This study aimed to evaluate in vitro and in vivo dietary supplementation with different levels of natural or nano-zeolite forms on rumen fermentation patterns and nutrient digestibility. In the in vitro experiment, a basal diet (50% concentrate: 50% forage) was incubated without additives (control) and with natural zeolite (10, 20, 30 g/kg DM) or nano-zeolite (0.2, 0.3, 0.4, 0.5, 1.0 g/kg DM) for 24 h to assess their effect on ruminal fermentation, feed degradability, and gas and methane production using a semi-automatic system of in vitro gas production (GP). The most effective doses obtained from the in vitro experiment were evaluated in vivo using 30 Barki goats (26 ± 0.9 SE kg body weight). Goats were allocated into three dietary treatments (n = 10/treatment) as follows: control (basal diet without any supplementations), natural zeolite (20 g/kg DM diet), and nano-zeolite (0.40 g/kg DM diet). The in vitro results revealed that only the nano-zeolite supplementation form quadratically (p= 0.004) increased GP, and the level of 0.5 g/kg DM had the highest GP value compared to the control. Both zeolite forms affected the CH₄ production, linear, and quadratic reductions (p < 0.05) in CH₄ (mL/g DM), consistent with linear increases in truly degraded organic matter (TDOM) (p = 0.09), and propionate molar proportions (p = 0.007) were observed by nano zeolite treatment, while the natural form of zeolite resulted in a linear CH₄ reduction consistent with a linear decrease (p = 0.004) in NH₃-N, linear increases in TDOM (p = 0.09), and propionate molar proportions (p = 0.004). Results of the in vivo experiment demonstrated that the nutrient digestibility was similar among all treatments. Nano zeolite enhanced (p < 0.05) the total short-chain fatty acids and butyrate concentrations, while both zeolite forms decreased (p < 0.001) NH₃-N compared to the control. These results suggested that both zeolite supplementation forms favorably modified the rumen fermentation in different patterns.

Background: Montmorillonite clay modified by organosulfur surfactants possesses high cation exchange capacity (CEC) and adsorption capacity than their unmodified form (UM), therefore they may elevate the adverse impact of aflatoxin B1 (AFB1) on ruminal fermentation and methanogenesis. Chemical and mechanical modifications were used to innovate the organically modified nano montmorillonite (MNM). The UM was modified using sodium dodecyl sulfate (SDS) and grounded to obtain the nanoscale particle size form. The dose-response effects of the MNM supplementation to a basal diet contaminated or not with AFB1 (20 ppb) were evaluated in vitro using the gas production (GP) system. The following treatments were tested: control (basal diet without supplementations), UM diet [UM supplemented at 5000 mg /kg dry matter (DM)], and MNM diets at low (500 mg/ kg DM) and high doses (1000 mg/ kg DM).Results: Results of the Fourier Transform Infra-Red Spectroscopy analysis showed shifts of bands of the OH-group occurred from lower frequencies to higher frequencies in MNM, also an extra band at the lower frequency range only appeared in MNM compared to UM. Increasing the dose of the MNM resulted in linear and quadratic decreasing effects (P < 0.05) on GP and pH values. Diets supplemented with the low dose of MNM either with or without AFB1 supplementation resulted in lower (P = 0.015) methane (CH₄) production, ruminal pH (P = 0.002), and ammonia concentration (P = 0.002) compared to the control with AFB1. Neither the treatments nor the AFB1 addition affected the organic matter or natural detergent fiber degradability. Contamination of AFB1 reduced (P = 0.032) CH₄production, while increased (P < 0.05) the ruminal pH and ammonia concentrations. Quadratic increases (P = 0.012) in total short-chain fatty acids and propionate by MNM supplementations were observed.Conclusion: These results highlighted the positive effects of MNM on reducing the adverse effects of AFB1 contaminated diets with a recommended dose of 500 mg/ kg DM under the conditions of this study.

Yeast feed additives present a natural approach for mitigating ruminal greenhouse gases (GHG) in an environmentally sustainable manner. This study aimed to isolate yeast strains from ruminal fluids capable of reducing GHG from Aflatoxin (AFB1) contaminated diets. Two isolates of Pichia manchuria (FFNLYFC1 and FFNLYFC2) were isolated and identified from the ruminal contents of dairy Zaraibi goats. An in vitro gas production assay was conducted to evaluate the impact of the yeast supplementations on a basal diet contaminated with AFB1 or not. The treatments were control (-AFB1; basal diet without supplements), control with AFB1 contamination (+ AFB1; basal diet containing 20 ppb AFB1), and yeast-supplemented diets (basal diet supplemented with Saccharomyces cerevisiae, and three treatments of P. manchuria [FFNLYFC1, FFNLYFC2, and their mixture at 1:1 ratio (Mix)]. High biological components were detected in abundance of both FFNLYFC1, FFNLYFC2 filtrates (e.g., diisooctyl phthalate). The Mix and FFNLYFC2 of P. manchuria reduced (P < 0.05) methane by 23.5 and 20.8%, respectively, while only Mix inhibited carbon dioxide by 44% compared to the + AFB1 diet. All yeast diets improved (P < 0.05) ammonia concentration, total protozoal and Entodinium spp. counts compared to + AFB1 diet. The Mix exhibited higher (P < 0.05) values of ruminal degraded cellulose, total short-chain fatty acids, acetate and propionate compared to the individual isolates diets. The results suggest synergistic interactions among P. manshurica isolates, leading to enhanced ruminal fermentation and reduced GHG emissions while alleviating the adverse effects of AFB1. Therefore, we recommended the Mix of P. Manchuria as a novel feed additive to ruminant diets.