Development and evaluation of a mechanistic model of post-absorptive nitrogen partitioning in lactating goats

[EN] Context. Goats contribute to global warming through emission of nitrous oxide from urine and faeces. To reduce nitrogen (N) excretion, improvements of N efficiency of goats is necessary. Aims. The aim of the present study was to develop and evaluate a dynamic mechanistic research-oriented model that explicitly represents N partition into faeces, urine and milk in dairy goats fed total mixed rations. Methods. Data from five N-balance dairy-goat experiments were used to develop a mechanistic dynamic model of post-absorptive N partition. Various representations considering either mass action or Michaelis-Menten kinetics of N usage for milk were proposed. Key results. The data for faecal and urine N responses were best fit by a straight line; whereas, data for milk N responses were best fit by curvilinear saturating curve. The model with curvilinear saturating curve had more precise parameter estimates, with the predicted N excretion in faeces (15.6 g/day), urine (15.4 g/day) and milk N output (11.7 g/day) being very close to the observed values, namely, 15.31 g N/day in faeces, 18.78 g N/day in urine and 12.24 g N/day in milk. Independent datasets with 12 studies were used to evaluate the model. The model tended to under-predict faecal N outflow at a lower N intake level and urinary N outflow at a higher N intake level, with the lowest mean bias for milk N outflow. Conclusions. The final chosen model was adequate to represent faecal, urinary and milk N outflows in dairy goats. Implications. The model has provided a mechanistic description of N usage, which is useful to frame and test hypotheses of physiological regulation of N use by goats, and focus on a more efficient transfer of dietary N into milk, reducing the N excretion in faeces and urine.This work is supported by a Climate Change Mitigation Project LIFE16/CCM/ES/000088. The authors thank Dr Ranga Appuhamy, Professor Ermias Kebreab and Professor Mark Hanigan for the many helpful recommendations in model definition, building and computer simulation-language implementation.Fernández Martínez, CJ.; Castro, J. (2020). Development and evaluation of a mechanistic model of post-absorptive nitrogen partitioning in lactating goats. Animal Production Science. 60(4):510-523. https://doi.org/10.1071/AN19132510523604Aguilera, J. F., Prieto, C., & FonollÁ, J. (1990). Protein and energy metabolism of lactating Granadina goats. British Journal of Nutrition, 63(2), 165-175. doi:10.1079/bjn19900104Bava, L., Rapetti, L., Crovetto, G. M., Tamburini, A., Sandrucci, A., Galassi, G., & Succi, G. (2001). Effects of a Nonforage Diet on Milk Production, Energy, and Nitrogen Metabolism in Dairy Goats throughout Lactation. Journal of Dairy Science, 84(11), 2450-2459. doi:10.3168/jds.s0022-0302(01)74695-4Brown, D. L., & Taylor, S. J. (1986). Deuterium Oxide Dilution Kinetics to Predict Body Composition in Dairy Goats. Journal of Dairy Science, 69(4), 1151-1155. doi:10.3168/jds.s0022-0302(86)80515-xBrun-Bellut, J., Kelly, J. M., Mathison, G. W., & Christopherson, R. J. (1991). Effect of rumen degradable protein and lactation on nitrogen metabolism in dairy goats. Canadian Journal of Animal Science, 71(4), 1111-1124. doi:10.4141/cjas91-133Criscioni, P., & Fernández, C. (2016). Effect of rice bran as a replacement for oat grain in energy and nitrogen balance, methane emissions, and milk performance of Murciano-Granadina goats. Journal of Dairy Science, 99(1), 280-290. doi:10.3168/jds.2015-9472Criscioni, P., Marti, J. V., Pérez-Baena, I., Palomares, J. L., Larsen, T., & Fernández, C. (2016). Replacement of alfalfa hay ( Medicago sativa ) with maralfalfa hay ( Pennisetum sp.) in diets of lactating dairy goats. Animal Feed Science and Technology, 219, 1-12. doi:10.1016/j.anifeedsci.2016.05.020Dennis, J. E., Gay, D. M., & Walsh, R. E. (1981). An Adaptive Nonlinear Least-Squares Algorithm. ACM Transactions on Mathematical Software, 7(3), 348-368. doi:10.1145/355958.355965Dijkstra, J., Oenema, O., van Groenigen, J. W., Spek, J. W., van Vuuren, A. M., & Bannink, A. (2013). Diet effects on urine composition of cattle and N2O emissions. Animal, 7, 292-302. doi:10.1017/s1751731113000578Doepel, L., Pacheco, D., Kennelly, J. J., Hanigan, M. D., López, I. F., & Lapierre, H. (2004). Milk Protein Synthesis as a Function of Amino Acid Supply. Journal of Dairy Science, 87(5), 1279-1297. doi:10.3168/jds.s0022-0302(04)73278-6Francoise Domngue, B. M., Dellow, D. W., Wilson, P. R., & Barry, T. N. (1991). Nitrogen metabolism, rumen fermentation, and water absorption in red