Calcified seaweed in the diet of semi-heavy hens during the rearing and pre-laying phases

Abstract

Abstract Calcareous seaweed (Lithothamnium calcareum) is a source of organic minerals and has been used as an alternative food in poultry nutrition. The objective is to evaluate the levels of calcareous algae in the diet of chickens during the rearing and pre-laying phases, as also on the performance and thermoregulation variables. One hundred and forty-four semi-heavy Hisex Brown hens, aged 12 to 18 weeks, were used in the rearing and pre-laying stages. They were fed with four levels of calcareous algae (0%, 10%, 20%, 30%), which were used in place of the calcitic limestone. Six replications and six birds were used per experimental unit, distributed in a completely randomized design. Feed intake, weight gain, feed conversion, body weight, viability, and thermoregulation through cloacal temperature (°C), mean body temperature (°C), and mean skin temperature (°C) were evaluated. There was no significant difference (P > 0.05) in the thermoregulation of the birds. There was a difference (P < 0.05) in the feed intake during the pre-laying phase, however, the other parameters showed no difference (P > 0.05). The inclusion of up to 30% calcareous algae in the diet of semi-heavy laying hens in the rearing and pre-laying phases did not affect the performance or thermoregulation of the birds. Therefore, it is possible to substitute calcitic limestone with up to 30% of the calcareous algae in the diet of semi-heavy laying hens.