance of dairy cows.
Forages are usually inoculated with homofermentative and facultative heterofermentative lactic acid bacteria (LAB) to enhance lactic acid fermentation of forages, but effects of such inoculants on silage quality and the performance of dairy cows are unclear. Therefore, we conducted a meta-analysis to examine the effects of LAB inoculation on silage quality and preservation and the performance of dairy cows. A second objective was to examine the factors affecting the response to silage inoculation with LAB. The studies that met the selection criteria included 130 articles that examined the effects of LAB inoculation on silage quality and 31 articles that investigated dairy cow performance responses. The magnitude of the effect (effect size) was evaluated using raw mean differences (RMD) between inoculated and uninoculated treatments. Heterogeneity was explored by meta-regression and subgroup analysis using forage type, LAB species, LAB application rate, and silo scale (laboratory or farm-scale) as covariates for the silage quality response and forage type, LAB species, diet type [total mixed ration (TMR) or non-TMR], and the level of milk yield of the control cows as covariates for the performance responses. Inoculation with LAB (≥105cfu/g as fed) markedly increased silage fermentation and dry matter recovery in temperate and tropical grasses, alfalfa, and other legumes. However, inoculation did not improve the fermentation of corn, sorghum, or sugarcane silages. Inoculation with LAB reduced clostridia and mold growth, butyric acid production, and ammonia-nitrogen in all silages, but it had no effect on aerobic stability. Silage inoculation (≥105cfu/g as fed) increased milk yield and the response had low heterogeneity. However, inoculation had no effect on diet digestibility and feed efficiency. Inoculation with LAB improved the fermentation of grass and legume silages and the performance of dairy cows but did not affect the fermentation of corn, sorghum, and sugar cane silages or the aerobic stability of any silage. Further research is needed to elucidate how silage inoculated with homofermentative and facultative heterofermentative LAB improves the performance of dairy cows.
Instituto de Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso, Campus Sinop, Sinop, MT 78557-267, Brazil; Department of Animal Sciences, University of Florida, Gainesville 32611.
André S
AS
Oliveira
Department of Animal Sciences, University of Florida, Gainesville 32611; Department of Food Quality and Safety, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel.
Zwi G
ZG
Weinberg
Department of Animal Sciences, University of Florida, Gainesville 32611.
Ibukun M
IM
Ogunade
Department of Animal Sciences, University of Florida, Gainesville 32611.
Andres A P
AAP
Cervantes
Department of Animal Sciences, University of Florida, Gainesville 32611.
Kathy G
KG
Arriola
Department of Animal Sciences, University of Florida, Gainesville 32611.
Yun
Y
Jiang
Department of Animal Sciences, University of Florida, Gainesville 32611; Division of Applied Life Science (BK21plus, Institute of Agriculture and Life Science), Gyeongsang National University, Jinju 52828, South Korea.
Donghyeon
D
Kim
Department of Animal Sciences, University of Florida, Gainesville 32611; Institute of Grassland Science, China Agricultural University, Beijing, 100193, China.
Xujiao
X
Li
Department of Animal Sciences, University of Florida, Gainesville 32611; Instituto Federal Goiano, Campus Rio Verde, Rio Verde, GO 75901, Brazil.
Mariana C M
MCM
Gonçalves
Department of Animal Sciences, University of Florida, Gainesville 32611.
Diwakar
D
Vyas
Department of Animal Sciences, University of Florida, Gainesville 32611. Electronic address: adesogan@ufl.edu.
Adegbola T
AT
Adesogan
D000332:Aerobiosis; D000818:Animals; D002417:Cattle; D004063:Digestion; D007887:Fabaceae / Q000378:metabolism; D005260:Female; D005285:Fermentation; D007774:Lactation; D019344:Lactic Acid / Q000378:metabolism*; D007778:Lactobacillus / Q000378:metabolism*; D000455:Medicago sativa / Q000378:metabolism; D006109:Poaceae / Q000378:metabolism; D031786:Saccharum / Q000378:metabolism; D012820:Silage / Q000382:microbiology*; D045868:Sorghum / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism
D019344:Lactic Acid
Lactobacillus plantarum; Lactobacillus rhamnosus; Pediococcus pentosaceus; ensiling