deer, goats, and sheep. New Zealand Journal of Agricultural Research, 34(4), 391-400. doi:10.1080/00288233.1991.10417682DE JESUS DOS SANTOS, E., ALBUQUERQUE PEREIRA, M. L., PEREIRA DE FIGUEIREDO, M., DE OLIVEIRA SILVA, H. G., FERREIRA DA CRUZ, J., OLIVEIRA BARRETO, F., & BORGES SOUSA, L. (2016). Crude protein levels in diets of lactating goats: nitrogen balance, urea excretion and microbial protein synthesis. The Journal of Agricultural Science, 154(6), 1102-1109. doi:10.1017/s0021859616000277Fernández, C., Martí, J. V., Pérez-Baena, I., Palomares, J. L., Ibáñez, C., & Segarra, J. V. (2018). Effect of lemon leaves on energy and C–N balances, methane emission, and milk performance in Murciano-Granadina dairy goats. Journal of Animal Science, 96(4), 1508-1518. doi:10.1093/jas/sky028Fernández, C., Pérez-Baena, I., Marti, J. V., Palomares, J. L., Jorro-Ripoll, J., & Segarra, J. V. (2019). Use of orange leaves as a replacement for alfalfa in energy and nitrogen partitioning, methane emissions and milk performance of murciano-granadina goats. Animal Feed Science and Technology, 247, 103-111. doi:10.1016/j.anifeedsci.2018.11.008Harmeyer, J., & Martens, H. (1980). Aspects of Urea Metabolism in Ruminants with Reference to the Goat. Journal of Dairy Science, 63(10), 1707-1728. doi:10.3168/jds.s0022-0302(80)83132-8Kebreab, E., France, J., Mills, J. A. N., Allison, R., & Dijkstra, J. (2002). A dynamic model of N metabolism in the lactating dairy cow and an assessment of impact of N excretion on the environment1. Journal of Animal Science, 80(1), 248-259. doi:10.2527/2002.801248xLópez, M. C., Estellés, F., Moya, V. J., & Fernández, C. (2014). Use of dry citrus pulp or soybean hulls as a replacement for corn grain in energy and nitrogen partitioning, methane emissions, and milk performance in lactating Murciano-Granadina goats. Journal of Dairy Science, 97(12), 7821-7832. doi:10.3168/jds.2014-8424Malecky, M., Broudiscou, L. P., & Schmidely, P. (2009). Effects of two levels of monoterpene blend on rumen fermentation, terpene and nutrient flows in the duodenum and milk production in dairy goats. Animal Feed Science and Technology, 154(1-2), 24-35. doi:10.1016/j.anifeedsci.2009.07.004Molina-Alcaide, E., Morales-García, E. Y., Martín-García, A. I., Ben Salem, H., Nefzaoui, A., & Sanz-Sampelayo, M. R. (2010). Effects of partial replacement of concentrate with feed blocks on nutrient utilization, microbial N flow, and milk yield and composition in goats. Journal of Dairy Science, 93(5), 2076-2087. doi:10.3168/jds.2009-2628Rapetti, L., Bava, L., Tamburini, A., & Crovetto, G. M. (2005). Feeding behaviour, digestibility, energy balance and productive performance of lactating goats fed forage-based and forage-free diets. Italian Journal of Animal Science, 4(1), 71-83. doi:10.4081/ijas.2005.71Reynolds, C. K., & Kristensen, N. B. (2008). Nitrogen recycling through the gut and the nitrogen economy of ruminants: An asynchronous symbiosis1. Journal of Animal Science, 86(suppl_14), E293-E305. doi:10.2527/jas.2007-0475Romero-Huelva, M., Ramos-Morales, E., & Molina-Alcaide, E. (2012). Nutrient utilization, ruminal fermentation, microbial abundances, and milk yield and composition in dairy goats fed diets including tomato and cucumber waste fruits. Journal of Dairy Science, 95(10), 6015-6026. doi:10.3168/jds.2012-5573Sahlu, T., Goetsch, A. ., Luo, J., Nsahlai, I. ., Moore, J. ., Galyean, M. ., … Johnson, Z. . (2004). Nutrient requirements of goats: developed equations, other considerations and future research to improve them. Small Ruminant Research, 53(3), 191-219. doi:10.1016/j.smallrumres.2004.04.001Saltelli, A., Tarantola, S., & Chan, K. P.-S. (1999). A Quantitative Model-Independent Method for Global Sensitivity Analysis of Model Output. Technometrics, 41(1), 39-56. doi:10.1080/00401706.1999.10485594Santos, A. B., Pereira, M. L. A., Silva, H. G. O., Pedreira, M. S., Carvalho, G. G. P., Ribeiro, L. S. O., … Moreira, J. V. (2014). Nitrogen Metabolism in Lactating Goats Fed with Diets Containing Different Protein Sources. Asian-Australasian Journal of Animal Sciences, 27(5), 658-666. doi:10.5713/ajas.2013.13493Sari, M., Naserian, A. A., & Valizadeh, R. (2009). Effects of abomasal pectin infusion on milk production, digestion and nitrogen utilization pattern of lactating Saanen dairy goats. 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A nutrition mathematical model to account for dietary supply and requirements of energy and other nutrients for domesticated small ruminants: The development and evaluation of the Small Ruminant Nutrition System. Small Ruminant Research, 89(2-3), 174-184. doi:10.1016/j.smallrumres.2009.12.04

