Date of this Version
Published in Proceedings, Western Section, American Society of Animal Science (2009) 60: 219-222.
In 2006-2008 ‘Willow Creek’ winter wheat (Triticum aestivum L.) and ‘Trical 102’ triticale (X Triticosecale Wttn.) were evaluated, under dryland conditions, for biomass production and forage quality under grazing and haying systems. Grazing enclosures were constructed in uniform sites of the fields. Each enclosure was randomly assigned a treatment (date to be grazed) and a replication (r = 3 in 2006 and 2008, r = 4 in 2007). For the hay-only component, cereals were harvested at the anthesis stage (A). For pasture, the cereals were subjected to a single grazing event at three stages of maturity, vegetative (V), boot (B), and heading (H). Ewe lambs grazed plots to approximately 5 cm. Subsequent regrowth was harvested as hay at A, and forage yield and quality were measured. Ungrazed forage plots were evaluated for forage yield and quality at each stage of maturity. Hay yields of ungrazed plots at A were 4,030 to 13,072 kg/ha for wheat and 8,541 to 12,569 kg/ha for triticale. Grazing wheat at most stages of maturity reduced (P < 0.05) subsequent forage yields when regrowth was measured at A. Triticale grazed at early V, resulted in subsequent forage yields similar to ungrazed triticale (P > 0.05), when regrowth was measured at A. A single-grazing event of wheat at V had available forage yields of 61 to 3,159 kg/ha, and 215 to 601 kg/ha for triticale. Delaying grazing to later stages of maturity resulted in successively greater losses of subsequent forage yield. In a mixed pasture-hay system, total forage availability was impacted by -10 to -29% for wheat and -8 to -28% for triticale, when grazed at V. Forage quality was greatest at early V and declined throughout maturity. These data indicate that grazing winter cereals in a pasture-hay system at early V will maximize total available biomass and forage quality. High forage quality (CP and digestibility) and minimal risk of nitrate toxicity occurred in the mixed pasture-hay system.