Yield and Nutritive Value Trends for Stockpiled Small Grains in the Western Corn Belt.

Using annual, small grain forages has the advantage of providing a readily available source of high-quality grazing. However, evaluation of fall-grown small grains has not been widely evaluated as a stockpiled forage source.  The objective of this study was to determine herbage mass and nutritive value trends of fall-sown small grains as a source of high-quality winter stockpile.  This experiment was designed as a randomized complete block with 4 replications to evaluate seven annual, small grain species and varieties.  ‘Goliath’ (late maturity) and ‘Jerry’ (medium maturity) oats (Avena sativa L.), ‘Elbon’ cereal rye (Secale cereale L.), ‘Haybet’ spring and ‘P919’ winter barley (Hordeum vulgare L.), and ‘141’ spring and ‘441’ winter triticale (Triticosecale Wittmack) were planted in late August and hand-harvested four times at approximate 34-d intervals from 2 November through 17 February.  Whole-plant samples were used to calculate forage yield and forage nutritive value at each harvest date.  Several winter and spring species were still actively growing and did not reach maximum herbage mass until the December harvest date.  Herbage mass for the spring species averaged approximately 4100 kg ha^-1 for both cultivars of oats and spring barley on December 22.  Spring triticale had the lowest average herbage mass (2700 kg ha^-1), but the greatest nutritive value.  As a group, crude protein (CP) for the spring species ranged from 120 to 80 g kg^-1 and in vitro dry matter digestibility (IVDMD) ranged from 860 to 750 g kg^-1.  For the winter species, herbage mass was more consistent across winter harvest dates and did not appreciably decline after growth ceased with mean herbage mass accumulation near 2800 kg ha^-1.  As a group, CP for the winter species ranged from 150 to 140 g kg^-1 and IVDMD ranged from 950 to 840 g kg^-1.  The primary advantage for considering these systems is to provide an additional use for cropland outside of the traditional growing season. These can be used to provide alternative grazing options and extend the grazing season, especially for spring-calving cow herds.  Even though this a promising approach, it is important to understand both the agronomic and livestock risks and limitations of incorporating small grain annual forages into existing cropping systems.