Energy balance data from lactating dairy goats offered total mixed diets

[EN] The objective of the study was to develop a univariate model for analyzing energy balance data from lactating goats at mid lactation and determine maintenance requirements and partial efficiencies of energy utilization. Energy balance data from eight studies involving lactating Murciano-Granadina goats fed total mixed diets, which accounted for a variation in metabolizable energy (MEI) intake, milk energy output (EI), and tissue energy balance, were used. The database included records obtained by indirect calorimetry. Data were adjusted with a mixed model that included the study as a random effect. Then, two multivariate linear models were obtained: metabolizable and net energy models. The metabolizable model was MEI=ß0+ß2E1+ß3Tg+ß4T1+¿ and the net energy model was E1=ß0+ß1MEI+ß2Tg+ß3T1+¿; where ß0, ß1, ß2 and ß3 were the parameters, Tg was tissue energy retention and Tl the milk energy derived from body stores. For a better fitted proposed model, net energy for maintenance (NEm) was 283 kJ/kg of Body Weight 0.75 (BW) per day, and the efficiency of utilization of ME for lactation (k1), body weight gain (kg) and body tissue mobilization for milk production (kt) were 62%, 83% and 78%, respectively. Maintenance requirements and partial efficiencies for milk production and tissue energy mobilization were similar to the values proposed by INRA (2018). The increase in the efficiency of utilizing dietary energy for gain, compared with other feeding systems, was partially attributed to the stage of lactation, due to that goats were feeding at mid lactationFernández Martínez, CJ.; Romero Rueda, T. (2019). Energy balance data from lactating dairy goats offered total mixed diets. Open Journal of Animal Sciences (Online). 9(4):385-400. https://doi.org/10.4236/ojas.2019.94031S3854009

