Effects of a mixture of Lentilactobacillus hilgardii, Lentilactobacillus buchneri, Pediococcus pentosaceus and fibrolytic enzymes on silage fermentation, aerobic stability, and performance of growing beef cattle. Issue 4 (11th November 2022)

• Record Type: Journal Article
• Authors: Nair, Jayakrishnan; Yang, Hee-Eun; Redman, Abby-Ann; Chevaux, Eric; Drouin, Pascal; McAllister, Tim A; Wang, Yuxi
• Is Part Of: Translational animal science. Volume 6:Issue 4(2022)
• Publication Date: 2022-11-11
• Subjects: beef cattle -- growth performance -- heterofermentative lactic acid bacteria -- Lentilactobacillus hilgardii -- silage aerobic stability -- whole-plant corn silage; Livestock -- Periodicals; Livestock; Periodicals; 636.005
• DOI: 10.1093/tas/txac144
• Languages: English
• ISSNs: 2573-2102

Abstract

Abstract: This study evaluated the effects of novel silage inoculants containing lactic acid bacteria (LAB) and fibrolytic enzymes on ensiling, aerobic stability (AS), and the performance of growing beef cattle. Whole-plant corn forage was either uninoculated (CON) or inoculated with a mixture of LAB containing (cfu g −1 fresh forage) 1.5 × 10 5 L. hilgardii (CNCM I-4785), 1.5 × 10 5 L. buchneri (NCIMB 40788) and 1.0 × 10 5 P. pentosaceus (NCIMB 12455) for a total of 4.0 × 10 5 cfu g −1 fresh forage LAB (IB), or a combination of IB plus fibrolytic enzymes (xylanase + β-glucanase) (IC) . All treatments were ensiled in mini-silos, whereas CON and IC were also ensiled in silo bags for the growth performance study. Total bacteria (TB) counts were lower ( P = 0.02) for IC than CON after 14 d of ensiling, whereas TB counts of IC and IB were greater ( P ≤ 0.01) than CON after 60 d of ensiling in mini-silos. The LAB in IC and IB ensiled in mini-silos were greater than CON on d 60 ( P ≤ 0.01) and 90 ( P ≤ 0.001) of ensiling and after 3 d ( P ≤ 0.01) of aerobic exposure (AE) . Silage pH of IC ensiled in silo bags was lower than CON on d 3 ( P < 0.01), 7 ( P < 0.001), and 14 ( P = 0.02) of AE. Yeast counts were lower for IC than CON in terminal silage ( P < 0.001), and after 3 ( P < 0.001) and 7 d ( P < 0.01) of AE. Acetate (AC) concentrations were higher ( P ≤ 0.02) for IC than CON throughout AE, whereas lactate (LA) concentrations of IC were greater than CON on d 3 ( P < 0.001), 7 ( P < 0.01), and 14 ( P < 0.001) of AE. Greater AC concentration and lower yeast counts resulted in greater ( P < 0.001) stability for IC ensiled in silo bags than CON after 14 d of AE. Growth performance of steers was similar ( P > 0.05) as the nutrient composition of silage was similar across diets. Improved AS of IC could potentially have a greater impact on DMI, production efficiency, and growth performance in large-scale commercial feedlot operations where silage at the silo face may be exposed to air for longer periods of time. Abstract : Combining strains of heterofermentative LAB, including Lentilactobacillus buchneri and L. hilgardii could confer aerobic stability to silages ensiled in silo bags, offering producer flexibility in using silages over a wide range of storage periods. Lay Summary: Silages will deteriorate upon exposure to air due to microbial activity during feed-out. Inoculation with heterofermentative lactic acid bacteria (LAB) such as Lentilactobacillus buchneri confers aerobic stability (AS) to silages by producing acetic acid (AC) inhibiting yeasts. There is a need to develop inoculants with novel strains of hetero-fermentative LAB, such as L. hilgardii, having potential complementary and synergistic effect with L. buchneri to offer producer flexibility in using silages over a wide range of storage periods ranging from a few weeks to over a year of ensiling. Inoculant complexes (IC) combining fibrolytic enzymes (xylanase + β-glucanase) with the inoculants can potentially enhance ensiling fermentation, improve AS, and the feed value of corn silages. This study showed that inoculants containing a mixture of LAB and fibrolytic enzymes increased AC concentration and lowered yeast population in whole-plant corn silages ensiled in silo bags and markedly prolonged stability of the silages upon exposure to air. Improved AS by the inoculants could potentially have a more significant impact on the growth performance of steers in large-scale commercial feedlot operations where silages at the silo face may be exposed to air for longer periods of time, thereby deteriorating quality.