Table 2. Comparison between pig and baboon as donors.
The advantages and disadvantages of the pig as a potential source of organs and cells for humans, in contrast with those of the baboon in this role, are shown in this table.
| Pig | Baboon | |
| Availability | Unlimited | Limited |
| Breeding potential | Good | Poor |
| Period to reproductive maturity | 4–8 months | 3–5 years |
| Length of pregnancy | 114 ± 2 days | 173–193 days |
| Number of offspring | 5–12 | 1–2 |
| Growth | Rapid (adult human size within 6 months) | Slow (9 years to reach maximum size) |
| Size of adult organs | Adequate | Inadequate |
| Cost of maintenance | Significantly lower | High |
| Anatomical similarity to humans | Moderately close | Close |
| Physiological similarity to humans | Moderately close | Close |
| Relationship of the immune system to humans | Distant | Close |
| Knowledge of tissue typing | Considerable (in selected herds) | Limited |
| Necessity for blood type compatibility with humans | Probably unimportant | Important |
| Experience with genetic engineering | Considerable | None |
| Risk of transfer of infection (xenozoonosis) | Low | High |
| Availability of specific pathogen-free animals | Yes | Yes |
| Public opinion | More in favor | Mixed |