Reproductive characterization of hair ewe in the American tropics: a review part 1

Objective: to make a reproductive characterization of the hair sheep breeds in the American tropics. Design/methodology/approach: reproductive variables information was collected from scientific search engines, such as Web of Science, Redalyc, Dialnet, PubMed, SciELO and Latindex. Results: the age of puberty in ewe lambs is highly variable. Similar results were found in adult ewes regarding estrus duration and incidence, estrous cycle length, seasonal anestrus, ovulation rate, fertility, gestation, and prolificacy. Limitations on study/implications: information on reproductive variables of hair sheep breeds is poorly known or non-existent. Findings/conclusions: puberty onset in ewe lambs ranges from 175 to 335 d of age when animals weight 15 to 43 kg. The length of the estrous cycle of hair sheep in Mexico is 17 d during the autumn-winter and 21 d in spring-summer. In Brazil, it lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The estrous occurrence was 97.1% in autumn-winter and 76.5 % in spring-summer. The estrous duration ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. Fertility is 80 to 100 % in temperate and 37 % in warm months. Gestation length ranges from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval range from 244 to 294 d.Objective: To carry out a reproductive characterization of the breeds of hair ewe in the tropical region of the Americas. Design/Methodology/Approach: A search of scientific information about the reproductive variables of breeds of hair ewe was carried out and the results were analyzed in the Web of Science, Redalyc, Dialnet, PubMed, SciELO, and Latindex databases. Results: We described and discussed the highly-variable onset of puberty in ewe lambs. Similar results were found in adult ewes regarding the duration and occurrence of the estrous, estrous cycle length, seasonal anestrous, ovulation rate, fertility, gestation, and prolificacy. Study Limitations/Implications: Information about the reproductive variables of breeds of hair ewe is poorly known or non-existent. Findings/Conclusions: The onset of puberty in 15-43 kg ewe lambs ranges from 175 to 335 d of age. The estrous cycle of hair ewe in Mexico lasts 17 d in autumn-winter and 21 d in spring-summer. In Brazil, this cycle lasts 17 d in spring-summer and 18 d in autumn-winter. In the United States of America and Venezuela, the estrous cycle length was similar in both periods of the year. The occurrence of the estrous reached 97.1 % in autumn-winter and 76.5 % in spring-summer. The duration of the estrous ranges from 16 to 52 hours. Seasonal anestrous occurs from May to July. The ovulation rate ranges from 1 to 3 oocytes. The percentage of fertility fluctuates between 80 and 100 % in temperate months and reaches 37 % in warm ones. Gestation lasts from 144 to 152 d. Prolificacy ranges from 1.0 to 2.2 offspring per ewe. The lambing interval ranges from 244 to 294 d

Comparação de pH e matéria seca em três processos de silagem com forragem de gergelim (Sesamum indicum) nos trópicos secos.

