Productivity and reserve carbohydrates of pastures under cutting intensities

There is a need to better understand the effects that cutting or grazing exert on forage, thus to facilitate planning of management that will not be detrimental to the productivity or persistence of the plants. To this end, experimentation was conducted in the pastures of the Experimental Station of Empresa Pernambucana de Pesquisa Agropecuária, Itambé-PE to determine the effect of height of cutting on dry matter production (DMP), daily rate of DMP, total N accumulation, and concentration of reserve carbohydrate (RC) in the herbage. A completely randomized experimental design was used, with five replicates per treatment: Brachiaria decumbens and B. humidicola cut at heights of 5, 15, and 25 cm and at 25 cm plus 80 kg of N/ha; and Pennisetum purpureum cut at 5, 25 and 50 cm and 50 cm plus 80 kg of N/ha. Four cuttings took place, the first during the transitional season from dry to wet (Februrary 2001), and three during the wet season (April, July, and August 2001). The 5 cm cutting height resulted in the greatest DMP and total N accumulation. There was a tendency toward higher concentration of RC in the grass harvested in the transition period during which B. decumbens showed higher RC values than the other two species

Swine and Poultry Pathogens: the Complete Genome Sequences of Two Strains of Mycoplasma hyopneumoniae and a Strain of Mycoplasma synoviae

This work reports the results of analyses of three complete mycoplasma genomes, a pathogenic (7448) and a nonpathogenic (J) strain of the swine pathogen Mycoplasma hyopneumoniae and a strain of the avian pathogen Mycoplasma synoviae; the genome sizes of the three strains were 920,079 bp, 897,405 bp, and 799,476 bp, respectively. These genomes were compared with other sequenced mycoplasma genomes reported in the literature to examine several aspects of mycoplasma evolution. Strain-specific regions, including integrative and conjugal elements, and genome rearrangements and alterations in adhesin sequences were observed in the M. hyopneumoniae strains, and all of these were potentially related to pathogenicity. Genomic comparisons revealed that reduction in genome size implied loss of redundant metabolic pathways, with maintenance of alternative routes in different species. Horizontal gene transfer was consistently observed between M. synoviae and Mycoplasma gallisepticum. Our analyses indicated a likely transfer event of hemagglutinin-coding DNA sequences from M. gallisepticum to M. synoviae