Estimación de la producción de metano en caprino lechero y su papel sobre el cambio climático y la sostenibilidad

[EN] La población mundial de cabras produce alrededor del 5 % de las emisiones totales de CH4 del ganado. La producción de metano varía con la nutrición: la alimentación es una de las vías de reducción de las emisiones de CH4 en rumiantes. Además de la calidad de la dieta, existen diversos nutrientes que tienen un efecto directo sobre su producción.Fernández Martínez, CJ. (2021). Estimación de la producción de metano en caprino lechero y su papel sobre el cambio climático y la sostenibilidad. Albéitar. (248):20-22. http://hdl.handle.net/10251/189596202224

La Concha de la Plateria en la catedral de Santiago de Compostela: la estereotomía de las bóvedas cónicas

Título del trabajo presentado: La Concha de la Platería en la Catedral de Santiago de Compostela: la estereotomía de las bóvedas cónicas Entidad organizadora: Sociedad Española de Historia de la Construcción Congreso : Tercer Congreso Nacional de Historia de la Construcció

Caja desmontable para toma de muestras de suelo

Número de publicación: ES1079118 U (26.04.2013) También publicado como: ES1079118 Y (23.07.2013) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) U201201022 (26.10.2012)Caja desmontable para toma de muestras de suelo, caracterizada por incorporar un perfil rectangular abierto (1) donde el perfil queda abierto en toda su longitud mediante una abertura (4). El perfil (1) queda perfectamente acoplado en el interior de un perfil rectangular cerrado (2) que dispone de una pestaña (5) en forma de T en su cara interior, coincidiendo esta pestaña (5) con la abertura (4) del perfil (1). Dos tapas (3) cierran por la parte superior e inferior el conjunto. El perfil (2) presenta dos rebajes (6) que permiten el acceso a la pieza (1) para su desmontaje.Universidad de Almerí

MIRACLE’s hybrid approach to bilingual and monolingual Information Retrieval

The main goal of the bilingual and monolingual participation of the MIRACLE team at CLEF 2004 was testing the effect of combination approaches to information retrieval. The starting point is a set of basic components: stemming, transformation, filtering, generation of n-grams, weighting and relevance feedback. Some of these basic components are used in different combinations and order of application for document indexing and for query processing. Besides this, a second order combination is done, mainly by averaging or by selective combination of the documents retrieved by different approaches for a particular query

Low-cost mobile open-circuit hood system for measuring gas exchange in small ruminants: from manual to automatic recording

