| Popis: |
An experiment was conducted to compare bacterial counts of environmental mastitis pathogens in composted recycled manure solids bedding with those in fresh recycled manure solids. Eighteen Holstein cows were housed in 1 pen with 18 stalls. One row of 9 free stalls included mattresses and was bedded weekly with composted recycled manure solids. The second row of 9 free stalls included mattresses and was bedded weekly with fresh recycled manure solids. The back one-third of these stalls toward the alleyway was covered in 25 to 50 mm of bedding. Samples were taken from the back one-third of 4 stalls for both treatments on d 0, 1, 2, and 6 for each week. After 3 wk, bedding treatments were switched between rows, making the total duration 6 wk. Mean total gram-negative bacterial counts were lower in the composted recycled manure solids on day 0 and 1 compared with fresh recycled manure solids. Tetracycline resistant gram-negative bacteria were lower in composted recycled manure solids for d 0, 1, and 2 compared with fresh recycled manure solids. Coliforms and Streptococcus spp. bacteria were lower in composted than fresh recycled manure solids on d 0. Klebsiella spp. bacteria were reduced in composted recycled manure solids compared with fresh on d 0 and 6. Fresh recycled manure solids had a higher DM for d 1 and 2 compared with composted recycled manure solids. Ash content was higher in composted recycled manure solids compared with fresh recycled manure solids throughout the trial for d 0, 1, 2, and 6. Composting recycled manure solids was successful in reducing tetracycline resistant gram-negative bacteria as well as increasing ash. Despite the increase in ash after composting, bacterial counts in composted recycled manure solids were elevated throughout the trial after use as bedding. Composting recycled manure solids used as free stall bedding had minimal effect on reducing environmental mastitis pathogen exposure to teat ends. |
