title: Effect of level of acidification by phosphoric acid, storage temperature, and length of storage on the chemical and biological stability of ground poultry mortality carcasses.
abstract: Two experiments were conducted to evaluate the addition of feed-grade H3PO4 in comparison to lactic acid fermentation as a means of preserving ground poultry mortality carcasses. Mortality silage quality in both experiments was evaluated by measuring the rise in pH after initial acidification (deltapH) and the content of nonprotein N (NPN), volatile nitrogen (VN), NH3-N, and fecal coliform bacteria in the silage treatments. Preliminary work in Experiment 1 evaluated the preservative effects of six initial levels of acidification with H3PO4 (pH 2.0, 2.5, 3.0, 4.0, or 5.0) at two storage temperatures (21 and 45 C). Experiment 2 compared silages preserved with different levels of feed-grade 74.5% H3PO4 (4.13, 5.52, 6.90, and 8.28% wt/wt, concentrated acid basis) to silages made by lactic acid fermentation. Based on the evaluations in Experiment 1, acidification with H3PO4 to pH < or = 3.0, when incubated at 45 C, or pH < or = 2.0, when incubated at ambient temperatures, produced the most biologically favorable poultry mortality silage for subsequent use as a feed ingredient. In Experiment 2, mortality silages containing 8.28% H3PO4 (wt/wt, concentrated acid basis) contained significantly (P < 0.05) lower levels of the protein degradation by-products VN and NH3-N than silages prepared by lactic acid fermentation. Therefore, feedstuffs manufactured from mortality silages prepared using 8.28% H3PO4 would be expected to result in improved animal performance vs. feedstuffs manufactured using silages prepared by lactic acid fermentation.
authors.affiliation: Department of Poultry Science, North Carolina State University, Raleigh 27695-7608, USA.
authors.forename: T F
authors.initials: TF
authors.lastname: Middleton
authors.forename: P R
authors.initials: PR
authors.lastname: Ferket
mesh_terms: D000818:Animals; D002645:Chickens; D004755:Enterobacteriaceae / Q000254:growth & development; D005285:Fermentation / Q000187:drug effects; D005511:Food Handling / Q000379:methods; D005519:Food Preservation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000378:metabolism*; D009584:Nitrogen / Q000032:analysis; D010756:Phosphoric Acids / Q000494:pharmacology*; D012475:Salmonella / Q000254:growth & development; D012820:Silage / Q000032:analysis / Q000382:microbiology / Q000592:standards*; D013696:Temperature; D013997:Time Factors
chemical_list: D010756:Phosphoric Acids; D019344:Lactic Acid; C030242:phosphoric acid; D009584:Nitrogen