RESUMO
OBJECTIVE: The identification of nonlinear mixed models that describe the growth trajectory of New Zealand rabbits was performed based on weight records and carcass measures obtained using ultrasonography. METHODS: Phenotypic records of body weight (BW) and loin eye area (LEA) were collected from 66 animals raised in a didactic-productive module of cuniculture located in the southern Piauí state, Brazil. The following nonlinear models were tested considering fixed parameters: Brody, Gompertz, Logistic, Richards, Meloun 1, modified Michaelis-Menten, Santana, and von Bertalanffy. The coefficient of determination (R2), mean squared error, percentage of convergence of each model (%C), mean absolute deviation of residuals, Akaike information criterion (AIC), and Bayesian information criterion (BIC) were used to determine the best model. The model that best described the growth trajectory for each trait was also used under the context of mixed models, considering two parameters that admit biological interpretation (A and k) with random effects. RESULTS: The von Bertalanffy model was the best fitting model for BW according to the highest value of R2 (0.98) and lowest values of AIC (6,675.30) and BIC (6,691.90). For LEA, the Logistic model was the most appropriate due to the results of R2 (0.52), AIC (783.90), and BIC (798.40) obtained using this model. The absolute growth rates estimated using the von Bertalanffy and Logistic models for BW and LEA were 21.51g/d and 3.16 cm2, respectively. The relative growth rates at the inflection point were 0.028 for BW (von Bertalanffy) and 0.014 for LEA (Logistic). CONCLUSION: The von Bertalanffy and Logistic models with random effect at the asymptotic weight are recommended for analysis of ponderal and carcass growth trajectories in New Zealand rabbits. The inclusion of random effects in the asymptotic weight and maturity rate improves the quality of fit in comparison to fixed models.
RESUMO
Enterobacteriaceae can be present in the environment and in the intestine of warmblooded animals. This study aimed to isolate and identify enterobacteria in informally marketed milk in cities of South of the Piaui. 52 milk samples were acquired at different points of Bom Jesus, Redenção do Gurguéia, Santa Luz and Cristino Castro, Piaui, which were taken into Styrofoam containing ice to food microbiology laboratory of the Federal University of Piauí, in Bom Jesus, where held the bacterial isolation in MacConkey, EMB and XLD. The conclusive biochemical identification and agglutination test was held at the Enterobacteria Laboratory of FIOCRUZ, (Rio de Janeiro-RJ). From the 37 strains, identified the species Escherichia coli, Enterobacter cloacae, Enterobacter gergoviae, Enterobacter aerogenes, Klebsiella pneumoniae, Citrobater freundii, Providencia rettigeri and Serratia marcescens. The informally marketed milk is contaminated by Enterobacteriaceae that can be pathogenic and should be taken preventive measures, such as pasteurization of milk.(AU)
Assuntos
Leite/microbiologia , Enterobacteriaceae/química , Abastecimento de Alimentos , Escherichia coli , Enterobacter , Klebsiella pneumoniae , Providencia , Serratia marcescensRESUMO
Enterobacteriaceae can be present in the environment and in the intestine of warmblooded animals. This study aimed to isolate and identify enterobacteria in informally marketed milk in cities of South of the Piaui. 52 milk samples were acquired at different points of Bom Jesus, Redenção do Gurguéia, Santa Luz and Cristino Castro, Piaui, which were taken into Styrofoam containing ice to food microbiology laboratory of the Federal University of Piauí, in Bom Jesus, where held the bacterial isolation in MacConkey, EMB and XLD. The conclusive biochemical identification and agglutination test was held at the Enterobacteria Laboratory of FIOCRUZ, (Rio de Janeiro-RJ). From the 37 strains, identified the species Escherichia coli, Enterobacter cloacae, Enterobacter gergoviae, Enterobacter aerogenes, Klebsiella pneumoniae, Citrobater freundii, Providencia rettigeri and Serratia marcescens. The informally marketed milk is contaminated by Enterobacteriaceae that can be pathogenic and should be taken preventive measures, such as pasteurization of milk.