Audasley Tadeu Santos Fialho
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Audasley Tadeu Santos Fialho has a total of 21 co-authors. Here are the top co-authors by number of shared publications:
- As Silva
Universidade Estadual de Maringá
2 shared publications - Nilva Kazue Sakomura
Department of Animal Science, College of Agrarian and Veterinary Science, São Paulo State University, Jaboticabal 14884-900, Brazil
2 shared publications - Rony Riveros Lizana
Department of Animal Science, College of Agrarian and Veterinary Science, São Paulo State University, Jaboticabal 14884-900, Brazil
2 shared publications - Valdir Ribeiro Junior
Universidade Federal de Sergipe, Brazil
2 shared publications Amélia K. Almeida
School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand
1 shared publication- Bruno Balbino Leme
Universidade Estadual de São Paulo/FCAV, Brasil
1 shared publication
Latest Publications
- Open Access
- 1 March 2026
- Published by KEAI Publishing in Animal Nutrition
- Vol. 24, 192-199
Exploring the net energy for maintenance and the allometric exponent of the metabolic body weight in different categories of poultry: A Meta-analysis approach
The basal metabolic rate in poultry, expressed as net energy requirements for maintenance (NEm), is often characterized by measuring fasting heat production (FHP) under standardized conditions. This study applies meta-analysis techniques to 206 individual observations from 23 peer-reviewed papers to evaluated the allometric relationship between FHP and body weight (BW), described by the model: , where FHP is the fasting heat production, BW is the body weight, is the NEm requirement per unit of metabolic body weight (MBW), and is the allometric exponent. The objective of this study was to estimate and determine the appropriate NEm for growing broiler chickens, laying hens, and roosters. We evaluated three non-linear models: Model 1, category-specific exponents; Model 2, common exponent across categories; and Model 3, exponent fixed at the theoretically value of 0.75. Model 1 showed distinct b of 0.73, 0.65, and 0.58 for growing broilers, laying hens, and roosters, respectively, with corresponding NEm values of 450, 352, and 385 kJ per kg of MBW. Model 2, which estimated a common exponent (b = 0.64), improved model fit (root mean square prediction error (RMSPE) = 173 kJ/d, R2 = 0.76). Model 3, using the standardized b = 0.75, yielded NEm of 478 kJ/kg BW0.75 for growing chickens and 320 kJ/kg BW0.75 for adult birds (RMSPE = 184 kJ/d, R2 = 0.78), with a model performance comparable to Model 1 (RMSPE = 187 kJ/d, R2 = 0.72). Error decomposition further indicated that Model 3 presented a lower error due to regression (0.66%), a lower intercept (80 kJ/d) and a higher slope (0.68) in the observed-predicted regression, demonstrating its robust predictive ability. In conclusion, while category-specific exponents offer a precise FHP characterization, adopting a wide-know exponent of 0.75 is a practical alternative, provided the NEm is adjusted for each category. These findings provided a framework for estimating NEm recommending values of 480 kJ/kg BW0.75 for growing chickens and 320 kJ/kg BW0.75 for adult birds, to support accurate energy requirements models and cross-study comparison in poultry nutrition.- 1 March 2026
- Published by KEAI Publishing in Animal Nutrition
- Vol. 24, 192-199
Open AccessExploring the net energy for maintenance and the allometric exponent of the metabolic body weight in different categories of poultry: A Meta-analysis approach
The basal metabolic rate in poultry, expressed as net energy requirements for maintenance (NEm), is often characterized by measuring fasting heat production (FHP) under standardized conditions. This study applies meta-analysis techniques to 206 individual observations from 23 peer-reviewed papers to evaluated the allometric relationship between FHP and body weight (BW), described by the model: , where FHP is the fasting heat production, BW is the body weight, is the NEm requirement per unit of metabolic body weight (MBW), and is the allometric exponent. The objective of this study was to estimate and determine the appropriate NEm for growing broiler chickens, laying hens, and roosters. We evaluated three non-linear models: Model 1, category-specific exponents; Model 2, common exponent across categories; and Model 3, exponent fixed at the theoretically value of 0.75. Model 1 showed distinct b of 0.73, 0.65, and 0.58 for growing broilers, laying hens, and roosters, respectively, with corresponding NEm values of 450, 352, and 385 kJ per kg of MBW. Model 2, which estimated a common exponent (b = 0.64), improved model fit (root mean square prediction error (RMSPE) = 173 kJ/d, R2 = 0.76). Model 3, using the standardized b = 0.75, yielded NEm of 478 kJ/kg BW0.75 for growing chickens and 320 kJ/kg BW0.75 for adult birds (RMSPE = 184 kJ/d, R2 = 0.78), with a model performance comparable to Model 1 (RMSPE = 187 kJ/d, R2 = 0.72). Error decomposition further indicated that Model 3 presented a lower error due to regression (0.66%), a lower intercept (80 kJ/d) and a higher slope (0.68) in the observed-predicted regression, demonstrating its robust predictive ability. In conclusion, while category-specific exponents offer a precise FHP characterization, adopting a wide-know exponent of 0.75 is a practical alternative, provided the NEm is adjusted for each category. These findings provided a framework for estimating NEm recommending values of 480 kJ/kg BW0.75 for growing chickens and 320 kJ/kg BW0.75 for adult birds, to support accurate energy requirements models and cross-study comparison in poultry nutrition. - Open Access
