Suchergebnisse

A decision support tool for sheep farming systems (PASTOR-DSS) was developed to investigate trade-offs between economic and environmental objectives on Spanish dairy sheep farms. The tool combines a hierarchical stochastic simulation model at three levels with a multi-objective optimisation procedure based on genetic algorithms. The first level of simulation includes rumen, reproduction and nutrient balance submodels. These three submodels are integrated into an animal model, which constitutes the second level. The third level is the farm, which includes the flock, the feeding and reproductive management, the availability of feeding resources, and the farm economics. The multi-objective genetic algorithm applies to the farm level. The tool was validated for the different levels of simulation, with outputs having an acceptable level of accuracy and representing correctly the links between feeding and reproduction. The tool was used to optimise the Latxa breed farming systems of the Basque Country (Spain). Two farm types were simulated: a COAST farm located in low-altitude Atlantic conditions and longer grazing period, and the INLAND farm located in mountain areas with a shorter grazing period. The optimisation provided a set of optimal solutions with different economic and environmental (N excretion) performances. The optimal solutions increased the financial margin over feed costs in both farms (+24% and+22% for COAST and INLAND, respectively). The final space of solutions showed a clear trade-off between the economic and environmental performance (nitrogen excretion). The difference in the financial margin over feed costs between the solutions could be interpreted as the opportunity cost of greening in policy design, i.e., the payment that farmers should receive to change their farming methods to reduce nitrogen pollution. ; Funding for this research was provided by INIA (RTA2010-00057, RTA2011-01332), as well as by the Department of Economic Development and Competitiveness of the Basque Government.

Context. Improving feed efficiency in livestock production is of great importance to reduce feeding costs. Aims. To examine the relationship between ruminal microbiota and variation in feed efficiency in beef cattle fed concentrate-based diets. Methods. Residual feed intake of 389 fattening bulls, supplied with corn-based concentrate and forage ad libitum, was used to estimate animals' feed efficiency. Faeces and ruminal fluid samples, from 48 bulls chosen at random, were collected to estimate their forage intake and to determine their apparent digestibility, ruminal fermentation and microbiota. Those animals with extreme values of feed efficiency (high-efficiency (HE, n = 12) and low-efficiency (LE, n = 13)) were subjected to further comparisons. Alpha biodiversity was calculated on the basis of the normalised sequence data. Beta diversity was approached through performing a canonical correspondence analysis based on log-transformed sequence data. Genera differential abundance was tested with an ANOVA-like differential expression analysis and genera interactions were determined applying the sparse correlations for compositional data technique. Keyresults.No differences in dry matter intake were found between the two categories of feed efficiency (P = 0.699); however, HE animals had higher apparent digestibility of dry matter (P = 0.002), organic matter (P = 0.003) and crude protein (P = 0.043). The concentration of volatile fatty acids was unaffected by feed efficiency (P = 0.676) but butyrate proportion increased with time in LE animals (P = 0.047). Ruminal microbiota was different between HE and LE animals (P = 0.022); both a biodiversity and genera network connectance increased with time in LE bulls (P = 0.005 for Shannon index and P = 0.020 for Simpson index), which suggests that LE animals hosted a more robust ruminal microbiota. Certain genera usually related to high energy loss through methane production were found to establish more connections with other genera in LE animals' rumen than in HE ones. Microbiota function capability suggested that methane metabolism was decreased in HE finishing bulls. Conclusions. Rumen microbiota was associated with feed efficiency phenotypes in fattening bulls fed concentrate-based diets. Implications. The possible trade-off between feed efficiency and robustness of ruminal microbiota should be taken into account for the optimisation of cattle production, especially in systems with intrinsic characteristics that may constitute a disturbance to rumen microbial community. ; This study is a part of GenTORE project and received funding from the European Union H2020 program under grant agreement nº 727213 and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (RTA-14-038-C02). S. Costa-Roura is recipient of a research training grant from Spanish Ministry of Science and Innovation (FPU 2016/03761). A. R. Seradj contract is financed by GenTORE project.

This experiment evaluated the effects of subnutrition during early gestation on hematology in cows (Bos Taurus) and on hematological, metabolic, endocrine, and vitality parameters in their calves. Parda de Montaña and Pirenaica dams were inseminated and assigned to either a control (CONTROL, 100% requirements) or a nutrient‐restricted group (SUBNUT, 65%) during the first third of gestation. Dam blood samples were collected on days 20 and 253 of gestation, and calf samples were obtained during the first days of life. Pirenaica dams presented higher red series parameters than Parda de Montaña dams, both in the first and the last months of gestation. During early pregnancy, granulocyte numbers and mean corpuscular hemoglobin were lower in Pirenaica‐SUBNUT than in Pirenaica‐CONTROL cows. Calves from the SUBNUT cows did not show a physiological reduction in red series values in early life, suggesting later maturation of the hematopoietic system. Poor maternal nutrition affected calf endocrine parameters. Newborns from dystocic parturitions showed lower NEFA concentrations and weaker vitality responses. In conclusion, maternal nutrition had short‐term effects on cow hematology, Pirenaica cows showing a higher susceptibility to undernutrition; and a long‐term effect on their offspring endocrinology, SUBNUT newborns showing lower levels of IGF‐1 and higher levels of cortisol. ; This work was supported by the Spanish Ministry of Economy and Business and the European Union Regional Development Funds (INIA RTA 2013‐00059‐C02 and INIA RZP 2015‐001) and the Government of Aragon under the Grant Research Group Funds (A14_17R). A. Noya received a PhD grant from INIA‐Government of Aragon.