Table 2 contained an incorrect footnote. The correct version is supplied at: http://dx.doi.org/10.1017/S0021859615000556[EN] Improvements of a home-made mobile open-circuit respirometry system for the rapid determination of methane (CH4) and carbon dioxide (CO2) production, oxygen (O-2) consumption and, thereafter, heat production (HP) for small ruminants are described and validated. Upgrades consisted of three main features: utilization of a head hood (replacing the previous face mask); use of a computerized control system, data acquisition and recording for gases and air flux (replacing collecting bags for air sampling); and use of a gas cooler to remove the air sample moisture (replacing the chemical drier (silica gel) approach). Calibration factors were established by injecting nitrogen (N-2) and CO2 in the system into the head hood. Repetitive and consistent values for the calibration factor were obtained for O-2 and CO2 which confirmed the absence of leaks and the good performance of the system. In addition, an experimental test with 12 Manchega female dry sheep was conducted to validate the system. Three diets based on cereal grain, fibrous by-products and alfalfa hay (ALH) were used with four sheep per diet. Metabolizable energy intake was close to metabolizable energy for maintenance. Average HP measured by indirect calorimetry (respiratory quotient (RQ) method) was close to the average HP determined from Carbon-Nitrogen balance (CN method) accounting for 443 and 426 kJ/kg(075) body weight (BW) per day, respectively. Fasting HP was determined by the RQ method with two sheep from the ALH diet accounting for 269 kJ/kg(075) BW per day. The head hood and computerized control, data acquisition and recording as well as the gas cooler improved the system by reducing the labour input without loss of functionality for measuring gas exchange and energy metabolism in small ruminantsThis study was supported by INIA Project (ref. no. RTA2011-00107-C02-02).Fernández Martínez, CJ.; López Luján, MDC.; Lachica, M. (2015). Low-cost mobile open-circuit hood system for measuring gas exchange in small ruminants: from manual to automatic recording. Journal of Agricultural Science. 153(7):1302-1309. https://doi.org/10.1017/S0021859615000416S130213091537Tovar-Luna, I., Puchala, R., Sahlu, T., Freetly, H. C., & Goetsch, A. L. (2010). Effects of stage of lactation and dietary concentrate level on energy utilization by Alpine dairy goats. Journal of Dairy Science, 93(10), 4818-4828. doi:10.3168/jds.2010-3315Freetly, H. C., Nienaber, J. A., Leymaster, K. A., & Jenkins, T. G. (1995). Relationships among heat production, body weight, and age in Suffolk and Texel ewes. Journal of Animal Science, 73(4), 1030-1037. doi:10.2527/1995.7341030xJust A. , Fernández J. A. & Jørgensen H. (1982). Nitrogen balance studies and nitrogen retention. In Digestive Physiology in the Pig. 2nd International Seminar Jouy-en-Josas, Versailles, 27–29 October 1982 (Eds J. P. LaPlace , J. Corring & A. Rerat ), pp. 111–122. Paris, France: INRA.Blaxter, K. L. (1967). Techniques in energy metabolism studies and their limitations. Proceedings of the Nutrition Society, 26(1), 86-96. doi:10.1079/pns19670016Fernández, C., López, M. C., & Lachica, M. (2012). Heat production determined by the RQ and CN methods, fasting heat production and effect of the energy intake on substrates oxidation of indigenous Manchega sheep. Animal Feed Science and Technology, 178(1-2), 115-119. doi:10.1016/j.anifeedsci.2012.09.007Lachica, M., & Aguilera, J. F. (2008). Methods to estimate the energy expenditure of goats: From the lab to the field. Small Ruminant Research, 79(2-3), 179-182. doi:10.1016/j.smallrumres.2008.07.016Lachia, M., Aguilera, J. F., & Prieto, L. C. (1997). Energy expenditure related to the act of eating in Granadina goats given diets of different physical form. British Journal of Nutrition, 77(3), 417-426. doi:10.1079/bjn19970042Fernández, C., López, M. C., & Lachica, M. (2012). Description and function of a mobile open-circuit respirometry system to measure gas exchange in small ruminants. Animal Feed Science and Technology, 172(3-4), 242-246. doi:10.1016/j.anifeedsci.2012.01.006Freetly, H. C., Nienaber, J. A., & Brown-Brandl, T. (2002). Relationships among heat production, body weight, and age in Finnsheep and Rambouillet ewes2. Journal of Animal Science, 80(3), 825-832. doi:10.2527/2002.803825xKelly, J. M., Kerrigan, B., Milligan, L. P., & McBride, B. W. (1994). Development of a mobile, open-circuit indirect calorimetry system. Canadian Journal of Animal Science, 74(1), 65-71. doi:10.4141/cjas94-010Christensen, K., Chwalibog, A., Henckel, S., & Thorbek, G. (1988). Heat production in growing pigs calculated according to the RQ and CN methods. Comparative Biochemistry and Physiology Part A: Physiology, 91(3), 463-468. doi:10.1016/0300-9629(88)90619-6YOUNG, B. A., WALKER, V. A., & WHITMORE, W. T. (1988). PROCEDURE FOR MEASURING RESTING AND SUMMIT METABOLISM IN SHEEP AND CALVES. Canadian Journal of Animal Science, 68(1), 173-182. doi:10.4141/cjas88-016Brouwer E. (1965). Report of subcommittee on constraints and factors. In Proceedings of the 3rd Symposium on Energy Metabolism (Ed. K. L. Blaxter ), pp. 441–445. EAAP Publication No. 11. London: Academic Press.Brockway, J. M., Boyne, A. W., & Gordon, J. G. (1971). Simultaneous calibration of gas analyzers and meters. Journal of Applied Physiology, 31(2), 296-297. doi:10.1152/jappl.1971.31.2.296Lachica, M., & Aguilera, J. F. (2005). Energy expenditure of walk in grassland for small ruminants. Small Ruminant Research, 59(2-3), 105-121. doi:10.1016/j.smallrumres.2005.05.002Puchala, R., Tovar-Luna, I., Goetsch, A. L., Sahlu, T., Carstens, G. E., & Freetly, H. C. (2007). The relationship between heart rate and energy expenditure in Alpine, Angora, Boer and Spanish goat wethers consuming different quality diets at level of intake near maintenance or fasting. Small Ruminant Research, 70(2-3), 183-193. doi:10.1016/j.smallrumres.2006.03.002Takahashi, J., Chaudhry, A. ., Beneke, R. ., & Young, B. . (1999). An open-circuit hood system for gaseous exchange measurements in small ruminants. Small Ruminant Research, 32(1), 31-36. doi:10.1016/s0921-4488(98)00163-1Takahashi, J., & Young, B. A. (1992). The modulation of nitrate-enhanced hypothermia by sulphur compounds in cold-exposed sheep. 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Effect of the inclusion of lemon leaves and rice straw by-products in the diet of dairy goats on the quality characteristics of milk and matured cheeses

