Pasture structure and production of supplemented cattle in deferred signalgrass pasture

Anselmo de Deus Santos,Dilermando Miranda da Fonseca,Braulio Maia de Lana Sousa,Manoel Eduardo Rozalino Santos,Angélica Nunes de Carvalho

doi:10.1590/1809-6891v21e-43578

Abstract

Abstract The effects of supplement doses (0, 1, 2 and 3 kg ha-1 day-1) and grazing periods (1, 28, 59, 89 and 103 days) on the B. decumbens cv. Basilisk structure and cattle production in deferred pastures were evaluated. The design was a randomised complete block design with two replications. The sward height and the total forage and stem masses decreased with grazing period. The crude protein (8.12%) and in vitro organic matter digestibility (52.74%) were not affected by grazing period. The fibre content in neutral and acid detergent increased linearly with the grazing period. The average daily gain of cattle ranged from 0.419 to 1.019 kg animal-1 day-1; the stocking rate ranged from 2.7 to 3.9 animal unit ha-1; and the average gain per area ranged from 2.7 to 7.9 kg ha-1 day-1, with the maximum values obtained with the highest dose of concentrate. Concentrate supplementation increases cattle production in deferred pastures. During the use of deferred pasture in winter there are decreases in the quantity and quality of forage, as well as limitations in its structure.

Highlights

Pastures are an important source of food in Brazil, seasonal forage production results in limited animal performance throughout the year
There was a reduction in pasture height and plant extended height when animals were supplemented with 1 kg animal-1 day-1, with a subsequent increase in values of these variables with levels of 2 and 3 kg animal-1 day-1 (Table 1)
There was an interaction (P < 0.10) between supplement level and grazing period for falling index (Table 1). This response can be best understood by analysing the extreme levels of the grazing period (1 and 103 days) of the secondary factor at each primary factor level (Figure 2)

Summary

Introduction

Pastures are an important source of food in Brazil, seasonal forage production results in limited animal performance throughout the year. To increase the efficiency of concentrated supplementation, forage availability and deferred pasture structure should not limit animal consumption[1] These conditions can be obtained by proper pasture management before the deferment period. It is noteworthy that forage availability decreases and the canopy structure becomes limited during the grazing period, due to the phenological alteration of the plants and the effect of grazing itself[5] These changes in deferred pasture structure in the grazing period affect ingestive behaviour and animal performance. In this sense, understanding of the plant–animal interface during the grazing period, under conditions of concentrate supplementation, may help in the recommendation of more efficient management practices in deferred pastures.

Material and methods

Results and discussion

Conclusions