burr damage .3,The two sides of leakage dung board are ladder type,avoiding sundries blocking between boards4.Advantages of long service life,non-toxic,non-pollution,good ventilation effect,no hurting to pig feetand nipples,good dung leakage effect,labor saving.with high tensile strength, good rigidity, anti-aging and anti-corrosion.High ductility,interlock by rabbet..Made of ductile cast iron ;Interlocking and unique seamless joining system for easy to clean;Unique design with additional rib fo