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1.
J Dairy Res ; 90(2): 111-117, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37039499

RESUMEN

The experiments reported in this research paper address the effects of replacing ground corn (GC) with full-fat corn germ (FFCG) on nutrient intake and digestibility, nitrogen utilization efficiency, performance, and predicted methane production in dairy cows fed cactus cladodes and sugarcane. We hypothesized that the inclusion of FFCG in the diet would not alter the performance of lactating cows but would reduce the predicted methane production in vivo. Ten multiparous Holstein cows at 90 ± 10 d of lactation and yielding 24.2 ± 3.5 kg milk/d were assigned to dietary treatments consisting of different levels of replacement of GC by FFCG (0; 25; 50; 75 and 100% of diet dry matter) in a replicated 5 × 5 Latin square design with 21-d periods. Methane production was predicted using an automated gas in vitro production system. Except for ether extract intake, which increased, the intake of all nutrients decreased linearly with the replacement of GC by FFCG. The digestibility of dry matter, organic matter and neutral detergent fiber reduced, whereas the digestibility of ether extract increased linearly with FFCG. There were no changes in the digestibility of crude protein. The nitrogen intake and daily excretion in urine and feces decreased, while nitrogen use efficiency increased linearly. There was no significant effect of diets on nitrogen balance or microbial protein synthesis and efficiency. The yield of protein, lactose and total solids in milk showed a quadratic behavior. On the other hand, milk fat yield and energy-corrected milk yield decreased linearly with the replacement of GC by FFCG. No effect on pH or ammonia nitrogen was observed. The production of methane (CH4, g/kg DM) and total CH4 (g/d), and CH4 intensity decreased linearly with the replacement of GC by FFCG. In conclusion, FFCG has been shown to be an effective source of fat to reduce methane production in dairy cows, partially supporting our initial hypothesis. However, as it decreases milk fat production, it is not recommended to replace more than 50% of GC by FFCG for lactating cows fed cactus cladodes and sugarcane.


Asunto(s)
Lactancia , Zea mays , Femenino , Bovinos , Animales , Zea mays/metabolismo , Digestión , Ensilaje/análisis , Fibras de la Dieta/metabolismo , Leche/metabolismo , Dieta/veterinaria , Metano/metabolismo , Nitrógeno/metabolismo , Extractos Vegetales , Rumen
2.
J Anim Physiol Anim Nutr (Berl) ; 105(2): 232-246, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33111420

RESUMEN

Based on low 18:0 contents observed in milk fat of cows fed cactus cladodes (CC), we hypothesized that including Opuntia stricta cladodes in a soybean oil (SO)-supplemented diet would promote incomplete rumen biohydrogenation of supplemental PUFA, leading to increased trans-11 18:1 and cis-9, trans-11 CLA contents in milk. Twelve Holstein cows were used in a two-period study: (a) Baseline: all cows received a total mixed ration (TMR) composed of sorghum silage (SS) and a concentrate containing no SO for 14 days; (b) Treatment: cows received one of the following SO-supplemented diets for 21 days: (1) SS-TMR: a TMR composed of SS and a SO-enriched concentrate, (2) CC-TMR: a TMR containing CC as a partial substitute for SS plus the SO-enriched concentrate, and (3) CC-PMR: same diet as in treatment 2, but CC were mixed with the SO-enriched concentrate and fed as a partial mixed ration (PMR). Both CC diets increased relative abundances of trans-11 18:1, cis-9, trans-11 CLA, and 18:2 n-6 in milk fat, whereas opposite effects were observed on 18:0 and cis-9 18:1. Proportion of 18:2 n-6 increased, and cis-9, trans-11 CLA tended to increase with CC-PMR as compared to CC-TMR, whereas 18:3 n-3 was higher with CC-PMR than with SS-TMR. Proportions of several odd- and branched-chain fatty acids, certain 18:1 isomers, and trans-9, cis-11 CLA changed with CC diets, notably with CC-PMR. Milk yield and intake of most nutrients (except fibre) increased or tended to increase with the CC diets, whereas gross milk composition was unaltered. Stearoyl-CoA desaturase-1 index for C18 (SCD18 ) was higher with CC-PMR than with SS-TMR, and milk n-6:n-3 FA ratio and apparent transfer of 18:2 n-6 to milk increased with CC diets. These results indicate that Opuntia stricta cladodes can be a valuable feed ingredient for improving the nutraceutical value of milk fat.


