Aerobic and Anaerobic Transformations in Estrogens and Nutrients in Swine Manure: Environmental Consequences

Abstract

Pig manure is an excellent fertilizer and rich source of organic carbon and nitrogen compounds such organic nitrogen (O-N) (95% of total nitrogen) that is plant-unavailable-nitrogen (PUN) and mineralized nitrogen (about 1% of total nitrogen) such as ammonium (NH4 + ) and nitrate (NO3) that are plant-available-nitrogen (PAN). In addition, manure also contains two forms of estrogens: (i) poorly estrogenic thus essentially nontoxic conjugated estrogens (cEs) such as estrone (cE1), estradiol (cE2) and estriol (cE3); and (ii) highly estrogenic and toxic free estrogens (fEs) such as fE2, fE1 and fE3. This study showed that aerobic processing reduced concentrations of total carbon (TC), O-N, PAN and NH4 + /NH3 ratio, transiently hydrolyzed cEs (cE2 > cE1 > cE3) into corresponding fEs, transiently increased estrogenic activity and potential toxicity, and rapidly degraded fEs (fE2, fE1 > fE3), thus reducing the estrogenic activity in manure. Unlike aerobic processing, anaerobic processing stabilized and increased PAN and NH4 + /NH3 ratio, thus increasing the manure's fertilizer value. However, anaerobic processing, relative to aerobic processing, poorly hydrolyzed cEs (reducing transient toxicity and increasing reserve toxicity potential) and poorly degraded fEs (increasing toxicity) in manure. Thus, aerobic and anaerobic environments have distinct effects on manures' PAN and estrogenic activity, presenting an interesting dilemma: anaerobic incubation that increases manures' PAN does not effectively degrade estrogens, while aerobic incubation that effectively degrades estrogens (after transiently increasing their estrogenic activity) also decreases PAN, thus making manure less profitable. New techniques are need to fully use manure as organic fertilizer. OPEN ACCESSAgriculture 2015, 5 698

Distribution, Sorption and Desorption of Tylosin, Chlortetracycline and their Metabolites in Pig Manure

“…Whole manure samples were collected from pig farms and handled as described previously (Singh et al 2013, Singh 2015, 2016. Immediately after collection, each sample was mixed with internal standards to track possible degradation and then split in two parts.…”

Litter Type and Number of Flocks Affect Sex Hormones in Broiler Litter

“…Full cleanout refers to total removal of litter from a broiler house, whereas cake cleanout refers to removal of caked litter only. Cake cleanout accounts for 30 to 46% of total litter production (cake+full cleanouts; Malone, 1992; NRAES, 1999; Sistani et al, 2003). Each broiler house typically raises ∼20,000 to 28,000 birds for 42 to 63 d, depending on the bird target market weight.…”