Selenium (Se) is essential for livestock, and selenium-enriched yeast (SY) is widely used to produce Se-enriched eggs. However, the optimal dosage for late-peak laying hens remains unclear. This 8-week trial evaluated graded SY (0, 0.1, 0.3, and 0.5 mg/kg Se) in 28-week-old Hy-Line Brown laying hens to explore the comprehensive effects. SY did not affect laying performance or egg quality (p > 0.05), whereas egg Se content increased dose-dependently from 0.211 to 0.521 mg/kg (p < 0.001). SY enhanced antioxidant capacity, with glutathione peroxidase and catalase activities rising from 90.67 and 7.91 U/mL to 493.33 and 21.43 U/mL (p < 0.001), and malondialdehyde decreasing from 0.46 to 0.13 nmol/L (p < 0.001). Serum lipid parameters were markedly improved, with total cholesterol and triglycerides declining from 8.82 and 17.60 mmol/L to 2.86 and 13.73 mmol/L (p < 0.001). Humoral immunity was also positively modulated, as immunoglobulin G and A increased from 401.68 and 73.06 μg/mL to 756.30 and 115.80 μg/mL (p < 0.001). Integrating egg enrichment efficiency, laying hen physiological health, and economic benefits, 0.3 mg/kg Se was identified as optimal, achieving 0.358 mg/kg egg Se. This study provides a novel paradigm for standardized and cost-effective commercial production of Se-enriched eggs.
The aquatic pathogen Aeromonas salmonicida SRW-OG1 is responsible for substantial mortality in Epinephelus coioides and many other cultured fish species. This study investigates the contribution of trpE to the pathogenicity of A. salmonicida SRW-OG1 in E. coioides. Specifically, trpE encodes a key enzyme in tryptophan biosynthesis; however, its function in regulating virulence in A. salmonicida remains uncertain. Phenotypic assays indicate that deletion of trpE markedly impaired bacterial growth and significantly reduced multiple virulence-associated traits, including swimming motility, biofilm formation, chemotaxis, hemolytic activity, and extracellular enzyme activity. Transmission electron microscopy revealed that the ΔtrpE mutant lacked flagella, indicating that trpE is involved in flagellar formation or maintenance. In an E. coioides infection model, fish infected with ΔtrpE showed a cumulative survival rate of 48.3%, whereas those infected with the wild-type SRW-OG1 suffered 100% mortality. The ΔtrpE mutant also exhibited reduced bacterial loads in target organs (liver, head kidney, and spleen), while pretreatment with ΔtrpE provided 53.3% protection against a subsequent wild-type challenge. Transcriptomic analysis identified 616 differentially expressed genes, mainly enriched in pathways including flagellar assembly, bacterial chemotaxis, two-component systems, quorum sensing, and biofilm formation. Metabolomic analysis further showed a significant decrease in N-butyryl-L-homoserine lactone, an acyl-homoserine lactone quorum-sensing signal in the ΔtrpE mutant. These findings suggest that trpE contributes to mesophilic A. salmonicida SRW-OG1's virulence by partially affecting quorum-sensing signal production and motility-related pathways. The attenuated phenotype and protective effect of ΔtrpE indicate its potential as a live attenuated vaccine candidate for controlling A. salmonicida infection in aquaculture.
