12 3 the relevant markets introduction 1 every time an animal reared for food production is slaughtered some part of its body becomes a waste product in consequence volume such raw determined by number animals mainly cattle pigs and sheep more directly output slaughter houses abattoirs knacker industry which deals with dead or diseased fallen stock other original although much smaller source products knackers particularly hides wool from have commercial value as material to indus tries slaughtering process mostly inedible fat bone offal are collected processed rendering sector main outputs tallow meat meal structural flow principal shown schematic form at figure poultry separately not considered here detail 2 this chapter will first look briefly abattoir industries
