Chemical fractionation of carbohydrate and protein composition of corn silages fertilized with increasing doses of nitrogen

Abstract

The use of nitrogen fertilizers in corn crops for silage can improve both production and, theoretically, nutritional quality, especially carbohydrate and protein fractions, thereby optimizing animal production. Thus, the aim of this study was to evaluate the effect of increasing levels of nitrogen fertilization in carbohydrate and protein fractionation on the resulting corn silage (Zea mays L.). Nitrogen fertilization was carried out in the urea form (45-00-00) in V5 stage, at the following doses: T1: 0kg N ha-1; T2: 45kg N ha-1; T3: 90kg N ha-1; and T4: 135kg N ha-1. Crops were harvested at R4 stage and submitted to ensiling in experimental PVC silos. The chemical composition of the resulting silage was evaluated after silo opening. There was no statistical difference (P<0.05) in the average contents of gross protein (GP), as well as its C fraction, showing that increasing nitrogen doses in coverage linearly increased GP and linearly decreased its C fraction. For total carbohydrates, there was a linear decreasing behavior due to such consumption with the highest levels of nitrogen applied. Increased nitrogen fertilization dose in corn also linearly enhanced pH in the resulting silage. Therefore, nitrogen increases in coverage can alter carbohydrates and GP fractionation of corn silage, with increases in soluble fiber, GP, and pH, and reduction in the protein indigestible fraction.

Avaliação de doses crescentes de nitrogênio em cobertura em milho para silagem

“…Ao passo que há um aumento da produtividade de biomassa fresca (Tabela 1), ou seja, peso de planta, há um incremento dos compostos fibrosos que auxiliam na sustentação dessa planta mais pesada. (Neumann et al, 2017). O maior valor de CNF+EE na dose de 225,5 kg ha -1 pode estar relacionado ao menor número de folhas secas mencionadas outrora, pois essas são ricas em compostos fibrosos.…”

“…A digestibilidade da FDN também aumentou quando se elevou a dose de nitrogênio em cobertura, onde a dose de 225,5 kg ha -1 apresentou superioridade aos demais tratamentos (73,29% (Neumann et al, 2017). Segundo Fernandes et al (2010) o aproveitamento de N decresce com o aumento da dose aplicada, tal fato é devido ao suprimento de N exceder as necessidades da cultura, podendo explicar o fato da dose de 175,5 kg ha -1 ter a maior taxa de desaparecimento e não a dose de 225,5 kg ha -1 que possui a maior dose de nitrogênio disponibilizado.…”

“…Além de influenciar na composição física da planta, a quantidade de nitrogênio disponibilizado irá influenciar na composição química da mesma, onde possui grande influência principalmente sob a qualidade da fração fibrosa, podendo aumentar ou diminuir tanto o teor como a digestibilidade da FDN (Neumann et al, 2017).…”

Chemical and Mineral Composition, Kinetics of Degradation and in vitro Gas Production of Native Cactus

“…Variation in carbohydrate fraction C content was not considered high, and according to Neumann et al, (2017) and Brandstetter et al, (2019) are significant differences in this fraction among forage species, since this fraction interferes with ruminal repletion, causing a lower energy availability due to its indigestible characteristic, as it results in lower food consumption in unit time. Plants with high levels of this fraction interfere with the animal food intake, so this forage should be supplemented with energy sources of rapid rumen availability (Mendoza et al, 2014), when it does not have protein limitation in quantity and quality.…”

Corn hybrid silage quality according to harvesting time

“…In this case, harvesting requires machinery adaptations to improve grain processing by exposing the endosperm and making more substrate available to the fermenting microorganisms (Marafon et al, 2015). For Neumann, Nörnberg, Leão, Horst and Figueira (2017), the vegetative portion is of great importance in the final quality of the silage, which is mostly constituted by the NDF, and with the advancement of the vegetative stage, there is an increase in the deposition of lignified structures in the NDF, thus promoting a reduction in plant digestibility.…”