Lambing interval is an indicator of reproductive efficiency in ewes. This study characterized population-level lambing interval patterns in Hu and Tan sheep and evaluated three previously reported candidate SNPs in ADAMTSL1, CD226, and PAPPA. Among 256 genotyped Hu ewes and 94 genotyped Tan ewes, 244 and 92 ewes, respectively, had at least two valid lambing dates. After applying a unified quality-control range of 180-450 days, 711 intervals from 230 Hu ewes and 219 intervals from 82 Tan ewes were retained. The raw mean lambing intervals were 277.81 ± 27.56 days in Hu sheep and 368.81 ± 22.51 days in Tan sheep. After adjustment for parity, year, season, preceding litter size, and repeated ewe records, Tan sheep had an 80.99-day longer interval than Hu sheep (95% CI: 75.34-86.64 days; p = 3.17 × 10-126). This difference remained significant across all parity groups. None of the three candidate SNPs was significantly associated with adjusted lambing interval after false-discovery-rate correction. Analyses of within-ewe interval variability also yielded no supported associations, although CD226 showed a weak, non-significant tendency toward lower variability in Hu sheep. These findings demonstrate a marked population-level difference in reproductive timing but do not support the immediate use of the tested SNPs as markers for lambing interval or within-ewe interval variability.
Achieving accurate cattle detection in complex barn environments is a critical technical challenge for smart livestock farming. Cattle exhibit highly similar appearances, severe occlusion, and significant multi-scale variations, making it difficult for existing detection methods to balance accuracy with model efficiency. This paper proposes a lightweight cattle detection model, DMFRNet, with YOLO11 as the baseline. To address these challenges, DMFRNet introduces three targeted improvements. First, C3K2-DIMB is designed to enhance multi-scale feature extraction by adaptively reweighting multi-branch depthwise convolution features, thereby improving the representation of cattle with different body sizes, poses, and viewing distances. Second, SimAM is embedded after the SPPF layer to refine high-level semantic features without introducing additional parameters, which improves feature discrimination under occlusion, low contrast, and complex backgrounds. Third, LSCDH replaces the original decoupled detection head to reduce parameter redundancy through cross-scale shared convolution while preserving multi-scale prediction capability. These designs jointly address the key challenges of multi-scale cattle appearance, occlusion, and lightweight model construction in complex barn scenes. Experimental results on the combined CBVD-5 and Dairy Cow dataset demonstrate that DMFRNet achieves a Precision of 93.49%, F1 of 89.84%, mAP50 of 93.85%, and mAP50-95 of 61.74%, with only 2.16 M parameters, 5.10 GFLOPs, and a model size of 4.5 MB. Comparative experiments demonstrate that DMFRNet provides a favorable accuracy-efficiency trade-off for lightweight dairy cow detection.
Oyster mushroom cultivation results in the generation of large amounts of by-products, the improper disposal of which can have adverse environmental consequences. The utilization of mushroom stem waste as a functional feed ingredient could serve as a promising strategy for its sustainable management and the development of alternative feed resources. This experiment investigates the effects of dietary enrichment with dried oyster mushroom stem waste of the Pleurotus ostreatus species (OMSW) on lamb growth performance and meat quality indices. Twenty-four 3-month-old male Chios lambs were randomly assigned to three groups; a control group (C) that received a basal diet; the P2 group that was offered a concentrate supplemented with 2% dried OMSW; and the P4 group, supplemented with 4% OMSW. Individual feed intake and body weight measurements were recorded weekly during the 28-day experimental period for each lamb. At the end of the feeding trial, lambs were fasted for 12 h and slaughtered. The internal organs (spleen, kidneys, liver, lungs, and heart) were then weighed, along with the hot carcass for each lamb. After 24 h at refrigerated storage, cold carcass weight was recorded and samples of longissimus thoracis muscle were collected from each lamb for subsequent meat quality assessment. No significant differences were observed among the three groups in feed intake and body weight throughout the experiment. Hot and cold carcass and internal organs' weights were also not affected by OMSW addition. Moreover, meat quality characteristics, such as pH, color, water holding capacity, shear force values and intramuscular fat were similar among the experimental groups. Meat oxidative stability during refrigerated storage was ameliorated (p = 0.002), possibly due to the antioxidant activity exerted by the phenolic compounds contained in OMSW, without any adverse effects on the meat fatty acid profile. These findings indicate that OMSW may be successfully incorporated into growing lamb diets up to 4% as an alternative feed without adverse effects on intake, production or meat quality.
