Diferentes intervalos de arraçoamento de matrizes avícolas tipo corte na fase de recria e seus efeitos na fase produtiva Different intervals of feeding in broiler breeders in growing period and its effects in the production phase

Matrizes avícolas, tipo corte (linhagem Ross), foram submetidas a três intervalos de arraçoamento: T1=48/48h, T2=programa 5/2 e T3=48/57/63h. O período de recria foi da 5&ordf; até a 20&ordf; semana. As variáveis estudadas neste ensaio foram: uniformidade de peso corporal, viabilidade criatória, ganho de peso e conversão alimentar. Na fase de produção (29&ordf; a 44&ordf; semana de idade), avaliou-se o efeito residual das aves submetidas aos tratamentos da fase de recria sobre os parâmetros produtivos. As variáveis estudadas foram: produção de ovos, peso médio de ovos, ovos incubáveis e conversão alimentar por dúzia de ovos. Os dados foram submetidos à análise de variância e as diferenças comparadas pelo teste de Tukey. Durante o período de recria, o aumento do intervalo de arraçoamento (T3) apresentou melhor uniformidade de peso corporal, bem como melhor conversão alimentar (P<0,05). O consumo de ração foi preestabelecido, não sendo, portanto, analisado estatisticamente. A viabilidade criatória não diferiu significativamente (P>0,05) nos períodos estudados. Os parâmetros ganho de peso e a conversão alimentar apresentaram piores resultados para as aves que receberam o menor intervalo de arraçoamento (P<0,05). Na fase de produção, os tratamentos não proporcionaram diferenças (P>0,05) quanto aos parâmetros estudados, pois os dados de produção mostraram-se homogêneos para os diferentes tratamentos.<br>Broiler breeders (Ross Line) were submitted to three different systems of feeding intervals namely: T1= 48/48h, T2 = scheme 5/2 and T3 = 48/57/63h. The study 1 was during the growing period from the fifth to the twentieth week. The variables studied in this assay were: body weight, uniformity, viability, weight gain and feed conversion. In the study 2, which as developed from the 29th to 44th week of age, the residual effect of the assay 1 was evaluated in regard to the productivity parameters. The variables mensured were egg production, egg weight, hatchability percentage and feed conversion per eggdozen. Data collected were subjected to analyses of variance and the differences were compared by the Tukey test. In the study 1 the increasing feed intervals resulted in better body weight uniformity as well as better feeding conversion (P<0.05). The feed consumption was pre-established and it was not statistically analyzed. The production viability did not show significant differences (P>0.05). The results were lower in the parameters of weight of gain and feed conversion for the birds that had received the smaller feed interval (P<0.05). In the second study (production period), the treatments did not show differences relating to the parameters studied (P>0.05), the production data shoved hight similarity in the different treatments

Effects of green tea polyphenols, insulin-like growth factor I and glucose on developmental competence of bovine oocytes

The present study examined the effects of green tea polyphenols (GTP), insulin-like growth factor-I (IGF-I) and glucose on oocyte in vitro maturation, subsequent embryo development and blastocyst quality in bovine. Cumulus-oocyte complexes (COC) were aspirated from the ovaries and cultured in synthetic oviduct fluid supplemented with MEM amino acids (SOFaa) media supplemented with one of the following supplements: GTP (0, 10, 15 and 20 µM), IGF-I (0, 50, 100 and 150 ng/mL) or glucose (0, 1.5, 5.6 and 20 mM) for 24 h. The results showed that oocytes cultured in media supplemented with 15 µM GTP, 100 ng/mL IGF-I and 5.6 mM glucose, in separate experiments, have higher cleavage and blastocyst rates compared with oocytes cultured in media without or with other concentration of GTP, IGF-I and glucose. Then these three substances with the concentration above were added together into SOFaa media and constituted a modified medium (Modified SOFaa). The COC were cultured in control SOFaa media and modified SOFaa media, respectively. The results showed that modified SOFaa media increased the intracellular glutathione concentration of matured oocytes, blastocyst rates and total cell numbers and cell numbers of inner cell mass per blastocyst compared with the control. Supplementing of GTP, IGF-I and glucose synchronously to maturation media can increase the intracellular GSH concentration of oocytes after in vitro maturation, and improve the embryo development and blastocyst quality in bovine

Structural aspects of the zygotic embryogenesis of Acca sellowiana (O. Berg) Burret (Myrtaceae)

(Structural aspects of the zygotic embryogenesis of Acca sellowiana (O. Berg) Burret (Myrtaceae)). Acca sellowiana has anatropous, bitegmic and crassinucellate ovules. The outer and inner integuments are double-layered except in the micropyle, where they are composed of more layers; the micropyle is zig-zag shaped. The egg apparatus lies at the micropylar pole, and the zynergids present a conspicuous filiform apparatus. The antipodal cells are present in the chalazal region, persisting before the occurrence of double fertilization. The zygote is visible 21 days after pollination; nuclear endosperm is already present. The first mitotic division of the zygote occurs at 24(th) day. The globular, cordiform and torpedo embryo stages can be seen at 30, 45 and 60 days after pollination, respectively. The mature embryo characterized by the presence of a well-developed hypocotyl-radicular axis with two fleshy and folded cotyledons was observed 120 days after pollination. Endosperm is absent in the seeds, and the embryo has spiral form, characteristic of Myrtinae. The zygotic embryology studies of A. sellowiana indicate that this species has embryological characteristics which are in agreement with those reported for Myrtaceae (Myrteae, Myrtinae), and also broaden the knowledge about the sexual reproduction of this native species, whose commercial cultivation has been growing

Involvement of Plant Hormones and Plant Growth Regulators on in vitro Somatic Embryogenesis

In spite of the importance attained by somatic embryogenesis and of the many studies that have been conducted on this developmental process, there are still many aspects that are not fully understood. Among those features, the involvement of plant hormones and plant growth regulators on deTermining the conversion of somatic onto embryogenic tissues, and on allowing progression and maturation of somatic embryos, are far away from being completely comprehended. Part of these difficulties relies on the frequent appearance of contradictory results when studying the effect of a particular stimulus over a specific stage in somatic embryogenesis. Recent progress achieved on understanding the interaction between exogenously added plant growth regulators over the concentration of endogenous hormones, together with the involvement of sensitivity of the tissues to particular hormone groups, might help clarifying the occurrence of divergent patterns in somatic embryogenesis, and in tissue culture in general. The aspects described above, emphasizing on the effect of the concentration of plant hormones and of the addition of plant growth regulators during the different phases of somatic embryogenesis, will be reviewed in this paper. Citations will be limited to review articles as much as possible and to individual articles only in those cases in which very specific or recent information is presented.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS