Chaff Feed Quality of Winter Wheat, Spring Wheat, Barley, and Oat Cultivars

Little data exist regarding differences in chaff (i.e., glums, lemma, palea, and awns when present) feed quality among cultivars of small grains although large amounts are fed to livestock each year. This study was conducted to determine if in vitro organic matter disappearance (IVOMD), and concentration (conc) of ash, crude protein (CP), and P differed significantly among chaff from 19, 22, and 17 cultivars of spring wheat (Triticum aestivum L. and T. durum Desf.), barley (Hordeum vulgare L.), and oat (Avena sativa L.), respectively, grown on an irrigated site (fine montmorillonitic soil, Typic Argiborolls) and among 16 cultivars of winter wheat grown on a dryland site (fine-loamy, mixed Typic Argiborolls) near Sidney, MT for 2 years. Correlation of heading date, plant height, grain test weight, and grain yield with chaff IVOMD were calculated to determine if high chaff IVOMD was negatively correlated with agronomic traits important in grain production. Typical chaff piles were also sampled to determine the content of true chaff, weed seed, and grain in them. Chaff IVOMD, ash, and CP levels differed as much or more among cultivars of each species as between the 2 years. Chaff IVOMD differed by 84,136, 106, and 56 g kg⁻¹; chaff ash by 45, 68, 52, and 49 g kg⁻¹; chaff CP by 17, 25, 41, and 26 g kg⁻¹ among cultivars of winter wheat, spring wheat, barley, and oat, respectively. The chaff P (without high P fertilization) cone differed by 0.3, 1.7, 1.7, and 2.4 g kg⁻¹ among cultivars of winter wheat, spring wheat, barley, and oat, respectively. High P fertilization and variation between years increased chaff P cone of barley, spring wheat, and oat 0.5,1.5, and 2.5 times, respectively. High chaff IVOMD was generally not negatively correlated with agronomic traits important in grain production. Typical chaff piles of winter wheat, spring wheat, barley, and oat consisted of 898, 58, and 44 g kg⁻¹ of true chaff, weed seed, and cereal grain, respectively.