Intercropping techniques improve pasture quality and beef cattle performance compared to livestock systems

Abstract

In integrated crop-livestock systems (ICLS), pasture is intercropped with crops to provide grain for feed and forage mass for grazing. Although scientific results have shown the benefits of using ICLS instead of conventional livestock systems, few studies have investigated the best way to implement these integrated systems. The hypothesis of this study was that ICLS improves the nutritional value of forage and beef cattle performance. The aim of the study was to evaluate (1) different ways to intercrop maize and Marandu grass for pasture establishment, and (2) the effects of intercropping maize and Marandu grass on herbage mass, nutritional value and beef cattle performance. The control treatment consisting exclusively of Marandu grass pasture (livestock system, LS) was compared to four ICLS: maize plus Marandu grass sown simultaneously without herbicide (ICLS-1); maize plus Marandu grass sown simultaneously with herbicide (ICLS-2); maize plus Marandu grass in lagged sowing (ICLS-3), and maize plus Marandu grass sown simultaneously in maize rows and inter-rows with herbicide (ICLS-4). A randomised block design with five treatments and three replicates was used. The experiment was carried out in a field of 13.35 ha, divided into 15 paddocks of 0.89 ha each. The animals grazed for 370 days under continuous stocking. A put-and-take approach was used to adjust stocking rates throughout the year. Herbage mass was higher in the LS treatment than in ICLS-2 and ICLS-4 as a result of the greater accumulation of dead material. Light interception and leaf area index were higher in ICLS-4, in which Marandu grass was sown in maize rows and inter-rows, promoting better pasture establishment. Crude protein content of Marandu grass leaves was greater in the ICLS-4 treatment compared to LS and ICLS-2. Stem crude protein content was greater in ICLS-4 compared to LS, ICLS-1 and ICLS-2. The mean body weight gain was lower in the LS treatment (410 kg) compared to ICLS-2 (429 kg), ICLS-3 (437 kg) and ICLS-4 (426 kg). Intercrop maize with Marandu grass can be used for pasture establishment. The treatment ICLS-4 using maize plus Marandu grass sown simultaneously in maize rows and inter-rows with herbicide provides better pasture establishment and nutritive value.