Milk production, principal composition and economic assessment of Holstein cows in a silvopastoral system with Mexican sunflower and yacon silage as partial concentrate replacement

Dairy livestock systems in the Colombian highlands are characterized by grass monoculture, high fertilization, concentrate supplementation, and predominantly Holstein cows. Limited pasture diversity and inadequate management have negatively affected soil and forage quality, increasing dependence on fertilizers and concentrates, raising production cost and reducing profitability. Intensive silvopastoral systems (ISS) represent an agroecological alternative by integrating grasses with trees and shrubs and strategic supplementation to improve production efficiency. Yacon (S. sonchifolius), a native Andean Asteraceae, produces high yields of leaves, steams and tubers, making this plant a valuable local resource for supplementation in ISS. This study evaluated milk production, principal milk composition, somatic cell count, and production cost of Holstein cows in an ISS with Mexican sunflower (T. diversifolia) and yacon silage as partial replacement for concentrated, compared to Kikuyu grass monoculture supplemented with concentrate. A Latin square crossover design (AB/BA) was used with two evaluation periods, two treatments, and two groups of four cows. Treatments were SPI (ISS + yacon) and MON (kikuyu monoculture). Response variables included total dry matter intake, milk yield, principal milk composition, somatic cells, feed efficiency, energy efficiency, and a descriptive economic analysis. Milk yield or principal composition did not differ between treatments, except for somatic cells (p < 0.05), which were lower in SPI. An economic simulation for 50 cows showed annual feed cost savings of USD 4,937.13 with SPI. Results indicate that ISS supplemented with yacon silage can reduce production costs while maintaining milk performance and reducing somatic cell count in dairy systems of the Colombian highlands.