Highlights of FY2004 CSREES Investments in KA305
In fiscal year 2004, CSREES invested approximately $8.6 million in KA305. Below are some of the projects that terminated in 2004. A printable, 2-page color brochure detailing these highlights may also be downloaded.
A printable, 2-page color brochure detailing these highlights is also available.
Novel Gene Identified in Skeletal Muscle Growth: Scientists at Purdue University identified a novel gene (Asb-15) in muscle that is downregulated after administration of beta agonists. Although Asb-15 did not affect proliferating myoblasts, Asb-15 stimulated differentiation of myoblasts into myotubes. These findings are the first to show a direct association between the novel gene, Asb-15, and skeletal muscle growth. (NRI)
Altered Gene Expression During Intestinal Repair: Colic results in annual losses of ~$177 million in the $25.3 billion US equine industry Scientists at North Carolina State University have shown that cyclooxygenase isoforms are critical to intestinal repair following colic-related ischemic injury and that neutrophils augment the repair process by enhancing COX-2 expression. In addition, they identified ~80 genes that are either increased or decreased in recovering mucosa. (NRI)
TGF Regulates Mammary Development: Researchers at the University of Vermont demonstrated that changes in the amounts of transforming growth factor TGF-alpha and TGF-beta caused different rates of mammary epithelial and/or stromal cell growth and death as well as changes in gene expression and protein production. TGF-beta-1 also stimulated development of the bovine mammary gland by providing a matrix for epithelial cells to grow in after stimulation of the stroma during prepubertal development. Thus, TGF-beta could play a critical role in regulating milk production. (Hatch)
Glucagon Prevents Fatty Liver Disease: Up to 50% of US dairy cows may have mild to pathological fatty liver disease during early lactation, resulting in millions of dollars in losses due to treatment and lost milk production. Currently, fatty liver can neither be prevented consistently nor treated effectively. Scientists at Iowa State University demonstrated that glucagons, when administered on the day of, and for 14 days after, calving prevented fatty liver disease. The prevention involves a decrease in fatty acid mobilization from adipose tissue and an increase in glucose availability via gluconeogenesis. Administration of glucagons to periparturient dairy cows should improve dairy cow health and producer profitability. (NRI)
ACTH Stimulates GH in Chick Embryos: Scientists at the University of Maryland studied the mechanisms that control differentiation of the cells that secrete growth hormone (GH) during embryonic development. Their results demonstrate that administration of chicken adrenocorticotropin (ACTH) induces production of GH prematurely during chicken embryonic development. More than 350 genes in the chick embryonic pituitary gland were regulated by glucocorticoid. This information is being used to identify genetic markers to select genetically superior breeding broilers with improved growth and feed efficiency traits. (NRI)
Transcription Factors Control Muscle Fibers: Understanding the mechanisms responsible for the formation of diverse muscle types in the early embryonic chicken may lead to methods to control the amount of white or red meat in poultry. Investigators at Stanford University showed that fibroblast growth factor-8 (FGF-8) regulates myogenesis and chondrogenesis and is controlled by the transcription factor, sonic hedgehog . Pax-7 is another transcription factor that is expressed from early embryonic day 5 through adult and is a marker of commitment to the myogenic lineage. Understanding the mechanisms that alter the type and growth of muscle fibers could provide a genetic basis for control of poultry meat quality and quantity. (NRI)
Biomarkers for Avian Medullary Bone Metabolism: Eggshell breakage and bone fragility represent a multi-million dollar loss to the US poultry industry. The industry has tools to maximize dietary calcium utilization; however, there are no non-invasive tools to evaluate medullary bone metabolism. Researchers at Pennsylvania State University have shown that medullary bone has higher proteoglycan content than cortical bone and that keratin sulfate concentration in blood reflects medullary bone formation rather than degradation. Additional bone matrix proteins have been identified in the plasma of laying hens and further studies will determine if these proteins can be used as biomarkers for avian medullary bone metabolism. (Hatch)
Synthesis of Milk Proteins from Sows: Scientists at the University of Illinois conducted in vitro studies to characterize the utilization of substrates by sow mammary tissue. Only ~30% of proteins synthesized in vitro by lactating porcine mammary tissue were milk-specific proteins. The major milk-specific proteins (alpha-lactalbumin and beta-lactoglobulin) were readily synthesized and secreted by porcine mammary tissue in culture, but the caseins were secreted at a lower than expected rate. (Hatch)
Improved Nutritional Recommendations for Dairy Cows: Scientists at Cornell University have shown that increasing the supply of absorbable choline to periparturient cows decreased the rate of triglyceride accumulation in liver and increased milk yield. Feeding trans-10, cis-12 conjugated linoleic acid decreased milk fat synthesis; however, cows increased milk yield in response to reduced milk fat synthesis. Peripartum chromium supplementation increased dry matter intake and milk yield during the immediate postpartum period. Research and outreach efforts conducted by these scientists have improved the nutritional recommendations for periparturient dairy cows, impacting more than 75% of US dairy cows. (Hatch)
Stair-Step Nutrition Enhances Lactation: Research conducted at North Dakota State University showed that the stair-step compensatory nutrition regimen (a unique combination of dietary energy restriction and refeeding) has lasting effects on mammary development, differentiation, and lactation. This permanent enhancement of mammary gland growth and lactation potential suggests a link between nutritionally-induced compensatory growth, epigenetic control of mammary gene expression, and metabolic imprinting. The ability to influence heritable genes that regulate milk synthesis may be used to improve milk quality and quantity and lactation longevity. (Hatch)
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