Asunto(s)
Opuntia , Sorghum , Animales , Bovinos , Dieta/veterinaria , Suplementos Dietéticos , Ácidos Grasos , Lactancia , Leche , Rumen , Ensilaje/análisis , Aceite de Soja
3.
Eur Biophys J ; 49(6): 473-484, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32813035

RESUMEN

The aim of the present work was the biophysical characterization of the Amynthas gracilis hemoglobin (HbAg). The oxy-HbAg optical absorption data, with Soret and Q bands centered at 415, 540 and 575 nm, were stable and unchanged at pH 7.0. An increase in pH promotes decrease in the intensity in the optical absorption bands, suggesting an oligomeric dissociation and partial oxidation. Identical stability at pH 7.0 was observed in DLS results that presented a hydrodynamic diameter of 28 nm, characteristic of the whole oligomer. DLS shows that HbAg undergoes oligomeric dissociation and an aggregation/denaturation process that corroborates spectroscopic data. Our results showed that the monomer d presents four isoforms with molecular mass (MM) ranging from 16,244 to 16,855 Da; the trimer subunit presents two isoforms, (abc)1 and (abc)2, with MM of 51,415 ± 20 Da and 51,610 ± 14 Da, respectively, and a less intense species, at 67,793 Da, assigned to the tetramer abcd. Monomeric chains a, obtained from reduction of the disulfide-bonded trimer abc, present four isoforms with MM 17,015 Da, 17,061 Da, 17,138 Da and 17,259 Da. DLS and LSI revealed an isoeletric point (pI) of oxy-HbAg of 6.0 ± 0.3 and 5.5, respectively. Data analysis by IEF-SDS-PAGE revealed that the pI of oxy-HbAg is 6.11, correlating with DLS and LSI data. These studies indicate that oxy-HbAg is very stable, at pH 7.0, and has differing properties from orthologous giant hemoglobins.


Asunto(s)
Espacio Extracelular/metabolismo , Hemoglobinas/química , Hemoglobinas/metabolismo , Oligoquetos/citología , Animales , Concentración de Iones de Hidrógeno , Peso Molecular
4.
Mol Neurobiol ; 54(8): 6471-6489, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27730513

RESUMEN

Type 2 diabetes (T2D) is a highly concerning public health problem of the twenty-first century. Currently, it is estimated that T2D affects 422 million people worldwide with a rapidly increasing prevalence. During the past two decades, T2D has been widely shown to have a major impact in the brain. This, together with the cognitive decline and increased risk for dementia upon T2D, may arise from the complex interaction between normal brain aging and central insulin signaling dysfunction. Among the several features shared between T2D and some neurodegenerative disorders (e.g., Alzheimer disease (AD)), the impairment of insulin signaling may be a key link. However, these may also involve changes in sex hormones' function and metabolism, ultimately contributing to the different susceptibilities between females and males to some pathologies. For example, female sex has been pointed as a risk factor for AD, particularly after menopause. However, less is known on the underlying molecular mechanisms or even if these changes start during middle-age (perimenopause). From the above, we hypothesized that sex differentially affects hormone-mediated intracellular signaling pathways in T2D brain, ultimately modulating the risk for neurodegenerative conditions. We aimed to evaluate sex-associated alterations in estrogen/insulin-like growth factor-1 (IGF-1)/insulin-related signaling, oxidative stress markers, and AD-like hallmarks in middle-aged control and T2D rat brain cortices. We used brain cortices homogenates obtained from middle-aged (8-month-old) control Wistar and non-obese, spontaneously T2D Goto-Kakizaki (GK) male and female rats. Peripheral characterization of the animal models was done by standard biochemical analyses of blood, plasma, or serum. Steroid sex hormones, oxidative stress markers, and AD-like hallmarks were given by specific ELISA kits and colorimetric techniques, whereas the levels of intracellular signaling proteins were determined by Western blotting. Albeit the high levels of plasma estradiol and progesterone observed in middle-aged control females suggested that they were still under their reproductive phase, some gonadal dysfunction might be already occurring in T2D ones, hence, anticipating their menopause. Moreover, the higher blood and lower brain cholesterol levels in female rats suggested that its dysfunctional uptake into the brain cortex may also hamper peripheral estrogen uptake and/or its local brain steroidogenic metabolism. Despite the massive drop in IGF-1 levels in females' brains, particularly upon T2D, they might have developed some compensatory mechanisms towards the maintenance of estrogen, IGF-1, and insulin receptors function and of the subsequent Akt- and ERK1/2-mediated signaling. These may ultimately delay the deleterious AD-like brain changes (including oxidative damage to lipids and DNA, amyloidogenic processing of amyloid precursor protein and increased tau protein phosphorylation) associated with T2D and/or age (reproductive senescence) in female rats. By demonstrating that differential sex steroid hormone profiles/action may play a pivotal role in brain over T2D progression, the present study reinforces the need to establish sex-specific preventive and/or therapeutic approaches and an appropriate time window for the efficient treatment against T2D and AD.


