Introduction of a Greenhouse as an Alternative Housing System to a Conventional House and Its Impact on Broiler Performance and Blood and Carcass Variables

A study was conducted to compare the growth performance as well as blood and carcass variables of two broiler strains reared in a conventional broiler house and a modified greenhouse equipped with cooling pads and tunnel ventilation system. Eight hundred day-old chickens of two commercial strains (Ross 308 and Lohmann) were selected and placed in 8 floor pens (4 pens of 50 broilers for each strain in each housing system). The pens were located randomly throughout the modified greenhouse or the conventional broiler house (two-way ANOVA design). The broilers were provided a standard starter and grower diets ad libitum. The environmental conditions (i.e. temperature, relative humidity, lighting program and ventilation rate) were kept similar between the two houses. The results showed that the birds in the greenhouse consumed significantly (P < 0.05) more feed during the starter period (1-21d) and throughout the trial (1-42d) in comparison with those reared in the conventional house. Strain difference and strain × house interaction had no significant effect on the measured parameters i.e. body weight gain, feed conversion ratio, hematocrit, heterophil:lymphocyte ratio, serum nitric oxide concentration, carcass and breast yields. However, birds reared in the greenhouse deposited more fat in their abdominal cavity compared to their counterparts in the conventional house (P < 0.05). Interestingly, from the economic point of view, the construction cost of a greenhouse was estimated approximately onethird of a conventional house (?40.00 vs 120.00 US$ per square meter). In conclusion, modified greenhouses equipped with cooling pads and tunnel ventilation system are recommended for low-cost rearing of broiler chickens.