Customers and Suppliers - Holding Numbers
Depending on the direction of the movement , I.E On or off your holding the lists 'From Holding' and 'To Holding' will list customers and supplier who have a specified holding number. If they do not they will not be listed.
Also when sending animals to market or slaughter house you should ensure that the customer catagory is set to 'Slaughter House' or 'Market', this will ensure that the slaughter house is listed when sending animals to slaughter houses and markets are listed when sending animals to markets.
When sending animals to keep, only suppliers identified as suppliers of keep are listed. (SEE the supplier record).