# Seasonal variation in meat quality of Angus steers raised in a Mediterranean forage-fed system: A farm case study

**Authors:** Viviana Bolletta, Valentina Roscini, Emanuele Lilli, Chiara Fodaroni, Jacopo Gabriele Orlando, Valentino Mercati, Bernardo Valenti, Mariano Pauselli

PMC · DOI: 10.1371/journal.pone.0344517 · PLOS One · 2026-03-24

## TL;DR

This study found that seasonal diets of forage-fed Angus steers affect meat quality traits, with fresh forage diets improving color stability and antioxidant levels.

## Contribution

The study introduces a multivariate approach to trace seasonal feeding strategies in grass-fed beef through combined meat quality indicators.

## Key findings

- Meat from spring and summer fresh-forage-fed steers had higher α- and γ-tocopherol and myoglobin levels.
- Multivariate analysis achieved 89.5% correct classification of meat samples based on feeding season.
- Fresh forage diets improved color stability and reduced lipid oxidation in stored meat.

## Abstract

This study monitored the impact of seasonal feeding variability on meat quality traits in forage-fed Angus steers. A total of 38 steers were selected based on their diets during the last three months before slaughter: a hay-based winter diet (WIN), a spring fresh-forage-based diet (SPR), or a summer fresh-forage-based diet (SMM). Meat quality was assessed through fatty acid profiling, antioxidant capacity, myoglobin content, color stability, and lipid oxidation during refrigerated storage. Principal components and linear discriminant analysis were used to uncover, underlying patterns, and classify the observations based on the multivariate profile. Meat fatty acids showed limited variation across seasons, with differences restricted to minor polyunsaturated fatty acids. The n-6/n-3 ratio and other health-related lipid indices remained within recommended values despite the feeding season. Meat from SPR and SMM animals showed higher α- and γ-tocopherol levels and greater myoglobin content compared to WIN meat. Color parameters and lipid oxidation were moderately affected by diet and storage time, with better stability observed in meat from animals receiving fresh forage. Despite the subtle impact on individual quality traits, multivariate discriminant analysis effectively differentiated meat samples based on the feeding season, achieving 89.5% correct classification. The most discriminating variables included fatty acids (17:1 c9, 18:1 t10, 22:0, 22:5 n-6), color attributes (b*), and oxidative markers (TBARS, metmyoglobin %). With the caution due to the nature of the study, these findings suggest that while single quality indicators may not strongly reflect dietary differences, their combination may provide a tool to trace seasonal feeding strategies in grass-fed beef production.

## Linked entities

- **Chemicals:** α-tocopherol (PubChem CID 2116)

## Full-text entities

- **Genes:** MB (myoglobin) [NCBI Gene 4151] {aka MYOSB, PVALB}, Myoglobin [NCBI Gene 780509]
- **Diseases:** AI (MESH:D050197), carcinogenic (MESH:D011230), SMM (MESH:D017688), inflammation (MESH:D007249), TI (MESH:D013927), metabolic disorders (MESH:D008659)
- **Chemicals:** TA (MESH:D013634), eicosapentaenoic acid (MESH:D015118), iron (MESH:D007501), sodium acetate trihydrate (MESH:D019346), thiobarbituric acid (MESH:C029684), hydrochloric acid (MESH:D006851), butylated hydroxytoluene (MESH:D002084), Trolox (MESH:C010643), sodium sulfite (MESH:C025026), trans fatty acids (MESH:D044242), alpha-linolenic acid (MESH:D017962), acetic acid (MESH:D019342), KOH (MESH:C029943), 1,1,3,3-tetraethoxypropane (MESH:C022168), n-6 fatty acid (MESH:D043371), silica (MESH:D012822), Vaccenic acid (MESH:C050413), PVPP (MESH:C077842), trichloroacetic acid (MESH:D014238), water (MESH:D014867), carotenoid (MESH:D002338), ferric chloride hexahydrate (MESH:C024555), potassium persulfate (MESH:C009007), alpha-tocopherol (MESH:D024502), Lipid (MESH:D008055), 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (MESH:C002502), n (MESH:D009584), hexane (MESH:D006586), Nonadecanoic acid (MESH:C517969), gamma-tocopherol (MESH:D024504), acetate (MESH:D000085), isoflavones (MESH:D007529), sulfuric acid (MESH:C033158), heme (MESH:D006418), lignin (MESH:D008031), FAMEs (MESH:C508762), Tocopherols (MESH:D024505), H (MESH:D006859), vitamin E (MESH:D014810), MUFA (MESH:D005229), linoleic acid (MESH:D019787), cholesterol (MESH:D002784), docosahexaenoic acid (MESH:D004281), rumenic acid (MESH:C046938), 18:2 n-6 (-), PUFA (MESH:D005231), methanol (MESH:D000432), carbon (MESH:D002244), Fatty acid (MESH:D005227), polystyrene (MESH:D011137), acetone (MESH:D000096), n-3 PUFA (MESH:D015525), malonaldehyde (MESH:D008315), terpenes (MESH:D013729), TBARS (MESH:D017392), ethanol (MESH:D000431), PVC (MESH:D011143), Helium (MESH:D006371), phenols (MESH:D010636), oxygen (MESH:D010100)
- **Species:** Homo sapiens (human, species) [taxon 9606], Trifolium alexandrinum (species) [taxon 97006], Lolium multiflorum (Italian ryegrass, species) [taxon 4521], Onobrychis viciifolia (common sainfoin, species) [taxon 3882], Sorghum x drummondii (chicken-corn, species) [taxon 171959], Lolium (genus) [taxon 4520], Bos taurus (bovine, species) [taxon 9913], Trifolium incarnatum (species) [taxon 60916], Medicago sativa (alfalfa, species) [taxon 3879], Vicia sativa (common vetch, species) [taxon 3908], Vicia villosa (hairy vetch, species) [taxon 3911], Avena sativa (cultivated oat, species) [taxon 4498]
- **Cell lines:** WIN — Rattus norvegicus (Rat), Transformed cell line (CVCL_U977)

## Full text

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## References

73 references — full list in the complete paper: https://tomesphere.com/paper/PMC13012490/full.md

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Source: https://tomesphere.com/paper/PMC13012490