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1.
J Environ Manage ; 147: 236-45, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25231026

RESUMO

Rangeland-based livestock systems have to deal with the significant instability and uncertainty of the agricultural context (policy changes, volatility of input prices, etc.), and especially of the climatic context. Thus, they are particularly concerned by adaptive management strategies. To support the development of such strategies, we developed a board game including a computer model called "Rangeland Rummy". It is to be used by groups of farmers and agricultural consultants in the context of short workshops (about 3 h). Rangeland Rummy builds upon five types of material object: (i) a game board; (ii) a calendar stick indicating the starting date of the game board; (iii) sticks marked with the feed resources available for combinations of vegetation types and their management practices; (iv) cards to define animal groups and their feeding requirements throughout the year; (v) cards related to types of feed that can be attributed to animal groups throughout the year. Using these material objects, farmers collectively design a rangeland-based livestock system. This system is immediately evaluated using a computer model, i.e. a spreadsheet providing graphs and indicators providing information on, among other things, the extent to which quantitative and qualitative animal feeding requirements are covered across the year. Playing the game thus consists in collectively and iteratively designing and evaluating rangeland-based livestock systems, while confronting the players with new contextual challenges (e.g. interannual variability of weather, volatility of input prices) or new farmers' objectives (e.g. being self-sufficient for animal feeding). An example of application of Rangeland Rummy with 3 farmers in southern France is reported. Applications show that it tends to develop farmers' adaptive capacity by stimulating their discussions and the exchange of locally-relevant knowledge on management strategies and practices in rangeland-based livestock systems.


Assuntos
Agricultura/economia , Agricultura/organização & administração , Jogos Experimentais , Gado/crescimento & desenvolvimento , Animais , Educação , França , Humanos
2.
Domest Anim Endocrinol ; 46: 37-48, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24188681

RESUMO

Throughout an entire year, 41 Romane ewes reared in an extensive rangeland were used to investigate temporal changes in body reserves (BRs) and profiles of related metabolites and metabolic hormones. Ewes were allocated to homogeneous groups according to BW and BCS and were distributed by parity (primiparous [PRIM], n = 21; multiparous [MULT], n = 20) and litter size (LSi; lambing singletons [SING], n = 21 or TWINS, n = 20). The feeding system was based on rotational grazing of rangeland paddocks and progressive supplementation with hay, silage, and barley at late pregnancy during the winter. Individual BW, BCS, plasma NEFA, ß-hydroxybutyrate (ß-OHB), glucose, insulin, leptin, and triiodothyronine (T3) were monitored at -56, -12, 8, 49, 76, 107, 156, 195, 216, 246, and 301 d relative to lambing. The BR mobilization was observed from late pregnancy to the end of suckling and varied as a function of the ewe energy balance but also because of transitions from fertilized to native rangeland paddocks and by supplementation. Contrarily, BR accretion occurred from weaning, during the dry-off, and until the start of the next pregnancy. Lipolysis was well reflected by NEFA, ß-OHB, and T3 kinetics. Mean BW (but not mean BCS) was affected by parity (MULT > PRIM), whereas both BW and BCS were influenced by LSi (SING > TWINS) but only for MULT. The most drastic BW loss was observed during the mid-suckling period (49 d in milk [DIM]) in all ewes. The lack of effects of LSi in PRIM but not in MULT was also evident in the majority of blood plasma kinetics, which were affected (P < 0.0001) by physiological stage in all ewes. A tendency to ketosis (ß-OHB) was found in ewes nursing TWINS around lambing, irrespective of parity. Glucose concentrations were greater during suckling and dry-off, and a peak (0.96 ± 0.05 g/L) was attained at 156 DIM in MULT nursing TWINS. The highest plasma leptin concentration was observed during the start and the middle of the next pregnancy in MULT (107-216 DIM; 9.6 ± 0.44 ng/mL). In all ewes the physiological stage affected T3, which was affected by LSi just in MULT (from late pregnancy, MULT by SING > MULT by TWINS; 99.91 vs 85.52 ng/dL) and during suckling (111.7 ± 4.18 ng/dL). Lamb BW was affected at birth and weaning by parity (MULT > PRIM) and LSi (SING > TWINS). Overall, temporal changes in BR were directly affected by the transition of physiological states and feeding levels, whereas individual responses were predetermined by parity. In MULT, the reactivity and magnitude of response was influenced by LSi. The whole set of parameters allowed us to detect sensitive and critical periods throughout the entire annual cycle. We thus identified opportunities for improved nutritional management, for example, during physiological states usually underestimated such as early and mid-pregnancy. This work indicates the applicability of long-term studies about BR dynamics in ruminants as a potential component contributing to farm economic resilience.


