4,770 research outputs found

    Study of the impact of breeding seasons in the dynamics of dairy goat herds.

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    Abstract: The competitiveness in the animal production field has forced the smaller activities to be more efficient when compared to big business of the agro-industries. The dairy goat production is one of those market niches that need a better understand of its sector. For those reasons it has been proposed that by changing the number of reproduction seasons would increase income of the producers. The objectives of this study were to evaluate the impact of 1 or 2 annual reproductive cycles on production and economical health of dairy goats and to identify differences of production costs and revenues associated with changes in the herd dynamics as predicted by a mathematical model. A previously developed goat model using the System Dynamics approach to study long-term changes in the dynamics of the herd was used in these simulations. The model simulations used feeds, labor, and fixed costs as inputs and the outputs were revenues from milk production sales and sales of animals from all categories of the herd. The simulation time unit was ?month? and a long-term horizon of 10 years was considered for these simulations. The model was set up to simulate a freestall facility of a herd in equilibrium with 100 does in lactation. All parameters considered in this model assumed average values reported in production systems in the Southeast region of Brazil. The simulations results indicated that improvements of 10% in the fertility rate would increase the number animals in the herd up to 185% and 35% for one and two breeding season, respectively. Establishing a milk price as US0.68thebreakevenforoneandtwobreedingseasonswasrespectivelyUS0.68 the break even for one and two breeding seasons was respectively US0.62, and US$0.50, giving the systems with two breeding a capacity to support reductions on milk price up to 26% against 9% with one breeding season. When comparing the models with 1 or 2 breeding seasons was found that models with 2 breeding seasons was considerably more profitable and had a higher turnover than the model with 1 breeding season. The results indicate that the use of a second (artificial) breeding season might be an important management strategy to improve the efficiency of the dairy goat production systems. [Estudio del impacto de la estación reproductiva sobre la dinâmica de los rebaños lecheros]

    A dairy goat model to study the impacts on herd dynamics.

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    The understanding of a dairy goat production system is crucial to establish a more competitive activity. Therefore, a simulation model was built to evaluate the dynamics of dairy goat herd under different scenarios of production. A System Dynamics approach was used to identify management policies that affect the behavior of the herd. All parameters considered in this model assumed average values reported in production systems in the Southeast region of Brazil. To simulate a herd in dynamic equilibrium, the culling and retention rates were used. Thereafter, simulations were performed based on changes in reproductive and mortality rates. All the simulations were planned to take the variation in herd development based on simple management strategies over 10 years of simulation. The dynamic equilibrium of 50 lactating does was obtained when fixed culling and retention rates of 20 and 70%, respectively, were assigned to the does after 36 months of simulation. A sensitivity analysis was made and indicated that an increase of 20% in the reproduction rates increased the number of animals in the herd in 56%. A decrease in the reproduction rate of 20% reduced the number of animals in 43%. A third simulation indicated that increasing mortality rate from 4 to 10% of the female kids decreased the number of lactating does by 36%. These results indicated that small changes in reproduction and mortality rates can considerably affect the dynamics of the herd, even though the herd may not be immediately affected because of the intrinsic delays in the system. This result is extremely important to justify the need of activity planning to consider the gap between a measurement taken and the consequences, preparing the producers to potential delays in the system. The use of mathematical models is important to understand the relationships between variables and the dynamic of the system and to assist in applying best management strategies to enhance productivity of dairy goats. [Modelo de cabras lecheras para evaluar el impacto de las estrategias de manejo en la dinámica del rebaño]

    A Pair Polarimeter for Linearly Polarized High Energy Photons

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    A high quality beam of linearly polarized photons of several GeV will become available with the coherent bremsstrahlung technique at JLab. We have developed a polarimeter which requires about two meters of the beam line, has an analyzing power of 20% and an efficiency of 0.02%. The layout and first results of a polarimeter test on the laser back-scattering photon beam at SPring-8/LEPS are presented

    Nutritional Quality of Meat Analogues: Results From the Food Labelling of Italian Products (FLIP) Project

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    Nowadays, the interest in meat substitutes is increasing, and consumers perceive their nutritional quality better than that of the animal products they intend to resemble. Therefore, this work aimed to investigate the overall nutritional quality of these new products. Regulated information [Regulation (EU) 1169/2011], the presence/absence of nutrition or health claim and organic declarations, the gluten-free indication, and the number of ingredients were collected from the food labels of 269 commercial meat analogues currently sold on the Italian market. Nutritional information of reference animal meat products was used to compare the nutrition profile. As an indicator of the nutritional quality, the Nutri-Score of meat analogues and counterparts was also determined. Plant-based steaks showed significantly higher protein, lower energy, fats and salt contents, and better Nutri-Scores than the other analogues. All the meat analogues showed a higher fibre content than meat products, while plant-based burgers and meatballs had lower protein contents than meat counterparts. Ready-sliced meat analogues showed a lower salt content than cured meats. Overall, all these plant-based products showed a longer list of ingredients than animal meat products. Results from this survey highlighted that plant-based steaks, cutlets, and cured meats have some favourable nutritional aspects compared to animal-based products. However, they cannot be considered a “tout-court” alternative to meat products from a nutritional point of view

    Thermally-induced lactosylation of whey proteins: Identification and synthesis of lactosylated β-lactoglobulin epitope

