Crescimento, comportamento ingestivo e desempenho reprodutivo de novilhas mestiças holandês x zebu, em pastejo, submetidas à suplementação protéica durante a época das águas

The objective of this study was to evaluate the effect of supplemental protein during the rainy season on body growth, ingestive behavior and reproductive performance of crossbred Gir x Holstein dairy heifers, with mean age of 21 ± 4.1 months and average initial body weight of 296.7 ± 57.3 kg, distributed in a completely randomized design with four treatments and six replicates per treatment. Heifers remained on Brachiaria brizantha cv. Marandu pasture, managed according to a rotational grazing system and, as treatment, it was supplemented with protein concentrate (34%, 43%, 56% and 66% BW) and level of supply of 0.30% body weight (BW). The animals were weighed and the mean weight of the lot was used for the calculation of adjustment of the amount of concentrate offered. Heifers that reached 330.0 kg of live weight were artificially inseminated and, 45 days after insemination, pregnancy diagnosis was performed for the calculation of pregnancy rate and age at conception. No significant difference of protein levels was observed on grazing, eating behavior, productive performance and age at conception of dairy heifers on pasture. The average daily weight gain of BW and age at conception were, on average, 0.907 kg/animal and 24.03 months, respectively.

Trait contributions to fish community assembly emerge from trophic interactions in an individual-based model

Community ecology seeks to understand and predict the characteristics of communities that can develop under different environmental conditions, but most theory has been built on analytical models that are limited in the diversity of species traits that can be considered simultaneously. We address that limitation with an individual-based model to simulate assembly of fish communities characterized by life history and trophic interactions with multiple physiological tradeoffs as constraints on species performance. Simulation experiments were carried out to evaluate the distribution of 6 life history and 4 feeding traits along gradients of resource productivity and prey accessibility. These experiments revealed that traits differ greatly in importance for species sorting along the gradients. Body growth rate emerged as a key factor distinguishing community types and defining patterns of community stability and coexistence, followed by egg size and maximum body size. Dominance by fast-growing, relatively large, and fecund species occurred more frequently in cases where functional responses were saturated (i.e. high productivity and/or prey accessibility). Such dominance was associated with large biomass fluctuations and priority effects, which prevented richness from increasing with productivity and may have limited selection on secondary traits, such as spawning strategies and relative size at maturation. Our results illustrate that the distribution of species traits and the consequences for community dynamics are intimately linked and strictly dependent on how the benefits and costs of these traits are balanced across different conditions. © 2012 Elsevier B.V.

Parâmetros genéticos de características associadas à integridade óssea em frangos de corte

Pós-graduação em Zootecnia - FCAV

Ajustes de curvas de crescimento e estimativas da variabilidade genética de peso corporal de avestruzes (Struthio camelus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modelos de crescimento e das respostas de frangas de postura submetidas a diferentes ingestões de aminoácidos sulfurados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação do ganho de peso e aspectos reprodutivos de primíparas zebuínas suplementadas com uréia no período seco

Este trabalho teve como objetivo avaliar o desempenho produtivo e reprodutivo de vacas de corte primíparas, suplementadas com uréia no período seco. Foram utilizadas 58 fêmeas mestiças Tabapuã x Nelore, prenhas, com idade média de 39 meses e peso médio de 399 kg. Os animais experimentais foram vermifugados e divididos em dois grupos, um grupo (A) suplementado com sal mineral e o outro (B) com sal mineral enriquecido com uréia, na proporção de 80:20 (sal:uréia). Os animais foram mantidos em uma área de 50 hectares de capim Brachiaria brizantha, sendo 25 hectares para cada grupo. Durante os meses de agosto a novembro, período mais seco do ano na região, o pasto apresentou em média 5.800 kg de matéria seca por hectare com 6,2% de proteína bruta. As misturas minerais foram administradas em cochos cobertos de forma a atender um consumo ad libitum durante o período seco. O delineamento experimental utilizado foi o inteiramente casualizado com dois tratamentos. Foi verificada diferença no peso vivo ao final do experimento (PVF) entre os tratamentos com sal mineral e sal mineral com uréia, com valores médios de 360,1 kg e 385,8 kg, respectivamente. Também foi observada diferença para o ganho médio diário, com média de 0,465 kg/an/dia para o grupo tratado com uréia, e 0,284 kg/an/dia para o grupo controle, com ganho pós-parto de 41,2 e 26,5 kg/animal, respectivamente. O melhor desempenho dos animais suplementados deve estar relacionado ao aumento no consumo de matéria seca promovido pela suplementação com uréia (12,610 kg contra 8,744 kg). O melhor desenvolvimento corporal (peso e escore corporal) ao início da estação de monta refletiu na manifestação de cio dos animais, sendo que 75% das vacas suplementadas com uréia já haviam manifestado cio durante os primeiros 60 dias da estação de monta contra apenas 53,33% das não suplementadas. Quando se avaliou o período integral da estação de monta não foi observado diferença entre a manifestação de cio das fêmeas suplementadas ou não, fato relacionado ao bom escore corporal apresentado pelos animais ao fim da estação de monta, 3,7 nas fêmeas suplementadas e 2,9 nas não suplementadas.

