Final answer:
The postretirement benefit expense for the current year is $50,000.
Step-by-step explanation:
To calculate Jaybird Company's postretirement benefit expense for the current year, we need to consider the service cost and the interest cost. The service cost is the cost of newly earned benefits, which is $10,000. The interest cost is the increase in the benefit obligation due to the passage of time, which is calculated as the beginning obligation multiplied by the discount rate. In this case, the interest cost is $400,000 * 0.10 = $40,000.
Therefore, the postretirement benefit expense for the current year is the sum of the service cost and the interest cost, which is $10,000 + $40,000 = $50,000.