Effect of feeding duration and rumen fill on behaviour in dairy cows

The aim of the present experiment was to test the hypothesis that oral mani pulation of feed is a behavioural need in cattle, irrespective of actual ru men load. Twelve rumen fistulated cows were used and subjected to four diff erent treatments: low rumen content+long duration of eating (A), high rumen content+short duration of eating (B), high rumen content+long duration of eating (=positive control) (C) and low rumen content+short duration of eati ng (=negative control) (D). To obtain treatment A and B, rumen content was transferred by hand from cow A to B through the rumen fistulaes. Each treat ment lasted for 3 days with 2 weeks of recovery between each new treatment. The experiment was repeated twice during two consecutive years. All cows w ere fed the same mixture of silage, concentrate and hay. The cows were vide otaped under normal conditions (24 h), and on the third day of the experime nt. From these videotapes, the behaviours (frequency and duration per 24 h) have been analysed. Time spent eating differed between the four treatments (P<0.001), with shor test eating-times in B and D. The cows with low rumen content (A and D) spe nt shorter time ruminating (P<0.001) than the cows with filled rumen (B and C). The B and D cows (short duration of eating) spent longer time (P<0.001 ) with behaviours related to feed-searching than the cows with long duratio n of eating (A and C). The C cows had fewer (P<0.001) bouts of behaviours r elated to feed-searching than the A, B and D cows. Time spent with stereoty pies (tongue-rolling) was longer (P<0.01) in D than in the other treatments . There was a difference (P<0.001) between treatments in eating bouts. The A cows had more (P<0.05) eating bouts than the cows in B, C and D. The cows with low rumen content (A and D) had fewer ruminating bouts (P<0.001) than the cows with filled rumens (B and C). The number of bouts with stereotypi es differed (P<0.01), the cows in D having the highest figures compared wit h all the other treatments. In conclusion, our results support the hypothesis that oral manipulation of feed is a behavioural need in cattle irrespective of rumen load. A low dur ation of feeding behaviours combined with a low rumen load, which is a comm on practice in certain categories of growing cattle or dry dairy cows, seri ously impairs the welfare in cattle. (C) 2000 Elsevier Science B.V. All rig hts reserved.