Background: Ensiling technology holds promise for preserving and providing high-quality forage. However, the preservation of rice straw poses challenges due to its high lignocellulosic content and low water-soluble carbohydrate levels. Developing highly effective lactic acid bacteria (LAB) for rice straw silage remains a priority. Results: This study evaluated the impact of three LAB strains, Lactobacillus brevis R33 (Lac33), L. buchneri R17 (Lac17), and Leuconostoc pseudomesenteroides (Leu), on the fermentation quality of rice straw silage. Rice straw silage inoculated with Lac33 alone or in combination with other strains exhibited significantly lower neutral detergent fiber (NDF) (66.5% vs. 72.3%) and acid detergent fiber (ADF) (42.1% vs. 47%) contents, along with higher lactic acid (19.4 g/kg vs. not detected) and propionic acid (2.09 g/kg vs. 1.54 g/kg) contents compared to control silage. Bacterial community analysis revealed Lactobacillus dominance (> 80%) and suppression of unwanted Enterobacter and Clostridium. Metabolomic analysis highlighted increased carbohydrates and essential amino acids, indicating improved nutrient values in Lac33-inoculated rice straw silage and a potential explanation for Lac33 dominance. Conclusions: This research identified a highly efficient LAB candidate for rice straw silage, advancing our comprehension of fermentation from integrated microbiology and metabolomic perspectives.

(1) Estimation of grazing livestock intake is the basis for studying animal–plant relationships and the nutritional status of grazing livestock and has important implications for grassland composition and productivity. (2) We used the saturated alkanes method to determine the feed intake and vegetation nutrient digestibility of livestock at different grazing intensities and in different months. (3) We found that C₃₁ had the highest concentration in both pasture and fecal output, and the average recovery of C₃₁ was 77.99%. The different grazing intensities significantly affected livestock intake. As the grazing intensity increased, there was a decreasing trend of livestock intake and the highest livestock feed intake was 6.11 kg DM/day in light grazing. With the increase in grazing season months, the highest livestock intake was 6.67 kg DM/day in the cold period in September. The month also had a significant effect on the digestibility of livestock for all nutrient variables when compared to the grazing intensity. Livestock weight and medium palatability species are more important for livestock intake. (4) Our study provides a more accurate measurement of grazing livestock intake, which can be used as a reference for the scientific management of grazing livestock and the rational use of grazing pastures.

The aim of this research was to compare growth performance, nutrient utilization, rumen fermentation, blood parameters, antioxidant status, and meat colour stability of lambs fed diets that partially or completely substituted corn with sorghum. Twenty-four male German merino weaned lambs (16.19 ± 2.05 kg body weight) were divided into four treatments in a completely randomized design. The diets for four treatments contained 450 g kg⁻¹ of ground corn (C), 300 + 150 g kg⁻¹ of ground corn and sorghum (CSM1), 150 + 300 g kg⁻¹ of ground corn and sorghum (CSM2) and 450 g kg⁻¹ ground sorghum (S); all diets consisted of 70% concentrated feed and 30% Leymus chinensis hay. The lambs were fed the experimental diets for 56 d. Inclusion of sorghum tended to increase average daily weight gain and total gain (P = 0.06), and lower feed conversion ratio (P = 0.10). Significant increase in nitrogen (N) intake and fecal N excretion was observed after substitution of corn with sorghum, and the apparent digestibility of crude protein was significantly reduced. Concentrations of ammonia N in rumen fluid were affected by treatment (P = 0.01) and an interaction (P < 0.01) between treatment and sampling time. No significant effects were found on blood parameters among treatments. Replacement of corn with sorghum significantly decreased b* (yellowness) values of meat during storage. Sorghum instead of corn is feasible in lamb diets, and it has positive effects on the lamb growth and meat quality.

Soil ingestion by livestock is common in grazing ecosystems, but few studies have been conducted to assess its effect on the animal organism. The topic is worthy of attention because these potential effects are likely to be enriched in the food chain and interfere with animal and human health. In this study, we present an indoor feeding trial conducted based on a completely randomized design to comprehensively evaluate the effects of simulated soil ingestion during grazing on nutrient digestibility, rumen fermentation, and microflora, and mineral deposition in the organs and tissues of sheep. Eighteen Mutton Merino crossbred sheep (42.7 ± 2.34 kg) were randomly allotted to three treatments and fed diets containing 0% (Control), 5% (SOIL5), and 10% (SOIL10) for 62 d, including a 7-d metabolism trial. It was found that soil intake altered the rumen fermentation in sheep, as evidenced by a decrease in total volatile fatty acids (VFA) and acetate concentrations in rumen fluid of 50.6% and 51.3%, respectively (p < 0.01), with soil proportion in the diet increased from 0% to 10%. Soil ingestion also reduced the species richness of rumen bacteria, with the relative abundance of Bacteroidetes decreasing significantly (p < 0.01), while that of Firmicutes and Proteobacteria increased considerably (p < 0.05). In terms of mineral elements deposition, higher levels of iron (Fe) were detected in the spleen and liver, and a higher concentration of copper (Cu) and zinc (Zn) in the liver were found in sheep fed a diet containing 5% soil compared to the other two groups (p < 0.05). Moreover, the concentrations of lead (Pb) in the liver and kidney, and arsenic (As) in the heart were also clearly increased after ingestion of soil (p < 0.05). Our findings indicate that although soil intake had no significant effect on the growth performance of sheep, it altered ruminal fermentation and increased the risk of excessive Fe, Pb, and As in their organism. This study supplies a theoretical basis for risk assessment of soil ingestion in grazing livestock.