SUCKLING IN FREE-RANGING BEEF-CATTLE - TEMPORAL PATTERNING OF SUCKLING BOUTS AND EFFECTS OF AGE AND SEX

Suckling was studied in primiparous cross-bred beef cattle (Bos primig enius f. taurus) kept on a 1000-ha grazing area. Observations were mad e at mean calf ages of 1, 7, 65 and 123 d on 20 calves of each age. Re cordings of four different behaviours were made at 12-s intervals and recordings of butting were made continuously during one suckling bout per calf and age. Two types of sucking, occurring within the same suck ling bouts, were distinguished: sucking 1 (rhythmic sucking movements) and sucking 2 (<3 sucking movements followed by release of tear). It was found that sucking 1 made up 18.5-35.2 % of the total suckling tim e. The highest proportion of sucking 1 was recorded at 65 d of age. Su cking 2 made up 39.3-50.0 % of the total suckling time and it tended t o decrease with age. The first recording of sucking 1 was made on aver age 7.3 (+/-4.4) recordings after start of a suckling bout and continu ed for about 5 min thereafter. Sucking 2 was recorded both before, dur ing, and after sucking 1 activity, which is here suggested as being th e main period of milk intake. Buttings were recorded during the whole suckling bout, but tended to be most frequent towards the end of the s ucking 1 period. Calves did not show any regular suckling pattern at 1 d of age, but at 7 d, a distinct pattern had been established. The ca lves initiated the suckling bouts, with increasing calf age, more ofte n than the mothers. The suckling bouts were mostly terminated by the c alves, especially after 7 d of age. Suckling bouts were significantly longer in bull calves than in heifer calves at 7 d, but sucking 1 was recorded significantly more often in heifer calves at 123 d. From this study, it is suggested that, in cattle, the temporal patterning of th e suckling bout appears to consist of three main parts: prestimulation , milk intake, and post-stimulation.