Pasture feeding improves the nutritional, textural, and techno-functional characteristics of butter.

Some consumers prefer pasture-derived dairy products, as they perceive outdoor pasture-based feeding systems as a more natural environment for animals. Despite this, the number of grazing animals globally has declined as a result of the higher milk yields achieved by indoor TMR feeding systems, in addition to the changing climatic conditions to control the milking environment. This in some countries has led to the development of pasture-fed standards, stipulating the necessity of pasture and its minimum requirements as the primary feed source for products advertising such claims, with various requirements depending on the region for which it was produced. From that perspective, the study cited investigated the differences in the composition and techno-functional properties of butters produced from high, medium and no pasture allowance diets during early, mid, and late lactation.

Butters were produced using milks collected from three feeding systems: outdoor pasture grazing (high pasture allowance); indoor TMR (no pasture allowance); and a partial mixed ration (medium pasture allowance) system, which involved outdoor pasture grazing during the day and indoor TMR feeding at night. Butters were manufactured during early, mid, and late lactation.

The results showed that the creams derived from the TMR-based feeding system exhibited the highest milk fat globule size. The fatty acid profiles of butters also differed significantly as a function of diet and could be readily discriminated by partial least squares analysis. The most important fatty acids in such an analysis, as indicated by their highest variable importance projection scores, were CLA C18:2 cis-9, trans-11 (rumenic acid), C16: 1n -7 trans (trans-palmitoleic acid), C18:1 trans (elaidic acid), C18: 3n -3 (α-linolenic acid), and C18: 2n -6 (linoleic acid). Increasing the pasture allowances resulted in reduced crystallization temperatures and hardness of butters and concurrently increasing the “yellow” colour, which is associated with carotenoids. The milk fat globule size of the cream decreased with advancing stage of lactation and the churning time of cream was lowest in early lactation. Differences in the fatty acid and triglyceride contents of butter as a result of lactation and dietary effects demonstrated significant correlations with the hardness, rheological, melting, and crystallization profiles of the butters.

This work highlighted the improved nutritional profile and functional properties of butter with increasing dietary pasture allowance, primarily as a result of increasing proportions of unsaturated fatty acids. Biomarkers of pasture feeding (response in milk proportionate to the pasture allowance) associated with the pasture-fed status of butters were also identified as a result of the significant changes in the fatty acid profile with increasing pasture allowance.