The park says the animals have been "peacefully put to sleep" due to age-related health conditions.
Greg Rutherford, whose son is autistic, hopes other venues will follow Woburn Safari Park's example.
The stately home has put the Claude Lorrain masterpiece on the market to fund restoration work.
Heating issues cause schools to close as temperatures plummet.
Police say they do not yet know the full circumstances behind the accident.
A safari park believes the procedure is a step forward in the field of giraffe care.
The eastern mountain bongo calf is the first female born at Woburn Safari Park for more than a decade.
Schoolchildren are among those lining the route between Milton Keynes and Ampthill.
The artwork is by artist Leah Wood, who hopes to inspire donations to support the species.
