Performance and Carcass Characteristics of Beef Cattle Fed Diets Containing Whole Corn Plant Ensiled With Swine Manure Solids

Abstract

Two feeding trials, one with beef steers and one with heifers, were conducted to determine the nutritive value and safety of feeding swine manure solids with fermented whole corn plant. Manure solids collected from an open concrete growing-finishing swine feedlot were ensiled with chopped mature whole corn plant at a 20:80 ratio (DMB) in exp. I and at a 27:73 ratio (DMB) in exp. II. Fermentation characteristics of the swine manure-corn forage silage mixture were evaluated. Diets for two trials were 1) corn silage, corn grain and vitamin-mineral mix (negative protein control; NPC), 2) corn silage, corn grain, vitamin-mineral mix and soybean meal (positive protein control; PPC) and 3) waste silage plus corn grain (swine manure silage; SMS). Average daily gains were similar for cattle fed the SMS and PPC diets in both experiments. Gains for cattle fed the NPC diets were lower (P ◄ .01) in both trials. Dry matter intakes (DMI) were higher (P ◄ .05) for steers fed the PPC diet compared with the SMS diet in the first trial, but not with heifers in the second trial. In both trials, DMI were lower (P ◄ .05) for the NPC diet. Feed efficiency was similar for steers fed the SMS and PPC diets, but was superior (P ◄.05)for heifers fed the PPC diet. Carcass values were not affected adversely by the addition of swine manure to whole plant corn before ensiling. Extra Cu in the swine manure (1,600 and 100 mg/kg DM) increased Cu in liver tissue from cattle in both trials. Extra Fe and Zn from manure increased liver Fe and Zn in the second trial, but only increased Fe in liver and kidney in the first trial. Mineral contents (Na, Fe, Zn, Cu) in other tissues (muscle and fat) were not affected by the addition of swine manure whole corn plant silage to cattle diets. Volatile fatty acids (VFA), N and ash levels were higher in swine waste silage compared to corn silage. Swine manure ensiled with whole corn plant resulted in a safe and preserved feed that supported efficient cattle growth when balanced with corn grain.