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Item The Impact of Management Decisions and their Effect on Reproductive Performance of Beef Cattle(North Dakota State University, 2014) Schook, Mellissa ReneeTwo experiments were conducted to evaluate two management decisions made by beef cattle producers and their impacts on reproduction. In experiment 1, growth, attainment of puberty, and pregnancy rates were evaluated in crossbred heifers originating from two different breeding systems: 1) cows only exposed to natural service herd bulls (NS), or 2) cows exposed to ovulation synchronization and fixed-time AI followed by natural-service bulls (TAI, fixed-time artificial insemination). Artificial insemination did not influence growth rate during the development phase, attainment of puberty, or pregnancy rates in heifer progeny. In experiment 2, pregnancy attainment and calving distribution of beef females administered a control saline dose, killed virus, or modified-live pre-breeding vaccine per label recommendations were compared. No differences in pregnancy attainment were observed among the 3 time points measured, d 28, 56, and 90 as well as no differences seen among the calving distribution.Item Biological Abnormalities in the Ruminant Small Intestine and Its Relationship to Carbohydrate Assimilation(North Dakota State University, 2019) Trotta, RonaldSeveral biological abnormalities exist between the ruminant and nonruminant small intestine and influences carbohydrate assimilation. Two experiments were conducted to identify potential mechanisms to improve carbohydrate utilization in cattle. Experiment 1 evaluated the effects of duodenal starch infusions with casein or glutamic acid on post-ruminal carbohydrase activities. Experiment 2 evaluated the effects of dietary fructose on visceral organ development and expression of nutrient transporters and digestive enzymes involved in carbohydrate assimilation. In experiment 1, the results suggest that small intestinal starch digestion may be improved in cattle with increased small intestinal flow of casein through increases in post-ruminal carbohydrase activities. In experiment 2, dietary fructose supply influenced nutrient utilization, visceral organ growth, and digestive enzyme mRNA expression and activity in neonatal calves.Item Estimating the Impacts of Litter Size and Non-Additive Genetic Effects on Ewe Longevity and Stayability in a U.S. Western Extensive Range Production System(North Dakota State University, 2021) Oribamise, Babatunde VictorNon-additive genetic effects are usually ignored in animal breeding programs due to data structure, computational limitations, and over-parameterization of the models. Non-additive genetic effects play an important role in the expression of complex traits in livestock species, such as longevity and stayability. Components of genetic variance for additive and non-additive genetic effects were estimated for longevity and stayability in U.S. Western ewes using pedigree relationship matrices. Litter size were also investigated for direct and maternal effects. For longevity, a larger proportion of phenotypic variance was explained by non-additive genetic effects than by additive effects for model A+D, indicating that including dominance genetic effects are important. Results suggest that inclusion of non-additive genetic effects in animal models is possible in estimating longevity and stayability and will improve selection accuracy and reduce overestimation of additive genetic effects.Item Effects of Linseed Meal on Growth and Reproductive Performance in Ruminants(North Dakota State University, 2011) Ilse, Breanne RoseLinseed meal (LSM) was fed to ovariectomized ewes exposed to estradiol 17-ß (E2) implants over time, and LSM was supplemented to beef cows during late gestation and early lactation to evaluate the estrogenic potential of the phytoestrogen secoisolariciresinol diglycoside (SDG) found in LSM. Forty-eight ovariectomized ewes were fed a diet containing 12.5% LSM for 0, 1, 7, or 14 d and implanted with estradiol-17ß (E2) for 0, 6, or 24 h before tissue collection. Uterine cellular proliferation, vascularity, and the expression of the angiogenic factors and their receptors were recorded. There was an interaction of LSM and E2 on uterine mass (P = 0.05). At 24 h of E2 exposure, proliferation was reduced (P < 0.001) when ewes were fed for 14 d compared to being fed 0 or 1 days. There was a LSM x E2 interaction (P ≤ 0.03) on VEGF receptor-2 (KDR) and hasicfihrohlast growth factor receptor (FGFR2) decreasing by 24 h E2 exposure. Exposure of LSM and E2 may impact the estrogenic response of sensitive tissue. Two studies were conducted to examine the effects of supplementing beef cows with LSM during late gestation or early lactation on calf growth and development. In Experiment 1, multiparous cows received either LSM or a control (CON) supplement (approximately 10% diet dry matter) for the last 60 d of gestation. Offspring weights, ADG, heifer age at puberty, conception percentage and steer carcass characteristics were recorded. In Experiment 2, multiparous cows received LSM or CON supplements (approximately 10% diet dry matter) during the first 60 d of lactation, and only heifer calf development performance was observed and recorded. Heifer calf weight, average daily gain, and attainment of puberty were assessed. For both experiments, birth weight, weaning weight and ADG were not affected (P > 0.31) by LSM supplementation. While final body weights were heavier (P = 0.04) for steer calves in Experiment 1, there was no effect (P = 0.09) of supplementation on carcass characteristics. In Experiment 1 and 2, attainment of puberty in heifer calves was not influenced (P > 0.58) by supplement type. Linseed meal supplementation during late gestation or early lactation does not appear to have a negative impact on calf growth, onset of puberty in heifer calves, or steer carcass quality, implicating that it may make a good supplement choice in cattle.Item Management Considerations for Successful Technology Implementation in Beef Production Systems(North Dakota State University, 2015) Black, Danielle NicoleTwo experiments were conducted to evaluate