- 1 January 2025
- Published by FapUNIFESP (SciELO) in Scientia Agricola
- Vol. 82, e20240036
Optimal methionine: cystine ratio for performance and nitrogen balance in growing chickens fed low protein diet
This study aimed to determine the optimal methionine:cystine (Met:Cys) ratio in diets with reduced crude protein (CP). Two trials were carried throughout14 to 28 days. In trial 1, 1200 broiler chicks were distributed under a random design of ten treatments in a 2 × 5 factors of variability arrangement with two protein levels (21.5 and 19.5 % CP) and five digestible Met:Cys ratios (42:58, 46:54, 50:50, 54:46, and 58:42). Each treatment consisted of six replicates each, with 20 birds per experimental unit. In trial 2, 36 birds were selected and randomly allocated in six treatments with three replications each to carry out a nitrogen (N) balance study. The treatments were designed in a 2 × 3 factorial arrangement with two levels of protein (21.5 and 19.5 % CP) and three Met:Cys ratios (42:58, 50:50, and 58:42). Statistical analyses were performed as two-way analysis of variance (ANOVA) with interactions and main effects compared by Tukey's test. All statistical procedures were performed using the PROC GLM, and PROC NLIN was used to fit the quadratic broken line. No interaction was observed for weight gain, but there was a significant effect of the Met:Cys p < 0.05. There was a significant interaction between Met:Cys and CP level for feed intake (FI) and feed conversion rate p < 0.05. The CP level did not affect N retention (NR) p > 0.05 but significantly affected N intake (Nin), excretion (Nexc), and utilization (kN) efficiency. Therefore, an average Met:Cys ratio of 52:48 promoted a better performance response, improved in kN, and even CP reduction.
- 1 January 2025
- Published by FapUNIFESP (SciELO) in Scientia Agricola
- Vol. 82, e20240036
Open AccessOptimal methionine: cystine ratio for performance and nitrogen balance in growing chickens fed low protein diet
This study aimed to determine the optimal methionine:cystine (Met:Cys) ratio in diets with reduced crude protein (CP). Two trials were carried throughout14 to 28 days. In trial 1, 1200 broiler chicks were distributed under a random design of ten treatments in a 2 × 5 factors of variability arrangement with two protein levels (21.5 and 19.5 % CP) and five digestible Met:Cys ratios (42:58, 46:54, 50:50, 54:46, and 58:42). Each treatment consisted of six replicates each, with 20 birds per experimental unit. In trial 2, 36 birds were selected and randomly allocated in six treatments with three replications each to carry out a nitrogen (N) balance study. The treatments were designed in a 2 × 3 factorial arrangement with two levels of protein (21.5 and 19.5 % CP) and three Met:Cys ratios (42:58, 50:50, and 58:42). Statistical analyses were performed as two-way analysis of variance (ANOVA) with interactions and main effects compared by Tukey's test. All statistical procedures were performed using the PROC GLM, and PROC NLIN was used to fit the quadratic broken line. No interaction was observed for weight gain, but there was a significant effect of the Met:Cys p < 0.05. There was a significant interaction between Met:Cys and CP level for feed intake (FI) and feed conversion rate p < 0.05. The CP level did not affect N retention (NR) p > 0.05 but significantly affected N intake (Nin), excretion (Nexc), and utilization (kN) efficiency. Therefore, an average Met:Cys ratio of 52:48 promoted a better performance response, improved in kN, and even CP reduction.
- Open Access
- 1 March 2021
- Published by FapUNIFESP (SciELO) in Arquivo Brasileiro de Medicina Veterinária e Zootecnia
- Vol. 73 (2) , 539-542
Nutritional composition of larvae of mealworm (Tenebrio molitor L.) and crickets (Gryllus assimilis) with potential usage in feed
Thus, the use of insects can be an alternative to solve this problem. However, there is little information about the chemical composition of different types of insects. In addition, the nutritional composition of insects can be changed depending on their diet (Siemianowska et al., 2013). The aim of the present study was to determine the nutritional composition of Tenebrio molitor larvae and crickets of the genus Gryllus assimilis for usage in animal feed.
- 1 March 2021
- Published by FapUNIFESP (SciELO) in Arquivo Brasileiro de Medicina Veterinária e Zootecnia
- Vol. 73 (2) , 539-542
Open AccessNutritional composition of larvae of mealworm (Tenebrio molitor L.) and crickets (Gryllus assimilis) with potential usage in feed
Thus, the use of insects can be an alternative to solve this problem. However, there is little information about the chemical composition of different types of insects. In addition, the nutritional composition of insects can be changed depending on their diet (Siemianowska et al., 2013). The aim of the present study was to determine the nutritional composition of Tenebrio molitor larvae and crickets of the genus Gryllus assimilis for usage in animal feed.
- Open Access
- 1 January 2020
- Published by FapUNIFESP (SciELO) in Brazilian Journal of Poultry Science
- Vol. 22 (3)
Fat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age
This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p≤0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.
- 1 January 2020
- Published by FapUNIFESP (SciELO) in Brazilian Journal of Poultry Science
- Vol. 22 (3)
Open AccessFat-Soluble Vitamin Supplementation Levels in Diets for Laying Hens from 28 to 44 Weeks of Age
This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p≤0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.