Beef packer margins deteriorated sharply last week, with estimated net margins falling to -$330.80/hd, down $60.58/hd week over week. The Choice cutout held nearly flat at $365.62/cwt, but fed cattle prices continued to climb, with live steers at $246.91/cwt and dressed prices surging to $387.96/cwt, widening the gap between packer breakevens and cash cattle. Gross margins slipped into negative territory at -$20.27/hd, underscoring that firm cattle costs are fully absorbing modest wholesale strength. With breakeven dressed values now $35.21/cwt above cattle prices, the near-term outlook remains defensive for packers.  Feedlot placement margins improved but ...