Ismael Nacarati da Silva

This study evaluated the effects of increasing doses of rosemary, citronella, and tea tree essential oils on fermentation characteristics, nutritional value, microbial count, losses, and aerobic stability of sorghum silage. A completely randomized design was used in a 3 × 4 factorial scheme, consisting of three essential oils (citronella, rosemary, and tea tree) and four inclusion levels: 0 (control silage without additive), 500, 1000, and 2000 mg kg ⁻¹ of fresh forage, with four replicates per treatment. The inclusion of rosemary essential oil increased crude protein content ( p = 0.006), while reducing ammonia nitrogen ( p = 0.029) and butyric acid concentration ( p < 0.001). Increasing essential oil levels resulted in a quadratic response for silage pH ( p = 0.003) and a linear decrease in lactic acid concentration ( p = 0.018). Additionally, higher inclusion levels led to reduced dry matter recovery ( p = 0.001) and increased lactic acid bacteria counts ( p = 0.016). Regarding aerobic stability, the addition of 1000 mg kg ⁻¹ of citronella essential oil increased stability by 96 h. Essential oil treatments also influenced silage pH dynamics during aerobic exposure ( p < 0.05). Overall, essential oils modified the fermentation and aerobic stability of sorghum silage. Rosemary essential oil was associated with lower NH ₃ ‐N and butyric acid concentrations, whereas higher inclusion levels increased LAB counts.

The present study evaluated the effects of increasing levels of sweeping cassava flour (SCF) on the chemical composition, in vitro degradability, fermentation parameters, microbial populations, and aerobic stability of sugarcane top silage. The experiment was carried out in a completely randomized design with four treatments (0, 5, 10, and 15% SCF on an as‐fed basis) and four replicates. Contents of dry matter, organic matter, crude protein, crude fiber, and ash showed quadratic responses ( p < 0.05), while most other variables presented linear behavior ( p < 0.05). Lignin and in vitro neutral detergent fiber degradability were not influenced ( p > 0.05). Regarding fermentation, lactic and acetic acid concentrations decreased ( p < 0.05) with SCF inclusion, although with different patterns, while other variables remained unchanged ( p > 0.05). Fermentative losses were also affected as SCF increased gas losses ( p < 0.001), reduced effluent losses ( p < 0.001), and lowered dry matter recovery ( p = 0.002). Microbial counts indicated no changes in lactic acid bacteria ( p > 0.05), but yeast populations were reduced ( p = 0.048). Aerobic stability decreased with SCF, as exposure time was shortened ( p < 0.001), and silage pH increased during the first 48 h of air exposure ( p < 0.001). In conclusion, the addition of 5% SCF improved nutritional value but did not enhance fermentation and reduced aerobic stability of sugarcane top silage.

Energy-demanding processes in animal production rise in tandem with increased nutritional intake. This meta-analysis aimed to quantify the metabolizable energy (ME) requirements for maintenance (kMEm) and metabolizable energy to support metabolism (HiEv), considering genotype and gender, in beef cattle under tropical conditions. A total of 273 individual records of comparative slaughter from seven studies (theses and dissertations) grouped by animal gender (intact males and castrated males), and genotype (Nellore or crossbreed) were used in the current study. We estimated kMEm and HiEv based on the independent variables’ ME intake and full body weight (FBW). The meta-analysis showed no effect of genotype on kMEm (p = 0.66). However, intact males exhibited a 34.41 % lower kMEm compared to castrated males (p = 0.01). Crossbred steers had a 61.33 % higher HiEv than Nellore steers (p < 0.001). Similarly, intact males had a 41.07 % higher energy support demand (p = 0.05) than castrated males. In addition, we observed positive correlations (medium to high) between body protein (r = 0.67; p > 0.001), body fat (r = 0.59; p > 0.001), and retained energy (r = 0.71; p > 0.001) and HiEv. Thus, the greater the deposition of protein (mainly), fat, and body energy, the greater the HiEv. In conclusion, the genotype of the animals did not affect the kMEm. Intact males had lower HiEv than castrated males. Both Nellore steers and intact males utilized HiEv more.

