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1.
Front Vet Sci ; 8: 587168, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34179151

RESUMO

One of the main production challenges associated with climate change is the reduction of carbon emissions. Increasing the efficiency of resource utilization is one way to achieve this purpose. The modification of production systems through improved reproductive, genetic, feed, and grazing management practices has been proposed to increase technical-economic efficiency, even though the "environmental viability" of these modifications has not always been evaluated. The objective of this study was to evaluate the use of feeding and management strategies on the carbon footprint (CF) and economic variables in the traditional cow-calf system in southern Chile using a simulation model. The modifications evaluated corresponded to combinations of stocking rate, use of creep feeding practices with different supplementation levels, and the incorporation of feed additives to the supplement, using factorial experiments. Additionally, the scenarios were evaluated with and without carbon sequestration. The CF for the baseline scenarios was 12.5 ± 0.3 kg of CO2-eq/kg of live weight (LW) when carbon sequestration was considered and 13.0 ± 0.4 kg of CO2-eq/kg of LW in the opposite case. Changes in stocking rate, supplementation level, and consideration of carbon sequestration in pasture and soil had a significant effect on the CF in all simulated scenarios. The inclusion of additives in the supplement did not have a significant effect on production costs. With regard to reducing greenhouse gas (GHG) emissions, incorporating canola oil presented the best average results. The model developed made the selection of environmentally viable feed strategies or management adaptations possible.

2.
Braz. j. microbiol ; 47(3): 640-646, July-Sept. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-788973

RESUMO

ABSTRACT Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7 g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively.


Assuntos
Ácido Láctico/biossíntese , Lacticaseibacillus rhamnosus/metabolismo , Resíduos Industriais , Temperatura , Biodegradação Ambiental , Biotransformação , Adsorção , Fermentação , Técnicas de Cultura Celular por Lotes , Concentração de Íons de Hidrogênio
3.
Braz J Microbiol ; 47(3): 640-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27266630

RESUMO

Lactic acid, which can be obtained through fermentation, is an interesting compound because it can be utilized in different fields, such as in the food, pharmaceutical and chemical industries as a bio-based molecule for bio-refinery. In addition, lactic acid has recently gained more interest due to the possibility of manufacturing poly(lactic acid), a green polymer that can replace petroleum-derived plastics and be applied in medicine for the regeneration of tissues and in sutures, repairs and implants. One of the great advantages of fermentation is the possibility of using agribusiness wastes to obtain optically pure lactic acid. The conventional batch process of fermentation has some disadvantages such as inhibition by the substrate or the final product. To avoid these problems, this study was focused on improving the production of lactic acid through different feeding strategies using whey, a residue of agribusiness. The downstream process is a significant bottleneck because cost-effective methods of producing high-purity lactic acid are lacking. Thus, the investigation of different methods for the purification of lactic acid was one of the aims of this work. The pH-stat strategy showed the maximum production of lactic acid of 143.7g/L. Following purification of the lactic acid sample, recovery of reducing sugars and protein and color removal were 0.28%, 100% and 100%, respectively.


Assuntos
Resíduos Industriais , Ácido Láctico/biossíntese , Lacticaseibacillus rhamnosus/metabolismo , Adsorção , Técnicas de Cultura Celular por Lotes , Biodegradação Ambiental , Biotransformação , Fermentação , Concentração de Íons de Hidrogênio , Temperatura
4.
Ciênc. rural ; 40(12): 2555-2561, dez. 2010. ilus, tab
Artigo em Português | LILACS | ID: lil-570593

RESUMO

O comportamento ingestivo e os padrões de deslocamento e procura de forragem de cordeiras em pastagem de milheto (Pennisetum glaucum (L.)) foram avaliados quando estas foram mantidas exclusivamente em pastagem ou em pastagem recebendo suplemento (ração comercial fornecida diariamente às 17h. O delineamento experimental foi inteiramente casualizado, com duas repetições de área. Os animais que receberam suplemento reduziram o tempo de pastejo e aumentaram o tempo destinado às outras atividades. Os padrões de ingestão, deslocamento e procura de forragem foram alterados pelas mudanças na estrutura do pasto ao longo dos estádios de desenvolvimento do milheto e não foram modificados pelo recebimento de suplemento.


The ingestive behavior and displacement and forage searching patterns of female lambs in Pearl millet (Pennisetum glaucum (L.)) were evaluated when lambs were kept exclusively on Pearl millet pasture and on pearl millet pasture receiving supplement. The supplement used was a commercial ration given daily at 17h. The experimental design was completely randomized, with two area replicates. The animals that received supplement reduced the grazing time and increased the idling time. The intake, displacement and forage searching patterns were influenced by changing on pasture structure along the Pearl millet stage of development and were not modified by supplement supply.

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