931 resultados para Reproductive Immunology


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The objectives of this study were to (1) evaluate if dietary lysine (Lys) has an effect on the free amino acid (FAA) pool of Yellow Perch Perca flavescens eggs, and (2) determine how dietary Lys influences the reproductive performance and eggs fertilization rate (embryo survival) of female Yellow Perch. Two-year-old Yellow Perch of initial size of approximately 75 g were randomly distributed into six 400-L tanks at 32 +/- 1 fish per tank. This experiment included two wheat gluten-based diets in triplicate Lys-deficient ([-] Lys) and Lys-supplemented ([+]Lys; 2.23% in dry feed) diets. Females from the reference group were fed a commercial diet. Females from reference, (+) Lys, and (-) Lys groups were stripped and their eggs divided into 0.4-1.2-g portions and mixed with sperm (21.4 +/- 4.3 mu L) from either reference, (+) Lys, or (-) Lys males. The mean weight of Yellow Perch females and mean total weight of ovulated eggs were the greatest in the reference group compared with both (+) Lys and (-) Lys groups. There were no differences in the ratio of weight of eggs to female body weight as well as egg size among groups. There was no difference among treatments in the concentration of free amino acids except glutamic and aspartic acids in Yellow Perch eggs. There was significant effect of female dietary treatments on the egg fertilization rate averaged across all males. The higher fertilization rate was observed in the reference and (+) Lys groups compared with the (-) Lys group. The effect of female dietary treatment on the egg survival was also dependent on the dietary treatment of males.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The phenology, flower morphology, pollination mechanism and reproductive biology of Epidendrum secundum were studied in a semi-deciduous forest at the Serra do Japi (SJ), and in the Atlantic rain forest of Picinguaba, both natural reserves in the State of Sao Paulo, southeastern Brazil. E. secundum flowers all year round, with a flowering peak between September and January. This species is either a lithophytic or terrestrial herb in the SJ, whereas, in Picinguaba, it grows mainly in disturbed areas along roadsides. E. secundum is pollinated by several species of diurnal Lepidoptera at both study sites. In Picinguaba, where E. secundum is sympatric with E. fulgens and both share the same pollinators, pollen transference between these two species was recorded. E. secundum is self-compatible but pollinator-dependent. It is inter-compatible with E. fulgens, producing fertile seeds. In contrast to the population of the SJ, in the Picinguaba region, floral morphology is quite variable among plants and some individuals present flowers with characteristics in-between both sympatric species, suggesting that natural hybridization occasionally occurs. The anthropogenic perturbation is probably the cause of the occurrence of E. secundum in the Picinguaba region, enabling its contact with E. fulgens.

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

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Temperament in cattle is defined as the fear-related behavioral responses when exposed to human handling. Our group evaluates cattle temperament using 1) chute score on a 1 to 5 scale that increases according to excitable behavior during restraint in a squeeze chute, 2) exit velocity (speed of an animal exiting the squeeze chute), 3) exit score (dividing cattle according to exit velocity into quintiles using a 1 to 5 scale where 1 = cattle in the slowest quintile and 5 = cattle in the fastest quintile), and 4) temperament score (average of chute and exit scores). Subsequently, cattle are assigned a temperament type of adequate temperament (ADQ; temperament score <= 3) or excitable temperament (EXC; temperament score > 3). To assess the impacts of temperament on various beef production systems, our group associated these evaluation criteria with productive, reproductive, and health characteristics of Bos taurus and Bos indicus-influenced cattle. As expected, EXC cattle had greater plasma cortisol vs. ADQ cattle during handling, independent of breed type (B. indicus x B. taurus, P < 0.01; B. taurus, P < 0.01; B. indicus, P = 0.04) or age (cows, P < 0.01; heifers or steers, P < 0.01). In regards to reproduction, EXC females had reduced annual pregnancy rates vs. ADQ cohorts across breed types (B. taurus, P = 0.03; B. indicus, P = 0.05). Moreover, B. taurus EXC cows also had decreased calving rate (P = 0.04), weaning rate (P = 0.09), and kilograms of calf weaned/cow exposed to breeding (P = 0.08) vs. ADQ cohorts. In regards to feedlot cattle, B. indicus EXC steers had reduced ADG (P = 0.02) and G:F (P = 0.03) during a 109-d finishing period compared with ADQ cohorts. Bos taurus EXC cattle had reduced weaning BW (P = 0.04), greater acute-phase protein response on feedlot entry (P <= 0.05), impaired feedlot receiving ADG (P = 0.05), and reduced carcass weight (P = 0.07) vs. ADQ cohorts. Acclimating B. indicus x B. taurus or B. taurus heifers to human handling improved temperament (P <= 0.02), reduced plasma cortisol (P < 0.01), and hastened puberty attainment (P <= 0.02). However, no benefits were observed when mature cows or feeder cattle were acclimated to human handling. In conclusion, temperament impacts productive, reproductive, and health characteristics of beef cattle independent of breed type. Hence, strategies to improve herd temperament are imperative for optimal production efficiency of beef operations based on B. taurus and B. indicus-influenced cattle.

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Function of the uterus is often compromised in cattle by bacterial contamination of the uterine lumen after parturition. Pathogenic bacteria often persist, causing uterine disease, a major cause of infertility in cattle. Knowledge of the immunological aspects of the uterus involved in maintaining reproductive healthiness is fundamental to the study of uterine infections that affect the uterus postpartum. Polymorphonuclear leukocytes have an important role because they are the first line of defense against colonization of bacteria in utero (Hammon and Goff, 2006). The establishment of uterine infection depends in parts of endocrine environment, particularly progesterone, which suppresses the immune system (Lewis, 2003). In the puerperium may occur uterine disorders, such as retained placenta, puerperal metritis, clinical and subclinical endometritis and pyometra, this review was proposed a study of the immunology involved in uterine health and a better understanding of uterine disorders, using the model of Sheldon et al. al, (2006) for classification of diseases, and a study of best treatment options and discussion about its functionality, because a lot of controversy among authors about choosing a treatment and another and between treated and untreated

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We investigated the reproductive biology of Knodus moenkhausii, an abundantsmall-sized characin fish with broad occurrence in the Parana River basin, Bra-zil. Specimens were collected monthly to determine fecundity, length at firstmaturity, reproductive period and spawning type. Gonads were macroscopically classified according to their form, size and texture in three different stages(immature, maturing or mature). Histological procedures were conducted toconfirm gonadal developmental stages, and it was possible to notice thatmaturing females actually presented atretic oocytes, and all males that weremacroscopically classified as immature, maturing and mature actually presentedabundant spermatozoa in their gonads. Because of these discrepancies, a reclas-sification of gonadal maturations stages was needed after histological analysis,reinforcing its importance to studies on the reproduction of small characins.Reproduction occurred throughout the year though with two peaks. The lengthof the smallest mature individuals was 13 mm SL for males and 24 mm SL for females. Despite presenting relatively small batch fecundity, some life historytraits such as early reproduction, multiple spawning throughout the year, inassociation with known opportunistic feeding habits, explain the high abun-dance of this species in locations where it occurs.

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

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