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.

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.

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.

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.

This study aimed to compare the univariate analyses (relationship between dry matter intake (DMI) and average daily gain (ADG), Kleiber ratio, and residual feed intake) and multivariate analysis (bionutritional index [BNI]) to determine feed efficiency. Were used a total of 160 cattle (individual data) and the analyzed variables were dry matter intake, weight gain, and body weight of the animals. We used five methods to evaluate feed efficiency, the BNI, FE, corrected feeding efficiency (corFE), Kleiber ratio (KR), and residual feed intake (RFI). Study 1 demonstrated that only the FE (p=0.0472) was significant, although the FE after the transformation of Box-Cox (corFE) (p=0.0642) showed a statistical trend. In studies 2, 3, and 5, we observed that BNI was the best biological efficiency indicator. In the study 4, we observed that the best indicators were FE (0.110; p=0.0281), corFE (0.380; p=0.0429), and RFI (0.465; p=0.0340) for the genders. However, corFE decreased the coefficient of variation in all studies. In conclusion, the use of the Box-Cox transformation is as efficient as the multivariate analysis in discriminating experimental groups (genetic groups, different levels of concentrate in the diet, and genders) concerning the other univariate analyzes.

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.