Asunto(s)
Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Encéfalo/patología , Diabetes Mellitus Tipo 2/patología , Fragmentos de Péptidos/metabolismo , Enfermedad de Alzheimer/metabolismo , Animales , Encéfalo/metabolismo , Colesterol/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Susceptibilidad a Enfermedades , Estradiol/sangre , Femenino , Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Lípidos/sangre , Masculino , Ratas , Ratas Wistar
5.
Rev. bras. ciênc. mov ; 22(2): 163-172, jan.-mar.2014. tab
Artículo en Portugués | LILACS | ID: lil-733952

RESUMEN

O tênis de campo exige habilidades motoras específicas e complexas, sendo o saque um dos elementos que caracteriza a complexidade dos seus movimentos. Em virtude da importância deste fundamento, o saque vem sendo investigado por pesquisadores para uma melhor descrição e entendimento da técnica. Assim, o objetivo principal deste estudo foi analisar os escritos científicos referentes ao saque no tênis de campo, considerando a abordagem biomecânica, com a finalidade de verificar evidências de pesquisas sobre o “estado da arte” e a tendência dos estudos sobre este tema. O processo inicial de busca bibliográfica foi realizado por três pesquisadores através da avaliação dos títulos e resumos, a partir da análise de artigos científicos publicados em periódicos, de forma independente, no período entre 2000 e 2013, sendo selecionados para este estudo 31 artigos que se enquadraram nos critérios de inclusão. Os critérios de inclusão foram: (1) população (tenistas adultos ou juvenis), (2) intervenção (análise biomecânica do saque de tenistas), (3) desfecho (desempenho dos atletas na execução do saque) e (4) qualidade metodológica (validade dos estudos). Foi desenvolvida uma matriz com critérios de análise para avaliação da qualidade metodológica dos estudos, com base na Escala de PEDro. A matriz possibilitou avaliar os estudos quanto aos objetivos apresentados, critérios de inclusão dos sujeitos, desenho metodológico, número de sujeitos, presença de grupos de comparação, definição das variáveis e apresentação dos resultados estatísticos, sendo adotada como pontuação máxima um escore de 6 e mínimo 4. A partir dos resultados observou-se diferentes tendências de estudos sobre o saque no tênis de campo, predominando os estudos sobre análisesdinâmicas, cinemáticas e, eletromiográficas. Outra tendência foi observada em relação ao desenho metodológico dos estudos os quais 25 dos 31 são descritivos, 3 de revisão bibliográfica e 3 são experimentais.


Tennis demand specific and complex motor abilities, being the serve one of the elements that characterizes the complexity of its movements. Given the importance of this movement, researchers for a better understanding and description of its technique have investigated the tennis serve. Therefore, the aim of this study was to gather and analyze scientific researches related to tennis serve, considering the biomechanical approach, with the purpose of adding research evidence on the “state of the art” and the tendency of the studies on this topic. The initial review processes was conducted by three researchers trough review of titles and abstracts, based on the analysis of scientific articles published in journals independently, between 2000 and 2013. Inclusion criteria were: 1) population (junior or adult players);2) intervention (biomechanical analysis of the tennis serve); 3) outcome (performance of the athletes in the execution of the serve); 4) methodological quality (studies validity). We developed a matrix of analysis criteria for assessing the methodological quality of the studies, based on the PEDro Scale.In this study the matrix evaluated the studies regarding presented objectives, inclusion criteria of the subjects, methodological design of the study, number of the subjects in the studies, presence of comparison groups, definition of variables and presentation of statistical results, being adopted as the maximum score 6 and minimum 3.Through the results, we observed different tendencies of studies on the tennis serve; prevailing studies on dynamic, kinematic and electromyography analysis. Another tendency was observed in relation to the methodological design of studies which 25 of the 31 are descriptive, 3 reviewed the literature and 3 are experimental.


Asunto(s)
Humanos , Masculino , Femenino , Rendimiento Atlético , Deportes , Tenis , Desempeño Psicomotor
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