The primary concern in corn silage is aerobic deterioration. This study aimed to evaluate the impact of essential oil (EO) blends extracted from copaiba (Copaifera langsdorffii) (Co) and Eucalyptus staigeriana Branch (ES) on the fermentation parameters and losses, nutritional value, microbial counts, and aerobic stability of corn silage. A completely randomized design was employed with four treatments and four replicates. The following treatments were employed: control (CON) – corn ensiled without EO; blend 50:50 (50 % ES plus 50 % Co); blend 75:25 (75 % ES plus 25 % Co); blend 25:75 (25 % ES plus 75 % Co). The dose was administered at a rate of 500 mg kg^–1 of ensiled mass (as-fed basis). The chemical composition, in vitro degradability, NH₃-N, pH, acetic, propionic, and butyric acids, aerobic stability, and microbial counts of silages were evaluated. The 75:25 blend reduced (p < 0.038) crude protein (CP) by 7.96 % compared to the 25:75 blend. However, the 50:50 blend reduced (p < 0.03) the hemicellulose (HEM) content of the silage in comparison to the other treatments. The blends were observed to increase (p = 0.046) the concentration of acetic acid. The propionic acid concentration was reduced by 88.13 % with the 25:75 blend compared to the 50:50 blend. The blends increased (p = 0.003) gas losses. The fungal population was drastically reduced (p = 0.048) by the 25:75 blend compared to the other treatments. It can be concluded that the 50:50 blend resulted in high concentrations of acetic and propionic acids, thereby improving the aerobic stability of corn silage.

This study aimed to investigate the effect of different forage sources and forage-to-concentrate ratios on digestibility, energy concentration, fermentation parameters, and in vitro estimate of methane. The experiment was carried out in a completely randomized design using a 3 × 6 factorial arrangement with three forages varying the chemical composition (pineapple crop waste silage [PS], corn silage [CS], and Tifton hay [TH]) associated with concentrate feed (C) in six combinations, using triplicates for each ratio. We evaluated in vitro digestibility, metabolizable and net energy, pH, redox potential, volatile fatty acids (VFA), and methane production. The in vitro neutral detergent fiber digestibility (IVNDFD) decreased (p = 0.0011) with the inclusion of concentrate. It was also affected by the forage source, but this fact was only observed in CS up to the 50:50 ratio. In TH, this fact occurred from the 80:20 ratio, and this behavior was not observed in the PS. Data on methane production, VFA, and fermentation parameters varied according to forage source and concentrate inclusion. In conclusion, the inclusion of concentrate reduces methane production, increasing the system’s energy contribution. Overall, the different forage sources and the inclusion of concentrate change digestion and fermentation parameters.

This study aims to evaluate the effect of these essential oils and their blends on the fermentative profile, losses by gases and effluents, nutritional value, microbial count, and aerobic stability of sorghum silage. A completely randomized design was used with eight treatments and four repetitions. The evaluated treatments were the following: control (CON), without any essential oil; rosemary (Ros); tea tree (TT); citronella (Cit); Ros + TT (50% + 50%); Ros + Cit (50% + 50%); TT + Cit (50% + 50%); and Ros + TT + Cit (33% + 33% + 33%). A 1000 mg/kg dose of ensiled mass (as-fed basis) was used for each of the treatments. The addition of essential oils and their blends had a significant impact (p < 0.05) on the chemical composition of sorghum silage. Crude protein content increased (p < 0.001) with the use of essential oils and their blends. The Ros affected (p < 0.05) the fibrous fraction of sorghum silage. Neutral detergent fiber in vitro degradability was reduced (p = 0.003) when we used the blend TT + Cit compared to Ros and TT. We observed that only Ros did not reduce acetic acid concentration (p = 0.031) compared to the CON. The essential oils and their blends did not affect losses (p > 0.05). Lactic acid bacteria population increased (p = 0.039) when using the blend Ros + TT + Cit compared to the CON. However, the populations of entero-bacteria and fungi were not affected (p > 0.05) by the essential oils or their blends. For aerobic stability, we observed that Ros increased (p < 0.001) the air exposure time of the sorghum silage. Furthermore, the essential oils impacted the sorghum silage’s pH, which affected (p = 0.003) its aerobic stability. In conclusion, the essential oils did not reduce sorghum silage losses. However, the Ros improved the nutritional quality and aerobic stability of sorghum silage, while the blend Ros + TT + Cit increased the lactic acid bacteria count in the silage. More in-depth studies are needed to elucidate the action of essential oils as silage additives.

Corn silage is susceptible to losses through aerobic spoilage. Therefore, this study aimed to evaluate increasing sweet orange essential oil levels in chemical composition, in vitro degradability, losses, fermentation parameters, microbial count, and the aerobic stability of corn silage. The experiment was carried out in a completely randomized design with four treatment levels: Control (CON), ensiling corn without sweet orange essential oil; 200 mg kg^–1,400 mg kg^–1, and 600 mg kg^–1 of ensiling mass with four replicates per treatment. Sweet orange essential oil affected both the dry matter (p = 0.035) and the organic matter (p = 0.021), presenting quadratic behavior. Sweet orange essential oil did not affect (p ≥ 0.05) in vitro dry matter degradability, in vitro neutral detergent fiber degradability, or gross energy. Sweet orange essential oil had a quadratic effect (p = 0.022) on the acetic acid concentration in corn silage. There was a tendency (p = 0.097) for sweet orange essential oil to reduce the ammoniacal nitrogen linearly. The levels of sweet orange essential oil did not influence losses by gases or effluents (p ≥ 0.05). We observed no effect of sweet orange essential oil on Lactic acid-producing bacteria populations or fungi (p ≥ 0.05). Furthermore, increasing sweet orange essential oil levels decreased temperature (p = 0.02) over time but did not influence pH (p = 0.404). Sweet orange essential oil does not affect in vitro degradability, fermentation parameters, nor microbial count in corn silage. However, the 600 mg of ensiling mass increases corn silage’s acetic acid concentration and aerobic stability.

