Impact of Regenerative Pasture Management on Soil Health, Milk, and Meat Quality
This page presents the combined findings from two pilot farms — Pilot B (Beira Baixa) and Pilot D (Alentejo) — which together investigate how regenerative pasture and grazing management affect soil health, milk composition, and meat quality under Mediterranean conditions.
Pilot B – Beira Baixa
Location: Beira Baixa region, mainland Portugal · Mediterranean climate · Dairy goat production
Pilot Logic
A 4 ha plot was implemented with annual, biodiverse pasture mixtures and continuous soil coverage. This farm, previously managed as a conventional dairy goat system, is transitioning to regenerative agriculture. Monitoring focused on linking regenerative pasture management to measurable improvements in soil health and microbiome function compared to a conventional system. Soil analyses were conducted before and after the regenerative practices; milk analyses were performed on samples collected during concentrate-only feeding and 5 days after the introduction of 50% pasture / 50% concentrate feeding.
Results – Soil (Pilot B)
Clear evolution in soil fertility and nutrition:
| Indicator | Before | After |
|---|---|---|
| Organic matter | 2.2% | 6% |
| Total nitrogen | 0.14% | 0.27% |
| Phosphorus | 228 mg/kg | 326 mg/kg |
| Potassium | 348 mg/kg | 636 mg/kg |
| Calcium | 1,100 mg/kg | 1,500 mg/kg |
| Magnesium | 169 mg/kg | 289 mg/kg |
| CEC | 4.45 cmol⁺/kg | 7.43 cmol⁺/kg |
The increase in Cation Exchange Capacity (CEC) represents a major gain in the soil's ability to retain and buffer exchangeable nutrients, consistent with the rise in organic matter. Microbiological results showed an active presence of microorganisms involved in nutrient pathways — particularly nitrogen cycling — coherent with the physical-chemical results.
Results – Milk (Pilot B)
Amino Acids: Most free amino acids decreased under grazing, except glutamine. The reduction in many free essential amino acids under grazing may reflect improved capture of absorbed amino acids into casein and other milk proteins. Elevated glutamine concentrations may reflect differences in ruminal and mammary nitrogen metabolism associated with pasture-based production.
Lipid-related Compounds: Choline was higher before grazing; betaine showed the opposite pattern and increased under grazing, possibly reflecting an enhanced supply of plant-derived osmolytes and methyl-donor compounds from pasture. Proline betaine and propionylcarnitine both decreased after the introduction of grazing, indicating a measurable shift in methyl-donor metabolism and acyl-carnitine handling in milk.
Nucleotides & Nucleosides: A decrease was observed in milk nucleotides and nucleosides — components of the non-protein nitrogen fraction known to respond to lactation stage, milk production, and physiological state. These results may reflect alterations in mammary biosynthetic processes and changes in microbial and cellular turnover associated with the transition to a pasture-based diet.
Vitamins: The grazing milk was richer in niacin and vitamin C, but lower in pantothenic acid-related compounds. These vitamins and cofactors support energy production, antioxidant defense, and key metabolic reactions. Only 5 days of grazing can significantly affect milk composition, with notable benefits for human health including higher vitamin content.
Pilot D – Alentejo
Location: Alentejo (southern Portuguese interior), mainland Portugal · Mediterranean climate · Grassland-based pastoral system
Pilot Logic
Rotational grazing was implemented with 1.8-ha paddocks to allow grass recovery. Soil analysis was conducted at a 1-year interval; milk analysis was performed on samples collected before the animals entered the rotational grazing system and on 5 consecutive days thereafter; meat samples were compared with conventional systems.
Results – Soil (Pilot D)
Clear improvement in soil fertility and function under no-tillage and holistic grazing:
| Indicator | Before | After |
|---|---|---|
| Organic matter | 3.1% | 3.8% |
| Total nitrogen | 0.13% | 0.29% |
| C:N ratio | 13.8 | 7.6 |
| CEC | 3.21 cmol⁺/kg | 4.05 cmol⁺/kg |
The drop in C:N ratio indicates faster decomposition and more plant-available nitrogen. The increase in CEC represents an improved ability to retain and supply nutrients while reducing potential leaching losses. Several specific functional microbial pathways showed signs of improvement despite an overall low classification.
Results – Milk (Pilot D)
Polyunsaturated Fatty Acids (PUFA): The clearest patterns were seen in PUFA. Alpha-linolenic acid (ALA, omega-3), linoleic acid (omega-6), EPA, DHA, DPA, and arachidonic acid (ARA) all differed significantly across sampling days, with concentrations generally lowest on day 1 and peaking on days 3–5. Such short-term shifts in omega-3 and omega-6 PUFA are consistent with evidence that grazing rapidly influences milk fatty acid composition. Omega-3 fatty acids are considered cardioprotective, helping lower triglycerides and reduce the risk of heart attack. These findings align with other studies showing that pasture-based systems reduce the proportion of saturated fatty acids (SFA) and increase unsaturated fatty acids compared with confinement feeding.
Free Amino Acids: Both essential and non-essential free amino acids responded over the five-day period, consistent with evidence that milk free amino acid profiles are highly sensitive to diet, pasture composition, and stage of lactation.
Lipid-related Compounds: The rise in L-carnitine and shifts in acylcarnitines suggest changes in lipid mobilization and energy handling in the cow, consistent with a regenerative system where pasture intake, forage quality, and grazing behavior fluctuate daily.
Vitamins & Co-factors: A decline in riboflavin and pantothenic acid over time, together with a rise in biotin, suggests that the regenerative grazing environment may have altered microbial vitamin supply, rumen fermentation dynamics, and mammary secretion patterns across the 5-day period.
Terpene Profile: The terpene profile changed strongly over the 5 days. Alpha-pinene, beta-caryophyllene, alpha-caryophyllene (humulene), and α-copaene all increased — particularly during the later sampling stages. Limonene and p-cymene reached their highest concentrations earlier and subsequently declined. These patterns suggest that the milk terpene profile was influenced by short-term variations in pasture composition and grazing selection. Several of these compounds can be used to differentiate milk produced under grazing systems from that originating from more intensive feeding regimes.
Results – Meat (Pilot D)
Fatty Acids: Meat from Pilot D (Farm 1), Farm 2, and Farm 3 presented the highest levels of monounsaturated fatty acids (oleic and palmitic) and omega-3 PUFA (ALA, EPA, and DHA) compared with supermarket and control samples — consistent with studies showing that grass-fed animals have higher omega-3 and lower omega-6 content.
Nucleotides & Free Amino Acids: Pilot D (Farm 1) showed intermediate values compared with other pilot farms, the control, and supermarket samples.
Vitamins: Riboflavin and niacin remained lowest in Pilot D (Farm 1), Control Mertolenga, and supermarket samples, forming a distinct separation from the higher values observed in Farm 2 and Farm 3.
Overall, Farm 2 showed the best metabolic profile (rich in free amino acids and mono- and polyunsaturated fatty acids), followed closely by Farm 3, indicating that regenerative and pasture-based systems produce the most enriched metabolic profiles.