Cassava pulp (CS) is high in fiber and low in protein; hence, improving the nutritive value of CS is required to increase its contribution to enhancing ruminant production. The present work hypothesized that CS quality could be enhanced by fermentation with yeast waste (YW), which can be used to replace soybean meal (SBM), as well as lead to improved feed utilization in ruminants. Thus, evaluation of in vitro ruminal fermentation and feed digestibility, as influenced by YW-treated CS and different roughage (R) to concentrate (C) ratios, was elucidated. The design of the experiment was a 5 × 3 factorial arrangement in a completely randomized design. Each treatment contained three replications and three runs. The first factor was replacing SBM with CS fermented with YW (CSYW) in a concentrate ratio at 100:0, 75:25, 50:50, 25:75, and 0:100, respectively. The second factor was R:C ratios at 70:30, 50:50, and 30:70. The level of CSYW showed significantly higher (p < 0.01) gas production from the insoluble fraction (b), potential extent of gas production (a + b), and cumulative gas production at 96 h than the control group (p < 0.05). There were no interactions among the CSYW and R:C ratio on the in vitro digestibility (p > 0.05). Furthermore, increasing the amount of CSYW to replace SBM up to 75% had no negative effect on in vitro neutral detergent fiber degradability (IVNDFD) (p > 0.05) while replacing CSWY at 100% could reduce IVNDFD (p > 0.05). The bacterial population in the rumen was reduced by 25.05% when CSYW completely replaced SBM (p < 0.05); however, 75% of CSWY in the diet did not change the bacterial population (p > 0.05). The concentration of propionate (C3) decreased upon an increase in the CSYW level, which was lowest with the replacement of SBM by CSYW up to 75%. However, various R:C ratios did not influence total volatile fatty acids (VFAs), and the proportion of VFAs (p > 0.05), except the concentration of C3, increased when the proportion of a concentrate diet increased (p < 0.05). In conclusion, CSYW could be utilized as a partial replacement for SBM in concentrate diets up to 75% without affecting gas kinetics, ruminal parameters, or in vitro digestibility.

This study evaluates the effects of fresh cassava root (CR) and a solid feed-block containing sulfur (S-FB) on fermentation in the rumen, feed utilization, milk yield, and milk composition in lactating dairy cows. Four Holstein-Friesian cows with 470 ± 50.0 kg body weight (BW), 10 ± 2 kg day⁻¹ average milk yield, and 112 ± 15 days-in-milk were studied. A 2 × 2 factorial combination was arranged in a 4 × 4 Latin square design to evaluate the treatment-related effects. The treatments were obtained from a combination of two factors: (1) levels of CR at 10 g kg⁻¹ BW (CR-1) and 15 g kg⁻¹ (CR-1.5) and (2) levels of sulfur supplementation in solid feed-block at 20 g kg⁻¹ (S-FB-2) and 40 g kg⁻¹ (S-FB-4). The results showed that CR and S-FB had no interaction effect on feed intake, digestibility, fermentation, blood metabolites, milk yield, or its composition. Feeding CR up to 15 g kg⁻¹ of the BW significantly increased (p < 0.05) the milk fat concentration while it decreased (p < 0.05) the somatic cell count. The S-FB-4 of the sulfur significantly (p < 0.05) increased the acid detergent fiber when compared with the S-FB-2 of the sulfur. CR could be fed up to 15 g kg⁻¹ of BW with S-FB containing high sulfur (40 g kg⁻¹) in dairy cows without a negative impact.

This research aimed to investigate bioaccessibility of garlic oil extract (GOE) and riceberry rice bran oil extract (RBRBOE) and to enhance the stability and delivery of plant-derived essential oils. Two EOs were used to formulate through encapsulation techniques of microencapsulated black soldier fly (BSF) protein with a GOE matrix, (mBSF-GOE), and a nanoemulsified RBRBOE, (nRBRBOE). A completely randomized design was used for the treatments, with various ratios of feed additives between the mBSF-GOE and nRBRBOE supplementations at 0:0, 6:0, 4:2, 2:4, and 0:6 mg in diet, with the R: C ratio at 60:40 using in vitro gas study. The combination of mBSF-GOE and nRBRBOE at 4:2 mg for 12 and 24 h after fermentation had a significant impact on several factors (p < 0.01, < 0.05), including gas kinetics, cumulative gas production (96 h), in vitro dry matter degradability (IVDMD), and ruminal fermentation products. Specifically, the levels of propionate (C3) and total VFAs went up, while ruminal methane (CH4) production decreased by 48.2%. Subsequently, there was no negative effect (p > 0.05) on the ruminal pH, ammonia nitrogen (NH3-N) concentration, or the dynamics of the rumen microbiota population, while significantly decreasing the methanogen population in terms of Methanobacteriales (up to 3.3% after 24 h) (p < 0.01). Based on this study, it could be concluded that the supplementation of mBSF-GOE combined with nRBRBOE-based bioactive components could potentially be used as a ruminant feed enhancer to enhance fermentation efficiency and as technological feed additive substances to inhibit the methanogen population while mitigating CH4 production.

