This study was conducted to determine the effects of low-protein diet prepared with different levels of defatted rice bran (DFRB) and weight stages on growth performance and nutrient digestibility of growing–finishing pigs. The animal experiment included three stages. A total of 240 growing pigs with an initial body weight of 28.06 ± 8.56 kg for stage 1 were allocated to five diets including one control group and four DFRB diets supplemented with 2.5%, 5%, 7.5% and 10% DFRB, respectively. The 192 crossbred pigs with initial body weights of 55.03 ± 7.31 kg and 74.55 ± 9.10 kg were selected for stage 2 and stage 3, respectively. Pigs were allocated to four diets including one control group and three DFRB diets supplemented with 10%, 15% and 20% DFRB, respectively. The results showed that with the increase in DFEB intake, the gain: feed was linearly increased (p < 0.05), and the average daily feed intake tended to linearly decrease (p = 0.06) in stage 1. Except for the apparent total tract digestibility (ATTD) of acid detergent fiber (ADF) in stage 3, levels of DFRB had significant effects on the ATTD of gross energy (GE), dry matter (DM), ash, neutral detergent fiber (NDF) and ADF in three weight stages. In stage 1, with the increase in levels of DFRB, the ATTD of NDF and hemicellulose were firstly increased and then decreased (p < 0.01). In stage 2, with the increasing levels of DFRB, the ATTD of DM, ash and cellulose were firstly increased and then decreased (p < 0.01). In stage 3, the ATTD of GE, DM, ash, NDF and hemicellulose decreased linearly with the increase in levels of DFRB (p < 0.01). Collectively, DFRB could be used as a replacement for corns and soybean meal, and weight stage is important to consider when adjusting the additive proportion.

An experiment was conducted to determine the effect of oil sources with differing degrees of fatty acid saturation on endogenous losses of fat (ELF) and fatty acids (ELFA) in growing pigs, in which endogenous losses were estimated by two methods. Sixty-eight growing barrows (initial body weight 31.13 ± 4.44 kg) were randomly allotted to a completely randomized design with 17 diets. Sixteen added-oil diets were formulated by adding four levels (2%, 4%, 6% and 8%) of palm oil (PO), soybean oil (SBO), flaxseed oil (FSO) and rapeseed oil (RSO) to a diet poor in fat, respectively. One fat-free diet was formulated from cornstarch, soy protein isolate and sucrose. All diets contained chromic dioxide (0.4%) as an indigestible marker. Results indicated that, according to the regression equations, the amounts of ELF in PO, SBO, FSO and RSO were 6.28, 5.30, 4.17 and 4.84 g/kg of dry matter intake (DMI), respectively. The true total tract digestibility of fat was greater (p < 0.05) for FSO and RSO than for PO, and the ELFA were different from 0 only for C16:0, C18:0 and C18:1 in FSO, and C16:0 and C18:0 in RSO (p < 0.05). The estimated values for ELF and ELFAs in pigs fed PO, SBO, FSO or RSO were not different. The amount of ELF determined by the fat-free diet method was 2.60 g/kg DMI, and the amounts of C16:0, C18:0, C18:1 and C18:2 in ELFAs were 0.28, 0.26, 0.03 and 0.02 g/kg DMI, respectively. The fat-free diet method had lower ELF and ELFA values compared with the regression method (p < 0.01). Collectively, dietary vegetable oil sources do not affect estimation of ELF and ELFA, but different evaluation methods lead to varying estimates of endogenous losses in pigs.

The study was conducted to determine and compare the net energy (NE) of defatted rice bran (DFRB) from different sources and different processing technology fed to growing pigs using indirect calorimetry. Thirty-six growing barrows (30.7 ± 3.9 kg) were randomly allotted to 1 of 6 diets with 6 replicate pigs per diet. Diets included a corn-soybean meal basal diet and 5 test diets containing 30% DFRB, respectively. These five samples come from 4 different provinces (i.e., Heilongjiang, Jiangsu, Jilin, and Liaoning province within China) and two of them with the same origin but different processing technologies (i.e., extruded or pelleted). During each period, pigs were kept individually in metabolism crates for 21 days, including 14 days to adapt to the diets. On day 15, pigs were transferred to the open-circuit respiration chambers for adaptation, and the next day were ready to determine daily total heat production (HP) and were fed 1 of the 6 diets at 2.3 MJ metabolizable energy (ME)/kg body weight (BW)^0.6/day. Total feces and urine were collected for the determination of digestible energy (DE) and ME and daily total HP was measured from day 16 to day 20 and fasted on day 21 for the measurement of fasting heat production (FHP). The NE contents of extruded DFRB from different provinces were within the range of values (8.24 to 10.22 MJ/kg DM). There is a discrepancy of approximately 10.01% in the NE content between the DFRB origins. The NE contents of extruded DFRB and pelleted DFRB from the same province were 8.24 vs. 6.56 MJ/kg DM. Retained energy (RE) and FHP of diets containing extruded DFRB and pelleted DFRB were 1105 vs. 892 kJ/kg BW^0.6/day and 746 vs. 726 kJ/kg BW^0.6/day respectively, and those in extruded DFRB from different origins were within the range of values (947 to 1105 kJ/kg BW^0.6/day and 726 to 755 kJ/kg BW^0.6/day, respectively). In conclusion, NE values are affected by origin and processing technology of DFRB.

