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Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken

Department of Animal Science: Dissertations, Theses, and Student Research

Corn residue is an abundant feed source in Nebraska that can be utilized as an alternative winter feed. Calves were backgrounded on corn residue in order to determine gain and estimate forage intake when supplemented with distillers grains (DGS). Calves grazing the non-irrigated field gained more (1.03 kg/calf daily) when compared to those grazing the irrigated field (0.90 kg/calf daily; P < 0.01). In year 1, a quadratic effect for intake of DGS was present (P < 0.01) while year 2 observed a linear effect for increasing level of DGS (P < 0.01). The nutritional quality of corn residue was evaluated over time in order to determine changes in blade/sheath, cob, husk/shank and stem. Minimal changes in DM of the forage components occurred was grain reached 15.5% moisture. Digestibility of the blade/sheath declined linearly over time (P < 0.01) while the husk remained constant (P = 0.40). Cob digestibility decreased quadratically (P < 0.01) throughout the sampling period with few changes once grain reached 15.5% moisture. Differences observed in the digestibility of the blade/sheath were attributed to the effects of weathering. A third set of trials was conducted to evaluate the effects of by-product supplementation of calves grazing irrigated corn residue and supplemented with DGS or continuous access to lick tubs. The DGS treatment gained more (0.62 kg/calf daily) than the lick tub treatment (0.38 kg/calf daily; P < 0.01). Calves offered DGS consumed more supplement as a percentage of BW (0.52%) when compared with calves offered lick tubs (0.36%; P < 0.01) on a DM basis. Calves supplemented with DGS had a higher supplement efficiency (46.3% to 42.9%, DM basis) although no differences were present between treatments (P = 0.49). When analyzed on an OM basis, however, calves offered lick tubs had a numerically higher supplement efficiency (50.4%) in comparison to calves …

Feedlot Manure Management Considerations Including Anaerobic Digestion Potential And Mineral Retention, Andrea K. Watson

Department of Animal Science: Dissertations, Theses, and Student Research

Three anaerobic digestion trials were conducted to evaluate methane production from feedlot manure. As organic matter content of manure decreased, degradation of manure and methane production also linearly decreased (P ≤ 0.02). Quality, or organic matter content of manure, had a greater impact on anaerobic digestion than diet (with and without distillers grains) fed to cattle. Minerals are concentrated in effluent removed from anaerobic digesters.

Knowing mineral retention within cattle allows for more accurate calculation of mineral excretion in manure. Three serial slaughter trials measured mineral retention in growing and finishing cattle. During a growing phase, beef cattle gaining …

Feeding Alkaline Treated And Processed Crop Residue To Feedlot Cattle, Sarah J. Peterson

Department of Animal Science: Dissertations, Theses, and Student Research

Chemical treatment and decreased particle size are methods used to improve digestibility and utilization of the available nutrients in low quality forages. Previous research has indicated that chemically treated corn residue can take the place of corn when included in finishing rations containing distillers grains. Also, decreasing particle size utilizing methods such as pelleting has been shown to improve DMI and ADG. However, limited research has been completed on use of chemical treatment and pelleting in growing and receiving rations. Also, an ideal distillers inclusion has not yet been identified when including alkaline treated stalks in finishing rations. Therefore, a …

Determining Forage Intake Of Nursing Calves Grazing Native Sandhills Rangeland, Jennifer A. Walker

Department of Animal Science: Dissertations, Theses, and Student Research

Effective management of grazing lands is important for longevity and productivity. Accurate calculations of stocking rates per animal unit will aid in long term sustainability. Calculating stocking rates for cattle can prove challenging for cows and nursing calves. Limited research has been conducted to determine forage intake of the nursing calf pre-weaning. The objective of Trial 1 was to determine nursing calf forage intake over time until weaning. Trial 1 used 8 crossbred cow-calf pairs in experiment 1 and 12 pairs in experiment 2. Pairs were separated into two groups rotating between grazing upland range or housed in individual pens …

Model Development For The Prediction Of Intake And Carcass Measures To Be Used As Economic Marketing Determinants For Calf-Fed Steers, Mallorie F. Wilken

Department of Animal Science: Dissertations, Theses, and Student Research

Accurate prediction of intake and carcass characteristics can assist in projecting input costs and potential premiums when cattle are sold at optimum finishing so net profit/loss can be anticipated. Currently published DMI prediction equations and dietary NE values are based off of data collected over 50 years ago and have been shown to inaccurately predict intake compared to a prediction equation based of off performance data. Calculating dietary NE values from performance data increased precision and accuracy of prediction. Additionally, prediction accuracy was increased for diets containing ethanol byproducts. Since ethanol byproducts have been shown to have 110 to 140% …