DEVELOPMENT AND MODELLING OF ROBUST SOLAR ASSISTED AND CONTROLLED HOUSING FOR RAISING BROILER CHICKENS IN A TROPICAL ENVIRONMENT

Abstract

Designing environmental control systems for poultry requires understanding of the complex interactions between the biological systems within the space and the environment provided by the system. During extreme weather condition, it is important to balance the heat in the poultry housing by determining the required ventilation rate and possible needs in the building for supplemental heat. As a result of these requirements, a thermally controlled poultry house was developed and evaluated with a full control system for the supplemental thermal system at the Department of Agricultural and Environmental Engineering farm site, FUTA. The five (5) thermally controlled rooms were programmed to five (5) different temperature levels (41, 38, 35, 32 and 29 °C) with the fans programmed to produce air speed of 1.5 m/s. The replicates were subjected to three (3) different regimes of diet (100 %, 80 % and 60 %) according to the standard feed requirement for broiler. Clinical treatment was also based on three (3) different regimes of 100 %, 80 % and 60 % of standard vaccine application for broiler. The effects of the temperature on average body mass, growth rate, cloacal temperature, feed consumption, feed consumption rate, leftover feed, cloacal temperature difference were investigated. Experimental data acquired from data logger and through gravimetric methods were analyzed using multi- variable regression analysis and analysis of variance of the regression model were developed. The results showed that there was no temperature stability in the non-thermally controlled section of the poultry house, while stability of preset temperature was observed in the thermally controlled rooms. Broilers in the control group were consistently lower in weight (1536.58 g been the heaviest for this category) than broilers under a constant heat stress state (1990.76 g the highest value). It was also observed that an increase in the environmental temperature to 32 °C improved the performance of the broiler, while further increment was detrimental to the performance of the broilers. Growth of the broilers increased with increase in temperature between the 29 and 32 °C and progressively reduced as the temperature of poultry house increases from 32 – 41 °C. The experimental results also showed that cloacal temperature of broilers depends on temperature of the poultry housing, followed by percentage of standard diet, temperature-humidity index the age of the broiler and relative humidity. It was further observed that the feed intake of the broilers significantly (P < 0.05) depends on the percentage of the standard diet given to the broilers. Feed intake was observed to be significantly higher in heat free group and lowest for heat stress group. The study further shows that feed consumption rate of the broilers in the control group were consistently lesser than the broilers under a constant heat stress state. The quantity of feed leftover by the broilers significantly (P < 0.05) depends on the percentage of the standard diet given to the broilers, temperature of the poultry house and relative humidity. The standard parameter results for optimum broiler rearing condition are age of 7 weeks after stocking, relative humidity of 58.22 %, temperature of 30.99 °C, and 78.76% of the standard diet (feeding regime). With this optimal condition, a new feeding regime on weekly basis was established for broiler rearing in thermally controlled housing. The result therefore showed a better and more economical way of raising broilers using thermally controlled poultry house based on research output. Since chicken is an important source of animal protein raised in both extensive and semi-intensive poultry production systems account for more than 75 % of all poultry in Nigeria. Broiler birds provide food security and family income and play an important role in socio-cultural events. Based on this study, a good ventilation and heat control poultry housing is recommended for optimum broiler flock performance year-round.