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Evaluación de la cantidad de leche vendible y total bajo diferentes modalidades de amamantamiento restringido en vacas doble propósito
Drescher,Karin; Saddy,Jacqueline; Uzcátegui,Williams;
Zootecnia Tropical , 2009,
Abstract: with the aim to quantify variations on saleable milk (lv), milk consumed by the calf (cb), residual milk (lr), and total milk (lt) due to effect of restricted suckling modality an assay was conducted with 20 dual purpose cows (5/8 holstein and 3/8 brahman). three post partum periods between calving and weaning: 30, 70, and 105 days (ddp) were evaluated. treatments were t1: primiparous cows (g1) with restricted suckling after morning milking (a1), t2: g1 with restricted suckling after morning and afternoon milking (a2), t3: multiparous cows (g2) with a1, and t4: g2 with a2. the data were analyzed by manova for repeated measures in time. the results indicate an effect (p<0.01) attributable to the period of sampling (30, 70, and 105 ddp) for lv (10.18, 8.42 and 6.67 kg milk/d) and lt (14.37, 12.36 and 10.61 kg milk/d), but not for cb or lr. the highest production was for lt in t4 (15.39 kg/d) and the lowest in t2 (10.25 kg/d). these results demonstrate the beneficial effect due to milking and restricted suckling management. twice restricted suckling per day improved saleable and total milk production both in primparous than multiparous cows. its management produces benefits for milk production by the dual purposes system, and its use is effective in tropical areas.
Relación entre balance energético, concentración de metabolitos sanguíneos y expresión hipotalámica del receptor Tipo 1 de orexina y neuropéptido y en vacas mestizas durante el postparto Relationship among energy balance, blood metabolites and hypothalamic expression of orexin receptor type 1 and neuropeptide y in crossbred dairy cows during postpartum
Livia V Pinto-Santini,Nelson Martínez,Karin Drescher,Isamery Machado
Revista de la Facultad de Ciencias Veterinarias , 2011,
Abstract: En vacas mestizas bajo condiciones tropicales, donde la oferta y calidad de la dieta pueden ser limitadas, la relación entre el estatus energético (EE), metabólico y productivo de los animales son aún poco claras. En tal sentido, 27 vacas (3/4 a 5/8 Bos taurus x 1/4 a 3/8 Bos indicus) doble propósito (DP), fueron distribuidas al azar en los siguientes tratamientos, tomando en cuenta la condición corporal (CC) al parto (P) y el nivel de alimentación (A) postparto (PP): 1) CAAA: CC alta al P (CA: ≥2,5) y alto A PP (AA); 2) CBAA: CC baja al P (CB: < 2,5) y AA; 3) CAAB: CA y bajo A PP (AB) y, 4) CBAB: CB y AB. Se evaluó el balance energético (BE) PP; la concentración de glucosa (GLU), colesterol (COL) y nitrógeno ureico (NU) y, la expresión hipotalámica del neuropéptido Y (NPY) y el receptor tipo 1 de orexina (OX-1R) por Western Blot. Se aplicó ANAVAR para medidas repetidas en el tiempo, incluyendo el efecto de CC, nivel de A y su interacción. No hubo efecto de CC x A en las variables evaluadas. Las vacas AA consumieron (kg.anim.d-1) más alimento (10,9 a 12,9) que las AB (8,8 a 10,6) (P<0,01); sin embargo, el BE fue negativo (-7,9±19,4 para AA y -27,2±13,1 para AB; P<0,01). Se obtuvo una concentración promedio de GLU (mg.dL-1) de 61,5 y 56,7 (P<0,05) y COL (mg.dL-1) de 142,6 y 157,6 (P=0,10) para CA y CB, respectivamente, sin efecto de A. El NU (mg.dL-1) fue afectado por A (15,9 para AB y 19,2 para AA; P<0,05). Se observó una reducción de la expresión del neuropétido Y (NPY) y receptor-1 de orexina (OX-1R) en CBAB a los 45 d PP, asociado a una disminución de la respuesta del sistema nervioso central por la magnitud de la restricción energética. La CC al P es el componente del EE más importante a considerar en sistemas de DP, sobre todo, cuando la dieta no permite elevados consumos y aportes de energía neta. In crossbred dairy cows under tropical conditions, where supply and diet quality may be limited, the relationship among energy status (ES), metabolic and