El objetivo de este estudio fue comparar el pH y la materia seca (MS) en tres procesos de ensilaje con planta de ajonjolí en climas secos. Los experimentos se realizaron en la Facultad de Medicina Veterinaria y Zootecnia No. 1 de la Universidad Autónoma de Guerrero. En el experimento 1, se ensiló forraje de maíz combinado con forraje de ajonjolí (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 y T5: 00:100% respectivamente). En el experimento 2 se ensiló forraje de ajonjolí mezclado con melaza (T1:0, T2:4, T3:8 y T4:12% respectivamente) En el experimento 3 se ensiló planta de ajonjolí sola (T1), con melaza 8% (T2), planta presecada sola (T3) y planta presecada con melaza 8% (T4). Se realizaron síes microsilos por tratamiento (6 réplicas). Los diseños experimentales fueron completamente al azar. En el experimento 1, el pH más bajo fue para el T1 con un valor de 3.83, en el experimento 2 fue para el T4 con un valor de 3.94 y en el experimento 3 fue para el T2 con un valor de 4.00. Para la MS, el contenido fue mayor para el T1 con 28.55%, en el experimento 2 fue para el T4 con 27.63% y en el experimento 3 fue para el T3 con 36.00%. Todos los experimentos mostraron diferencia estadística (p< 0.0001) entre tratamientos. Sin embargo, los valores para pH y MS son aceptables para prácticamente todos los tratamientos, en acuerdo con otras investigaciones. Por lo tanto, se concluye que al ensilar forraje de ajonjolí mezclado con forraje de maíz, melaza o planta presercada se logra mejorar la fermentación ácida y se incrementa el contenido de materia seca. Sin embargo, es necesario realizar evaluaciones posteriores de las propiedades físico-químicas y determinar su valor nutritivo.The objective of this study was to compare the pH and dry matter (DM) in three silage processes with sesame plants in dry climates. The experiments were carried out at the Faculty of Veterinary Medicine and Zootechnics No. 1 of the Autonomous University of Guerrero. In experiment 1, corn forage combined with sesame forage was ensiled (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 and T5: 00:100% respectively). In experiment 2 sesame forage mixed with molasses (T1:0, T2:4, T3:8 and T4:12% respectively) was ensiled. In experiment 3 sesame plant alone (T1) was ensiled with 8% molasses ( T2), pre-dried plant alone (T3) and pre-dried plant with 8% molasses (T4). Six microsilos per treatment (6 replicates) were made. The experimental designs were completely randomized. In experiment 1, the lowest pH was for T1 with a value of 3.83, in experiment 2 it was for T4 with a value of 3.94 and in experiment 3 it was for T2 with a value of 4.00. For DM, the content was higher for T1 with 28.55%, in experiment 2 it was for T4 with 27.63% and in experiment 3 it was for T3 with 36.00%. All the experiments showed statistical difference (p< 0.0001) between treatments. However, the values for pH and DM are acceptable for practically all treatments, in agreement with other investigations. Therefore, it is concluded that ensiling sesame forage mixed with corn forage, molasses or presercated plant improves acid fermentation and increases the dry matter content. However, it is necessary to carry out further evaluations of the physical-chemical properties and determine its nutritive value.O objetivo deste estudo foi comparar o pH e a matéria seca (MS) em três processos de silagem com plantas de gergelim em climas secos. Os experimentos foram realizados na Faculdade de Medicina Veterinária e Zootecnia nº 1 da Universidade Autônoma de Guerrero. No experimento 1, a forragem de milho combinada com a forragem de gergelim foi ensilada (T1: 100:00, T2: 75:25, T3: 50:50, T4: 25:75 e T5: 00:100% respectivamente). No experimento 2 a forragem de gergelim foi ensilada misturada com melaço (T1:0, T2:4, T3:8 e T4:12% respectivamente) - planta seca sozinha (T3) e planta pré-seca com 8% de melaço (T4). Seis microsilos por tratamento (6 réplicas) foram feitos. Os delineamentos experimentais foram inteiramente casualizados. No experimento 1, o menor pH foi para T1 com valor de 3,83, no experimento 2 foi para T4 com valor de 3,94 e no experimento 3 foi para T2 com valor de 4,00. Para MS o teor foi maior para T1 com 28,55%, no experimento 2 foi para T4 com 27,63% e no experimento 3 foi para T3 com 36,00%. Todos os experimentos apresentaram diferença estatística (p< 0,0001) entre os tratamentos. No entanto, os valores de pH e MS são aceitáveis ​​para praticamente todos os tratamentos, concordando com outras investigações. Portanto, conclui-se que a ensilagem de forragem de gergelim misturada com forragem de milho, melaço ou planta preservada melhora a fermentação ácida e aumenta o teor de matéria seca. No entanto, é necessário realizar mais avaliações das propriedades físico-químicas e determinar seu valor nutritivo

Inhibitory control failures and blunted cortisol response to psychosocial stress in amphetamine consumers after 6 months of abstinence

Amphetamine abuse has been conceived as an addictive illness where stress regulation and inhibitory control may be crucial factors determining chronicity and relapse. Since amphetamine consumption may disrupt the cerebral systems regulating inhibition and stress behaviors, deregulation on these systems may be expected even after long-term abstinence periods. The present study aimed to evaluate the ability of abstinent amphetamine consumers to regulate stress parameters and to inhibit cognitive patterns under the acute trier social stress test (TSST) paradigm. Materials and Methods, a cohort study was conducted in a sample of 44 young individuals (average age: 24.6 years). The sample included 22 amphetamine consumers recruited from an addiction treatment center and 22 healthy nonconsumers belonging to the same sociodemographic conditions. Both groups were exposed to the TSST once the consumers completed 6 months in abstinence. To evaluate stress reactivity, we collected five saliva samples distributed before, during, and after stress exposure. Inhibitory capacity was also assessed before and after stress using the Stroop and d2 cancellation tests. Results, under stress conditions, cortisol measures were significantly lower in amphetamine consumers (1105.34 ± 756.958) than in healthy nonconsumers (1771.86 ± 1174.248) P = 0.022. Without stress, amphetamine consumers also showed lower cortisol values (1027.61 ± 709.8) than nonconsumers (1844.21 ± 1099.15) P = 0.016. Regarding inhibitory capacity, stress also was associated to consumer's lower scores on the Stroop (5.17 ± 8.34 vs. 10.58 ± 7.83) P = 0.032 and d2 tests (190.27 ± 29.47 vs. 218.00 ± 38.08) P = 0.010. Conclusion: We concluded that both the stress regulatory system and executive function system (attentional/inhibitory control) represent key vulnerability conditions to the long-term effect of compulsive amphetamine consumption