Assuntos
Metaboloma/fisiologia , Estado Nutricional/fisiologia , Ovinos/metabolismo , Ácido 3-Hidroxibutírico/sangue , Fenômenos Fisiológicos da Nutrição Animal , Animais , Animais Recém-Nascidos , Glicemia/metabolismo , Peso Corporal/fisiologia , Ácidos Graxos não Esterificados/sangue , Feminino , Insulina/sangue , Análise dos Mínimos Quadrados , Leptina/sangue , Gravidez , Distribuição Aleatória , Ovinos/sangue , Tri-Iodotironina/sangue
3.
Animal ; 7(6): 1028-43, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23257276

RESUMO

Agroecology and industrial ecology can be viewed as complementary means for reducing the environmental footprint of animal farming systems: agroecology mainly by stimulating natural processes to reduce inputs, and industrial ecology by closing system loops, thereby reducing demand for raw materials, lowering pollution and saving on waste treatment. Surprisingly, animal farming systems have so far been ignored in most agroecological thinking. On the basis of a study by Altieri, who identified the key ecological processes to be optimized, we propose five principles for the design of sustainable animal production systems: (i) adopting management practices aiming to improve animal health, (ii) decreasing the inputs needed for production, (iii) decreasing pollution by optimizing the metabolic functioning of farming systems, (iv) enhancing diversity within animal production systems to strengthen their resilience and (v) preserving biological diversity in agroecosystems by adapting management practices. We then discuss how these different principles combine to generate environmental, social and economic performance in six animal production systems (ruminants, pigs, rabbits and aquaculture) covering a long gradient of intensification. The two principles concerning economy of inputs and reduction of pollution emerged in nearly all the case studies, a finding that can be explained by the economic and regulatory constraints affecting animal production. Integrated management of animal health was seldom mobilized, as alternatives to chemical drugs have only recently been investigated, and the results are not yet transferable to farming practices. A number of ecological functions and ecosystem services (recycling of nutrients, forage yield, pollination, resistance to weed invasion, etc.) are closely linked to biodiversity, and their persistence depends largely on maintaining biological diversity in agroecosystems. We conclude that the development of such ecology-based alternatives for animal production implies changes in the positions adopted by technicians and extension services, researchers and policymakers. Animal production systems should not only be considered holistically, but also in the diversity of their local and regional conditions. The ability of farmers to make their own decisions on the basis of the close monitoring of system performance is most important to ensure system sustainability.


Assuntos
Criação de Animais Domésticos/métodos , Animais Domésticos/genética , Biodiversidade , Ecologia/métodos , Poluição Ambiental/prevenção & controle , Variação Genética , Modelos Teóricos , Animais , Animais Domésticos/fisiologia , Previsões
4.
Animal ; 4(10): 1746-57, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22445129

RESUMO

In the countries surrounding the Mediterranean basin, most of the semi-natural grazing lands are covered by rangelands. Rangelands can be defined as highly heterogeneous natural vegetation communities with high conservation value, growing in harsh environments (poor soils, unfavourable climatic conditions). In the recent socio-economic context, traditional livestock grazing practices that enabled one to reconcile rangeland preservation and animal production no longer apply, especially because they require labour that has become scarce and costly. The consequence is rangeland degradation, due to underutilization in Southern Europe, and overutilization in Northern Africa. We analysed issues raised by rangeland utilization in livestock farming systems of the Mediterranean basin. Based on a review of the scientific literature about rangeland utilization in this area, we argue that the best way to reconcile animal production and rangeland preservation would be to promote management practices allowing animals to express their adaptative capacities in feeding behaviour and productive response. In order to propose management practices adapted to extensive and simplified systems, we conclude that research efforts should focus on: (i) proposing a functional characterization of vegetation heterogeneity at the scale of the vegetation community, (ii) validating the criteria determining animals' foraging behaviour on Mediterranean rangelands, (iii) developing and using simulation models to test management strategies against seasonal and long-term variability in climatic conditions and (iv) evaluating the potential of modern technologies for improving rangeland utilization.

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