Several studies on the kinetics of sugarcane’s fiber digestion have been published, but, to date, no study has evaluated the influence of sugarcane rind on the digestion of fresh sugarcane by ruminants. This study aimed to evaluate the effects of sugarcane components (rind and pith) on chemical composition, in vitro digestibility, metabolizable energy, and sugarcane quality. A randomized block design was used in a split-plot scheme with five sugarcane genotypes [plot] (RB068027, RB058046, RB987917, RB867515, and RB855536) and three sugarcane components [sub-plot] (rind, pith, and whole cane), Each treatment consisted of four replicates. The chemical composition, in vitro gas production, in vitro digestibility, metabolizable energy, and sugarcane quality were evaluated. No interaction between components and genotypes was observed for the variables analyzed herein. Although the rind had a higher crude protein content, it showed a large amount of insoluble crude protein. The rind had higher fibrous fractions, comprising 87.33 % of the indigestible fraction of the neutral detergent fiber (NDF). The sugarcane rind showed ~ 71.20 % more lignin than the pith tissue. Further, the rind decreased by 6.5 % in vitro dry matter digestibility compared to the whole sugarcane. The in vitro NDF digestibility of the rind was 18.38 % lower than the whole sugarcane. The RB068027 genotype showed the lowest sugarcane quality. Despite the higher content of potentially digestible neutral detergent fiber (pdNDF) in the rind, its high lignin content influences the quality of the final fibrous fractions of sugarcane and negatively impacts the nutritional value. The genotypes do not differ nutritionally, but RB855536 presented higher biomass and energy yields.

This study aimed to investigate the associative effects caused by changes in the proportions of feed ingredients (forage-to-concentrate ratio) and the forage source in ruminant diets on in vitro gas production and fermentation parameters. The study consisted of two assays conducted in a completely randomized design with a 3 × 10 factorial arrangement consisting of three forages (pineapple crop waste silage [PS], corn silage [CS], and Tifton hay [TH]) associated with concentrate feed (C) (binary mixture) in 11 proportions, with triplicates of each combination. For the first assay, the asymptotic volume of gas did not show any difference among (p = 0.059) CS and PS (p = 0.464) and their proportions. We evaluated the associative effect among forages and their proportions and noticed there was an effect on gas production between the combination of forage and concentrate for the CS (p = 0.003) and PS (p = 0.003). In the second assay, volatile fatty acids (VFA) and ammonia nitrogen (p < 0.05) were affected by the forage source and concentrate inclusion. In conclusion, forages with a high content of soluble carbohydrates presented the lowest gas production, as well as higher concentrations of propionic acid and ammonia nitrogen. The associative effect on in vitro gas production was more pronounced in the first 12 h incubation. The different forage sources and the inclusion of concentrate change fermentation parameters.

Estratégias que objetivam condicionar o solo impactam positivamente no sistema de produção de ruminantes a pasto. A produção de serapilheira é diretamente responsável por melhorias nas características químicas, físicas e biológicas no solo. Objetivou-se neste estudo quantificar e qualificar a deposição de serapilheira do Sistema Silvipastoril com Eucalipto (SSP), a fim de compará-lo com Floresta Estacional Semidecidual (FL) e Sistema de Pastagem em Monocultivo (MN), assim como a decomposição do material decíduo. Para isso, foram instalados 12 coletores de serapilheira em cada ecossistema, onde foi mensurado e estratificado a deposição do material decíduo a cada 28 dias, por 11 meses. A decomposição da serapilheira foi avaliada através do método de litterbags. A produção total de serapilheira dos meses avaliados para SSP, FL e MN foi de 10,74, 7,17 e 1,01 t ha-1, respectivamente. A constante de decomposição (k) para SSP e FL foi de 0,0021 e 0,0025 g g-1 dia-1, enquanto o tempo de meia vida (T0,5) foi de 322 e 272 dias, respectivamente. A arborização das pastagens com eucalipto tem potencial de aumentar a produção de matéria orgânica no sistema e beneficiar os demais componentes do SSP.