No abstract

This study aimed to examine the effects of feeding corn silage inoculated without or with either Lactobacillus buchneri (LB) alone or a combination of LB and Lactobacillus plantarum (LBLP) on the apparent digestibility, ruminal fermentation, microbial protein synthesis, and growth performance of lambs. Thirty Santa Inês×Dorper crossbred intact males lambs weighing 20.4±3.8 kg were blocked by weight into 10 groups. Lambs in each group were randomly assigned to 1 of the following 3 dietary treatments: untreated (Control), LB, and LBLP silage. Lambs were fed experimental diets for 61 d. The apparent digestibility was indirectly estimated from indigestible NDF measured on d 57 to 59. Spot urine samples were collected from all animals on d 59 to estimate microbial protein synthesis. Lambs were slaughtered for carcass evaluation on d 61 when they weighed 32.4±5.2 kg. Six additional ruminally cannulated Santa Inês×Dorper crossbred wethers weighing 40.5±1.8 kg were used to examine dietary effects on ruminal fermentation. Average daily gain was increased when lambs were fed LBLP silage (P<0.05) but not LB silage. The LBLP silage had the highest (P<0.05) lactic acid concentration and both inoculated silages had greater acetic acid concentrations than the Control silage (P<0.05). Inoculation of corn silage increased intakes of DM, OM, CP, NDF, total carbohydrate (CHO), and GE by the lambs but decreased digestibility of DM, OM, CP, total and nonstructural carbohydrates, and concentration of GE and ME. (P<0.05). Nevertheless, lambs fed inoculated silages had greater microbial N supply than those on the Control treatment (P<0.05). The acetate to propionate ratio was lower in ruminal fluid of wethers in LBLP treatment than LB and Control treatment (P<0.05) and ruminal pH tended to be greater in LB lambs than in LBLP and Control wethers (P<0.10). Finally, the inoculation with both bacteria combined enhanced the silage fermentation. The intakes of DM, OM, CP, NDF, and GE were improved in the lambs fed corn silage inoculated with L. buchneri alone or combined with L. plantarum. The microbial N supply was enhanced in the lambs fed corn silage inoculated with L. buchneri. The inoculation of L. buchneri combined with L. plantarum reduced the acetate to propionate ratio in ruminal fluid and improved the ADG of lambs.

Chemical composition, fermentation characteristics, in vitro digestibility and aerobic stability were evaluated in corn silage inoculated with microbial additives in two different experiments. Inoculant treatments (untreated, Bacillus subtilis and B. subtilis combined with Lactobacillus plantarum) were applied to fresh forages. Chopped corn plants (2B655 Hx) were ensiled in laboratory silos for periods of 7, 14, 21 and 63 days to evaluate the fermentation parameters. The experimental silos were weighed to determine gas losses. After the ensiling period, the silage was sampled to determine chemical composition and in vitro organic matter digestibility. To evaluate aerobic stability, chopped corn plants (AG‐1051) were ensiled in laboratory silos that were opened after 96 days of ensiling. The silage was placed in different buckets containing data loggers. The silage was sampled after 0, 4, 8 and 12 days of exposure to air to evaluate the microbial populations and pH. The data were analysed as a completely randomised design using a mixed repeated-measures model in the MIXED procedure of SAS. To evaluate each treatment relative to the fermentation times, a regression analysis using the PROC REG procedure of SAS was applied. A significance level of P < 0.05 was used. Inoculation with both strains increased lactic acid concentration, whereas the use of B. subtilis alone or combined with L. plantarum improved in vitro apparent organic matter digestibility. In the B. subtilis and B. subtilis combined with L. plantarum silages, moulds and yeasts decreased, and aerobic stability was improved. Inoculation with B. subtilis alone or combined with L. plantarum improved the nutritional value and aerobic stability of corn silage.

Objetivou-se avaliar os efeitos da inoculação de Bacillus subtilis sobre as características e perdas ocorridas na fermentação, no desenvolvimento de leveduras e fungos filamentosos e na estabilidade aeróbia de silagens de milho. Estudou-se o milho híbrido 2B655, no qual avaliaram-se os seguintes tratamentos: silagem sem inoculação de B. subtilis e silagens inoculadas com B. subtilis nas concentrações de 5x10(4); 1x10(5) e 5x10(5)UFC/g de forragem. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, em que as silagens constituíram as parcelas e os tempos de exposição aeróbia as subparcelas, com quatro repetições. Os dados obtidos foram submetidos à análise de variância por meio do software SISVAR®, bem como aplicou-se a análise de regressão a 5% de significância. A aplicação de B. subtilis não alterou as características químicas e as perdas no processo de fermentação da silagem de milho. A contagem de leveduras na abertura dos silos foi reduzida, assim como a população de fungos filamentosos diminuiu durante a exposição aeróbia, o que implicou em menores valores de pH e resultou em maior estabilidade aeróbia, devido à utilização da maior dose de B. subtilis. A inoculação de Bacillus subtilis na concentração de 5x10(5)UFC/g de forragem controla o crescimento dos micro-organismos deterioradores e melhora a estabilidade aeróbia da silagem de milho, a manter os valores de pH mais estáveis na fase de pós-abertura dos silos.

