2007 Volume 43 Issue 3 Pages 154-163
Some behaviors and blood constituents of cows with an available salt-mineral block were compared with those of cows without salt-mineral block to investigate the significance of salt-licking. The measurements were made once in a month from May to September. The cows were housed in a tie-stalls barn. Salt-licking behavior was observed continuously, and the other behavior was observed at 10-min intervals for 18 hours in a measurement. Blood samples were collected after the behavioral observation. The daily consumption of salt block and frequency of salt-licking was higher in July (61.6±60.1g/day and 39.9±40.9 times/day, respectively) than in another months. The cows often licked salt block immediately after feeding. The cow without salt block spent the corresponding time for resting (44.9%), eating (28.6%) and ruminating (12.3%). The time spent for licking correlated with the frequency of eliminative behavior (r_s=0.37, p<0.05), investigative behavior (r_s=0.28, p<0.10), milk protein content (r_s=0.34, p=0.05) and milk yield (r_s=-0.36, p<0.05). The serum IgM content in cows with salt block was higher than that in cows without salt block (p<0.05). However, NEFA content was higher than in the cows without salt block than the cows with salt block (p<0.10). There was no significant difference in behavioral measurements between cows with and without salt block. In conclusion, salt-licking in lactating cows often occurred after every feeding, and increased serum IgM content significantly.
