Alternative calcium source effects on commercial egg production and quality
Brazilian Journal of Poultry Science
In high environmental temperatures poultry production is generally reduced, due to decreasing feed intake especially calcium (Ca) and try to overcome heat stress by panting. The purpose of present study was to determine the effect of heat stress on acid-base imbalance, plasma Ca concentration, egg production and egg quality( egg weight, specific gravity, egg shell thickness, egg shell weight and Haugh unit) in commercial layers. In this study two hundred laying hens (Hy-Line) 40 weeks age were
... 40 weeks age were divided into two groups, each group contains 100 hens (control group and purpose group). Every 4 hens were kept in a cage with water and same basal diet ad libitum. During the experiments, hen houses received 16h of light per day. Hen house's temperature was measured four times a day (06.00, 12.00, 18.00 and 24.00). The average minimum and maximum daily temperature respectively were 22°C and 36°C that recorded in hot season of year. The length of the experiment was 90 days. The control group was kept in the same experimental situation and average minimum and maximum temperature were 20°C and 26°C respectively. Results of present study showed that Ca concentration significantly decreased (p<0.05) in purpose group. PH levels in purpose group significantly increased (p<0.05). Results of present study also showed that heat stress in purpose group results in decrease egg production (p<0.05) and egg quality (p<0.05) that can be relation with PH increase, decreased ionized Ca of plasma. Our results could be helpful in establishing guidelines for temperature control in laying hen houses, especially during the summer months when birds are most susceptible to heat stress.