productive status of the animals are still not clear. In this regard, 27 dual purpose (DP) cows (3/4 to 5/8 Bos taurus x 1/4 to 3/8 Bos indicus), were randomly assigned to the following treatments, a combination of body condition (BC) at calving (AC) and feeding level (FL) postpartum (PP): 1) HBCHFL: High BC to PP (BC: ≥ 2.5) and high FL PP (HFL), 2) LBCHFL: Low BC to PP (BC: < 2.5) and HFL, 3) HBCLFL: HBC and low FL PP (LFL) and 4) LBCLFL: LBC and LFL. Energy balance (EB) PP, the concentration of glucose (GLU), cholesterol (COL) and urea nitrogen (UN) and hypothalamic expression of neuropeptide Y (NPY)
Relación entre los niveles de glucosa e insulina sanguínea y el reinicio de la actividad ovárica en vacas de doble propósito con diferentes condiciones corporales al parto y diferente nivel de alimentación postparto
Pinto-Santini,Livia; Drescher,Karin; Ruiz,Ana; Pérez,Rafael; Domínguez,Carlos; Benezra,Miguel; Martínez,Nelson;
Interciencia , 2009,
Abstract: the effect of body condition (cc) at parturition and feeding level (a) during the postpartum period (pp) on glucose concentration and pp insulin, as well as the resumption of ovarian activity in dual purpose cows, was evaluated. twenty-eight adult cows were randomly allocated to four different treatments, acaa: high cc (ac 32.5) at parturition and high a pp (aa); bcaa: low cc (bc<2.5) at parturition and aa; acba: ac and low a pp (ba); bcba: bc and ba. a during pp did not affect the variables studied. the accumulated glucose levels at 45 days pp were 239.4 and 262.6mg·dl-1 (p= 0.083) and those of insuline were 34.21 and 19.39μiu·mg-1 (p<0.01) for cows with ac and bc, respectively. either the cc at parturition or the a pp did not exert any effect on class 1 (c1) and 2 (c2) follicle population. in contrast, the cc at parturition affected (p<0.01) class 3 follicles (c3) and number of corpora lutea (cl). thus, cows with ac showed both higher c3 follicle populations and cl, when compared to cows with bc. this work confirms that cc at parturition is a determinant factor in the resumption of ao in dual purpose crossbred cows.
Pinto-Santini,Livia V; Martínez,Nelson; Drescher,Karin; Machado,Isamery; Domínguez,Carlos; Ruiz,Ana Z;
Revista de la Facultad de Ciencias Veterinarias , 2011,
Abstract: in crossbred dairy cows under tropical conditions, where supply and diet quality may be limited, the relationship among energy status (es), metabolic and productive status of the animals are still not clear. in this regard, 27 dual purpose (dp) cows (3/4 to 5/8 bos taurus x 1/4 to 3/8 bos indicus), were randomly assigned to the following treatments, a combination of body condition (bc) at calving (ac) and feeding level (fl) postpartum (pp): 1) hbchfl: high bc to pp (bc: ≥ 2.5) and high fl pp (hfl), 2) lbchfl: low bc to pp (bc: < 2.5) and hfl, 3) hbclfl: hbc and low fl pp (lfl) and 4) lbclfl: lbc and lfl. energy balance (eb) pp, the concentration of glucose (glu), cholesterol (col) and urea nitrogen (un) and hypothalamic expression of neuropeptide y (npy) and orexin receptor type 1 (ox-1r ) by western blot, were evaluated. the data was analyzed by anova for repeated time measures, including the effect of bc level of fl and their interaction. no effect of bc x fl on any variable was found. cows under hfl consumed (kg.anim.d-1) more feed (10.9 to 12.9 than lfl (8.8 to 10.6) (p<0.01), however, the eb was negative (-7.9 ± 19.4 for hfl and -27.2 ± 13.1 for lfl, (p<0.01). the glu (mg.dl-1) concentration was of 61.5 and 56.7 (p<0.05) and col (mg.dl-1) of 142.6 and 157.6 (p=0.10) for hbc and lbc, respectively, without effect of fl. the un (mg.dl-1) was affected by fl (15.9 to 19.2 for lfl and hfl, (p<0.05). a reduction of npy expression and ox-1r in the 45 d lbclfl pp was observed and was associated to a diminished central nervous system response caused by marked energetic restriction. the bc to pp is the most important component of es to consider in dp systems, especially when the diet does not allow high consumption and input of total energy.
