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Milk safety is a food safety concern in the U.S., and the cleanliness of on-farm milking systems directly affects raw milk quality. The conventionally accepted four-step procedure for milking system cleaning-in-place (CIP) includes: (1) warm water rinse, (2) alkaline wash, (3) acid wash, and (4) sanitizing rinse prior to the next milking event. Electrolyzed oxidizing (EO) water is an emerging technology that generates acidic and alkaline EO water by electrodialysis of a dilute sodium chloride solution. Previous studies have shown that EO water can be an alternative for conventional milking system CIP, both in pilot-scale milking systems and on commercial dairy farms. Recently, a one-step cleaning process has been adopted on an increasing number of dairy farms that combines the alkaline wash and acid wash to save chemical expenditure, water usage, energy cost, and time. By blending acidic EO water with alkaline EO water, a less corrosive but still effective blended EO water solution can be produced. Therefore, this study was undertaken to evaluate the blended EO water solution for one-step CIP using a pilot-scale milking system and compare the CIP effectiveness and cost with commercial one-step CIP chemicals. A Box-Behnken three-factor response surface method was used to determine the optimal cleaning time, the starting temperature of the blended EO water solution, and the acidic EO water percentage. Two commercial one-step CIP chemicals were used for comparisons of CIP effectiveness and cost. Results showed that a cleaning time of 17 min, a starting temperature of 59°C, and an acidic EO water percentage of 60% in the blended EO water solution could achieve the required 100% CIP performance and was comparable to the commercial one-step cleaning chemicals. Moreover, it was determined that the operating cost of one complete cleaning cycle, including the material cost and energy consumption, using blended EO water was 80% lower than using the commercial one-step cleaning chemicals. Overall, this study demonstrated that blended EO water has potential to be adapted as an alternative for onestep CIP for milking systems and possibility other food processing equipment. [ABSTRACT FROM AUTHOR]

Two lactating cow trials were conducted to evaluate the impact of diets differing in silage source (alfalfa/maize vs. grass/maize or maize/hay) and maize grain particle size (fine vs. coarse) on ammonia (NH3), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from a freestall barn floor with two groups of 60 cows each. In addition, the effects of environment (temperature, humidity) and management (manure depth, time since manure removal) factors were evaluated. Manure (feces and urine), spilled feed, bedding, and spilled drinking water were allowed to collect on the solid concrete, sloped barn alleys and were scraped twice a day. Gas fluxes from the freestall floor were measured at 64 locations over a 12 h period using a fast-response, non-steady-state flux chamber and an infrared photoacoustic gas analyzer during 18 trial days over a 9-month period. Fluxes of ammonia from manure on the barn floor were within average reported values for these 165 g kg-1 crude protein diets. All gas fluxes were similar (p = 0.253 to 0.977) regardless of silage source and maize grain particle size. The highest average ammonia emissions coincided with higher environmental temperature at 30 NH3 g AU-1 d-1, while the highest average greenhouse gas emissions from the manure on the floor were 10 g AU-1 d-1 for CH4 and 580 g AU-1 d-1 for CO2. Time in hours since scraping the floor had little impact on the production of ammonia, but greenhouse gas loss from the barn floor was reduced after scraping. Air and manure temperatures were positively correlated with emissions of NH3, CO2, and CH4 (p = <0.0001). NH3 (g AU-1 d-1) = 10(1.03+0.019*Tair) (R2 = 0.38) for indoor air temperatures (Tair, °C) over the range from -5 °C to 32 °C (AU = 500 kg animal unit). Ammonia emissions were positively correlated with CO2 and CH4 gas emissions, suggesting that NH3 release from the manure was controlled to some extent by microbial activity and similar environmental factors. Nitrous oxide emissions remained <0.1 g AU-1 d-1 and were relatively constant for all diets and trials. [ABSTRACT FROM AUTHOR]