Mid-lactation response of cows grazing pasture mixtures containing perennial plantain, white clover, and ryegrass

Incorporation of the perennial species plantain (Plantago lanceolata) and white clover (Trifolium repens) into pasture based dairy systems has the potential to improve the supply of highly digestible forage during times when perennial ryegrass (Lolium perenne) has low growth rates or poor nutritive value. The objective of this study was to determine the effect of grazing cows on pasture swards containing mixtures of plantain, white clover, and perennial ryegrass on milk production and energy and nitrogen status during mid-lactation. Four pasture sward treatments were assessed; perennial ryegrass monoculture; white clover and plantain mixture; perennial ryegrass, white clover and plantain mixture; and spatially adjacent monocultures of perennial ryegrass, white clover and plantain. Pasture swards were grazed with 4 replicate herds, balanced for age, breed, days in milk, and production to date. Each replicate was allocated 20kg DM/cow/day of pasture from their treatment sward. Liveweight, body condition score, milk yield, milk composition along with blood metabolites (non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB) and blood urea nitrogen (BUN)) were used to assess how treatments were affecting cows in mid-lactation. There was no effect from treatment swards on milk yield between treatments during the response period. NEFA and BHB indicated no signs of negative energy balance in all treatments. BUN concentrations were equal to or higher than perennial ryegrass for the treatments containing plantain and white clover. It was concluded that the incorporation of plantain and white clover into pasture based systems will have no negative effects on production or energy and nitrogen status during mid-lactation.