A Technique to Evaluate Persistence of Small Grain Cultivars Under Grazing Conditions.

Identification of forage cultivars than can tolerate grazing intensity is a concern for breeding programs. This 3-yr stocking × cultivar study  evaluated small grain cultivars under grazing without animal performance data. Cultivars (n = 24/ year) of oat, rye, wheat and triticale were replicated four times in a randomized complete block design each year.  Cultivars were seeded  in Nov at 112 kg/ha into 1.5 × 4 m blocks of a 0.2 ha paddock. The remainder of the paddock was seeded to a standard wheat variety such that the entire paddock had foliar cover. Plots were stocked at about 50 hd/ha (318 kg BW/hd) when canopy height reached 20 cm. Plots were grazed to a stubble of 5 to 7.5 cm during 2 – 3 d.  One 1 d represented too heavy  treading pressure  and stocking in excess of 5 d allowed for  leaf regrowth. At the initiation of each stocking period, all plots in one rep were hand-clipped to a 5-cm height to quantify DM yield.  Plant heights were taken prior to and immediately following each stocking period.  Forage was defoliated to a stubble height of approximately 4 cm and cattle were removed. Following each stocking, cultivars were visually scored for stage of maturity, tillering, preference and utilization. Forage utilization was least (P < 0.01) from triticale in the early season, but greatest (P < 0.01) during the mid-season. Preference tended to be greatest (P = 0.05) from oat, followed by wheat, and was least from rye, with triticale intermediate to the two during mid-season. Oats were revealed to be the most palatable of the small grains, and rye the least. However, due to extreme differences in preference among species, consideration should be given to evaluation of cultivars in plots of one species opposed to mixed types.