Evaluation of a Grazing Livestock Production System on Irrigated Tanzânia grass (Panicum maximum Jacq.)

• Grant number: 98/05805-5
• Support Opportunities: Research Projects - Thematic Grants
• Start date: January 01, 1999
• End date: September 30, 2003
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Moacyr Corsi
• Grantee: Moacyr Corsi
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Pesquisadores principais: Luiz Gustavo Nussio ; Marcos Vinícius Folegatti ; Max Lázaro Vieira Bose ; Ricardo Ferraz de Oliveira

Abstract

The project 'Evaluation of a Grazing Livestock Production System on Irrigated Tanzânia grass (Panicum maximum Jacq.)' will be carried out in pasture area established with Tanzânia grass (Panicum maximum Jacq.) dominant pastures irrigated by a center pivot irrigation system. The objectives of this research are to provide data to support economic and decision analysis in irrigated pastures and the development of a dynamic simulation model for livestock production from irrigated tropical pasture. This project includes the following areas of knowledge: soil science, plant physiology, pasture management, animal production and irrigation. The trials that will be conducted in this project will be related to: the dynamics of soil physical proprieties; soil organic matter dynamics; microbial biomass; different levels of post-graze residue (i.e. post-graze herbage mass) on the dynamics of root mass and carbohydrates reserve associated with physiological parameters and productivity indexes; tillering ontogeny of the forage crop; animal performanc; pasture production, utilisation and wastage; evaluation of herbage intake and rumen kinetics; evaluation of starch level and protein with different levels of ruminal degradability under two levels of post-graze residue and measurement of evapotranspiration in order to establish plant water demand. The trials will be accomplished in a 5.2 ha irrigated area. This area will be split out into 4 blocks, with three levels of post-graze residue (1000; 2500 and 4000kg DM/ha). The grazing cycle will be 36 days (3 days of grazing followed by 33 days rest.)Fertiliser will be applied when the animals area shifted to the next paddock, during the growth season. The post-graze residue will be determined by adjusting stocking rate; that is, higher stocking rates will be used to decrease in the treatments where it was planed. Beyond allowing economic analysis and simulation model development, this work will yield knowledge on: modifications on the soil physical structure due to animal trampling, which can reduce root growth after defoliation, in order to aid decision making on pasture management; evaluate grass tillering to identify the most important tiller types for forage production and to suggest pasture management strategies, evaluate animal performance, production and wastage under three levels of post-graze residue, establishing adequate stocking rate, grazing pressure (herbage allowance) and post-graze residue to maximise animal performance and utilisation of available pasture; evaluate rumen kinetics and consequently improve the understanding of the digestion process by the animal, so that diet formulation can be improved in such conditions, evaluate the use of supplements with different levels of starch and protein degradability for grazing livestock; verify the water demand by the pasture to establish frequency and intensity of irrigation. (AU)