management strategies that foster successful implementation of technology in beef production systems. In experiment 1, cow reproductive performance, BW, and serum concentrations of NEFA in cows and their calves were evaluated in response to moving cow-calf pairs from summer pastures into confinement feeding for a 10 d period of estrus synchronization and breeding. Reproductive performance was not impacted but calf BW were reduced in confined calves. In experiment 2, effects of moderate and aggressive implant strategies were evaluated in steers with varying genetic potential (GP) for gain and marbling. Steers with greater GP had greater intramuscular fat percentage before consuming high concentrate diets, and improved carcass marbling scores and quality grade compared with low genetic potential steers. Carcass marbling in steers of greater GP for marbling tended to be more sensitive to implant strategy than that of steers with lesser GP.Item Disseminating Agriculture Information using the BBQ Boot Camp Model(North Dakota State University, 2017) Germolus, Austen JohnThe BBQ Boot Camp program was designed to educate consumers about agriculture production and sustainability, while teaching outdoor cooking methods with meat as the focus. Through the BBQ Boot Camp model, consumer impact was analyzed using a pre- and post-program test. The test questions focused on outdoor cooking, agriculture practices, and food safety issues. Data were collected from 3,112 attendees from 31 BBQ Boot Camps in 2009–2013. Data were analyzed using the MIXED procedure in SAS with fixed effects of year, time, age, sex, and city size (1=population>15k; 2=population between 2.5k-15k; and 3=population<2.5k) and all two-way interactions were tested and removed from the model if P>0.1. Consumer demographics included men and women representing five age categories (18-29, 30-39, 40-49, 50-59, and 60+). Data collected provided a unique opportunity to observe factors influencing consumer purchase decisions and the ability to evaluate the effectiveness of this form of extension programming.Item Effects of Nutrient Restriction, Realimentation, and Parity on Umbilical Hemodynamics in the Pregnant Ewe(North Dakota State University, 2016) Vasquez Hidalgo, Manuel AlexanderSheep are normally managed within grazing systems; forage availability and quality are dependent upon seasonal conditions such as drought and humidity. It is therefore important for producers to know when during gestation it is critical to supplement animals with additional feed. Previous research has shown that nutrient restriction during mid-gestation causes a decrease in umbilical blood flow with a possible consequent decrease in fetal body weight and size. Our findings indicate that a decrease in umbilical blood flow upon nutrient restriction during mid-gestation is not solely a consequence of the restriction itself or an additional effect of parity. Moreover, it appears very probable that such a decrease is also an effect of maternal age during pregnancy. In order to address this question further investigation is needed.Item Effect of Maternal Metabolizable Protein Supplementation During Late Gestation on Fetal Visceralorgan Weight with Application of Proteomics to Investigate Skeletal Muscle Development in Sheep(North Dakota State University, 2012) Schwartz, Christina AnneThe experiment investigated supplementation of maternal metabolizable protein in an isocaloric diet during late gestation on fetal organ growth and skeletal muscle development in sheep. Although fetal body weight was unaffected by treatment, visceral organ weights were sensitive to MP treatment as alterations in small intestinal mass and perirenal adipose tissue content suggest impacts on postnatal growth. Two-dimensional gel electrophoresis and mass spectrometry compared the sarcoplasmic and myofibrillar protein fractions of fetal skeletal longissimus muscle, identifying spots from the sarcoplasmic and myofibrillar protein fractions (30 and 12, respectively). Increased expression of fructose-bisphosphate aldolase in fetal muscle from protein-supplemented and protein-restricted ewes when compared to those from control ewes suggests a positive influence on rate of glycolysis and muscle turnover in these offspring. Further research on maternal supplementation with metabolizable protein in isocaloric diets is needed to improve fetal growth efficiency, thereby optimizing offspring performance.Item The Effect of Hemp Byproduct Supplementation on Beef Quality(North Dakota State University, 2022) Gundersen, KierstenThe supplementation of hempseed cake (hemp byproduct) could be considered an alternative protein and fiber source for ruminants such as cattle. Hempseed cake might be a successful alternative feed source due to cattle’s digestive abilities. Yet, the physiological effects caused by cannabinoids in hemp (cannabidiol [CBD] and (-)-Δ9-tetrahydrocannabinaol [THC]) are of concern. However, hemp with much less than 0.3% THC on a dry matter basis can remain a potential alternative feed ingredient. The objective of this study was to evaluate the significance of hempseed cake inclusion in a late finishing ration on carcass characteristics, meat quality characteristics, retail shelf-life, proximate analysis, and fatty acid profile of muscle food obtained from commercial beef heifers.Item The Relationship between Pre-Harvest Stress and Carcass Characteristics and the Ability to Qualify for Kosher on Beef Steers and Heifers(North Dakota State University, 2013) Hayes, Nathan ScottThe objective of this study was to determine if there is a difference in pre-harvest stress and carcass characteristics between kosher and not-qualified-as kosher cattle. Cattle that had a shorter time from gate to exsanguination and a lower vocalization score were more likely to qualify for kosher. Kosher carcasses had a larger REA, a higher WBSF value, tended to have a heavier HCW. At each individual day, kosher steaks had lower L*, a*, and b* values. These data suggest that body composition and stress level may play a factor in the likelihood of a beef animal to qualify for kosher, and there is a defined quality difference between kosher and nonkosher steaks.