Investigation into the sensory-behavioural interactions between a dairy camel and a calf during milking

Feral Dromedary camels are increasingly being utilised in Australia and around the world to provide milk for human consumption. There are significant contradictions in the literature concerning the requirement of the presence of a calf for successful milking of the Dromedary camel. The first hypothesis tested in the current study was that presence of her own calf for the dairy camel is more successful than no calf or a non-kin calf, without any contact, for allowing milk let-down prior to machine milking. The second hypothesis was that full physical contact between the dairy camel and her calf is more successful than no calf or a non-kin calf (with contact) for allowing milk let-down prior to machine milking. An additional aim was to investigate the sensory behaviours associated with successful milking of the dairy camel. A total of 9 camels and their respective year-old calves were used in the study. A total of twelve experimental sessions were conducted, six kin sessions and six non-kin sessions. On the kin day, after the cow was situated in the race and the udder was washed, let-down was attempted by manual stimulation firstly without a calf. If let-down was successful, the cow was milked and moved into the release yard with the calf. If let-down was unsuccessful, a transparent plastic barrier was moved into place between the cow race and calf race to block physical contact. The kin calf was let into the calf race and the milker continued to use manual stimulation to elicit milk let-down with the calf present. If let-down was successful, the cow was milked, then both cow and calf were let into the release yard. If let-down was unsuccessful, the barrier was removed, and the calf given full physical contact access to the cow including suckling. This procedure was repeated for the non-kin day. Success of let-down, time taken to let-down and cow and calf behaviours were recorded. There was an overall effect of treatment (χ2=37.2; P<0.0001), with the presence of the kin calf stimulating milk let-down by the cow on 73% (n=64) of attempts, compared to 20% (n=64) for the presence of the non-kin calf and 42% (n=108) when no calf was present. There was also a significant effect of the barrier (χ2=24.8; P<0.0001), for when the barrier placed between the cow and calf, the kin calf elicited milk let-down on 50% of attempts, while the non-kin calf was unable to initiate let-down on any occasion. When the barrier was removed the kin calf successfully initiated let-down on 94% of attempts, while the non-kin calf was only successful on 40% of all attempts. The dominant behaviours associated with let-down were cow and calf vocalisations, vigilance of the cow looking at the calf, and udder nudges. The findings of the current study partially agrees with the majority of literature that stated that the presence of the kin calf was “essential” for achieving milk let-down in Dromedary camels. However, it is clear from this study that it is still possible to achieve milk let-down using no calf or a non-kin calf. This research may act as a platform to launch future study into the management and understanding of Dromedary camels and may be used to improve industry practises within the camel dairy industry.