* The sequence of photoperiod exposure makes a difference. Exposure to short days during the first 6 months of life, followed by increasing day lengths in the second 6 months of life is associated with the earliest puberty. This is true of calves born in the autumn with exposure to natural photoperiods. | * The sequence of photoperiod exposure makes a difference. Exposure to short days during the first 6 months of life, followed by increasing day lengths in the second 6 months of life is associated with the earliest puberty. This is true of calves born in the autumn with exposure to natural photoperiods. |