Comparison of Bacteria Populations in Clean and Recycled Sand used for Bedding in Dairy Facilities

Abstract

Bedding samples were collected twice from commercial dairy free-stall facilities that used recycled sand and clean sand in both the summer and winter. Collection began on the day sand was taken from the pile (d 0) and placed in the free stalls, and continued for 5 to 7 additional days. The number of colonies per gram of bedding of gram-negative bacteria, coliforms, Streptococcus spp., and Klebsiella spp. were estimated for each sand sample as well as amounts of dry and organic matter. Clean sand (CS) and recycled sand (RS) had the same bacterial counts when compared at any sampling time. The mean counts of bacterial populations did vary over the course of the study in both CS and RS. There was a significant increase in bacterial counts from d 0 to d 1 for gram-negative bacteria, coliforms, and Streptococcus spp. in both winter and summer. Counts of gram-negative bacteria, coliforms, Klebsiella spp., and Streptococcus spp. did not differ from d 1 to 7 in the winter. Total counts of gram-negative bacteria did not differ from d 1 to 7 in the summer. On d 1 in the summer, coliform counts were lower than at d 5 to 7, and Klebsiella spp. counts were lower than on d 3 to 7. Streptococcus spp. counts were high on d 1 and were constant through d 7 in both winter and summer trials. The number of coliform and Klebsiella spp. in both CS and RS was below the threshold thought to cause mastitis during the sampling times. The number of Streptococcus spp. was high in both CS and RS during the sampling periods. Other management factors need to be identified to decrease the number of Streptococcus spp. in bedding. Recycled sand had a higher organic matter and lower dry matter compared with CS in winter and summer. The results for this study were obtained from multiple herd comparisons, and herd was a significant effect suggesting that different management systems influence the number and types of bacteria in both CS and RS.

Fecal Shedding of Klebsiella pneumoniae by Dairy Cows

“…However, Klebsiella can also be present in sand, with average numbers ranging from 100 to 2,200 cfu/g for clean or recycled sand taken from the pile, to more than 100,000 cfu/g in sand taken from stalls during summer (Kristula et al, 2005). Klebsiella levels in sand reported by Kristula and coworkers (2005) are similar to the results from our study, which was conducted in summer: <200 cfu/g for the pile and 10 4.5 cfu/g (median value) for used sand.…”

“…Mean Klebsiella counts in sand bedding typically increased approximately 100-fold in winter. In summer, up to 1,000-fold increases in Klebsiella counts could be observed (Kristula et al, 2005).…”

“…Rates of teat-end contamination and clinical mastitis have been correlated to bacterial loads in bedding (Hogan et al, 1989;Zdanowicz et al, 2004), and use of inorganic bedding is recommended as an effective means of environmental sanitation and mastitis prevention (National Mastitis Council, 1999). Klebsiella levels in clean or recycled sand are generally low, especially when the sand is first brought into the stalls (Kristula et al, 2005). During use, Klebsiella counts in bedding increase.…”

Influence of Free-Stall Base on Tarsal Joint Lesions and Hygiene in Dairy Cows

“…Cows on sand beds were similarly affected (24%) in their study, with the dorsal tuber calcis being the most often injured location, perhaps as a result of contact with the concrete curb when sand becomes low. These injuries may be prevented by bedding more frequently, which could be advantageous in controlling Streptococcus spp., as suggested by Kristula et al (2005), who further noted that sand stalls are generally filled only once weekly. Low percentages of cows suffered lesions at the medial surface of the tarsal joint (3.0, 4.8, and 2.7) on RFM, sand, or waterbeds, respectively.…”

“…These cows were among the most likely candidates in the sand category to have swollen tarsal joints. Recycled sand contains more large particles than new sand (Kristula et al, 2005), and this may have been a contributing factor in the increased lesion rates. When dairies using a sand base were sorted into thirds by the percentages of cows with combined score 2 and 3 lesions, differences were found between the best and worst by lesion percentages for annual death rate (7.3 ± 1.1 vs. 4.1 ± 1.1%; P = 0.04) and the percentage reported lame on the day of the visit (3.2 ± 0.7 vs. 1.1 ± 0.7%; P = 0.05).…”