Effect of neonatal isolation on responses to subsequent exposure to isolation stress in young chickens.

The aim of the present study was to investigate effects of isolation at an early age on behavioral and physiological responses of chickens to an isolation challenge at two weeks of age. Birds were assigned to a control group or to one of three treatments where chicks were isolated for 5 min per day. The groups were 1) no isolation (control); 2) early isolation (EI; 2 to 4 days of age); 3) late isolation (LI; 5 to 7 days of age); or 4) full isolation (FI; 2 to 7 days of age).

The use of behavioral tests of fearfulness in chicks to distinguish between the Japanese native chicken breeds, Tosa-Kukin and Yakido.

The aim of this study was to investigate the differences in fearfulness between two Japanese native chicken breeds, Tosa-Kukin (TOK) and Yakido (YKD). In a tonic immobility test, TOK breed chicks showed longer duration and lower induction number compared with YKD. The number of peeps in YKD in an isolation test was lower than that in TOK, whereas there were more bouts of peeping in YKD than in TOK.