Browsing by Subject "Livestock"

Now showing 1 - 7 of 7
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    Biofilter design information
    (2020) Schmidt, David; Jacobson, Larry; Nicolai, David
    Odor emissions from livestock and poultry facilities are a source of contention in many areas of Minnesota and across the United States. Under certain conditions odor emissions have been known to affect neighbors and communities at distances of a mile or more from the odor source. One odor control technology that has been shown to be both economical and effective is a biofilter. Biofiltration can reduce odor and hydrogen sulfide emissions from livestock and poultry facilities by as much as 95% and ammonia by 65%. This method of odor control has been used in industry for many years and was recently adapted for use in livestock and poultry systems. Biofilters are most easily adapted to mechanically ventilated buildings or on the pit fans of naturally ventilated buildings. Biofilters can also treat air vented from covered manure storage covers.
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    Evaluating on-farm sampling strategies and corresponding gas emission estimation methods for livestock and poultry barns
    (2022-08) Soriano, Noelle Cielito
    The need for gas emission research is driven by multiple stakeholders to address avariety of concerns and priorities that stem from environmental, human, and animal impacts of gas emissions from barns. In this work, I first provide background on the mechanism of gas emission from these systems and an overview of emission estimation strategies in the literature. This is followed by a presentation of two thesis projects, which demonstrate outcomes and challenges related to different emission estimation strategies. In the first project, I investigate airflow patterns and estimate ammonia (NH3) and carbon dioxide (CO2) emissions using a multi-airspace model for a naturally ventilated deep-pit cattle barn, with discrete gas concentration data. The second project uses a mass balance approach to estimate volatile solids (VS) losses and NH3 emissions from a naturally ventilated poultry barn based on material flows in and out of a barn. Each estimation strategy is evaluated based on the practicality of the sampling approach in specific housing styles, and whether emission estimates are comparable to current emission estimation methods for each system. Findings from these two projects show that, ultimately, there will always be limitations to the various available emission estimation strategies, particularly related to in-barn sample collection. Understanding the appropriate application of each of these approaches is important when selecting an emission estimation approach that will allow researchers to obtain representative emission estimates from a variety of livestock and poultry systems.
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    Genome engineering in large animals for agricultural and biomedical applications
    (2013-08) Tan, Wenfang
    Precision genetics will enhance genome-based improvement of livestock for agriculture and biomedicine. This thesis aimed to modify large animal genomes with precision; as the technologies progressed, our capability expanded from random insertional transgenesis to nucleotide-level precision. It began with Sleeping Beauty (SB) transposon mediated rapid integration of dominant negative Myostatin alleles. All piglets generated from treated cells harbored the transgenes; however, we were unable to study phenotypes due to death of the founder animals. We then sought to introgress a SNP into porcine Myostatin through recombinant Adeno-associated Virus (rAAV) mediated gene targeting. We achieved a 2x10-4 targeting frequency but only one-half of the targeted colonies harbored the SNP. Similarly, we succeeded in porcine LDLR gene knockout; however, targeted clones were often confounded by "bystander" cells with only random insertions of the targeting vector. We turned to develop TALENs for efficient targeting of important genes. TALENs demonstrated high activity in both cultured primary fibroblasts and early stage embryos. A simple SB transposon based co-selection strategy enabled enrichment for TALEN modified cells and efficient isolation of modified clones: single gene mono- and bi-allelic modification was induced in up to 54% and 17% of colonies respectively. It also enabled isolation of colonies harboring large chromosomal deletions (10% of colonies) and inversions (4%) after treatment with two TALEN pairs. We derived miniature swine models of familial hypercholesterolemia from LDLR mono- and bi-allelic TALEN-knockout fibroblasts. We next utilized TALEN and CRISPR/Cas9 stimulated homology-directed repair (HDR) to edit genes with oligonucleotide, plasmid, and rAAV templates without any drug selection. We first introgressed a bovine POLLED allele into horned dairy bull fibroblasts to circumvent manual dehorning. We also introduced single-nucleotide alterations or small indels into 14 additional genes in pig, cattle and sheep, into 10-50% of cells from fibroblast populations treated with TALEN mRNA and oligonucleotides. Up to 67% of propagated colonies harbored the intended edits and over one-half were homozygous. Some edits were naturally occurring SNP alleles, equivalent to non-meiotic inter- or intra-species introgression of valuable alleles. We created pig models for infertility and colon cancer from colonies with TALEN-HDR knockout alleles in DAZL and APC.
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    The Impact of Diet Preference on Agricultural Productivity and the Environment
    (2013-11) Cassidy, Emily
    Worldwide demand for crops is increasing rapidly due to global population growth, increased biofuel production, and changing dietary preferences. Meeting these growing demands will be a substantial challenge that will tax the capability of our food system and prompt calls to dramatically boost global crop production. However, to increase food availability, we may also consider how the world's crops are allocated to different uses and whether it is possible to feed more people with current levels of crop production. Of particular interest are the uses of crops as animal feed and as biofuel feedstocks. We find that, given the current mix of crop uses, growing food exclusively for direct human consumption could, in principle, increase available food calories by as much as 70%, which could feed an additional 4 billion people (more than the projected 2-3 billion people arriving through population growth). Even small shifts in our allocation of crops to animal feed and biofuels could significantly increase global food availability, and could be an instrumental tool in meeting the challenges of ensuring global food security. We also illustrate how shifting even slightly away from beef and pork can reduce environmental impact by reducing the water footprints and greenhouse gas emissions associated with diets.
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    Source, Fall-Winter 2014
    (University of Minnesota Extension, 2014) University of Minnesota Extension
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    Source, Spring 2012
    (University of Minnesota Extension, 2012) University of Minnesota Extension
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    Source, Winter 2016
    (University of Minnesota Extension, 2016) University of Minnesota Extension