Evaluation of cardboard and dried poultry waste as feed ingredients for ruminants

Abstract

The nutritive values of cardboard and cage hen manure (CHM) for ruminants were evaluated using chemical analyses, alkali treatment, ensiling, in vitro digestion studies and in vivo digestion studies. Cardboards treated with or without alkali (4% NaOH or NH 4OH) were analyzed for chemical components. Other samples were supplemented with various N supplements (cottonseed meal (CSM), feather meal, urea and CHM plus urea) and used as substrates for in vitro fermentation. Ammonia nitrogen (NH 4-N) and volatile fatty acid (VFA) production were also determined. Cardboard silages (ensiled in polyethylene bags) consisted of untreated and NaOH-treated cardboards with or without cane molasses (10%) supplemented with various levels (10–50%) of CHM. Silage samples were evaluated for pH, dry matter loss and crude protein (CP) loss and also used as substrates for in vitro incubation and NH 4-N production. In vitro digestibility by sheep (20 wether lambs) of diets containing various levels of ground cardboard with and without poultry manure was determined by the total collection method. A control diet made up of ground corn, chopped ryegrass straw, cane molasses and CSM was compared with diets in which 15 or 30% cardboard replaced the same amounts of straw and a fourth diet (30% cardboard) in which CHM replaced 25% of the N supplied by the CSM. NaOH treatment decreased the fiber content, increased the ash content and increased in vitro fermentation of cardboard, while NH 4OH treatment increased CP content. Increased total VFA resulted from both NaOH and NH 4OH treatment. Supplementation with urea or CHM plus urea increased total VFA and propionic acid production. NaOH treatment enhanced microbial fermentation on cardboard silages, especially when supplemented with molasses. Silages did not undergo as much fermentation as expected. Cardboard silage was readily fermented by rumen microorganisms, especially when treated with NaOH and supplemented with molasses and CHM. In vivo digestibilities of dry matter, organic matter and gross energy were highest ( P < 0.05) for the 30% cardboard diet followed by the CHM diet. CSM was a better ( P < 0.05) source of digestible crude protein than CHM. Cardboard fiber was more readily digested ( P < 0.001) than that of ryegrass straw and the addition of CHM improved digestibility of cardboard fiber. Digestibility of the inorganic components of the diets (Ash) decreased ( P < 0.001) with each addition of cardboard and was further decreased with the addition of CHM. Fecal N increased slightly ( P < 0.05) when cardboard was fed and again when CHM was fed. N retention was increased ( P < 0.05) by each addition of cardboard, but decreased (to the 15% cardboard level) when CHM was added to the diet. The results indicate that (a) cardboard and CHM can be utilized effectively by rumen microorganisms; (b) alkali treatment (especially with NaOH) and ensiling of cardboard-CHM diet will improve its utilization; (c) cardboard and CHM can be fed to growing lambs to obtain a moderate to good level of production.