Concentrações in vitro de amônia a partir de ureias com diferentes tecnologias de encapsulamento e velocidades de liberação em líquido ruminal

• Ano de defesa: 2025
• Autor(a) principal: Ramos, Leidiane da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Faculdade de Agronomia e Zootecnia (FAAZ); UFMT CUC - Cuiabá; Programa de Pós-Graduação em Ciência Animal
• Palavras-chave em Português: Optigen; Amireia; Amônia; Bovino; Moagem; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA; Amiréia; Ammonia; Cattle; Grinding
• Link de acesso: http://ri.ufmt.br/handle/1/7295

In search of synchronization between the ammonia release rate and the degradation of dietary carbohydrates, the industry has developed slow-release compounds of non-protein nitrogen. Slow-release urea is essentially agricultural urea coated with layers of polymers and/or vegetable waxes. This process aims to reduce the nitrogen release rate in the rumen, allowing the microbiota more time to use it in their metabolism. In this context, the objective of this study was to evaluate in vitro ruminal ammonia (N-NH₃) concentrations produced from urea encapsulated with different technologies. The urea sources (experimental urea (UEX), Optigen (OP), Amiréia (AM), and agricultural urea (UR)), studied in whole and ground forms, were incubated in vitro in a medium containing ruminal fluid and buffer solution at times of 30, 60, 90, 120, 150, 180, 240, 300, 360, and 480 minutes. A completely randomized design in a 4 x 2 factorial arrangement (4 types of urea x 2 conditions) was used, totaling eight treatments. Conditions and urea types were considered fixed effects, and incubation times were treated as a random effect, with P<0.05. The N-NH₃ concentrations were influenced by the type and form of urea at all evaluated times (P<0.0001), showing a progressive increase over time. Grinding intensified N-NH₃ release in all treatments, while the OP treatment demonstrated greater control over release compared to the others in whole form (P<0.05). The UEX exhibited similar behavior to AM at certain times (P>0.05). In some periods, ammonia production in UEX and AM was comparable to that of UR (P>0.05). It is concluded that controlled urea release through different encapsulation processes allows modulation of nitrogen availability in the rumen, optimizing its utilization by microorganisms and reducing metabolic losses. The data indicate that the type of urea influenced ammoniacal nitrogen concentrations over time in most analyses, highlighting that the encapsulation technology impacts the degradation rate and, consequently, the utilization of urea by animals. Future studies could evaluate nitrogen retention efficiency and microbial production to better understand the mechanisms involved in this dynamic.