Early-life microbial community assembly is important for gastrointestinal development, immune maturation, and feed utilization in young ruminants, but the maternal reservoirs associated with neonatal lamb gut microbial profiles remain insufficiently defined. This exploratory study characterized bacterial and archaeal communities in maternal vaginal secretions, amniotic fluid, and colostrum, together with rectal feces from Hu lambs at birth and at 5 days of age, using 16S rRNA gene amplicon sequencing in six matched ewe–lamb pairs. Alpha-diversity differences were evaluated using the Kruskal–Wallis test followed by pairwise Wilcoxon rank-sum tests where appropriate, beta-diversity was assessed by principal coordinate analysis based on Bray–Curtis distance, and discriminatory taxa were identified using LEfSe; statistical significance was defined as p < 0.05. Microbial community structure differed among sample types. Feces collected at birth showed low bacterial richness and a distinct community profile, whereas feces from 5-day-old lambs displayed higher bacterial richness and a more complex taxonomic composition. Shared-ASV and LEfSe analyses suggested that vaginal-associated taxa were more closely associated with the initial fecal microbiota at birth, while colostrum-associated taxa were more evident in day-5 feces. Archaeal communities showed weaker separation than bacterial communities, but methanogenic lineages became more distinguishable by day 5. These findings suggest that early gut microbial assembly in Hu lambs is associated with multiple maternal reservoirs and rapid postnatal ecological selection. However, due to the limited sample size, short observation period, lack of formal source-tracking analysis, and absence of low-biomass negative controls, the results should be interpreted cautiously as preliminary associations rather than definitive evidence of vertical transmission.

This study investigated the effects of fermented Chinese chive (FCC) juice supplementation on growth performance, blood parameters, meat quality, and fresh meat volatile compounds in Small-Tailed Han sheep. Sixty sheep were randomly assigned to a control group (CG; basal diet) or an FCC juice treatment group (TG; basal diet supplemented with 1.0 mL/kg feed offered on an as-fed basis), with three pens per treatment and 10 sheep per pen. FCC juice significantly increased average weight gain (AWG) and average daily gain (ADG) (p < 0.05), whereas carcass traits were not significantly affected (p > 0.05). Most meat quality traits, antioxidant indices, and serum biochemical parameters were unchanged, although serum glucose (GLU) and cholesterol (CHO) decreased in the FCC juice treatment group (p < 0.05). GC × GC-TOF/MS analysis showed that FCC juice altered the volatile profile of fresh sheep meat. Compared with the control group, the FCC juice treatment group showed higher relative contents of aldehydes, ketones, and heterocyclic compounds, but lower contents of hydrocarbons and acids. Seventeen differential volatile compounds were identified using VIP > 1 and FDR-adjusted p < 0.05, with esters representing the major upregulated class. Based on the published odor descriptors of the identified volatile compounds, the FCC juice treatment group showed stronger green and apple-like aroma-associated characteristics. Overall, FCC juice showed a modest positive effect on growth performance and altered the volatile compound profile of fresh sheep meat; however, flavor-related findings should be regarded as preliminary because of the limited slaughter sample size and the absence of direct sensory validation.

Rumen viruses may influence methane-related fermentation indirectly by altering microbial populations that produce or consume hydrogen, formate, and methylated substrates, but evidence in sheep remains limited. The objective of this exploratory study was to determine whether the viral component recovered from bulk rumen metagenomes was associated with diet-induced differences in in vitro methane production through variation in viral community structure, predicted host associations, or metabolic functions. Forty-eight Hu rams were assigned to two dietary treatments with four pen replicates per treatment; one animal per pen was sampled, yielding eight rumen-fluid samples for 12 h in vitro methane determination and metagenomic sequencing. We characterized the viral component recovered bioinformatically from bulk rumen metagenomes. Phage-derived sequences predominated in both the low-methane (LMEG; 80.72%) and high-methane (HMEG; 79.95%) groups, with Uroviricota and Caudoviricetes as the dominant lineages. Global diversity, predicted-host composition, and KEGG and UniProtKB/ViralZone profiles did not show statistically supported group separation; however, two putative genus-level labels, Pakpunavirus and Fromanvirus, were enriched in LMEG after the reported false-discovery-rate correction. More than 99% of CHERRY host assignments were bacterial, and the conservative PHP–CHERRY consensus set was dominated by Bacillota and Bacteroidota. No methanogen-associated viral contig received concordant genus-level support. HMEG showed numerical increases in mtd, cofF, and fdhA, but none remained significant after correction, and canonical methyl-coenzyme M reductase genes were not detected. These findings identify candidate diet-associated viral signals consistent with a possible indirect virus–bacteria–fermentation relationship, but they do not establish a causal role of rumen viruses in methane production or identify phages for direct methane mitigation. Further studies with larger sample sizes, direct virus–host validation, and measurements of rumen fermentation and animal performance are required before potential methane-mitigation applications can be considered.