Chronic exposure of juvenile rats to environmental noise impairs hippocampal cell proliferation in adulthood

Increasing evidence indicates that chronic exposure to environmental noise may permanently affect the central nervous system. The aim of this study was to evaluate the long-term effects of early exposure to environmental noise on the hippocampal cell proliferation of the adult male rat. Early-weaned Wistar rats were exposed for 15 days to a rats′ audiogram-fitted adaptation to a noisy environment. Two months later, the rats were injected with the cellular proliferation marker 5΄bromodeoxiuridine (BrdU), and their brains were processed for immunohistochemical analysis. Coronal sections were immunolabeled with anti-BrdU antibodies to identify new-born cells in dentate gyrus (DG), cornu amonis areas CA1 and CA3. In addition, blood samples were obtained to evaluate corticosterone serum levels after noise exposure. All data are expressed as mean΁standard deviation. For mean comparisons between groups, we used the Student t test. We found an increase in corticosterone serum levels after environmental noise exposure. Interestingly, noise-exposed rats showed a long-term reduction of proliferating cells in the hippocampal formation, as compared to controls. These findings indicate that chronic environmental noise exposure at young ages produces persistent non-auditory impairment that modifies cell proliferation in the hippocampal formation

Combined approach for experimental Oto-neurosurgical procedures

Background: Experimental procedures will continue to be a key element while going through the learning curve in the use of the endoscope and minimally invasive procedures. We describe the technical procedure of an experimental approach to middle ear in New Zealand rabbits through external auditory canal and its relevance as an ideal model to study graft materials and serve as a training tool for potential applications in otoneurology. Methods: A group of 28 adult New Zealand rabbits were subjected to an experimental myringoplasty, combining the transmeatal and retroauricular approach with endoscopic assistance and microsurgical technique. The different anatomical steps and systematization of the complete experimental procedure are described. Results: An experimental approach to middle ear live model and basic anatomic description was successfully used, standardizing the ideal technique. The eardrum could regenerate with no complications and with functional preservation in all the myringoplasty cases. This strategy involves a safe combined approach to the tympanic membrane and others neurosurgical as transcochlear and translaberyntic approaches and is useful as a test of other experimental procedures to evaluate biomaterials to repair the eardrum currently studied. This experimental myringoplasty model also facilitates functional tests such as impedanciometry and the endoscopic follow-up of the whole process. Conclusions: The method described to perform an experimental myringoplasty (type I tympanoplasty) in a New Zealand rabbit is an option to be used as a basic model to study the behavior of the graft in the tympanic membrane. Also, basic concepts for the use of combined instrumentation are established in the treatment of eardrum lesions, as a refinement of the technical training application in microsurgery and assisted endoscopy in the transcochlear and translaberintic approaches and otoneurology areas. Copyright © 2012 Macías-Reyes. H

Early-life exposure to noise reduces mPFC astrocyte numbers and T-maze alternation/discrimination task performance in adult male rats

In this experiment, we evaluated the long-term effects of noise by assessing both astrocyte changes in medial prefrontal cortex (mPFC) and mPFC-related alternation/discrimination tasks. Twenty-one-day-old male rats were exposed during a period of 15 days to a standardized rats′ audiogram-fitted adaptation of a human noisy environment. We measured serum corticosterone (CORT) levels at the end of the exposure and periodically registered body weight gain. In order to evaluate the long-term effects of this exposure, we assessed the rats′ performance on the T-maze apparatus 3 months later. Astrocyte numbers and proliferative changes in mPFC were also evaluated at this stage. We found that environmental noise (EN) exposure significantly increased serum CORT levels and negatively affected the body weight gain curve. Accordingly, enduring effects of noise were demonstrated on mPFC. The ability to solve alternation/discrimination tasks was reduced, as well as the number of astroglial cells. We also found reduced cytogenesis among the mPFC areas evaluated. Our results support the idea that early exposure to environmental stressors may have long-lasting consequences affecting complex cognitive processes. These results also suggest that glial changes may become an important element behind the cognitive and morphological alterations accompanying the PFC changes seen in some stress-related pathologies