Forage intake by heifers on alexander grass (Urochloa plantaginea (Link.) Hitch) fertilized with different levels of nitrogen

Érica Dambrós De Moura,José Fernando Piva Lobato,Amanda Carneiro Martini,Lidiane Raquel Eloy,Maria José De Oliveira Sichonany,Marta Gomes Da Rocha,Tuani Lopes Bergoli,Paulo Roberto Salvador,Luciana Pötter

doi:10.33448/rsd-v10i11.19922

Érica Dambrós De Moura, José Fernando Piva Lobato + Show 7 more

Open Access

https://doi.org/10.33448/rsd-v10i11.19922

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Abstract

This work was conducted to study the efficiency of using nitrogen on Alexander Grass (Urochloa plantaginea (Link.) Hitch) through information about the characteristics of the pasture and forage intake of beef heifers. The experiment was carried out at the Federal University of Santa Maria (Universidade Federal de Santa Maria, UFSM) in Santa Maria, Rio Grande do Sul, Brazil, from January to April of 2014. The treatments consisted of doses of zero, 150, or 300 kg/ ha nitrogen (N) in the form of urea. The study used a rotational pasture method and 16 Angus heifers with a mean initial age and body weight (BW) of 15 months and 276 ± 17.4 kg, respectively. Forage intake was evaluated by treating two picketed test heifers with chromium oxide (Cr2O3) for eleven days as an external indicator of fecal production. The experimental design was completely randomized, and the measurements were repeated over time with three treatments and two repetitions per area. Crude protein content was 3.4% higher under 300 kg/ha nitrogen fertilization compared to 150 kg/ ha (18.7%). Independent of the N application rate, the heifers ingested 2.2 ± 0.09 kg DM 100/ kg BW of forage. Nitrogen fertilization of Alexander grass modified the structure of the pasture, increasing the quality and total production of the forage. Heifers pastured on Alexander grass fertilized with 300 kg/ha nitrogen harvested forage with higher levels of crude protein. The structural change in the canopy let the heifers reduce their consumption of forage at the end of the Alexander grass life cycle.

Highlights

Brazil has principally distinguished itself on the world agribusiness stage through its livestock production sector, and it possesses the second largest cattle herd in the world with approximately 213 million cattle (IBGE, 2016)
Nitrogen-fertilized Alexander grass has been studied by various authors; until now, there has been no study about its relationship with consumption by cattle
The canopy height at exit was similar between nitrogen doses (28.2 ± 0.84 cm) according to the adopted handling criterion

Summary

Introduction

Brazil has principally distinguished itself on the world agribusiness stage through its livestock production sector, and it possesses the second largest cattle herd in the world with approximately 213 million cattle (IBGE, 2016). One-hundred and sixty million hectares of pasture are dedicated to this herd, which makes the stocking rate 1.3 animals/ ha (IBGE, 2014). In the search for greater beef cattle production efficiency, Alexander grass (Urochloa plantaginea (Link.) Hitch) is a forage alternative with great production potential that provides suitable feed for post-weaning heifers (Costa et al, 2011), and it is possible to raise 2.3 extra heifers per hectare when the Alexander grass is fertilized with nitrogen (Salvador et al, 2016). Nitrogen-fertilized Alexander grass has been studied by various authors; until now, there has been no study about its relationship with consumption by cattle. In forage production, by be part of proteins and nucleic acids (Silva et al, 2013)

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