Effects of cutting height managements on yield and composition of different annual pastures

Danielli Dos Santos Comasseto,Renata Da Rosa Dornelles,Eduardo Avelino Faleiro,Deise Dalazen Castagnara,Eduardo Bohrer De Azevedo,Ricardo Pedroso Oaigen,Carine Rey Rodrigues,Augusto Gossmann Pinto,Tiago Antonio Del Valle

doi:10.1590/s1519-99402121282020

Danielli Dos Santos Comasseto, Renata Da Rosa Dornelles + Show 7 more

Open Access

https://doi.org/10.1590/s1519-99402121282020

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Abstract

ABSTRACT This study aimed to evaluate the effects of different pre-cutting and residual heights of Pearl millet, Sudangrass, and Sorghum pastures on yield, morphological and chemical composition. The experimental design was the randomized blocks, with four experimental units per treatment. It was evaluated three species of forage: 1) Pearl millet (MIL; Pennisetum americanum); 2) Sudangrass (SUD; Sorghum sudanense); and 3) Sorghum (SOR; Sorghum bicolor); and two cutting managements: I) 50:20 - cutting height at 50 cm and 20 cm residual height; and II) 85:10 - cutting height at 85 cm and 10 cm residual height. Managements of cutting height affected neither forage yield per cut nor total forage yield. Sudangrass had less cuts than MIL and SOR when submitted to the 50:20 management. The 85:10 management increased stem proportion and leaf to stem ratio, and reduced leaf proportion in comparison with the 50:20 management. The 50:20 management reduced forage contents of fiber and organic matter, and increased forage contents of crude protein and total digestible nutrient. Sorghum exhibited greater nutritive value due to increased leaf proportion. The 50:20 management increased number of cuts and improved nutritive value of forages, regardless of species evaluated in this study.

Highlights

The global requirement for animal products has improved in recent years, which needs to be associated with biosecurity and economic standards, becoming a challenge to farmers
Fonseca et al (2012) studied different pasture managements of SOR and found that herbage intake was increased using a management of 50 cm pre-grazing height and 20 cm residual height (i.e. 40% of the pre-grazing height)
This study evaluated three species of forage: 1) Pearl millet [Pennisetum americanum (L.) BRS 1503®, Embrapa]; 2) Sorghum (Sorghum bicolor 2501C; 3) Sudangrass (Sorghum sudanense BRS Estribo®, Embrapa); and two cutting height managements: I) 50:20 - cutting height at 50 cm and 20 cm residual height; and II) 85:10 - cutting height at 85 cm and 10 cm residual height

Summary

Introduction

The global requirement for animal products has improved in recent years, which needs to be associated with biosecurity and economic standards, becoming a challenge to farmers. Different forages and managements, need to be evaluated to obtain forages with nutritive value that converges towards the animal production goals (HUNT et al, 2014). In subtropical regions, such as the Southern region of Brazil, dry periods during the summer are frequent, compromising crop production (GOMES et al, 2015). To the best of our knowledge, there is no study evaluating differences in production and nutritive value of MIL, SOR, and SUD when pastures are submitted to different cutting height managements. This study evaluated the differences between MIL, SOR, and SUD when managed with pre-cutting and residual heights of 85:10 and 50:20, respectively

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