Effects of graded levels of supplemental feather meal on performance and carcass characteristics of finishing beef cattle

The NRC (1996) changed from the factorial protein system to a metabolizable protein (MP) system for beef cattle. In the MP system, dietary crude protein (CP) is subdivided into degraded intake protein (DIP) and undegraded intake protein (UIP). The quantity of microbial protein produced in the rumen dictates DIP requirements. Steam-flaked corn is the predominant grain used in the diets of finishing beef cattle in Great Plains. Because steam-flaked corn is rapidly and extensively fermented in the rumen, microbial protein production is high. Therefore, the NRC (1996) requirements for DIP are increased with steam-flaked corn diets compared with diets based on less extensively processed grain. Feather meal is a protein source that has a relatively low content of DIP and a relatively high content of UIP. As a result, most feedlot nutritionists who use the MP system would discount the value of feather meal in steamflaked corn diets. Our recent research (Gleghorn, 2003) suggests that DIP requirements with steam-flaked corn diets may not be as high as suggested by the NRC (1996) MP system. Hence, discrimination against high UIP sources like feather meal might not be justified. Data suggest that feather meal can increase performance by growing cattle (Klemesrud et al., 2000); however, data are lacking evaluating the use of feather meal as a protein source for feedlot cattle fed steam-flaked corn-based finishing diets.