Reducing feeding costs in suckler beef herds to improve economic returns could have detrimental impacts on fertility. This study sought to determine whether maternal nutrient restriction during early pregnancy affects interferon-stimulated gene (ISG) expression in peripheral blood mononuclear cells during the peri-implantation period in two beef cattle breeds. Relationships were also examined between subnutrition and pregnancy failure defined according to ISG fold changes on Days 18 and 21 and to plasma pregnancy specific protein B (PSPB) concentrations on Day 28 post-artificial insemination (AI). Pirenaica or Parda de Montaña dams were assigned to a control (n = 23) or subnutrition (n = 30) group, receiving 100% or 65% of their estimated nutritional requirements from Day 1 to 82 post-AI, respectively. Treatment did not affect ISG expression or fertility. According to ISG fold changes (chi-square P = .023) or PSPB levels (chi-square P = .04) recorded in the subnutrition group, late embryo loss was more likely than in controls. Positive correlation was detected between Day 28 PSPB concentrations and both Day 18 MX1, MX2 and ISG15 expression, and Day 21 OAS1 expression. OAS1 and MX1 fold changes were found to be the best variables to discriminate pregnancy status. Our findings indicate that maternal nutrient restriction during the first third of pregnancy does not impair embryo signalling yet may increase the risk of pregnancy failure. ; This work was supported by the Spanish Ministry of Economy and Business and the European Union Regional Development Funds (INIA RTA 2013-00059-C02-01/02, Grant Research Group Funds of the Government of Aragon (A14_17R) and INIA RZP 2015-001). A. Noya received a PhD grant from INIA-Government of Aragon.

El futuro de la agricultura, y en particular de la producción animal, es objeto de un intenso debate público y científico que gira alrededor de la sostenibilidad de los sistemas de producción. La sostenibilidad implica la capacidad de autorreproducción de los elementos esenciales —económicos, ambientales y sociales— de una determinada explotación o sector productivo, teniendo en cuenta las relaciones con el entorno socio-económico, cultural, político, de mercado, etc., que es crecientemente determinante y está sometido a cambios constantes y frecuentemente imprevisibles. En este trabajo se presentan dos ejemplos ilustrativos de metodologías aplicadas al análisis sistémico en ganadería de rumiantes en el norte de España. En el primer caso, se aplica el marco de evaluación MESMIS de sostenibilidad y manejo de recursos en sistemas ovinos con diverso grado de intensificación y orientación productiva. Se describe someramente el proceso de recogida de información, elección de puntos críticos e indicadores y valoración de atributos de sostenibilidad en las áreas ambiental, social y económica. En el segundo caso, se describe brevemente el programa de simulación dinámica NODRIZA para rebaños de vacuno de carne y se presentan resultados de evaluación de alternativas de manejo de rebaño y recursos de pastoreo en condiciones de montaña desde diversas perspectivas: técnica, económica, mano de obra y uso de la tierra. ; The future of agriculture and animal production in particular has become a fundamental issue of public and scientific debate. Sustainability of farming systems is placed in the centre of this debate. Sustainability implies the capacity of self-reproduction of any essential component –economic, environmental and social- of a farm, region or industry in relation of its socio-economic, cultural, political, and market environment. This environment is increasingly influential and changes occur frequently and often are unpredictable. In this paper we present two examples illustrating methodologies applied to the systemic analysis of ruminant farming systems in the north of Spain. In the first example, we use the MESM IS framework to assess the sustainability of a number of sheep farms with different degree of intensification and productive orientation. We briefly describe the data collection, the identification of critical points and indicators, and the assessment of sustainability attributes in environmental, social and economic dimensions. In the second example, we present the software NODR IZA for simulation of beef cattle herds and its application to the evaluation of longterm performance of mountain farms under diverse feeding, reproductive and land use management strategies. Trade-offs between production, economics, land use and labour are briefly discussed ; análisis de sistemas ; MESMIS ; programa NODRIZA ; ovino ; vacuno de carne ; España ; systems analysis ; NODRIZA software ; sheep ; beef cattle ; Spain ; Published