See footnote 272 https://books.google.com/books?id=U_ImCAAAQBAJ&lpg=PA67&ots=VSd5y0JY2X&dq=simlah%20chadashah%20ben%20pekuah&pg=PA66#v=onepage&q=simlah%20chadashah%20ben%20pekuah&f=false
However, Rashi explains [Chulin 75b] the problem is only on the first generation where the genetic code is 50% BP/50% Regular - the problem being that Shechitah requires cutting the MAJORITY of both Simanim which this beast does not have.
However, the next generation down, i.e. if this hybrid breeds with a regular beast, it will have a 75/25 ratio i.e. more than half of Kosher Simanim ready for Shechitah.
Some are confused by Rashi's comment that there is a Pessul of SheHiYa - which they think will also disqualify the 75/25. But this is an error. Rashi employs this argument of SheHiYa only to address the question he asks - why can the 2 Shechitas not be combined to provide a full Kosher Shechitah? [i.e. the Shechitah that is genetic meaning from the parent that is a BP which makes half the Simanim AS THOUGH they are Shechted, why can that not complement the Shechiath performed now with a knife? This Rashi explains cannot work because although they ARE compatible, nevertheless they cannot be combined due to ShehHiYa]