Impact of Grazing Management on Productivity of Tropical Grasslands

Beef and dairy cattle enterprises from tropical pasture-based systems are notoriously of low productivity. The low soil fertility, the exploitation of native grasslands, the low genetic potential of the animals and the poor management of soil, pasture and animal components are all arguments used to explain these “low-productivity systems”. In fact, research has consistently indicated up to 50% increase in calving rate when animals grazing unfertilized pastures were supplemented with trace-mineralized salt (Table 1) but unfortunately less than 90% of Brazilian farmers use this management strategy (Tosi, 1997). However, a recent survey conducted by São Paulo State government showed that almost 90% of farmers in the State use mineralized salt as a supplement (São Paulo, 1997). Similarly, well-fertilized and managed tropical pastures frequently have enough phosphorus in plant tissues to meet mineral requirements of most grazing animal categories (Table 2) and this might represent a significant reduction in mineral supplementation costs. Nevertheless, farmers do not frequently adopt use of fertilizers. A 1997 survey revealed that only 663.000 tons of NPK fertilizers were annually applied to 90 million ha of introduced pastures in Brazil, e.g., ca. 7,4 kg of NPK fertilizer/ha of pasture per year (ANDA, 1996/1997, cited by Ferreira et al., 1999)

Haplo-Cord Transplantation Using CD34+ Cells from a Third-Party Donor to Speed Engraftment in High-Risk Patients with Hematologic Disorders

AbstractAmong the strategies to optimize engraftment of cord blood (CB) stem cell transplantation (SCT), single CB with the coinfusion of CD34+ stem cells from an HLA-mismatched auxiliary donor (haplo-cord) provides a valid alternative for adult patients without a suitable donor. A total of 132 high-risk adult patients with hematological malignancies from 3 Spanish institutions underwent myeloablative haplo-cord SCT. The median age was 37 years and median weight was 70 kg; 37% had active disease. The median number of postprocessing CB total nucleated and CD34+ cells was 2.4 × 107/kg (interquartile range [IQR], 1.8 to 2.9) and 1.4 × 105/kg (IQR, .9 to 2), respectively. Neutrophil engraftment occurred in a median of 11.5 days (IQR, 10.5 to 16.5) and platelet engraftment at 36 days (IQR, 25.5 to 77). Graft failure was 2% overall and only 9% for CB. Cumulative incidence of acute graft-versus-host disease (GHVD) grades II to IV was 21% and cumulative incidence of chronic GVHD was 21%. Median follow-up was 60 months (range, 3.5 to 163). Overall survival was 43.5%, event-free survival was 38.3%, nonrelapse mortality was 35%, and relapse was 20% at 5 years. Myeloablative haplo-cord SCT results in fast engraftment of neutrophils and platelets, low incidences of acute and chronic GVHD, and favorable long-term outcomes using single CB units with relatively low cell content. Moreover, CB cell dose had no impact on CB engraftment and survival in this study. Therefore, haplo-cord SCT expands donor availability while reducing CB cell dose requirements

Morphogenetic characteristics and management of Tanzania grass Características morfogenéticas e manejo de capim-tanzânia

The objective of this work was to evaluate the effect of grazing interval and period of evaluation over tissue turnover in Tanzania grass pastures (Panicum maximum cv. Tanzania) and to ascertain if herbage accumulation rate can be used as a criterion to establish a defoliation schedule for this grass in Southeast of Brazil. A randomized block design with a split-plot arrangement was used. The effect of three grazing intervals was evaluated within seven periods between October 1995 and September 1996. Responses monitored were leaf and stem elongation rates, leaf senescence rate, stem length, and tiller density. Net herbage accumulation rate was calculated using tissue turnover data. The grazing intervals for Tanzania grass should be around 38 days between October and April (spring and early autumn) and 28 days during the reproductive phase of the grass (April/May). Between May and September (late autumn and winter), grazing interval should be around 48 days. Herbage accumulation rate is not a good criterion to establish defoliation time for Tanzania grass. Studies on the effects of stem production in grazing efficiency, animal intake and forage quality are needed to improve Tanzania grass management.<br>O objetivo deste trabalho foi avaliar o efeito do intervalo entre pastejos e do período de avaliação sobre algumas características morfogenéticas do capim-tanzânia (Panicum maximum cv. Tanzânia) e verificar se o manejo desse capim pode ser baseado na taxa de acúmulo de matéria seca na região Sudeste do Brasil. Foi utilizado um delineamento de blocos completos ao acaso com parcelas subdivididas no tempo. Foi avaliado o efeito de três intervalos entre pastejos e de sete períodos de avaliação entre outubro de 1995 e setembro de 1996 sobre: taxa de alongamento foliar e dos colmos, taxa de senescência foliar, altura dos colmos e densidade populacional de perfilhos. Essas informações permitiram determinar a taxa líquida de acúmulo de matéria seca. O capim-tanzânia deve ser pastejado com cerca de 38 dias no período de outubro a abril, com 28 dias na fase reprodutiva (abril/maio) e com aproximadamente 48 dias entre maio e setembro. O intervalo entre pastejos do capim-tanzânia não deve ser estabelecido apenas com base na taxa de acúmulo de matéria seca. São necessários estudos sobre as interações entre produção de hastes e eficiência de pastejo, consumo e qualidade de forragem, a fim de se determinar melhor o manejo desse capim