Invited Review: Using whole cottonseed and cotton harvest residue in southeastern US beef cattle diets: Quality, intake, and changes in feed characteristics

Purpose: Cotton (Gossypium sp.) is grown on over 4.5 million hectares in the United States annually. This article provides an overview of cotton industry changes and their influence on whole cottonseed and cotton residue quality and use in beef cattle operations in the southeastern United States. Sources: Whole cottonseed may vary depending on cotton growing and harvest conditions, seed composition, and ginning technologies. Most cottonseed is hand fed to beef cattle at a set feeding rate to control fat intake. However, there is variation in the literature in on-farm cottonseed feeding strategies and potential use of whole cottonseed in beef bull diets. Cotton residues are often used as a roughage alternative. Strategies to expand the use of cotton residues include integrated crop-livestock systems, gin byproduct baling applications, and evaluation of chemical residues to determine feeding safety. Synthesis: Periodic characterization of seed protein, fat, and gossypol can refine beef cattle feeding strategies. Grazing cotton field residue can reduce hay needs in beef cattle diets. There is limited information on animal growth performance, health, and safety of beef cattle fed cotton residues, which may potentially contain detectable levels of pesticides or herbicides. Conclusions and Applications: Use of whole cottonseed and cotton residues benefits both the cotton and beef cattle industries. Future research to more closely mimic on-farm beef nutritional management strategies may expand the use of whole cottonseed as a supplement. Quality evaluation of cotton byproducts ensures greater accuracy in ration development and may help elucidate threshold values for establishing safety of use.