Efecto de la condición corporal al parto y del nivel de alimentación sobre la involución uterina, actividad ovárica, pre？ez y la expresión hipotalámica y ovárica de los receptores de leptina en vacas doble propósito
Domínguez,Carlos; Ruiz,Ana Z; Pérez,Rafael; Martínez,Nelson; Drescher,Karin; Pinto,Livia; Araneda,Richard;
Revista de la Facultad de Ciencias Veterinarias , 2008,
Abstract: effect of body condition at calving and feeding level on uterine involution, ovarian activity, pregnancy and the hypothalamic and ovarian expression of leptin receptors in dual purpose cows abstract to evaluate the effect of body condition at calving (bcac) and different feeding levels (fl) on uterine involution (ui), ovarian activity (oa), pregnancy (pr), and hypothalamic and ovarian leptin receptor expression (lepexp) in postpartum cows, twenty seven crossbred cows (bos taurus x bos indicus) were randomly assigned in a 2 x 2 factorial design into four treatments (t): t1, low body condition (lbc; < 2.5) + low fl (lbclfl; n = 6); t2, lbc (< 2.5) + high fl (lbchfl; n = 7); t3, high bc (> 2.5) + low fl (hbclfl; n = 7) and; t4, high bc (>2.5) + high fl (hbchfl; n = 7). basal diet was made of hay from cynodon nlemfluensis (11% crude protein, cp) plus supplement (23% cp) at a 70:30 ratio. to assess uterine involution (ui), the following was considered: characteristic of uterine secretion (cus), uterine horn simmetry (uhs), cervix diameter (cd), and uterine position (up). weekly, from 15 to 45 days postpartum (dpp), the reproductive tract was evaluated by transrectal palpation, ultrasonography, and ria of plasma progesterone (p4). the oa was assessed through the ovarian follicles (of), which were classified as : c1 (≤ 5 mm), c2 (6-9 mm), c3 (≥ 10 mm); and the presence of corpora lutea (cl). the pr was verified by rectal palpation, ultrasound, and p4. metabolic changes were measured as total cholesterol (tc) and fructosamine (frts) at 3, 15, and 45 dpp. the hypotalamic and ovarian lepexp were determined by western blot from tissue samples of 8 cows slaughtered at 45 dpp. data were statistically analyzed by multivariate multiple regressions, anova for repeated measurements on time, cox？s multiple regression and a kruskal and wallis test. results show a correlation between t and c3 and between c3 and cus at 22 and 30 dpp. also, a correlation was detected between cl and cus a
Symmetry Breaking for Answer Set Programming
Christian Drescher
Computer Science , 2010,
Abstract: In the context of answer set programming, this work investigates symmetry detection and symmetry breaking to eliminate symmetric parts of the search space and, thereby, simplify the solution process. We contribute a reduction of symmetry detection to a graph automorphism problem which allows to extract symmetries of a logic program from the symmetries of the constructed coloured graph. We also propose an encoding of symmetry-breaking constraints in terms of permutation cycles and use only generators in this process which implicitly represent symmetries and always with exponential compression. These ideas are formulated as preprocessing and implemented in a completely automated flow that first detects symmetries from a given answer set program, adds symmetry-breaking constraints, and can be applied to any existing answer set solver. We demonstrate computational impact on benchmarks versus direct application of the solver. Furthermore, we explore symmetry breaking for answer set programming in two domains: first, constraint answer set programming as a novel approach to represent and solve constraint satisfaction problems, and second, distributed nonmonotonic multi-context systems. In particular, we formulate a translation-based approach to constraint answer set solving which allows for the application of our symmetry detection and symmetry breaking methods. To compare their performance with a-priori symmetry breaking techniques, we also contribute a decomposition of the global value precedence constraint that enforces domain consistency on the original constraint via the unit-propagation of an answer set solver. We evaluate both options in an empirical analysis. In the context of distributed nonmonotonic multi-context system, we develop an algorithm for distributed symmetry detection and also carry over symmetry-breaking constraints for distributed answer set programming.
Efecto del nivel de alimentación sobre la actividad ovárica, expresiónde transportadores de glucosa y tolerancia a la insulina en vacasmestizas durante el posparto
Ruiz,Ana Z; Rossini,Mario; Araneda,Richard; Fernández,Adriana; Rojas,Jesús; Martínez,Nelson; Pinto,Livia; Drescher,Karin; Pérez,Rafael; Domínguez,Carlos; Jerez,Nancy;
Zootecnia Tropical , 2008,
Abstract: to evaluate the feeding effect on ovarian structure (os), ovocyte quality, glut-1 receptor expression, and insulin tolerance test, eight crossbred (bos taurus x bos indicus), dual purpose cows were used. the animals were randomly allocated to two treatments: treatment 1: four cows with low and high corporal conditions and a low feed level (lf) and treatment 2: four cows with low and high corporal conditions and a high feed level (hf). the evaluation of reproductive activity was done weekly using trans-rectal palpation and ultrasound from 15 to 45 days post-partum. the os was assessed by the presence of corpus luteum and the classes of ovarian follicles. the ovocytes were classified as follows: a (ovocyte with the presence of a clear and compact cumulus oophurus and translucent ooplasm), type b (ovocyte with dark and compact cumulus oophurus and dark ooplasm), and type c (oocyte with dark and expanded cumulus oophurus and dark ooplasm). the expression of glut-1and glut-4 was evaluated by western blot analysis; additionally, an insulin tolerant test was performed. the correlation analysis showed an association between feed level and ovocytes type a (0.756; p<0.05). the glut-1 expressed more in animals under treatment 1 and glut-4 in animal under treatment 2. also, the feed level affected plasmatic glucose concentration before and after insulin injection. the results of this study suggest that the feed level affects the follicular development at its final stage of maturation because the nutritional supply is capable of modulating the reproductive response both at the hypothalamic and ovarian levels.
