Why does a sudden change in feed raw material particle size (from coarse to fine mash) cause flock cannibalism and vent pecking in brown layers?

In poultry behavior, feed physical structure is a powerful regulator of daily activity. When fed a coarse, high-uniformity mash or crumbled feed, hens must spend significant time and physical effort searching for and picking up particles, which occupies their natural foraging instinct. If a feed mill suddenly switches the feed structure to a finely ground, dusty mash, the physical feeding dynamics change. Hens can consume their daily feed allocation much faster because they do not have to pick individual particles. This drastically reduces their daily eating time, leaving the flock with massive "idle time". In high-density cage or deep-litter systems, this unoccupied time, combined with the frustration of eating dusty feed, triggers abnormal oral pecking behaviors. Birds redirect their pecking instinct toward their housemates, focusing on bright or moving areas, primarily the reddish mucosal tissue of the vent (vent pecking). Once a single hen draws blood, the red color attracts the entire flock, rapidly escalating into epidemic cannibalism, high mortality, and severe production drops. Maintaining coarse feed texture and uniform pelleting is vital. Farmers can read ethology studies in the Poultry Encyclopedia, buy professional feed mills and pelleting equipment on Poultry Plaza, monitor daily egg prices on Poultry Rates, and list stable flocks on Murghi Mandi.