[EN] The effect of the dietary inclusion of lemon leaves and rice straw by-products on the quality characteristics of goats' milk and cheese was evaluated. Twenty-six Murciano-Granadina goats were used in a crossover design experiment; milk from each experimental group was collected to produce 60-days matured cheeses. Fat and dry matter content was higher in milk and cheeses from the diet containing by-products; medium-chain fatty acids and total free fatty acids were lower. Triangle tests revealed significant differences in the organoleptic characteristics of the cheeses between diets. However, when sensory attributes differentiating cheeses were evaluated individually, differences did not become significant. The inclusion of lemon leaves and rice straw in balanced diets with soya oil could be beneficial, as it does not appear to adversely affect the quality of milk and related mature cheeses, contributing to the reduction of the cost of the diet and the recycling of agricultural by-products. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).This study was supported by LIFE Project (ref. LIFE2016/CCM/ES/000088 LOW CARBON FEED) , funded by the EU Commission (Brusels, Belgium) .Huanca, N.; Beltrán Martínez, MC.; Fernández Martínez, CJ.; Molina Pons, MP. (2021). Effect of the inclusion of lemon leaves and rice straw by-products in the diet of dairy goats on the quality characteristics of milk and matured cheeses. International Dairy Journal. 120:1-4. https://doi.org/10.1016/j.idairyj.2021.1050821412

Analysis of the effect of clock drifts on frequency regulation and power sharing in inverter-based islanded microgrids

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Local hardware clocks in physically distributed computation devices hardly ever agree because clocks drift apart and the drift can be different for each device. This paper analyses the effect that local clock drifts have in the parallel operation of voltage source inverters (VSIs) in islanded microgrids (MG). The state-of-the-art control policies for frequency regulation and active power sharing in VSIs-based MGs are reviewed and selected prototype policies are then re-formulated in terms of clock drifts. Next, steady-state properties for these policies are analyzed. For each of the policies, analytical expressions are developed to provide an exact quantification of the impact that drifts have on frequency and active power equilibrium points. In addition, a closed-loop model that accommodates all the policies is derived, and the stability of the equilibrium points is characterized in terms of the clock drifts. Finally, the implementation of the analyzed policies in a laboratory MG provides experimental results that confirm the theoretical analysis.Peer ReviewedPostprint (author's final draft