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2.
J Anim Sci ; 90(12): 4656-65, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952364

ABSTRACT

Increased animal performance is suggested as one of the most effective mitigation strategies to decrease greenhouse gas (GHG) and ammonia (NH(3)) emissions from livestock production per unit of product produced. Little information exists, however, on the effects of increased animal productivity on the net decrease in emission from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production systems in California that use various management technologies to enhance animal performance. The IFSM is a farm process model that simulates crop growth, feed production, animal performance, and manure production and handling through time to predict the performance, economics, and environmental impacts of production systems. The simulated beef production systems compared were 1) Angus-natural, with no use of growth-enhancing technologies, 2) Angus-implant, with ionophore and growth-promoting implant (e.g., estrogen/trenbolone acetate-based) application, 3) Angus-ß2-adrenergic agonists (BAA; e.g., zilpaterol), with ionophore, growth-promoting implant, and BAA application, 4) Holstein-implant, with growth implant and ionophore application, and 5) Holstein-BAA, with ionophore, growth implant, and BAA use. During the feedlot phase, use of BAA decreased NH(3) emission by 4 to 9 g/kg HCW, resulting in a 7% decrease in NH(3) loss from the full production system. Combined use of ionophore, growth implant, and BAA treatments decreased NH(3) emission from the full production system by 14 g/kg HCW, or 13%. The C footprint of beef was decreased by 2.2 kg carbon dioxide equivalent (CO(2)e)/kg HCW using all the growth-promoting technologies, and the Holstein beef footprint was decreased by 0.5 kg CO(2)e/kg HCW using BAA. Over the full production systems, these decreases were relatively small at 9% and 5% for Angus and Holstein beef, respectively. The growth-promoting technologies we evaluated are a cost-effective way to mitigate GHG and NH(3) emissions, but naturally managed cattle can bring a similar net return to Angus cattle treated with growth-promoting technologies when sold at an 8% greater premium price.


Subject(s)
Ammonia/chemistry , Animal Husbandry/methods , Carbon Footprint , Growth Substances/pharmacology , Meat/economics , Animal Husbandry/economics , Animals , California , Carbon Dioxide/chemistry , Carbon Dioxide/metabolism , Cattle/physiology , Computer Simulation , Greenhouse Effect , Growth Substances/administration & dosage , Growth Substances/economics , Hormones/administration & dosage , Hormones/economics , Hormones/pharmacology , Models, Biological
3.
J Immunol Methods ; 194(2): 191-9, 1996 Aug 14.
Article in English | MEDLINE | ID: mdl-8765172

ABSTRACT

The tryptic meat digest Primatone RL is a low-cost medium supplement of a complex nature which serves as a source of amino acids, oligopeptides, iron salts, some lipids and other trace low molecular weight substances. Its addition to mammalian and insect cell culture media significantly improves the cell growth properties of many cell lines. In this work the growth promoting effects of Primatone RL are described in more detail using different mouse hybridomas, a mouse myeloma cell line, and human promyelocytic leukemia HL-60 cells. The positive effects on cell growth induced by Primatone were observed in the presence of serum but were even more pronounced in serum-free culture. In addition the adaptation time from high serum to low (1%) or serum-free growth in the presence of Primatone is also significantly reduced. Primatone RL, when added to HL and DHI medium, improves cell growth under low serum or serum-free conditions by increasing the maximum cell numbers and in particular the viability of the culture. The observed decrease in cell death (apoptosis) induction leads to a significant improvement in antibody (recombinant protein) production by increasing the volumetric yields during long-term batch culture. The so-called anti-apoptotic effects of Primatone RL for mouse hybridomas, which is concentration dependent, is not fully understood.


Subject(s)
Apoptosis/drug effects , Culture Media, Serum-Free , Cytological Techniques , Growth Substances/pharmacology , Protein Hydrolysates/pharmacology , Animals , Cell Division/drug effects , Cells, Cultured , Cost-Benefit Analysis , Culture Media , Growth Substances/economics , HL-60 Cells/cytology , HL-60 Cells/drug effects , Humans , Hybridomas/cytology , Hybridomas/drug effects , Mice , Multiple Myeloma/pathology , Protein Hydrolysates/economics , Tumor Cells, Cultured/drug effects
4.
JAMA ; 276(7): 531-7, 1996 Aug 21.
Article in English | MEDLINE | ID: mdl-8709401

ABSTRACT

OBJECTIVE: To determine current expert opinion and recommendations regarding the controversial issue of the use of growth hormone (GH) to treat short children who do not have classical GH deficiency (non-GHD children). STUDY DESIGN: Analysis of a national survey mailed to 534 US physician experts on the management of short stature (pediatric endocrinologists) with a response rate of 81.3%. MAIN OUTCOME MEASURE: The experts' GH treatment recommendations. RESULTS: The physicians reported that approximately 58% of their current patients undergoing GH therapy have classical GH deficiency, while 42% have other conditions. The proportion of physicians who recommended GH treatment of short non-GHD children ranged from 1% to 74% over all case scenarios presented. The likelihood of GH being recommended depended on the physiological growth characteristics of the child (ie, the child's height, growth rate, and predicted adult height), contingency factors (ie, strong family wishes or a reduction in GH cost), and physician beliefs (ie, the impact of short stature on well-being, the effectiveness of GH therapy). Each of these factors exerted highly significant, independent, and additive effects on decisions to recommend GH. CONCLUSION: Our results indicate that many pediatric endocrinologists consider GH treatment appropriate for selected short non-GHD children, going beyond current Food and Drug Administration-approved indications for GH. Decisions to recommend GH for a non-GHD child rest on a combination of medical, social, and perceptual factors; variations in treatment patterns stem from variations in these influences. Future GH use will likely be determined not only by the results of controlled trials, but also by family preferences, producer pricing, and physician perceptions of the value of height and GH therapy.


Subject(s)
Body Height , Decision Support Techniques , Growth Substances/therapeutic use , Health , Patient Selection , Practice Patterns, Physicians' , Attitude , Body Image , Child , Drug Utilization/economics , Endocrinology , Growth Substances/economics , Humans , Logistic Models , Multivariate Analysis , Pediatrics , Practice Guidelines as Topic , Practice Patterns, Physicians'/statistics & numerical data , Risk Assessment , Social Values , Surveys and Questionnaires , Uncertainty , United States
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