TACTILE STIMULATION OF DAIRY HEIFERS: EFFECTS ON BEHAVIOR AND MILK PRODUCTION AFTER CALVING

The positive management of primiparous heifers before calving through tactile stimulation may have beneficial effects on behavior during routine milking. The objective of this study was to evaluate the use of tactile stimulation in dairy heifers and its effects on behavior and milk production after calving. Ten primiparous Holstein heifers were used. Half the group received training with tactile stimulation of all body regions, while the other group did not receive stimulation (control group). The training period was divided into three phases: early, days 1 to 6 of training; intermediate: days 7 to 12, and final, days 13 to 23. During training, movement and displacement scores were obtained over a period of 5 minutes. Physiological parameters were also recorded [ respiratory rate (FR) and minimum eye temperature (ETmin) measured with a thermal imaging camera]. After calving, the heifers were submitted to first milking when the evaluations were started for the first 10 days of milking (20 consecutive milkings). The behavior of the animals was evaluated by attributing a reactivity score of 1 (desirable behaviors) or 2 (undesirable behaviors): entry into the pen, teat disinfection, milking one or two jets of milk for mastitis testing, attachment of teat cups, and removal of milk, as well as the amount of milk produced. Mean ETmin and FR decreased over the training period. A significant difference was observed for displacement score (P=0.019), with a reduction in displacement from the early to the final period (from 60.0% to 25.7%). During the attachment of teat cups, stimulated heifers were less reactive (P=0.002), characterized by a lower frequency of undesirable behaviors (12.0%), than unstimulated heifers (30.2%). The average milk yield during the first 60 days of lactation was higher for the group of stimulated heifers (Ln y= 2.20-0.0102t+0.331lnt, R2=0.76) compared to unstimulated heifers (Ln y= 1.54-0.0191x+0.578lnx, R2=0.79), with this difference being significant (P<0.001). The tactile stimulation performed on primiparous heifers before calving had beneficial effects on their behavior during milking, reducing reactivity to the milker and increasing milk production.