Agriculture Commons^™

Feed Value And Utilization Of Corn Residue: Implications For Cow Performance And Grazing Strategies, Kaylee E. Wheeler

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

Two experiments were conducted to determine the correlation of corn residue feed value and utilization on cow performance and potential grazing strategies. A qualitative observation of corn residue grazing by 13 cattle herds across Nebraska was conducted over two years. Based on producer reported grain yields and stocking rates, it was found that these producers were generally not as aggressive as the recommended 1.2 animal unit months (AUM) for each 6,280 kg/ha (100 U.S. bushels/acre) of harvested grain. They stocked 17 to 101% of the recommendation and on average used 63% of the carrying capacity. Across herds, average body condition …

Investigation Of Breeding Objectives And Indexes-In-Retrospect, Hunter F. Valasek

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

This thesis presents two projects that investigate the impacts of breeding objectives and indexes-in-retrospect within the beef cattle industry. The first project synthesized how changes due to planning horizon, breeding system, and sale endpoint in the economic breeding goal of cattle influence the relative emphasis of traits as well as the re-ranking of selection candidates. A total of three breeding systems that represent straightbred and crossbred cattle were used along with six planning horizons (2, 5, 10, 20, 30, and 50 yrs.) for both a weaning and slaughter point of sale. The combination of these different breeding objective attributes resulted …

Supplemental Table 1. Influence Of The Count Of Positive Days On Dmi, Milk Yield, Milk Fat, Milk Protein, And Pregnancy Rate, Addison Carroll, Paul J. Kononoff

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

Response

Intercept

Devstarch

Devfat

DevNDF

DevPro

BIC

Dry-Aged Beef Flavor Development, And The Effect Of High Levels Of Vitamin-E On Beef Color Stability, Nicolas Herrera

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

Palatability and consumer purchasing are essential factors of fresh meat. To meet consumer expectations during purchasing and consumption, fresh beef must maintain desirable cherry-red color at retail and achieve desirable cooked flavor. Dry-aged beef popularity has grown, and identifying methods to ensure quality dry-aged meat is necessary to maintain demand. To understand dry-aged palatability, this dissertation addressed effects of moisture loss and aging time, fundamental factors of dry-aged beef, using bone-in and boneless strip loins. Study two investigated flavor development using cookery methods and internal temperatures in boneless and bone-in dry-aged beef. In study one, increased dry-aging time (creation effect) …

Identification And Assessment Of Lameness In Sows Through The Utilization Of Nutrack And Gaitfour Systems, Lexi M. Ostrand

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

Lameness is a financial concern for producers and a welfare concern for the animals. Utilizing both the GAITFour and NUtrack systems, gilts’ natural tendencies and gait were analyzed to better understand the onset of lameness and what indicators can be identified in a commercial setting. Beginning at 20 weeks of age, video on replacement gilts was collected for 9 consecutive days and processed using the NUtrack System to identify individual gilts’ distance travelled (m), avg speed (m/s), angle rotated (degrees), and time standing (s), sitting (s), eating (s), and laying (s). NUtrack is a deep learning-based multi-object …

Consequences Of Cow-Calf Production With Limited Perennial Forage Grazing, Hannah Speer

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

Conversion of perennial grasslands to cropland and rising land prices prompts a need to evaluate alternative beef cow-calf production systems. A 3-yr study was conducted comparing beef cow-calf performance between two August-calving cow systems: perennial forage and corn residue grazing; or summer drylot, fall grazing of late-summer-planted cover crop, and corn residue grazing. Cow body condition score differed between systems, but condition of cows in both systems never fell below adequate. There were no differences in pregnancy rates between systems. Calf weaning weights differed between systems each year; differences are attributed to feedstuff quantity, quality, and type available to calves …

Impact Of Distillers Removal And Impact Of Lowering Inclusions Of Distillers Grains Plus Solubles And Different Roughage Quality On Finishing Cattle Performance, Sofia Suarez Lorences