Anatomical evaluation of the cervical vertebrae of Wistar rats by means of digital radiographs and its correlation with the maturation stages of human cervical vertebrae

INTRODUCTION: Biological age is an important parameter for growth and development assessment. It can be evaluated through the observation of radiographic changes in skeletal maturation of cervical vertebrae. OBJECTIVE: This study aims to: a) verify if there is correlation between growth curve and the stages of bone age of animals used in laboratories, by evaluating radiographs of the cervical vertebrae; b) correlate these stages with their correspondents in humans. METHODS: 35 Wistar rats were evaluated for a period of 160 days, starting at day 22nd (weaning), with cross sections for periodic weighing, length measurement and digital radiography. Radiographs of the cervical vertebrae (C2 and C3) were measured by means of a computer program (Radio IMP). Data were submitted to statistical analysis (ANOVA) and Pearson correlation. RESULTS: Growth spurt was characterized by fast increasing in weight and length. Through ANOVA, differences were observed in the cervical measurements between days 22, 97, 127, 157, 187 and 217 (p <0.001). A high correlation was found between increasing in body length and weight, as well as in cervical vertebrae height (r = 0.86). Increments in concavities of vertebrae were also observed, similar to humans. CONCLUSIONS: There is correlation between body growth and maturation of cervical vertebrae in rats. Despite the continuous development of concavities, it was not possible to clearly identify the 5/6 stages as in studies of cervical vertebrae maturation in humans.

Desempenho de novilhos Nelore confinados alimentados com óleo de linhaça in natura ou protegido

Pós-graduação em Zootecnia - FCAV

Respiratory immunohistochemical study in rats exposed to cigarette smoke and alcohol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparação do desenvolvimento neurológico entre os gêneros em alunos ingressantes no ensino fundamental em uma escola municipal em Bauru

Human beings' motor capacity development is essential, because it facilitates movement, enabling the performance of motor activities and others. In pre-school, boys and girls acquire the motor capacity development considered basic that, through several factors such as neurological maturation, which is in charge of providing more complete movements, and body growth, which has the goal of a better body domain, makes them improve individually the performance of motor abilities, but it can minimize them if laterality does not develop spontaneously. There by, this study focused on assessing the neurological development between genders of students engaging in fundamental school. Forty-three children of both genders at age six took part in this study. The evaluation occurred through the LEFÉVRE protocol (1976), which aims at assessing the maturity and development of the Nervous System through tests of the Evolutionary Neurological Exam (ENE), which comprises a series of tests involving specific tasks, regarding age in the static balance items, dynamic balance, appendicular coordination, trunk-member coordination, motor persistency, sensibility and synkinesis. Neurological development comparisons were performed between boys and girls for each item of the battery of tests. The results of the motor persistency and sensitiveness and sensorial activity tests were below the average for six-year-old children, but there was not any difference in gender comparison for each item of the battery of tests, only a small tendency for one of the genders, but meaningless, having a variance in only two tests of the synkinesis exam (Foot-hand and paper ball with the dominant hand), in which boys had a bigger percentage of synkinesis presence than girls did. The results also showed that the majority of the children assessed, both boys and girls have a right manual and pedal preference and the ocular laterality is approximately the same for left and right-handers. It was..

Life history and DNA barcode of Oxyurella longicaudis (Birgei, 1910) (Cladocera, Anomopoda, Chydoridae)

Background: Cladocera is an important group of freshwater zooplankton, and the species plays an important role in energy transfer and in aquatic food webs. Oxyurella longicaudis is a Chydoridae species that has been recorded in North and South America. The aim of this study is to investigate the life cycle aspects of parthenogenetic females of O. longicaudis cultured in laboratory under controlled conditions: temperature (23 degrees C +/- 05 degrees C), photoperiod (12 h light/12 h dark), food supply, and reconstituted water.Results: Embryonic development duration (2.3 +/- 0.5 days), post-embryonic development (5.2 +/- 0.69 days), mean fecundity (two eggs female(-1) brood(-1)), total egg production (22.55 +/- 3.98 eggs), average longevity (58 days), and body growth of the species were recorded. We also report the first DNA barcode for O. longicaudis isolated in Brazil, which will allow for easy identification in future zooplankton community studies. The analysis shows a genetic divergence of around 7% between our Brazilian isolate and O. longicaudis isolates from Mexico.Conclusions: The time of embryonic and post-embryonic development of O. longicaudis was higher than that of the other species of the same family, which contributed to lower total egg production throughout its life cycle. The genetic divergence appears to be sufficient to classify the two isolates as different species.

