Non-Linear Models for Growth, Development, and Posture of L-33 White Leghorn Hens, according to Economic Indicators

Abstract

The Zootechnical Factors established by the main indicators of bioeconomic behavior were determined for the pro-ductive-commercial cycle of L-33 White Leghorn hens in the province of Ciego de Ávila, Cuba. A number of 55 cycles were analyzed for validation of mathematical models between 2002 and 2014; other 18 cycles were studied between 2014 and 2016. Descriptive statistics, generalized mixed models (GLIMMIX), and five-function modelling were used. SAS 9.3 for Windows was also used. The productive cycles were similar to the standard set up for the breed and line in Cuba. Laying was 293 eggs/poultry, with a conversion of 1.40 feed kg/10 eggs, and a cost of $ 0.36 CUP an egg. The starting sheds and year had effects on live weight, tarsus length, uniformity, and daily weight gain up to 175 days. Sexual maturity, conversion, egg production, egg cost, and net income were influenced by farm, whereas each farm´s starting shed and the years, had negative effects on most biological indicators. Low, but significant effects of combined climate variables were observed in the bioeconomic indicators. The Gompertz´s model for growth, and Mc Nally´s for laying, were the best predicting tools for production. Along with GLIMMIX, they will contribute with suitable criteria for better decision making to increase egg production.