Dissertação
Avaliação de dois sistemas forrageiros sob pastejo com vacas leiteiras
Fecha
2009-02-06Registro en:
STEINWANDTER, Edilene. Two based-pasture systems evaluation under grazing with dairy cows. 2009. 112 f. Dissertação (Mestrado em Zootecnia) - Universidade Federal de Santa Maria, Santa Maria, 2009.
Autor
Steinwandter, Edilene
Institución
Resumen
The objective of this work was evaluate two pasture-based systems (PS) with
elephantgrass (Pennisetum purpureum Schum.), ryegrass (Lolium multiflorum Lam.), and
spontaneous growth species varying in one system, the mixture with white clover (Trifolium
repens L.) and, in the other system, with forage peanut (Arachis pintoi Kraprov & Gregory),
handled under rotational grazing. The experiment was done from April 24th, 2007 to April
30th, 2008, totalizing 371 days. In order to evaluate were used four paddocks with 0.25 ha
each one, where the elephantgrass was established in lines with a distance of 4 m between
lines. In the winter period, in space between lines, was established the ryegrass and in two
paddocks the white clover was sown and, in the other two, the forage peanut was preserved,
which had already been established. The experimental design was completely randomized,
with two treatments (pasture-based systems), two replicates (paddocks) and in subdivided
parcels in the time (grazing cycles). The grazing were fertilized with 100, 60 and 100kg/ha de
N, P2O5 and K2O, respectively. As experimental animals were used Holstein cows, in
lactation, receiving 6 and 5 kg of complementary concentrate feed in winter and summer
periods, respectively. The cows live weight was 514±35.9 kg and mean milk production of
20.80±2.23 kg/day. During the evaluation 11 grazing were done, six in the winter period,
defined by ryegrass, and 5 in the summer period where the pre and post grazing were
analyzed; the botanical compositions of grazing and structural of elephantgrass, ryegrass and
legumes; accumulation rates and of disappearance of forage mass; stocking rate and pasture
chemical composition (by samples of grazing simulation). The results show that the appraised
botanical composition, in each treatment, contributed to compensate the offer and the forage
chemical composition during the year. It was verified a better performance in the pasturebased
system, using the forage peanut, considering the mean of the accumulation taxe and of
disappearance of forage mass. Pasture-based systems showed similar chemical composition,
indicating, the need of improving pasture-based systems to raise the pasture mass production
at the start winter period, mainly the legumes contribution.