Emissions Savings in the Corn-Ethanol Life Cycle from Feeding Coproducts to Livestock

Environmental regulations on greenhouse gas (GHG) emissions from corn (Zea mays L.)-ethanol production require accurate assessment methods to determine emissions savings from coproducts that are fed to livestock. We investigated current use of coproducts in livestock diets and estimated the magnitude and variability in the GHG emissions credit for coproducts in the corn-ethanol life cycle. The coproduct GHG emissions credit varied by more than twofold, from 11.5 to 28.3 g CO2e per MJ of ethanol produced, depending on the fraction of coproducts used without drying, the proportion of coproduct used to feed beef cattle (Bos taurus) vs. dairy or swine (Sus scrofa), and the location of corn production. Regional variability in the GHG intensity of crop production and future livestock feeding trends will determine the magnitude of the coproduct GHG offset against GHG emissions elsewhere in the corn-ethanol life cycle. Expansion of annual U.S. corn-ethanol production to 57 billion liters by 2015, as mandated in current federal law, will require feeding of coproduct at inclusion levels near the biological limit to the entire U.S. feedlot cattle, dairy, and swine herds. Under this future scenario, the coproduct GHG offset will decrease by 8% from current levels due to expanded use by dairy and swine, which are less efficient in use of coproduct than beef feedlot cattle. Because the coproduct GHG credit represents 19 to 38% of total life cycle GHG emissions, accurate estimation of the coproduct credit is important for determining the net impact of corn-ethanol production on atmospheric warming and whether corn-ethanol producers meet state- and national-level GHG emissions regulations

Effects of Lactobacillus acidophilus and Propionibacterium freudenreichii on growth performance and carcass characteristics of finishing beef cattle

There have been contradicting reports of the efficacy of direct-fed microbials in finishing cattle diets. Some researchers have observed improvements in daily gain and feed efficiency when direct-fed microbials are included in finishing diets, whereas others have reported no differences in dry matter intake or ruminal and blood pH. Many of these studies have been conducted on a relatively small scale and used few animals per pen compared with that of typical commercial feedlot operations. In our study, yearling crossbred beef steers and heifers (n=3,539; 796 lb body weight) were used in an experiment conducted at a commercial feedlot operation to characterize growth performance and carcass characteristics associated with the supplementation of direct-fed microbials (Lactobacillus acidophilus and Propionibacterium freudenreichii) in finishing cattle diets. Including direct-fed microbials in the diet throughout a 122-day finishing period had no measurable impact on growth performance or carcass characteristics of finishing cattle

Performance and carcass characteristics of yearling steers and heifers fed Agrado™ throughout the finishing period

A finishing experiment was conducted at a commercial feedlot facility in Larned, Kansas, using 3,295 yearling steers and heifers to evaluate effects of Agrado™ addition to finishing diets. Agrado (ethoxyquin) is a dietary anti-oxidant that protects against oxidative loss of critical vitamins and prevents rancidity and unpalatable odors. Supplementing finishing diets of yearling steers and heifers with 150 ppm Agrado had no measurable effects on growth performance or carcass characteristics

Effects of Optaflexx™ on finishing steer performance and USDA quality and yield grades

Crossbred yearling steers (2,015 head) were fed at a commercial feedyard near Larned, Kansas, to evaluate the effects of feeding Optaflexx™ at 0 or 200 mg ractopamine-HCl per steer daily for the final 29 days on feed. Steers were fed a common diet, based on steam-flaked corn, throughout their finishing period. Cattle that were fed Optaflexx™ had heavier final bodyweights (1264 vs. 1236 lb). Optaflexx™-fed cattle gained 17.9% faster (carcass adjusted basis) and tended to consume more feed during the last 29 days on feed. Feed efficiency was 14% better during the last 29 days for the Optaflexx™-fed steers. Feeding Optaflexx™ increased carcass weight by 19.7 lb and increased carcass weight gained during the last 29 days on feed by 11.2 lb. There were more liver abscesses for the control steers (19.7%) than for Optaflexx™-fed steers (13.5%). Quality grade was not affected by feeding Optaflexx™. There was a decrease in USDA Yield Grade 2 carcasses (49.6 vs. 54.8%) and an increase in USDA Yield Grade 4 carcasses (3.3 vs 1.7%) when cattle were fed Optaflexx™. Performance of the steers from the time that they were sorted into their treatment pens until slaughter (98 days) was improved by feeding Optaflexx™ during the last 29 days on feed. For the full 98-day period, daily gain was 8% greater for steers fed Optaflexx™ vs. control, feed intake was greater for the steers fed Optaflexx™, and feed efficiency was moderately improved (3.3%). Steers that received Optaflexx™ gained 6.4% more bodyweight during the 98-day feeding period. These data show that addition of Optaflexx™ into finishing diets fed to steers is beneficial, increasing bodyweight and carcass gain and improving conversion of feed to beef without affecting USDA quality grade

Growth performance and carcass characteristics of finishing beef steers implanted with component TE-S or component TE-S with Tylan

Component TE-S and Component TE-S with Tylan growth-promoting implants were compared in an experiment conducted at a commercial feedlot operation (Ward Feed Yard; Larned, Kansas) to evaluate effects on growth performance and carcass characteristics. Crossbred steers (n=1843; 827 lb body weight) were implanted with either Component TE-S or Component TE-S with Tylan and were fed a finishing ration based on steam-flaked corn for an average of 116 days before slaughter. Cattle were assigned randomly to the implant treatments at processing and were allotted to 12 pens, containing an average of 154 steers each. No differences were detected in dry matter intake (P=0.18), average daily gain (P=0.41), or feed efficiency (P=0.59) of cattle administered the different implants. Component TE-S with Tylan produced fewer (P<0.05) buller steers. Cattle implanted with Component TE-S with Tylan were more heavily conditioned than cattle implanted with Component TE-S. Cattle with the implant including Tylan had a greater percentage of USDA Choice or Prime carcasses (P=0.11) and a greater percentage of USDA Yield Grade 4 carcasses (P=0.03). Component TE-S with Tylan also tended to produce fewer (P=0.12) USDA Yield Grade 1 carcasses compared with cattle implanted with Component TE-S. Total carcass value was also greater for the Component TE-S with Tylan cattle, as calculated by either a muscle-based or quality-based marketing grid. Inclusion of a pellet of the antibiotic Tylan within Component TE-S implants seems to result in modest changes in carcass fattening, as well as significant reductions in the incidence of buller activity among feedlot steers