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

A feedlot trial (Exp. 1) was conducted to evaluate the impact of removing modified distillers grains plus solubles (MDGS) on performance and carcass characteristics. Cattle with MDGS removed on either d 79 or d 43 had reduced final BW, DMI, and ADG. Cattle with MDGS removed on d 43 were 5% less efficient than cattle fed 20% MDGS throughout the entire 124-d feeding period. Cattle fed 20% MDGS throughout the whole feeding had the greatest HCW and LM area. There were no differences in backfat and marbling scores among treatments, and no differences in percent of abscessed livers. In conclusion, …

Mid-Gestation Maternofetal Inflammation Impacts Growth, Skeletal Muscle Glucose Metabolism, And Inflammatory Tone In The Ovine Fetus During Late Gestation, Zena Hicks

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

Our 1^st and 2^nd studies assessed the impact of mid-gestation maternofetal inflammation on growth, skeletal muscle glucose metabolism, and inflammatory tone in the late gestation ovine fetus. The objective was to determine if inducing maternofetal inflammation during peak placental growth would lead to more profound IUGR characteristics in the fetus. MI-IUGR fetuses exhibited reduced body and skeletal muscle weights and hallmark asymmetric growth at late gestations. Fetuses had higher baseline glucose:insulin ratios and reduced glucose-stimulated insulin secretion. Moreover, hindlimb glucose oxidation was impaired independent of glucose uptake. Skeletal muscle specific glucose uptake and oxidation was reduced in MI-IUGR …

Effect Of Supplementation Prior To Artificial Insemination And During Gestation In Beef Females, Landon Tadich

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

Objectives of Experiment 1 was to evaluate the impact of increased energy prior to AI on BW, ADG, and reproductive efficiency in heifers developed on range or in a dry lot. During the winter development period (131 ± 3.5 d/yr) heifers (n= 100/yr) were assigned to either upland range (RANGE) or fed a dry lot diet in two pens that either remained constant (DLLO) or increased in energy prior to AI (DLHI). Heifers developed on RANGE grazed upland winter range until 38 d prior to AI where they then received the DLLO diet. Pre-breeding BW was greater (P £ …

Winter Hardy Small Cereals For Grazing Or Silage In Eastern Nebraska, Abigail Sartin

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

Two, 3-year studies were conducted to evaluate the value of cereal rye, winter wheat, and winter triticale as forage sources for either for silage or early spring grazing. For silage, the objective was to evaluate species and maturity effects on dry matter yield, nutritive value, and fermentation of small cereal silage. There are no major differences between wheat, rye, or triticale in terms of the relative timing of each species reached each maturity stage. There are no differences among species in dry matter (DM) yield, except for wheat which tends to decline at soft dough due to senescence of the …

Methods To Reduce Nitrogen And Carbon Losses From Finishing Beef Cattle, Hanna Cronk

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

A finishing experiment evaluated the effect of incremental supplemental rumen-protected lysine on beef cattle performance. All cattle were fed the same diet of high moisture corn, dried rolled corn, modified distillers grains plus solubles, corn silage, and supplement with inclusion levels of lysine ranging from 0 to 7 grams/day, in 1 g increments. Dry matter intake (P 0.04) and ADG (P ≤ 0.04) decreased linearly as supplemental lysine increased in the diet with no effect on final carcass adjusted feed efficiency (P ≥ 0.34). In the initial 64 days of the experiment, increasing lysine in the diet …

The Evaluation Of Encapsulated Megasphaera Elsdenii In An Accelerated Beef Step-Up Program And An Acidosis Challenge Model And The Evaluation Of Ramp Versus A Traditional Forage Grain Adaptation Strategy On Methane And Respired Carbon Dioxide, Cindy D. Mansfield

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

A metabolism experiment (Exp 1) was conducted to evaluate daily feeding of encapsulated Megasphaera elsdenii (M. elsdenii) NCIMB 41125 along with a one-time drench of 1×10¹¹ CFU of M. elsdenii on dry matter intake (DMI), in-vitro lactate utilization, volatile fatty acid (VFA), and lactate concentration. Treatments consisted of steers which were fed no M. elsdenii (CONTROL), steers drenched with the commercial dose 1×10¹¹ CFU of M. elsdenii (LactiproNXT) on d 1 of the experiment and received no other M. elsdenii (DRENCH), and steers drenched with a commercial dose of LactiproNXT on d 1 of the experiment …