Breeding improvement in alfalfa (Medicago sativa L.) is often constrained by the complexity of agronomic traits and trade-offs among yield-related characteristics. Conventional single-trait selection rarely captures the full range of phenotypic variation or the interactions among traits. To address this, we developed a principal component analysis (PCA)-based framework for multivariate selection in hybrid breeding. Six yield-related traits—plant height, branch number, fresh/hay yield ratio (FHR), leaf/stem ratio (LSR), multifoliolate leaf frequency, and dry weight per plant—were quantified in two parental lines and their F₁/F₂ generations. PCA identified three principal components (PC1–PC3) with eigenvalues >1, explaining 71.14% of the total phenotypic variance: PC1 (32.43% variance) was predominantly loaded with positive contributions from dry weight per single plant, height, and branches, biologically representing overall plant vigor and biomass accumulation; PC2 (21.77% variance) showed strong negative loadings for LSR, capturing architectural trade-offs between stem dominance and leaf production; PC3 (16.94% variance) had positive loadings on multifoliolate leaf rate and fresh/dry ratio, embodying quality and physiological resilience traits. Based on PCA scores, a composite selection index was constructed, and the top 31.1% of F1 hybrids were selected. Their F₂ progeny showed significant improvements in dry weight (+15.56%, p < 0.01), multifoliolate leaf frequency (+74.78%, p < 0.001), and reduced FHR (–8.2%, p < 0.05), accompanied by lower yield decline (−7.2% versus −14.1% in controls). These results show that PCA-based multivariate selection effectively balances trait trade-offs, enhances intergenerational stability, and improves selection efficiency. This framework offers a practical tool for alfalfa breeding.

Anthocyanins, crucial flavonoids in plants, enhance stress tolerance in alfalfa and are attracting attention due to their antioxidant properties. This study analyzed red- and green-stemmed alfalfa using spectrophotometry, frozen sections, and LC-MS/MS. Anthocyanins were concentrated in stem vascular cambium, with red stems peaking at 61.08 mg g⁻¹ DW during the bud stage. Seven anthocyanidins were identified, with their corresponding aglycones including cyanidin, peonidin, and malvidin. At early flowering, red-stemmed alfalfa contained 35 classes of anthocyanins compared to 17 in green-stemmed varieties, with cyanidin-3-O-glucoside levels significantly higher in red stems (4.423 μg g⁻¹, p < 0.05). Red-stemmed alfalfa also showed higher contents of acid detergent fiber, crude fat, Cu, Fe, and Zn (p < 0.05), especially Zn (p < 0.01). Correlation analysis revealed a strong positive link between cyanidin and crude fat (Spearman’s ρ = 0.93, p < 0.01) and a significant negative correlation with neutral detergent fiber (ρ = −0.88, p < 0.05). Cyanidin and peonidin are associated with stem color differentiation, with cyanidin contributing predominantly to red pigmentation, whereas zinc and crude fat exhibit a synergistic correlation with anthocyanin accumulation. These findings may inform breeding strategies to develop anthocyanin-enriched alfalfa.

Feather pecking can influence the welfare and health concerns of all farmed poultry and affect production and economic aspects. Although some information is available about feather pecking behavior in chickens and ducks, the risk factors of feather pecking in goslings have not been fully demonstrated. In this study, 3-day-old Yangzhou goslings were chosen, and risk factors of feather pecking injurious behavior were investigated, including stocking density, rearing method, flock uniformity, and environmental enrichment. The gosling performed three different pecking behaviors in starter barns from 3d of age to 10d, including gentle feather pecking (GFP), severe feather pecking (SFP), and aggressive pecking (AGP), and the corresponding proportions were 82.16%, 17.02%, and 0.82%, respectively, with peak aggressive feather pecking at 4–5 days of age. The pecked gosling also led to further pecking by conspecifics. Goslings preferred to peck the back (77.32%) and head (11.14%), which caused skin damage to the epidermal and dermal layers, accompanied by a decrease in feather follicle number and diameter. In addition, the effect of the stocking density and population uniformity on the occurrence of feather pecking was determined. The higher feather pecking frequencies and poorer feather quality of goslings were observed under high-density conditions than those of lower-density environments. Importantly, the lower population uniformity resulted in more aggressive pecking, potentially linked to the establishment of a social hierarchy. Finally, environment-related changes in pecking behavior were investigated. The results showed that damp and dirty housing conditions deteriorated plumage conditions and the occurrence of feather pecking, and environment enrichment (the grass section) could significantly reduce the incidence of pecking. Taken together, lower stocking density, higher population uniformity, and the provision of enrichment can reduce the prevalence of feather pecking. Meanwhile, feather pecking in goslings, with the back being the most commonly targeted area, can lead to the loss of back feathers and even skin damage. These results help to develop effective management and prevention strategies to reduce the negative effects of pecking behavior on goose health and performance.

Frozen storage has always been considered an effective process to extend the shelf-life of meat, although the underlying metabolic mechanisms driving quality changes remain poorly understood. This study investigated the impact of frozen storage (0, 30 and 90d) on the metabolome and proximate composition of Yangzhou goose breast muscle. UPLC-MS/MS-based metabolomic analysis identified 850 metabolites and observed distinct profiles across storage periods. Notably, a pronounced accumulation of Glycerophospholipids (GP) and Fatty acyls (FA) was observed from 30d to 90d, during which Arachidonic acid metabolism and Linoleic acid metabolism emerged as the main pathways. These shifts of metabolites corresponded with decreased moisture and elevated intramuscular fat content, suggesting that GP and FA can serve as potential markers for meat quality deterioration during the freezing process. Overall, these data provide dynamic metabolites for the process under frozen storage and highlight key pathways that underlie the quality alterations in goose meat.

FP is a detrimental behavior for chickens, ducks, and geese associated with numerous physiological and neurobiological characteristics, which have been identified in many species as regulated by the gut microbiota. However, it is unknown whether and how gut microbiota influences FP by regulating neurotransmitter systems in geese. This study aimed to investigate the phenotypic correlation between feather pecking and changes in physiological, neurobiological, and gut microbiota profiles in gosling. Three behavioral phenotypes were observed in goslings, including severe feather peckers (SFPs), victims of SFPs, and non-peckers (NFPs). The significantly lower feather scores and body weights were observed in victims compared to both SFPs and NFPs (p < 0.05). Regarding the physiological phenotype, victims had higher dopamine (DA) levels than NFPs, and SFPs had lower 5-hydroxytryptamine (5-HT) in the serum than NFPs (p < 0.001), with intermediate 5-HT levels in victims. Victims had lower glutathione peroxidase (GSH-Px) compared to SFPs and NFPs (p < 0.05). Moreover, higher mRNA expression levels of HTR1A, SLC6A4, and TPH2 in the 5-HT metabolic pathway were detected in NFPs than those in SFPs and victims (p < 0.05). In addition, regarding gut microbiota measured by 16S rRNA sequencing, SFPs had lower diversity and comparable cecal microbiota compared to victims and NFPs. Proteobacteria, Verrucomicrobia, Ruminococcus spp., and Bilophila spp. were enriched in SFPs, while Bacteroides and Parabacteroides were enriched in NFPs. From the predicted bacterial functional genes, the cAMP signaling pathway, cGMP–PKG signaling pathway, and pyruvate metabolism were activated in SFPs. The correlation analysis revealed that the genera Bacteroides spp. were associated with differences in 5-HT metabolism between the SFPs and NFPs. In summary, differences in the cecal microbiota profile and 5-HT metabolism drive FP phenotypes, which could be associated with the reduced gut abundance of the genera Bacteroides spp.