A study on cow comfort and risk for lameness and mastitis in relation to different types of bedding materials

Discipline: cow comfort; Key words: bedding material, lying behavior, hock assessment, bacterial load.

Lameness is, as mastitis, one of the most pressing health concerns in housed cows. Bedding can contribute, also to comfortable conditions, and therefore acceptable bedding materials should be identified and continuously researched. A study by Dr S van Gastelen and co-workers on the subject was reported in the Journal of Dairy Science, Volume 94 of 2011, pages 4878 to 4888. The title of their article is:  A study on cow comfort and risk for lameness and mastitis in relation to different types of bedding materials.

The aim of the study was to evaluate the effects of four free stall bedding materials on cow comfort and risks for lameness and mastitis. The bedding materials were box compost, sand, horse manure (the deep litter materials) and foam mattresses. The comfort of free stalls was measured by analyzing the way cows entered the stalls, the duration and smoothness of the descent movement, and the duration of the lying bout. The cleanliness of the cows was evaluated on three different body parts: udder, flank, and lower rear legs, and the bacteriological counts of the bedding materials were also determined. For the purpose of the study, it was accepted that the combination of the cleanliness of the cows and the bacteriological count of the bedding material would provide an estimate of the risk to which the dairy cows are exposed to udder infections.

The results of the hock assessment revealed that the percentage of cows with healthy hocks was lower (20.5%), the percentage of cows with both damaged and swollen hocks was higher (26.8%), and the severity of the damaged hock was higher (2.32%) on farms using foam mattresses compared with deep litter materials. The deep litter material results for these three criteria were: box compost 64.0%, 3.5% and 1.85% respectively, sand 54.6%, 2.0% and 1.91% respectively, and horse manure 54.6%, 5.5% and 1.85% respectively. In addition, cows needed more time to lie down (140.2 seconds) on farms using foam mattresses compared with sand (50.1 seconds) and horse manure (32.9 seconds). Furthermore, the duration of the lying bout was shorter (47.9 minutes) on farms using foam mattresses compared to sand (92.0 minutes). These results indicate that deep litter materials provide a more comfortable lying surface compared with foam mattresses. The three deep litter bedding materials differed in relation to each other in terms of comfort and their estimate of risk to which cows were exposed in terms of udder infections: The bacteriological counts, expressed in colony forming units (cfu), were: box compost: 17.8 × 1.0⁴ cfu per gram; sand: 1.2 × 1.0⁴ cfu per gram and horse manure: 110.5 × 1.0⁴cfu per gram. Box compost had a low gram-negative bacterial count compared with horse manure, and was associated with less hock injury compared with foam mattresses, but did not improve lying behaviour. Overall, sand provided the best results, with a comfortable lying surface and a low bacterial count.