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1.
J Anim Sci ; 90(12): 4656-65, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22952364

RESUMO

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.


Assuntos
Amônia/química , Criação de Animais Domésticos/métodos , Pegada de Carbono , Substâncias de Crescimento/farmacologia , Carne/economia , Criação de Animais Domésticos/economia , Animais , California , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Bovinos/fisiologia , Simulação por Computador , Efeito Estufa , Substâncias de Crescimento/administração & dosagem , Substâncias de Crescimento/economia , Hormônios/administração & dosagem , Hormônios/economia , Hormônios/farmacologia , Modelos Biológicos
2.
J Immunol Methods ; 194(2): 191-9, 1996 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-8765172

RESUMO

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.


Assuntos
Apoptose/efeitos dos fármacos , Meios de Cultura Livres de Soro , Técnicas Citológicas , Substâncias de Crescimento/farmacologia , Hidrolisados de Proteína/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Análise Custo-Benefício , Meios de Cultura , Substâncias de Crescimento/economia , Células HL-60/citologia , Células HL-60/efeitos dos fármacos , Humanos , Hibridomas/citologia , Hibridomas/efeitos dos fármacos , Camundongos , Mieloma Múltiplo/patologia , Hidrolisados de Proteína/economia , Células Tumorais Cultivadas/efeitos dos fármacos
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