Browsing by Subject "feedlot"

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    Effects of backgrounding nutrition and ratio of high-moisture to dry-rolled corn in finishing cattle diets on feedlot and carcass performance, and beef quality and fatty acid profile
    (2024-09) Zellmer, Chris
    Two experiments were conducted in 2019 and 2020 at the Beef Research and Education Center feedlot near Rosemount, MN. Experiment one evaluated the effects of intake management, ad-libitum (AD-LIB) or restricted (REST), and dietary energy concentration, high (HI) or moderate (MOD), fed to steers (n = 139) during a 49-d backgrounding period in a 2 × 2 factorial design and finished on a common-finishing diet. Dietary treatments were 1) 1.43 NEg Mcal/kg ad-libitum (HI AD-LIB); 2) 1.43 NEg Mcal/kg fed to gain 1.13 kg/day (HI REST); 3) 1.31 NEg Mcal/kg ad-libitum (MOD AD-LIB); 4) 1.31 NEg Mcal/kg fed to gain 1.13 kg/day (MOD REST). Steers fed REST treatments exhibited reduced DMI in the backgrounding and finishing periods, and overall (P < 0.0001). Daily gain was reduced during the backgrounding phase and overall (P < 0.0001), but similar during the finishing phase. Carcass traits were poorer for cattle on REST treatments (P ≤ 0.04). There were no effects of intake management on live performance in the backgrounding or finishing periods or overall (P ≥ 0.15). Quality grade was improved for steers fed HI treatments (P = 0.04), but there were no other impacts on carcass characteristics (P ≥ 0.44). There were interactions for BF (P = 0.04) and HCW (P = 0.06). In experiment two incremental increases in the ratio (HMC-RAT) of high-moisture (HMC) to dry-rolled corn (DRC) were fed to steers (n = 115) during the finishing phase to investigate the effects of HMC-RAT on feedlot performance and carcass characteristics. Dietary treatments consisted of 1) 20:80 HMC:DRC; 2) 40:60 HMC:DRC; 3) 60:40 HMC:DRC; 4) 80:20 HMC:DRC with similar concentrations of corn silage, dried distiller grains with solubles, and supplement. Ratio of HMC:DRC did not impact feedlot performance. Yield grade was greatest for steers fed a 40:60, intermediate for 20:80, and least for 60:40 and 80:20 HMC:DRC, respectively (P = 0.04). Other carcass traits were similar across dietary treatments. Feeding AD-LIB during the backgrounding period improved live performance and carcass characteristics. Ratio of HMC:DRC did not exhibit effects on finishing performance or a majority of carcass traits. Key Words: cattle, backgrounding, finishing, feedlot, programmed gain, intake management, high-moisture corn, dry-rolled corn
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    Modeling nutrient requirements and measuring nutrient outputs of feedlot cattle
    (2017-12) Kenney-Rambo, Nicole
    Improvements in genetics, nutritional strategies, and management, combined with the use of growth promoting agents have resulted in heavier carcass weights. Animal nutrient requirements are dynamic and the ability to accurately predict the requirements of modern, heavy cattle based on historic data has not been explored. A dataset derived from 19 studies containing 289 means for treatments testing ractopamine during the final 14 to 42 days of finishing was subjected to a meta-analysis to develop a regression equation (Heavy Model; HM) describing energy requirements of heavy weight steers at the end of finishing. A validation dataset derived from 13 studies containing 41 means for treatments testing zilpaterol during the final 21 to 35 days of finishing was used to validate the regression equation generated by the HM and the Nutrient Requirements of Beef Cattle (NRC; 2016) energy equation in a group of heavy weight steers. The equation developed from the test dataset for the HM is RE = (68.82*EBG)-(3.68*EBG^2)*EQEBW0.75/1000. Predicted RE of cattle in the validation dataset did not differ from observed RE for the NRC (P = 0.65) or HM (P = 0.49). The NRC model explained 78% of the variation in RE, with a 1.11% over-prediction bias and the HM explained 88% of the variation in RE, with a 0.27% under-prediction bias. Compared with the NRC model, utilization of the HM to predict energy requirements in heavy weight steers at the end of finishing explains a greater portion of the variation in observed versus predicted RE with a lower bias. Volatility in fertilizer prices have generated interest in capturing value through manure in integrated crop and cattle feeding systems. The impact of facility design (Open lot, Pack, Stockpile, Pit, Lagoon), cattle type (Beef or Holstein), and dietary energy value (Grower or Finisher) on manure nutrient concentration was measured. Manure nutrients were expressed as kg nitrogen (N), phosphate (P2O5), or potash (K2O)/tonne of as-is solid material or as kg/3,785 L liquid material. Projected annual manure production values of 2.7 and 4.5 tonne/head and 9,463 L/head, respectively, for Open lot, Pack and Pit, were utilized to project effects of facility on yearly manure nutrient contributions per head space. Nutrient concentrations of liquid manure samples from Pit was greater (P < 0.05) than that from Lagoon across all nutrients. Nitrogen concentrations of liquid samples was greater (P < 0.05) for Holstein, and P2O5 tended to be greater (P < 0.10) for Holstein. Nitrogen in solid samples was not impacted by facility type (P > 0.10); however, P2O5 concentrations were lower (P < 0.05) in Pack compared to Open lot and Stockpile. Concentrations of nutrients in solid manure samples were greater (P < 0.05) for Beef as compared to Holstein. Dietary energy value did not impact (P > 0.10) nutrient concentrations of solid manure samples. Projected annual manure N yield per animal headspace was greatest for Pit, intermediate for Pack, and least for Open lot (P < 0.05). Projected manure P2O5 yield was greater (P < 0.05) for Pack and Pit facilities as compared to Open lot. These results confirm that greater manure nutrients are captured by indoor confinement feedlot facilities.