Does advanced age disqualify a Shochet from being able to preform the ritual slaughter? If so what is the cut off age?
Related question: What's the youngest that a shochet could be? (lower age limit)
Strictly speaking, there is no upper age limit, though some have the custom to impose an across-the-board limit of age 70 (perhaps to kindly retire certain aged shochtim who won't admit to their waning stamina, and who cannot be forced out due to political considerations). On the Nirbater Rav's list of policies for the Meal Mart company under his hashgacha, it states that one may not perform shechitah or bedikah (checking for tereifos) after reaching age 70, in accordance with the ruling of the Satmar Rebbe (R' Yoel) zt"l.
As Ze'ev mentioned in his answer, Simlah Chadashah says (1:36) that an older person should not shecht, due to the practical limitations that accompany old age, such as shaky hands and weaker eyesight.
The Mordechai at the beginning of Chullin quotes Eldad HaDani in his הלכות ארץ ישראל (Hebrewbooks link I did not find exactly where in that book this הלכה is mentioned. If anyone finds the exact link, drop me a comment or just edit it in; thanks.) that the absolute limit is 80, and if one were to shecht over the age of 80 the meat is "פיגול" (my conjecture is that he used "פיגול" like we use "טריף" today); though the Mordechai says that it is "חומרא ולא נהגינן כוותיה," a stringency that we do not hold ourselves to.
I'm told that the OU's upper limit is 70. (Though I'm sure they'd let you eat the meat even if it was shechted by someone older, so long as he was reliably capable.)
[Tried to find this policy written online, but failed....if you find it let me know!]
First Mishnah in Hullin: "HaKol Shohtin Hutz MeHeresh Shoteh VeKatan Shema Yikalkelu eth Shehitathan."
If a person's advanced age makes him a Shoteh, for example, then presumably he would be disqualified.
Of course, this is pretty high up the TSB"P ladder, and some later prohibitions may have been added. I don't know of any as pertain to age, however. Incidentally, RaMB"aM adds a prohibition against a drunk person, putting him in the same category. http://www.mechon-mamre.org/i/5304.htm
The Simla Chadasha in Siman 1, Seif 36 says that a "zaken muflag" should not do shechita because his hands are heavy (same thing it says about drinkers) and his eyes are bad. This is assessed individually, but there is at least some concept of an age limit.