Bacteria in the air of housed Swine units.

Two housed, swine-growing-finishing units were studied for numbers of total bacteria, fecal coliforms, Staphylococcus, and Salmonella in the air. At 30.5 and 122 cm from the floor, total colony-forming particles, as tested, averaged 3.4 x 10 and 1.3 x 10/m of air, respectively; whereas fecal coliform counts averaged 24 x 10 and 1.9 x 10/m of air, respectively. Only 41% of the organisms growing on Staphylococcus 110 medium tested as Staphylococcus. Of 458 Staphylococcus isolates, 5 were coagulase-positive. No Salmonella were detected in the air of the units tested.

Effect of short-chain Fatty acids extracted from beef cattle manure on germination and seedling development.

Composted and fresh beef cattle manure samples were extracted with distilled water, acetone, methanol, 2 N sodium hydroxide, 2 N hydrochloric acid, and ether. Bioassay techniques, using the extracts, showed that composted manure extracts had limited effect on seed germination and seeding development of wheat and sorghum. All the extracts of fresh manure, other than distilled water, retarded germination. Acetic, butyric, propionic, valeric, and isovaleric acids were found in ether extracts of fresh manure at average concentrations of 348, 876, 578, 34, and 19 mug/g, respectively, on a dry-weight basis. However, only trace amounts of these acids were present in composted manure. Propionic acid up to the 200-mug/ml level stimulated seedling growth. Acetic and butyric below the 200-mug/ml level had no detrimental or beneficial effects on seedling development. When acetic, butyric, and propionic acids were mixed in equal parts, germination and seedling growth were reduced at all levels (50 to 500 mug/ml).

Effects of patulin and method of application on growth stages of wheat.

When a single, 100-mug/ml application of patulin, produced by Penicillium urticae Bainier, was applied to growth stages 7, 9, 10, and 10.1 (Feekes scale) of Lee spring wheat (Triticum aestivum L.), decreases in internodal elongation, floret number, seed weight, and seed number were observed. Yields were reduced according to the proximity of application prior to heading. Application of patulin to the soil in crystalline form and dissolved in aqueous solution were also investigated, and the solution method of application was found to be the treatment of choice. A single exposure of growing wheat plants to patulin can produce yield reductions similar to those observed in stubble-mulch farming.

Ammonium, nitrate, and total nitrogen in the soil water of feedlot and field soil profiles.

A level feedlot, located in an area consisting of Wann silt loam changing with depth to sand, appears to contribute no more NO(3) nitrogen, NH(4) nitrogen, and total nitrogen to the shallow water table beneath it than an adjacent cropped field. Soil water samples collected at 46, 76, and 107 cm beneath the feedlot surface generally showed NO(3) nitrogen concentrations of less than 1 mug/ml. During the summer months, soil water NO(3) nitrogen increased at the 15-cm depth, indicating that nitrification took place at the feedlot surface. However, the low soil water NO(3) nitrogen values below 15 cm indicate that denitrification takes place beneath the surface.

Patulin production by Penicillium urticae Bainier in batch culture.

A still, batch-culture method, with potato dextrose medium and Penicillium urticae Bainier, produced patulin yields of 1.2 to 1.7 g/liter of medium. Incubation was at 25 C for 14 days. Ethyl acetate extraction of condensed culture filtrate and drying with anhydrous MgSO(4), followed by solvent change to dry ethyl ether and purification on alumina (pH 4.5), produced pure crystalline patulin. The use of 2-liter, round-bottom flasks and a rotating vacuum evaporator provided versatile equipment and easy manipulation in the operations. Soil from wheat fields provided a convenient natural P. urticae source. Potato dextrose medium was superior to potato sucrose or Raulin-Thom media.