Robert - that trip south would come under the multiple pick-up rule.
This is quite complicated, and not for the amateur! The professional guys will know the ins and outs of stops on way, not parking within 100 metres of other livestock, knowing where you can legally stop, carrying portable disinfectant, picking up from other farms only from isolated (disease wise) areas, rules on dropping tailgate, cleaning area lorry has parked in etc. etc. etc. (4 pages of regs). This will get further complicated by e-aml so more fun.
Anyway the commercial guys know what they're doing, would suggest that without careful reading of the rules, multiple pick-up/drop off should not be attempted !
and I agree Robert - the rules never get easier, you'd think sometimes we were carrying Nuclear waste !