Seems to me that, all things being equal, pork and chicken will go “off” sooner than lamb or beef.

Am I right? If so, why?

If

http://www.csiro.au/Outcomes/Food-and-Agriculture/shelf-life-of-foods/Factors-influencing-shelf-life.aspx

maybe helpful.

Manual on simple methods of meat preservation

All things are never being equal

anyone I have met with food poisoning has always gone under thanks to beef

saying that ive been made violently ill by tuna in Palestine once

“We need to teach our trainees never to put themselves in a vulnerable position like that, no matter how nice, married and well-meaning the man seems.”
http://www.abc.net.au/news/2015-03-07/sexual-harassment-rife-in-medical-profession-surgeon-says/6287994

dv said:

Seems to me that, all things being equal, pork and chicken will go “off” sooner than lamb or beef.

Am I right? If so, why?

My sister lectures in food preservation. The two factors that immediately occur to me are size: lamb and beef tend to come in thicker slices than port and chicken. And water activity: any food with more free water will tend to go off faster. Pork and chicken both tend to be moister and both use salt as a preservative, to reduce the water activity, whereas lamb and beef don’t use any preservative.

As for whether you’re right. Test it. Place a quantity of each in a similar warm environment, eg. outdoors, and time how long it takes them to go off. Also note HOW each goes off. Fungal degradation requires a lower water activity than bacterial degradation, which is why bread goes off by fungal rather than bacterial attack.