Glyphosate impairs male offspring reproductive development by disrupting gonadotropin expression

Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring. Sixty-day-old male rat offspring were evaluated for sexual behavior and partner preference; serum testosterone concentrations, estradiol, FSH and LH; the mRNA and protein content of LH and FSH; sperm production and the morphology of the seminiferous epithelium; and the weight of the testes, epididymis and seminal vesicles. The growth, the weight and age at puberty of the animals were also recorded to evaluate the effect of the treatment. The most important findings were increases in sexual partner preference scores and the latency time to the first mount; testosterone and estradiol serum concentrations; the mRNA expression and protein content in the pituitary gland and the serum concentration of LH; sperm production and reserves; and the height of the germinal epithelium of seminiferous tubules. We also observed an early onset of puberty but no effect on the body growth in these animals. These results suggest that maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters. These changes associated with the hypersecretion of androgens increased gonadal activity and sperm production.

Evaluation of mannan-oligosaccharides offered in milk replacers or calf starters and their effect on performance and rumen development of dairy calves

The objective of this study was to evaluate the route of administration of mannan-oligosaccharides in the diet of dairy calves and their effects on performance and plasma parameters indicative of rumen development. Following birth, twenty-four male Holstein calves were used in a completely randomized design and assigned to the following treatments: Control; 4 g/d Bio-Mos (R) (Alltech Biotech.) added to starter concentrate; and 4 g/d Bio-Mos (R) mixed into milk replacer. Animals were housed in individual hutches with free access to water, and fed 4L/d of milk replacer until weaning at six weeks. Calves also received 23g/kg crude protein of starter concentrate ad libitum. Fecal scores were evaluated daily. Body weights, growth measurements and blood samples for glucose, urea-N and beta-hidroxibutyrate analyses were taken weekly until 8 weeks of age. There were no significant effects of treatment or treatment x age interactions for mean starter concentrate intake, weight gain or body growth. However, there was a significant age effect for all parameters. Fecal scores were not affected by treatments. Also, plasma concentration of glucose, urea-N or beta-hidroxibutyrate were not affected by treatment or the treatment x age interaction. However, urea-N and beta-hidroxibutyrate concentrations significantly increased with age, suggesting adequate rumen development. Under the conditions of this study, there were no calf performance benefits when mannan-oligosaccharides were incorporated into milk replacer or calf starter concentrate.

Population biology of the barbel drum Ctenosciaena gracilicirrhus (Metzelaar, 1919) (Perciformes: Sciaenidae) in Caraguatatuba Bay, Southeastern Brazil

This study evaluated the population biology of Ctenosciaena gracilicirrhus (Perciformes: Sciaenidae) in a shallow non-estuarine coastal area of southeastern Brazil. Monthly samples were taken from October 2003 through October 2004, in two distinct areas at depths from 1 to 4 m. C. gracilicirrhus was generally among the most abundant fish species during the period. Its density was significantly higher in a single sampling month, May 2004, in the South area, which may be explained by its migratory behavior together with its preference for deeper areas. Such behavior may lead to bias in community estimates that use few or only seasonal samples. C. gracilicirrhus individuals ranged from 4.0 to 10.2 cm long, with a main mode from 7.5 to 9.0 cm and a significant decrease in mean size from June onward. The estimation of body growth parameters was compromised by this population feature. Similarly, the prey spectrum was difficult to determine because of the deteriorated condition of the stomach contents, although crustaceans were clearly the most important items ingested. Amphipoda was the only subgroup that could be identified more precisely, mainly by the construction of their tubes.

Changes in food intake, metabolic parameters and insulin resistance are induced by an isoenergetic, medium-chain fatty acid diet and are associated with modifications in insulin signalling in isolated rat pancreatic islets

LLong-chain fatty acids are capable of inducing alterations in the homoeostasis of glucose-stimulated insulin secretion (GSIS), but the effect of medium-chain fatty acids (MCFA) is poorly elucidated. In the present study, we fed a normoenergetic MCFA diet to male rats from the age of 1 month to the age of 4 months in order to analyse the effect of MCFA on body growth, insulin sensitivity and GSIS. The 45% MCFA substitution of whole fatty acids in the normoenergetic diet impaired whole body growth and resulted in increased body adiposity and hyperinsulinaemia, and reduced insulin-mediated glucose uptake in skeletal muscle. In addition, the isolated pancreatic islets from the MCFA-fed rats showed impaired GSIS and reduced protein kinase Ba (AKT1) protein expression and extracellular signal-related kinase isoforms 1 and 2 (ERK(1/2)) phosphorylation, which were accompanied by increased cellular death. Furthermore, there was a mildly increased cholinergic sensitivity to GSIS. We discuss these findings in further detail, and advocate that they might have a role in the mechanistic pathway leading to the compensatory hyperinsulinaemic status found in this animal model.