Comparison Of Two Different Grazing Systems Incorporating Cool And Warm Season Forages For Organic Dairy Cattle

Abstract

Two pasture systems with enhanced in-field and landscape level species diversity were analyzed for yield, forage quality, and mineral characteristics across the grazing season at the West Central Outreach and Research Center organic dairy in Morris, MN from 2013 to 2015. System 1 was a diverse-mixture of cool season grasses and legumes. System 2 was the same combination of perennial grasses and included warm season annual grasses (BMR sorghum-sudangrass (Sorghum × drummondii; BMRSS) and teff (Eragrostis tef) grass). Organic dairy cows (n = 90) of Holstein and crossbred genetics were used to evaluate the effect of the two pasture systems on milk production, milk components (fat, protein, MUN, SCS), body weight, body condition score (BCS), and activity and rumination (min/d). The rumen fermentation of BMRSS, teff, cool season perennial pastures, and alfalfa were also studied using a dual flow continuous culture rumen fermentation system.