Effects of amount of milk, milk flow and access to a rubber teal on cross-sucking and non-nutritive sucking in dairy calves

The aim of this study was to test the effects of different amounts of milk, how rate of milk, and access to a teat after milk intake on non-nutritive sucking on an empty teat and on cross-sucking on other calves in Bos taurus dairy calves. An additional aim was to test if calves prefer to perform no n-nutritive sucking on a teat with the taste of milk or on a clean teat. Fi rst experiment involved 11 groups of three calves during gradual decrease f rom 5 to 2.5 and 1 to 01 of whole milk per meal twice daily. Milk flow was either 0.5 or 1 1/min, and the teat buckets were either left or removed aft er milk intake. When the calves were fed with 51 of milk, non-nutritive suc king and cross-sucking decreased (P < 0.001), compared to 1 and 2.5 1. Remo ving the empty teat after mill;intake increased cross-sucking (P < 0.001). Slow milk flow reduced non-nutritive sucking after milk intake (P < 0.05), but did not influence cross-sucking. Duration of recorded milk intake was s imilar with fast flow and 51 of milk, compared to slow flow and 2.51 of mil k. The latter combination increased non-nutritive sucking and cross-sucking , suggesting that amount of milk is more important than duration of milk in take. Second experiment was carried out on 12 individually kept calves. The calve s received 2.51 of milk either in an open bucket, in a rubber teat bucket, or half/half in both buckets. When not used for feeding, the open bucket an d the teat bucket were filled and emptied again to make them 'tasty' with s ome drops of milk. The tasty teat bucket was either removed or present afte r milk intake. The calves had always access to a second clean teat bucket. Source of milk had no influence on recorded behaviour after milk intake. Th e tasty teat was sucked for twice as long as the clean one when both teats were present (P < 0.001). When the tasty teat was removed, the calves incre ased sucking on the clean teat (P < 0.001), but decreased total time spent sucking (P < 0.001). We conclude that a high amount of milk and the presenc e of the teat bucket after milk intake reduces cross-sucking, and that a cl ean teat is less effective in encouraging calves to suck than a teat with t aste of milk. (C) 2001 Published by Elsevier Science B.V.