Cotton Byproduct Use in Southeastern Beef Cattle Diets: Quality, Intake, and Changes in Feed Characteristics

Abstract Cotton is grown on over 4.5 million hectares in the southeastern U.S. annually, and byproducts of cotton production are utilized as feedstuffs in beef systems. Cotton breeding efforts and variety recommendations for crop production represent potential changes in cotton seed size, density, and quality, which may influence whole cottonseed feed quality characteristics. Also, cotton breeding to reduce gossypol concentration without compromising yield may improve value in ruminant diets. A recent feed intake trial demonstrated greater consumption of ultra-low gossypol seed compared with seed derived from a more widely planted cotton variety (0.072% vs 0.53% free gossypol, respectively) in growing steers (1.9 and 1.1 kg/hd/d, respectively). Historically, cottonseed is limited in bull diets due to the associated of decreased fertility in males due to gossypol. However, a recent study found that feeding up to 3.2 kg/hd/d over a 60-d period to developing beef bulls did not affect sperm quality. Heat damage commonly occurs in cottonseed during storage after the ginning process, but the feed value of heat damaged cottonseed is unknown. A recent study indicated that in situ dry matter (52.2 vs 69.2%) and N (78.1 vs 91.6%) disappearance decreased for heat damaged compared to normal cottonseed, respectively. Cotton gin trash remains a prevalent byproduct with traditionally limited use. Some gins have equipment for baling gin trash in 180-to-270 kg modules, which allow ease of access and transport of gin trash waste for cow-calf producers. Similar to gin trash, grazing cotton crop residue after harvest can decrease the amount of hay fed during the winter. A recent 3-yr study indicated a 2.5 hd/ha stocking rate of mature, non-lactating cows over a 30-d period decreased hay consumption by 65 %. By understanding the feed characteristics and management needed to utilize cotton byproducts, cattle operations can decrease feed cost while maintaining animal performance.