The fertilization in rangelands has a positive effect in the forage production. The increased nitrogen (N) availability improves plant growth and forage quality of native pastures. However, in the Pampa biome conditions of Rio Grande do Sul State, Brazil, these responses occur surprisingly fast and consistently. Therefore, the objective of this work was to quantify the N effect in the botanical composition of a natural pasture overseeded with annual ryegrass in Southern Brazil. The effects of three rates of N fertilization (zero, 100 and 200 kg N ha-1) were evaluated. Forage biomass was estimated on a monthly basis using the double sampling approach. The different botanical components of each forage sample were manually sorted in the laboratory. In order to calculate the Rényi diversity profile, two floristic composition evaluations were performed in the experimental area in December of 2010 and September of 2011. The ryegrass biomass production is highly affected by the N fertilization. The botanical composition of natural pastures modifies most probably by increasing ryegrass competition at early spring.

O presente trabalho teve como objetivo avaliar os componentes de produção e a qualidade das sementes de soja RR, em função da aplicação de doses crescentes de glyphosate. Os experimentos foram instalados em campo, no município de Mandaguari, Paraná, durante as safras 2006/2007 e 2007/2008. Os tratamentos foram compostos por cinco doses de glyphosate. Todas as aplicações foram realizadas em modalidade única entre o estádio V4 e V5. O delineamento experimental utilizado foi em blocos casualizados com quatro repetições. Os dados foram submetidos à análise de variância e; quando significativos, aplicou-se o teste t e análise de regressão aos tratamentos. Foram avaliadas a qualidade fisiológica e sanitária das sementes, a produtividade e a massa de mil sementes. Os resultados indicam que a qualidade das sementes pode ser afetada negativamente pelo glyphosate e, também, demonstram provável redução nos componentes de produtividade com incrementos na dose.

This study aimed to evaluate the production components and quality of RR soybean seeds (Roundup Ready®), after application of increasing rates of gliphosate. Field experiments were conducted in Mandaguari, Paraná, during two seasons. Treatments consisted of five doses of glyphosate. All applications were performed once, between development stages V4 and V5. The experiment was arranged in a completely randomized block design, with four replicates. Data were subjected to analysis of variance, and when significant, t-tests and a regression analysis were applied to verify the behavior of the treatments. The physiological and sanitary quality, yield and mass of one thousand seeds were evaluated. The results indicated that seed quality can be adversely affected by glyphosate, and also showed a probable reduction in yield components with increasing rates of application.

It was evaluated the oocyte and embryo in vitro production of 42 Nellore mixed breed cows (Bos taurus indicus) come from de same genetic group, aging from 4 to 9 years, with mean body weight of 420 kg, stimulated with FSH and eCG. The animals were distributed into three groups: group 1, control (n= 14), only with follicular aspiration (OPU); group 2, treated with 1400 UI of eCG in a single dose plus OPU (n= 14); and group 3, treated with 120 UI of FSH administered four times plus OPU with 12 h of interval (n= 14). All groups received auricular implant with 3 mg of Norgestomet on the first day (D0) associated with 2 mg of estradiol benzoate intramuscularly. At the seventh day (D7) the implants were removed and the ovarian aspirations were realized on the cows of group 1(OPU). Group 2 had the eCG applied at the fifth day and the OPU was performed at D7. The animals from group 3 were treated with FSH at fifth and sixth day and the aspiration occurred at D7 (OPU). The follicular aspiration procedure was done via transvaginal guided with ultrasound. It was performed 42 aspirations obtaining 627 oocytes, where 502 were viable and 125 non-viable. Then, it was realized the in vitro maturation and fecundation. The cleavage, blastocyst and eclosion rate were evaluated. There were no significant difference (p>0.05) at these parameters between the groups. In conclusion, the gonadotrophic stimulation with FSH and eCG, at the doses used in this study, was insufficient to increase the quality of the viable oocytes submitted to in vitro fertilization to produce embryos.

Avaliou-se a recuperação de oócitos e produção de embriões in vitro de 42 vacas, mestiça Nelore proveniente de grupo genético homogêneo, com idade de 4 a 9 anos, com peso médio de 420 kg, estimuladas com FSH ou eCG. Estas foram distribuídas em três grupos: grupo 1, controle (n=14), apenas OPU, grupo 2, tratadas com 1400 UI de eCG, em dose única seguida de aspiração folicular (OPU) (n= 14); e, grupo 3, tratadas com 120 UI de FSH, administrados com intervalo de 12 horas em quatro doses seguida de OPU (n= 14). Todos os grupos receberam implante auricular contendo 3 mg de Norgestomet no primeiro dia (D0) associado a administração de 2 mg de benzoato de estradiol via intramuscular. No sétimo dia (D7) foram retirados todos os implantes e na sequência foram realizadas as aspirações ovarianas das vacas do grupo 1. O grupo 2 recebeu a aplicação de eCG no quinto dia e a OPU foi realizada no D7. Já o grupo 3 recebeu o tratamento com FSH no quinto e sexto dia, e foram aspiradas em D7. O procedimento de aspiração folicular foi realizado via transvaginal guiada por ultrassom. Foram realizadas 42 aspirações com obtenção de 627 oócitos, sendo 502 viáveis e 125 inviáveis. Realizou-se a maturação e fecundação in vitro. Avaliaram-se as taxas de clivagem, blastocisto e eclosão. Não houve diferenças significativas (p>0,05) nos parâmetros avaliados entre os grupos. Conclui-se que o estímulo ovariano com FSH ou com eCG nas doses utilizadas, foram insuficientes para incrementar o número e a qualidade de oócitos viáveis submetidos a fertilização in vitro para produção de embriões.