These chickens haven't come to market yet, but it seems from the video that Professor Cahaner is still developing them. I have a feeling, though, that even if they are eventually commercialized, someone's going to asser them because of the Pri Megadim. The Pri Megadim in YD 59 SD 2 says they although the issur in the Beis Yosef and the Maharshal on birds that were stripped before shechita won't apply here, where the birds naturally grow like that. However, he also brings the Hagahos Ashri's opinion that they are assur because they are just too ugly to eat. I can't say I disagree with him. In the video, please listen to what the narrator says at 3:50. We are reminded of Plato's definition of Man: animal bipes implume; a two-legged animal without feathers. Were Plato alive, he might have to rethink his definition. (For a more scholarly discussion, (at least until the final pictures,) please see "Remarks" after the video.)
Featherless birds are discussed in two places in Yoreh Dei'ah, in Siman 59 and Siman 15. The discussion in 59 involves the issue of גלודה, whether an animal that has been skinned alive is kosher, and the discussion in 15 is about the kashrus of an animal before it is fully developed, in the case of a bird, before it opens its eyes and before it is fledged. As for the Siman 59 issue, that is irrelevant here, because that only deals with the viability of an animal after a traumatic assault on its integrity. Obviously, our featherless friends have been bred to be perfectly healthy without feathers, so the גלודה issue is moot. As for the Siman 15 question, there are two separate issues involved. One is that an unhatched chick, or a chick before it opens its eyes, is so lizard-like that it is prohibited because of its reptile appearance- it looks like a שרץ. This is purely an issur derabbanan. On the other hand, we find some poskim, particularly the Shach, that adds another consideration; that it is repulsive in such a state, and there would be in issur of שקץ. Not שרץ (reptile,) but instead שקץ (disgusting.) The Taz is mattir, but the issur of the Shach is a consideration that would have to be dealt with.
I have seen poskim that conflated these two issues, but, as you see, they are entirely different considerations. In any case, with this in mind, you understand that when I said they are assur because they are ugly, that was just my way of rephrasing the Shach in a more down-to-earth manner.
I think that you can't go wrong following the Aruch Hashulchan (YD 59:8).
העוף שניטלה נוצתו כשר ויש אוסרים לפי שהנוצה לעוף כעור לבהמה דעור העוף רך ודק וכתב רבינו הרמ״א דטוב להחמיר אם נפלו כולם מיהו אם נפלו נוצותיו מרוב שומן אע״פ שנפלו כולם ונשאר ערום מ״מ כשר הואיל ונעשה מרוב שומנו עכ״ל כלומר שא״א שבדבר שמשתבחת בו תטרף בו ואם כי יש מגמגמים בזה אמנם אין להחמיר כי מעיקר הדין דעת רוב רבותינו להכשיר לגמרי דכן מבואר מגמ׳ [נ״ז:] אמנם אסטנים שדעתו קצה עליו לא יאכלנו, משום בל תשקצו [יש"ש סק״ט] דכעין זה נתבאר כםי׳ ט״ו באפרוח שעדיין לא נתנדלה בנוצתה ע״ש
What he says is, basically, that some say you shouldn't eat it, but that's really only a matter of refinement and aesthetics, so unless it really bothers you, don't worry about it. He brings this from the יש"ש, the Maharshal, in Eilu Treifos Siman 109.
Also, thank you, Eli, for directing us in your comments to an excellent and far more serious article about these birds, by Rabbi Levinger, available here.
Rabbi Levinger tells us that this phenotype arises from a spontaneous genetic mutation, not inter-species hybridization. He also discusses גלודה, and concludes, as I do, that this is not a problem here. He doesn't discuss the issue of ugly. מקום הניחו לי.
Despite the author's certainty that nobody could possible think this is a new species, Eli believes that it remains possible that someone will claim that these birds are so different from standard breeds that they no longer fall under the definition of "Chicken" as far as satisfying the requirement of having a mesora that a particular species of bird is kosher. The definition of species is unclear, as we know from the Muscovy duck and the turkey controversies. From listening to the Professor, it appears that they don't have scales on their legs either, and that, too, might lend itself to a "too different to be called a chicken" argument. I certainly hope not. What it looks like is irrelevant, because a יוצא מן הטהור is טהור, period. But we have a surplus of people who would be happy to gain publicity and burnish their credentials by prohibiting things, so watch out.
I came across a דרכי תשובה in Siman 59 that brings from R Avraham Ankawa, a Moroccan Posek, author of the Get Mekushar, in his זבחים שלמים ס"ס נ"ט that says that he was brought such "naked chickens" several times, and he was mattir because he was told that they were a local peculiarity but perfectly healthy and kosher.
וכמה פעמים באה לידינו מין תרנגולת ערום ושאלתי ואמרו לי שזה המין כך הוא לעולם ....התרנו אותה ע"פ מנהג העולם
The Darkei Teshuva's comment is ואם קבלה הוא נקבל.
In 1782. America chose as its emblem
The Bald Eagle.
In 2008. Israelis chose the דוכיפת, the Hoopoe, as their national bird. Despite my currently diminished capacity, it is my considered opinion that we need to re-think that designation. The דוכיפת, after all, is not kosher. The דוכיפת has no special place in the hearts and minds of the Jewish People. But Chicken soup! I guarantee that if Meah She'arim had voted, the outcome would have been different. And who knows what the future holds? Maybe someday Israel's national bird will be
The Bald Chicken