Our objective was to investigate Lactobacillus buchneri as a silage additive and the forage:concentrate (F:C) ratio on growth performance and meat quality of finishing beef cattle. The trial was a 2 (corn silage untreated or inoculated with L. buchneri) × 2 (two F:C ratios, 60:40 or 40:60) factorial. Bulls fed a 40:60 F:C diet containing inoculated silage had greater dry matter (DM) intake (P < 0.01) and average daily gain (P = 0.029) compared with other treatments. DM (P = 0.02) and neutral detergent digestibility (P < 0.01) were depressed by inoculation of corn silage with L. buchneri. Thiobarbituric acid concentration in meat increased (P < 0.01) by 15% in bulls fed the 60:40 F:C diet compared with the 40:60 F:C diet. Inoculation of silage increased (P = 0.02) the ratio of unsaturated fatty acids to saturated fatty acids. Compared with the 60:40 F:C diet, the concentrations of polyunsaturated fatty acids (P = 0.03) and omega-6 fatty acids (P = 0.02) increased in longissimus muscle by 23% and 26%, respectively, in bulls fed the 40:60 F:C diet. Inoculation of corn silage with L. buchneri inconsistently improved the growth performance and meat traits of finishing bulls consuming diets differing in F:C.

Our objective was to investigate Lactobacillus buchneri as a silage inoculant or probiotic on in vitro ruminal measurements of low dry-matter whole-crop maize silage. In vitro gas production was conducted using untreated (without inoculant) and inoculated (treated with L. buchneri CNCM I-4323 at 1 9 10 5 cfu g À1 of fresh forage) maize silages (wet-ground) incubated with three different ruminal inocula, in a 2 9 3 factorial arrangement. Ruminal fluids were collected from wethers consuming (i) untreated maize silage (RF-U); (ii) inoculated maize silage (RF-I); and (iii) untreated maize silage with a daily dose of L. buchneri CNCM I-4323 administered directly into the rumen (1 9 10 7 cfu g À1 of supplied silage [LB-probiotic]). Gas production was consistently higher when inoculated silage was used as the substrate of fermentation, compared to the untreated silage. When untreated silage was used as substrate, the total volatile fatty acid concentration was higher using RF-I and LBprobiotic inocula, compared to the RF-U inoculum, at 9 hr and at 48 hr of fermentation. It is concluded that L. buchneri should be used as a silage inoculant rather than as a probiotic because it alters fermentation within the silo thereby improving silage quality and enabling some benefits for ruminal fermentation.

Lactobacillus buchneri was investigated as a silage inoculant and as a probiotic on feed intake, apparent digestibility, and ruminal fermentation and microbiology in wethers fed low‐dry‐matter (DM) whole‐crop maize silage. Maize forage (279 g/kg DM) was ensiled without inoculant (untreated) and with L. buchneri CNCM I‐4323 at 1 × 105 cfu/g fresh forage (inoculated). Six cannulated wethers were arranged in a double 3 × 3 Latin square and assigned to one of three diets: (i) untreated maize silage (untreated), (ii) inoculated maize silage (inoculated), and (iii) untreated maize silage with a daily dose of L. buchneri (1 × 107 cfu/g supplied silage) injected directly into the rumen (LB‐probiotic). Wethers fed the inoculated diet had a higher (p = .050) DM intake (1.30% body weight [BW]) than wethers fed untreated and LB‐probiotic diets (1.17% and 1.18% BW respectively). The relative proportion of Ruminococcus flavefaciens (proportion of total estimated rumen bacterial 16S rDNA) in the rumen of wethers fed inoculated and LB‐probiotic diets (both 0.42%) tended (p = .098) to be lower than in the untreated diet (0.83%). Lactobacillus buchneri as a silage inoculant or as a probiotic had little effect on the variables measured in wethers.

The current study aimed to investigate the effects of corn silage inoculation and dietary supplementation with amylolytic enzymes, and their interactions, on feed intake, apparent digestibility, and microbial protein synthesis in wethers. Whole-crop corn forage was ensiled either with water (untreated) or with Lactobacillus plantarum MA 18/5U at 1 × 10 5 cfu/g fresh forage combined with Bacillus subtilis AT553098 at 1 × 10 5 cfu/g fresh forage (inoculated). Eight ruminally cannulated Dorper × Santa Inês crossbred wethers were used in a double 4 × 4 Latin square design. Wethers were assigned to one of four diets, as follows: 1) untreated corn silage with no amylolytic enzyme supply (US-NE); 2) untreated corn silage with amylolytic enzyme supply (US-WE); 3) inoculated corn silage with no amylolytic enzyme supply (IS-NE); and 4) inoculated corn silage with amylolytic enzyme supply (IS-WE). α-Amylase (602 dextrinizing units/kg of dry matter (DM)) was supplied to the wethers at total mixed ration delivery. Dietary supplementation with amylolytic enzyme increased (P = 0.045) DM and starch (P = 0.014) intake in wethers fed the US diet (+245 and +136 g/d, respectively), but not in those fed the IS diet. Inoculation of corn silage (P = 0.026) improved organic matter (OM), crude protein (CP), neutral detergent fiber (aNDFom), and gross energy (GE) digestibility by 5.3%, 11.5%, 25.8%, and 7.1%, respectively. Likewise, enzyme supply increased (P = 0.042) the apparent digestibility of DM, OM, CP, aNDFom, and GE by 5.1%, 4.7%, 9.4%, 20.7%, and 6.2%, respectively. Enzyme supply increased the molar proportion of propionic acid (P = 0.002; 24.1 vs. 19.6 mM / 100 mM) in wethers fed the US diet, but not in those fed the IS diet. Enzyme supply decreased microbial N synthesis (P = 0.025; 6.33 vs. 8.05 g/d) when the wethers were fed the IS diet, but not the US diet. In conclusion, despite the improved OM digestibility, dietary supplementation