Complex sentence: It was also discovered that younger broods (those less than six weeks old) had three times the rate of pecking than older broods, perhaps due to the relative inability of younger brood B-chicks to defend themselves from the attack.
Split into simpler sentences: It was also discovered that younger broods (those less than six weeks old) had three times the rate of pecking than older broods. Perhaps due to the relative inability of younger brood B-chicks to defend themselves from the attack.