Banca de QUALIFICAÇÃO: RAYANE APARECIDA LINO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: RAYANE APARECIDA LINO
DATA: 21/03/2023
HORA: 14:00
LOCAL: Online via GoogleMeet
TÍTULO:

Impact of urea source and flint corn processing method on digestive parameters, ruminal fermentation, and nitrogen metabolism of Nellore heifers fed finishing diets

PALAVRAS-CHAVES:

metabolism, nitrogen, retention, starch, urea recycling

PÁGINAS: 90
GRANDE ÁREA: Ciências Agrárias
ÁREA: Zootecnia
SUBÁREA: Nutrição e Alimentação Animal
ESPECIALIDADE: Avaliação de Alimentos para Animais
RESUMO:

The low efficiency of Nitrogen (N) utilization in ruminants may be associated with peaks of ammonia concentration in the rumen, caused by the widespread use of conventional urea (UC). Post-ruminal release urea sources may be beneficial in utilizing endogenous urea recycled in the liver. In the rumen, recycled urea is synthesized in microbial protein (MIC), as a guarantee of the occurrence of this process. In this process, energy from carbohydrates is essential, and the type of processing of this ingredient can influence its degradation, and amount of synthesized MIC. The objective of the study will be to evaluate the interaction between two sources of non-N protein and different corn grain processing in beef cattle finishing diets. The experiment will be carried out at the Federal University of Lavras. It will be used 8 Nelore heifers, cannulated in the rumen, with an average age of 20 months and average initial body weight (BW) of 285 kg. The experimental design used will be the replicated 4 × 4 Latin square, balanced for residual effects, with a 2 × 2 factorial arrangement, totaling 4 periods and 4 treatments. Evaluated treatments will be: i) conventional urea (UC) + ground corn grain (GC), ii) UC + rehydrated and ensiled corn grain (REC), iii) post-ruminal release urea (ULP) + GC, and iv) PRU + REC. The animals will be housed in individual stalls, with unrestricted access to water, and fed twice a day, at 7:00 am and 4:00 pm. The duration of the experiment will be 104 days, divided into four periods of 26 days, each experimental period will have 14 days of diet adaptation and 12 days of data collection. The dry matter intake will be estimated through 15th and 23rd. Between the 16th and 20^th day, digestibility assay and total collection of urine will be carried out. The heifers will be equipped with foley tubes attached to hoses, at the end of 24 hours the storage containers will be changed, and this interval will be reduced to 4 hours in the last two days of collection, to provide N excretion pattern throughout the day. Also between the 16th and 20^th day, ruminal and blood collection will be performed simultaneously every 10 hours. From the 20th, samples of omasal fluid will be collected every 9 hours for 3 days. The omasal collection will be performed using a vacuum pump and the marker cobalt - EDTA infused every 18 hours from the 16th. On the 24th and 26th the animals will undergo a ruminal evacuation 4 hours after and before morning feeding, respectively. On day 24, solid and liquid phases will be sampled for microbiome evaluation and on 26th day, a ruminal biopsy will be performed. Statistical analyzes will be performed using PROC MIXED implemented in the SAS program (Statistical Analysis System, version 9.4), adopting a significance level of 5%.

MEMBROS DA BANCA:
Interno - THIAGO FERNANDES BERNARDES (Membro)
Externo ao Programa - PRISCILLA DUTRA TEIXEIRA - DZO/FZMV (Suplente)
Presidente - MARCIO MACHADO LADEIRA (Membro)
Externo à Instituição - JOANIS TILEMAHOS ZERVOUDAKIS - UFMT (Membro)
Externo à Instituição - EDENIO DETMANN - UFV (Membro)