The objective of this study was to investigate the effect of microencapsulated bioactive compounds from lemongrass mixed dragon fruit peel pellet (MiEn-LEDRAGON) supplementation on fermentation characteristics, nutrient degradability, methane production, and the microbial diversity using in vitro gas production technique. The study was carried out using a completely randomized design (CRD) with five levels of MiEn-LEDRAGON supplementation at 0, 1, 2, 3, and 4% of the total dry matter (DM) substrate. Supplementation of MiEn-LEDRAGON in the diet at levels of 3 or 4% DM resulted in increased (p < 0.05) cumulative gas production at 96 hours (h) of incubation time, reaching up to 84.842 ml/ 0.5 g DM. Furthermore, supplementation with 3% MiEn-LEDRAGON resulted in higher in vitro nutrient degradability and ammonia–nitrogen concentration at 24 h of the incubation time when compared to the control group (without supplementation) by 5.401% and 11.268%, respectively (p < 0.05). Additionally, supplementation with MiEn-LEDRAGON in the diet led to an increase in the population of Fibrobacter succinogenes at 24 h and Butyrivibrio fibrisolvens at 12 h, while decreasing the population of Ruminococcus albus, Ruminococcus flavefaciens, and Methanobacteriales (p < 0.05). Moreover, supplementation of MiEn-LEDRAGON in the diet at levels of 2 to 4% DM resulted in a higher total volatile fatty acids (VFA) at 24 h, reaching up to 73.021 mmol/L (p < 0.05). Additionally, there was an increased proportion of propionic acid (C3) and butyric acid (C4) at 12 h (p < 0.05). Simultaneously, there was a decrease in the proportion of acetic acid (C2) and the ratio of acetic acid to propionic acid (C2:C3), along with a reduction of methane (CH₄) production by 11.694% when comparing to the 0% and 3% MiEn-LEDRAGON supplementation (p < 0.05). In conclusion, this study suggests that supplementing MiEn-LEDRAGON at 3% of total DM substrate could be used as a feed additive rich in phytonutrients for ruminants.

Objective: Tropical plants are composed of phytonutrients (PTNs) and are utilized for their capacity to manipulate rumen fermentation characteristics and methane production. The aim of this experiment was to determine the impact of microencapsulated PTNs-extracted from lemongrass and mangosteen peel (M-LEMANGOS), as well as crude protein (CP) levels on nutrient degradability, rumen ecology, microbial population, and methane emission in an in vitro study.Methods: The treatments were randomly assigned in a 2×4 Factorial arrangement in a completely randomized design. The two factors consisted of CP percentage in the concentrate diet (16% and 18% CP) and the levels of M-LEMANGOS addition (0%, 2%, 4%, and 6% of the total substrate).Results: The results showed that nutrient degradability both 12 and 24 h were significantly increased with M-LEMANGOS at 4% total substate. In part of volatile fatty acids (VFAs), particularly propionate and total VFA, these were enhanced by %CP and M-LEMANGOS combination. The %CP increased ruminal ammonia-nitrogen concentration (NH3-N), while M-LEMANGOS supplementation reduced such concentration. Methane production and Methanobacteriales population at 12 and 24 h were reduced when supplemented with M-LEMANGOS at 4% total substate. The population of Fibrobacter succinogenes, Ruminococcus flavefaciens, and Megasphaera elsdenii were increased with the interaction between %CP and M-LEMANGOS addition.Conclusion: M-LEMANGOS indicates promising potential as a plant-based PTN for dietary modulation of rumen fermentation and mitigation of methane production.