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    The high temperatures used in the production of milk may induce modifications in proteins structure. Due to occurrence of the Maillard reaction, lactose binds lysine residues in proteins, affecting the nutritional value. Milk is also an important source of allergenic proteins (i.e., caseins, β-lactoglobulin and α-lactalbumin). Thus, this modification may also affect the allergenicity of these proteins. Focusing on milk whey proteins, a screening on different Ultra High Temperatures (UHT) and pasteurized milk samples was performed to identify lactosylation sites, in particular in protein known epitopes, and to verify the correlation between lactosylation and the harshness of the treatment. Whey proteins were extracted from milk samples after caseins precipitations at pH 4.6 and, after chymotryptic and tryptic in solution digestion, peptides were analysed by UPLC-MS and LTQ-Orbitrap. Results show the presence of lactosylated lysine residues in several known epitopes. Then, a β-lactoglobulin epitope was selected and synthesized by solid phase synthesis followed by in solution lactosylation, obtaining high reaction yields and purities. The synthesis of lactosylated allergenic epitopes, described here for the first time, is a useful tool for further studies on the technological impacts on food allergenicity

    The multifaceted nature of aminopeptidases ERAP1, ERAP2, and LNPEP: from evolution to disease

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    In the human genome, the aminopeptidases ERAP1, ERAP2 and LNPEP lie contiguously on chromosome 5. They share sequence homology, functions and associations with immune-mediated diseases. By analyzing their multifaceted activities as well as their expression in the zoological scale, we suggest here that the progenitor of the three aminopeptidases might be LNPEP from which the other two aminopeptidases could have derived by gene duplications. We also propose that their functions are partially redundant. More precisely, the evolutionary story of the three aminopeptidases might have been dictated by their role in regulating the renin–angiotensin system, which requires their controlled and coordinated expression. This hypothesis is supported by the many species that lack one or the other gene as well as by the lack of ERAP2 in rodents and a null expression in 25% of humans. Finally, we speculate that their role in antigen presentation has been acquired later on during evolution. They have therefore been diversified between those residing in the ER, ERAP1 and ERAP2, whose role is to refine the MHC-I peptidomes, and LNPEP, mostly present in the endosomal vesicles where it can contribute to antigen cross-presentation or move to the cell membrane as receptor for angiotensin IV. Their association with autoinflammatory/autoimmune diseases can therefore be two-fold: as “contributors” to the shaping of the immune-peptidomes as well as to the regulation of the vascular response

    Make Bow-tie Dynamic by Rethinking it as a Hierarchical Bayesian Network. Dynamic Risk Assessment of an LNG Bunkering Operation

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    In the present era, the spread of cyber-physical systems in the framework of the so-called Industry 4.0, is leading towards a complete automation of industrial processes, which are increasingly decentralized, smart, and require fewer and fewer frontline personnel. The risk assessment process is certainly not excluded from the revolution, and in perspective needs to be automatic, dynamic and linked with the conditions that emerge, moment by moment, in the life of a complex system. Analytical techniques can help in converting data in information and hence system knowledge to spot trends in operational performance, thus improving risk assessment quality. Even though the bow-tie approach is widely used within the context of complex systems, it still evidences several limitations, mainly connected to the actual assessment of likelihood and interdependencies in the fault and event trees. This paper shows how a bow tie analysis can be reframed as a Hierarchical Bayesian Network, where the probability distributions of the network nodes are updated with real time predictions during the operations. The proposed model was then applied to the risk assessment of a shore-to-ship LNG bunkering operation

    Ultrasound and Microwave-assisted Extraction of Proteins from Coffee Green Beans: Effects of Process Variables on the Protein Integrity

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    The demand for proteins is constantly increasing and green extraction methodologies are needed to achieve environmental sustainability goals. The recovery of the by-products of the agri-food chain has also become a priority from a circular economy perspective. Some by-products are still little exploited for the extraction of proteins, such as coffee by-products. In this work, various innovative extraction technologies were applied to recover the protein fraction from the non-compliant coffee green beans (CGB), using a methodological approach that allowed to correlate the process parameters with the final quality of the extracted proteins. The ultrasound-assisted extraction (UAE) technique has been shown to have a minor impact on the quality of the proteins, thanks to the possibility of refrigerating the system, while the microwave-assisted extraction (MAE) shows a certain degree of degradation due to the high temperatures reached. The results indicate that strict temperature control is required during alkaline extraction to preserve the quality of the protein fraction

    Characterization of defatted products obtained from the Parmigiano–Reggiano manufacturing chain: Determination of peptides and amino acids content and study of the digestibility and bioactive properties

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    Parmigiano–Reggiano (PR) is a worldwide known Italian, long ripened, hard cheese. Its inclusion in the list of cheeses bearing the protected designation of origin (PDO, EU regulation 510/2006) poses restrictions to its geographic area of production and its technological characteristics. To innovate the Parmigiano–Reggiano (PR) cheese manufacturing chain from the health and nutritional point of view, the output of defatted PR is addressed. Two defatting procedures (Soxhlet, and supercritical CO2 extraction) were tested, and the obtained products were compared in the composition of their nitrogen fraction, responsible for their nutritional, organoleptic, and bioactive functions. Free amino acids were quantified, and other nitrogen compounds (peptides, proteins, and non-proteolytic aminoacyl derivatives) were identified in the extracts and the mixtures obtained after simulated gastrointestinal digestion. Moreover, antioxidant and angiotensin converting enzyme (ACE) inhibition capacities of the digests were tested. Results obtained from the molecular and biofunctional characterization of the nitrogen fraction, show that both the defatted products keep the same nutritional properties of the whole cheese
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