Effects of perennial ryegrass infected with either AR1 or wild endophyte on dairy production in the Waikato

摘要

Abstract A 3‐year farmlet experiment was carried out at Dexcel, Hamilton to compare the effects of ryegrass infected with either AR1 (no lolitrem B or ergovaline production) or wild endophyte on milksolids production and cow health. Two farmlets (7 ha each) were managed as self‐contained systems with cows grazing rotationally from September 2000 to May 2003, with 2.6 cows ha–1 in 2000/01 and 3.0 cows ha–1 in 2001/02 and 2002/03. AR1‐infected ryegrass pastures remained free of contamination from volunteer wild‐endophyte‐infected ryegrass plants for at least 3 years after sowing. Mean annual pasture production and ryegrass tiller density were similar for both AR1‐ and wild‐endophyte‐infected ryegrass farmlets in 3 years, with low numbers of black beetle. A combined analysis of the three lactations data showed that cows grazing AR1‐infected ryegrass pastures produced 8.9% more total milk‐solids than cows grazing wild‐endophyte‐infected pastures (318 versus 292 kg cow–1, SED = 9.2, P = 0.006). The difference ...