An evaluation of mattresses and mats in two dairy units.

In order to investigate the relative merits of mats and mattresses in terms of cow comfort, production and performance, 29 cows were housed on ethylethene vinyl acetate (EVA) mats and 29 on mattresses of loose rubber crumb with a polypropylene cover, at each of two similar dairy units (SAC Auchincruive and Myerscough). Both mats and mattresses were newly installed at the start of the trial. The cows were housed in the autumn after calving. Milk yield was recorded daily. Cows were weighed and scored for body condition, locomotion, dirtiness and hock and knee injury at fortnightly intervals. Feed offered was recorded daily and refusals were weighed weekly. Monthly milk records of milk yield, milk composition and somatic cell count data were available for both herds. In addition, 24 h behavioural observations of 15 core cows in each group were made at weeks 0, 2, 4, 6, 8, 16, and 32 post-housing. There was no difference between cows on mats and mattresses in milk yield, composition or quality; in feed intake; in weight loss or body condition score; in severe hock or knee injury, or in the incidence of lameness. Cows on mattresses tended to have slightly higher total dirtiness scores than those on mats (7.06 vs. 6.95, P=0.074) and had dirtier udders (mattress, 7.50 vs. mat, 6.52, P<0.05). However, over the whole housing period, cows on mattresses spent longer feeding, ruminating and lying and a greater proportion of their lying time was spent ruminating. They spent less time standing doing nothing (idling) than cows on mats and less time idling in cubicles. Cows on mattresses appeared to adapt to housing more quickly than those on mats. Overall, neither mat nor mattress gave advantages in terms of production or performance, cows were slightly cleaner on mats but behavioural indices suggest that cow comfort was greater on mattresses.