Effect of feeding before, during and after milking on dairy cow behaviour and the hormone cortisol

The present study was performed to find out how dairy cow behaviour and the level of the adrenocortical hormone cortisol were influenced by feeding in relation to milking The experiment was designed as a Latin square and performed on 24 primiparous and multiparous Swedish Red and White dairy cows. Each treatment period lasted for 21 days, including 11 days when the cows became accustomed to the new routines. The cows were exposed to three treatments: feeding 1.5 h before milking (FBM), feeding exactly at the same time as milking (FDM) and feeding 1.5 h after milking (FAM). Recordings of individual behaviour were made with instantaneous direct observation of each cow. For the statistical analyses the recordings were divided into two groups: 0 to 1.5 h after feeding and 0 to 1.5 h after milking. Results with a P-value below 0.05 were regarded as statistically significant. The interesting findings in this study were: (a) 0 to 1.5 h after feeding, the percentage of lying was higher in FDM and the percentage of lying while ruminating was higher in FDM; (b) 0 to 1.5 h after milking, the cows in FAM had a significantly lower percentage of social interactions and a significantly higher percentage of oval activity; and (c) feeding-related level of cortisol stayed higher 30 to 60 min after feeding in FAM compared with FBM and FDM, whereas milking-related cortisol secretion tended to be lower in FDM than in FBM and FAM These results demonstrate that feeding during milking may be an important management routine, also for dairy cow behaviour.