A phonetic behavior of lamb separated from the mother as an animal welfare index─From the research in the Mongolian summer pasture─

Abstract

We analyzed a phonetic behavior at 617 scenes for a possible animal welfare index where a lamb was separated from the Ewe (“the mother”, hereafter). From the significance test for discriminal coefficient by discrimination analysis, the utterance time was different in 2 groups of the mother and the group subject and it was significantly different (P＜0.05).Furthermore, we found a difference among the mother as an utterance subject, utterance time at utterance location and F2 depending on the utterance location and it was significantly different (P＜0.05).

Furthermore, a difference between the mother as an utterance subject and the utterance time by behavior occurs by each behavior and it was significantly different (P＜0.05). From these results, it was suggested that a lamb changed its utterance method toward the mother by utterance time, utterance location, and behavioral pattern.

The utterance time for the utterance subject group and the utterance location were different depending on a utterance location and it was significantly different (P＜0.05). The utterance subject group and the utterance time/sound pressure by behavior were different depending on a behavior pattern and it was also significantly different (P＜0.05).

For the reason why the utterance subject of lamb was tented to be more for the mother than the group, it is considered that a sheep group structured by a matrilineal society in the Mongolian grassland maintains ties between a lamb and the mother for a long period of time, a lamb actively also contacts with the mother by utterance, and it eventually leads to a caretaking behavior such as suckling. It was also clarified that the utterance time of lamb toward the mother or the subject group during the migration/feeding, feeding/migration, and feeding was over 1 second as being longer than other behavioral patterns. It was considered that this long utterance time would be maintained for communication between a lamb and the mother with a long phonetic sound since they visually pay attention to a foraging activity and also suggested that it was an utterance characteristic to surely communicate with a certain information in accordance with the extensive Mongolian grassland environment.

It was also clarified that the sound pressure of lamb toward the mother is the lowest during the feeding/migration, and a lamb also specifically changes its sound pressure toward the mother during the feeding/migration as well. From these results, it was suggested that a lamb communicates with the mother and the group by changing its phonetic sound pressure with behavioral pattern, but the adjustment method of sound pressure would be different by the mother and the group.

For future, it will be an issue that a relation between an assessment of lamb separated from the mother and its management assessment should be more clarified.