ABSTRACT
In the present trial, the levels of serum aflatoxin B1 (AFB1)-lysine and their relationship with biochemical parameters in broiler chicks fed an AFB1-contaminated diet were determined. The experimental design was completely randomized with two treatments (control and 222.17 µg/kg AFB1) and 20 bird per treatment. Feeds were offered to broiler chicks for 14 days, from 28 to 42 days of age. Animals were vaccinated against Newcastle's and Marek's diseases on the 14th day of life, and were killed at 42 days of age. Broilers receiving AFB1 did not demonstrate any sign of toxicity. Compared with controls, aspartate aminotransferase and globulin levels were not affected in the AFB1-treated group. However, higher levels of gamma-glutamyl transferase and lower concentrations of total protein and albumin were observed in the group receiving AFB1 on days 35 and 42. AFB1-lysine were detected in the serum of all broilers fed the AFB1-contaminated diet, at mean levels of 56.52-77.83 ng/mg albumin on days 35 and 42 of age, respectively. These values indicated the internal dose of AFB1 in birds, which negatively correlated with total protein, albumin, and globulin levels. Data indicated that AFB1-lysine shows the potential to be a sensitive and specific biomarker for the evaluation of broiler exposure to dietary aflatoxin, as well as for diagnostic purposes. Further studies are necessary to determine physiologically-based toxicokinetics of serum AFB1-lysine in broilers.
Subject(s)
Aflatoxin B1/blood , Animal Feed/microbiology , Chickens/blood , Food Microbiology , Lysine/blood , Aflatoxin B1/toxicity , Age Factors , Animal Husbandry , Animals , Biomarkers/blood , Lysine/toxicity , Male , Time FactorsABSTRACT
Feed formulation using linear programming consists of determining the mixture of feedstuffs required to meet pre-established animal nutritional requirements at the lowest cost. On the other hand, with the use of non-linear programming, it is possible to define nutritional requirements at the time of formulation, aiming at maximum profit. The objective of the present study was to compare feeds formulated using linear and non-linear programming in terms of live performance and internal and external egg quality of commercial laying hens. A total of 288 Hisex® White laying hens, 1.540 ± 0.128 g body weight, were evaluated from 33 to 45 weeks of age. Hens were distributed in a completely randomized block design, including six treatments with six replicates of eight birds each. Three treatments consisted of feeds formulated using linear programming and based on the nutritional requirements of Rostagno et al. (2011), of the genetic strain manual, or mathematical models to maximize performance. The other three treatments consisted of feeds formulated using non-linear programming considering typical, favorable, or unfavorable market scenarios. Data were submitted to analysis of variance, and in case of significance (p 0.05), means were grouped using the Scott-Knott test (5%).The treatments did not influence (p>0.05) Haugh unit, albumen height, or external egg quality parameters. Treatment effects (p 0.05) on yolk weight, albumen weight, yolk color, yolk percentage, albumen percentage, and performance parameters were described. In general, feeds formulated using linear programming and based on nutritional requirements obtained by mathematical models and the genetic strain manual promoted better performance results because the feeds were nutritionally denser. However, the treatments that maximized live performance did not result in higher profitability, which was obtained with the diet formulated for a favorable market scenario using non-linear programming.
Subject(s)
Female , Animals , Eggs/analysis , Eggs/classification , Nonlinear Dynamics , ChickensABSTRACT
Feed formulation using linear programming consists of determining the mixture of feedstuffs required to meet pre-established animal nutritional requirements at the lowest cost. On the other hand, with the use of non-linear programming, it is possible to define nutritional requirements at the time of formulation, aiming at maximum profit. The objective of the present study was to compare feeds formulated using linear and non-linear programming in terms of live performance and internal and external egg quality of commercial laying hens. A total of 288 Hisex® White laying hens, 1.540 ± 0.128 g body weight, were evaluated from 33 to 45 weeks of age. Hens were distributed in a completely randomized block design, including six treatments with six replicates of eight birds each. Three treatments consisted of feeds formulated using linear programming and based on the nutritional requirements of Rostagno et al. (2011), of the genetic strain manual, or mathematical models to maximize performance. The other three treatments consisted of feeds formulated using non-linear programming considering typical, favorable, or unfavorable market scenarios. Data were submitted to analysis of variance, and in case of significance (p 0.05), means were grouped using the Scott-Knott test (5%).The treatments did not influence (p>0.05) Haugh unit, albumen height, or external egg quality parameters. Treatment effects (p 0.05) on yolk weight, albumen weight, yolk color, yolk percentage, albumen percentage, and performance parameters were described. In general, feeds formulated using linear programming and based on nutritional requirements obtained by mathematical models and the genetic strain manual promoted better performance results because the feeds were nutritionally denser. However, the treatments that maximized live performance did not result in higher profitability, which was obtained with the diet formulated for a favorable market scenario using non-linear programming.(AU)