Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW) as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively) were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture

Practical technologies for the improvement of pastures in Central America. Conference paper

3 tab. 14 ref. Sum. (En). ReportAnimal production in tropical regions has lagged behind plant production and the main reason is that there has been little application of forage production improvement. For all but the (semi-arid) regions technology is available for forage production improvement for the different animal production systeMON, ranging from intensive dairying to extensive ranching. The key to improvement is the use of legumes with minimal fertiliser inputs. The adoption of forage production improvement depends on the need for improvement, the value and marketability of animal products, the motivation of farmers and the availability of resources. Sustainability of improved pastures is mainly a function of the persistence of the legumes. This in turn depends on the growth habit of the plant and management. Trailing species are most sensitive to high grazing pressure, whilst prostrate species are the most tolerant. Erect species take an intermediate position