Banca de DEFESA: CAMILA GUEDES VALADARES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAMILA GUEDES VALADARES
DATE: 29/08/2025
TIME: 08:00
LOCAL: Departamento de Zootecnia
TITLE:

Addition of natural zeolites with and without protein reduction in broiler diets

KEY WORDS:

clinoptilolite, broiler chickens, performance, digestibility, crude protein, litter quality, microbiota.

PAGES: 146
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Nutrição e Alimentação Animal
SPECIALTY: Avaliação de Alimentos para Animais
SUMMARY:

The use of natural additives in broiler diets has been investigated as a strategy to improve growth performance, nutrient digestibility, gut health, and environmental quality in poultry production systems. Among these additives, natural zeolite of the clinoptilolite type stands out for its adsorptive capacity, which can influence digestive physiology and intestinal conditions, modulate metabolism, reduce gas emissions in excreta, and improve litter quality. However, results regarding its effectiveness are still inconclusive, and little is known about the interaction between different inclusion levels and dietary protein content. In this context, this thesis aimed to evaluate the effects of including natural zeolite (0, 1.0, 2.0, and 3.0%) in diets with either adequate or 3%-reduced crude protein levels on performance, nutrient digestibility, blood biochemical parameters, immune indicators, litter quality, carcass and organ yield, and cecal microbiota of broiler chickens. Two experiments were conducted using male Ross broilers from 1 to 42 days of age, in a completely randomized design with a 4×2 factorial scheme (zeolite level × protein level), six replicates, and 14 birds per experimental unit. The first experiment evaluated growth performance, carcass and organ yield, and litter quality (ammonia concentration and microbiological profile). The second experiment assessed nutrient metabolizability coefficients, serum biochemical parameters, immune markers, and cecal microbiota composition. Data were analyzed using ANOVA, polynomial regression, and Dunnett’s test at a 5% significance level. The inclusion of up to 1% zeolite was effective in reducing litter ammonia concentration without impairing performance or carcass yield, regardless of protein level. Higher inclusion levels negatively affected weight gain and feed conversion, especially in protein-reduced diets. The best digestibility coefficients of dry matter, crude protein, and metabolizable energy were observed with 2% zeolite in diets with adequate protein. Zeolite reduced the heterophil/lymphocyte ratio and increased spleen relative weight, indicating lower physiological stress. It also contributed to reduced total cholesterol and LDL levels, increased HDL, and improved bone strength in birds fed zeolite from day one. No effect was observed on the Escherichia coli population. It is concluded that natural zeolite has functional potential as a dietary additive for broilers, promoting benefits in digestibility, performance, litter quality, and physiological parameters, especially when used at moderate levels in nutritionally balanced diets.

COMMITTEE MEMBERS:
Presidente - MARIA DO CARMO MOHAUPT MARQUES LUDKE
Interno - JULIO CEZAR DOS SANTOS NASCIMENTO
Interno - CARLOS BOA VIAGEM RABELLO
Externa ao Programa - 2974126 - TAYARA SOARES DE LIMA - UFRPEExterno à Instituição - MARCOS JOSÉ BATISTA DOS SANTOS
Externa à Instituição - CLAUDIA DA COSTA LOPES - UFRN
Externo à Instituição - ROGERIO VENTURA DA SILVA JUNIOR