No worries whatsoever! I have done it a few times.
Babies move just in. Dominance may be heavy depending on the herd dynamics, but it is usually just short as soon as the babies have been firmly put in their place at the bottom of the herd hierarchy. The baby is going to attach itself to one of the herd piggies; it can be the boar or one of the sows. The girls are not hurt when being humped. My mounting Carwyn could basically still stand on his front legs when he and his 5 week old wifelet Heini met and fell head over heels for each other! You have to remember that babies are fast - they can't be caught by the bigger piggies unless they stand stil!
My 6 week old Heini with 3 year old Carwyn
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My 4 week old Tegan with the Tribe boar Hywel who couldn't catch her...
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And during intros with the whole Tribe who in age ranged from 10 months to 4 years
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The 8 week old TEAS sanctuary Triplets with husboar Bedo and adult TEAS mum and daughter foster pair Essylt/Jessica and Crisiant/Krystal. Lilac/orange Bedo made a lovely nursery nurse for the triplets, who happily bounded after him!
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