Explorative Teaching and Research—From Memory Work to Experience Stories  [PDF]
Karin Widerberg
Creative Education (CE) , 2016, DOI: 10.4236/ce.2016.714196
Abstract: Memory work is an approach developed to help us problematize the things we take for granted and as such an invitation to methodological explorations in teaching and research. By our own stories of memories and experiences we are invited to look for variety—in our own stories as well as in relation to the stories of the others—regarding content as well as interpretations. A set of techniques is developed to make this happen, in writing as well as in analyzing. Focusing on the social aspects of a story does not only imply a possibility to connect different analytical levels (micro and macro) and verify concepts and theories. It also allows us to question or specify fixed or simplified categories and concepts by making other memories, experiences and understandings visible. As such it is an approach that stimulates creativity and knowledge production in both teaching and research, to the joy of all participants. In this article it is illustrated how the approach can be used in different settings and on different themes in both teaching and research hereby also illuminating the kinds of knowledge that can be gained. Cases and detailed accounts of how the approach can be used when teaching a one-day workshop, a three-day course but also in a two-hour lecture in a regular class on BA-level are given. Examples of the use of the approach in different research projects are also presented so as to illuminate the bridge between research and teaching and how research approaches can be made into teaching approaches. The illustrations are meant to inspire further use and development of the approach so as to fit different situations and themes in teaching and research.
Impacts of agricultural innovation and transformation of the mountainous hinterland in the Mediterranean: An example from Southern Spain (Costa Granadina)
Drescher, A. W.
Pirineos : Revista de Ecología de Monta？a , 1995,
Abstract: Between 1985 and 1989 and in 1994 an agroecologicaI research was carried out at the Mediterranean coast of Andalucía (Southern Spain). Comparison of aerial photos of 1950 and 1978, interviews with farmers and field work made clear that the landscape is subject to enormous changes. The innovation of agricultural practices cause manifold ecological consequences. Main results are: The traditional land use pattern was replaced by market oriented agricultural practices. The changes of the land use pattern occurred very quickly starting in the early eighty's, not reaching their peak up to now. Main feature of the development is the destruction of the landscape by ecologically non - adapted methods of terracing steep slopes, which were formerly protected by traditional terraces. Heterogeneous development of the higher Alpujarra and the coastal plains with respect to the emigration and immigration pattern is threatening the interaction between both areas, especially the water management. The coastal plains are entirely dependent on the water resources of the Sierra Nevada and upper Alpujarra. Dryland farming has been abandoned nearly completely. Una investigación agroecológica se llevó a cabo entre 1985 y 1989, y en 1994, en la costa mediterránea de Andalucía (Sur de Espa a). La comparación de fotografías aéreas de 1950 y 1978, las entrevistas a agricultores y el trabajo de campo revelan que el paisaje ha sufrido grandes cambios. Las innovaciones en las prácticas agrícolas han tenido múltiples consecuencias ecológicas. Los principales resultados son: El uso tradicional de la tierra ha sido sustituido por prácticas agrícolas orientadas al mercado. Los cambios en las pautas de uso del suelo han sido muy rápidos, iniciándose a comienzos de la década de los ochenta y no alcanzando el máximo hasta hoy. El rasgo principal del desarrollo ha sido la destrucción del paisaje mediante métodos ecológicamente inapropiados de construcción de terrazas en fuertes pendientes, que antes quedaban protegidas por el aterrazamiento tradicional. El desarrollo diferente de la Alta Alpujarra y de las llanuras costeras en relación con las pautas de inmigración y emigración está amenazando la interacción entre ambas áreas, especialmente en lo que respecta a la gestión del agua. Las llanuras costeras dependen por completo de los recursos hídricos de la Sierra Nevada y de la Alta Alpujarra. El cultivo de secano ha sido abandonado casi por completo.
Reformulation of Global Constraints in Answer Set Programming
Christian Drescher,Toby Walsh
Computer Science , 2010,
Abstract: We show that global constraints on finite domains like all-different can be reformulated into answer set programs on which we achieve arc, bound or range consistency. These reformulations offer a number of other advantages beyond providing the power of global propagators to answer set programming. For example, they provide other constraints with access to the state of the propagator by sharing variables. Such sharing can be used to improve propagation between constraints. Experiments with these encodings demonstrate their promise.
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