Briskors And Red Cows

The Rambam (Laws of Parah Adumah 1:9) says that if the cow was slaughtered with intent to be used for mundane purposes it shall be redeemed and doesn’t affect kaparah.  Why must it be redeemed, why is it different from any korban if slaughtered with intent for chullin that its kosher even if it doesn’t affect kaparah?  The Briskor Rav (Maaseh Korbanot 4:11) brings his father explained that we see from here that the parah adumah only assumes the status of a korban after it is slaughtered as a parah adumah, before that it is merely bedek habais.  [The Gemorah in Yoma 42a, Shavout 11b and another half dozen places says its bedek habais.]  The reason why the parah is invalidated as a korban isn’t because of a pasul of שלא לשמה, rather it never assumed the status of a korban and is redeemed as kodshai bedek habais. 

The Raavad Parah Adumah (1:1) says that one can’t designate a calf for the parah adumah because it is a pesul of מחוסר זמן for the cow must be at least three years old.  From here Rav Chayim (stencil) proves that there is the kedusha of a korban once the animal is designated as the parah adumah.  He brings another support to this from the Rambam Laws of Meilah (2:5) that says there is mielah in the parah once it is designated for the parah.  However, this Rab Chayim seems to contradict the previous one that says the parah isn’t considered a korban until it is slaughtered?

It is also noteworthy that the Toras Hakodesh (26:3) brings the Rash in Parah (4:4) explains that the mielah on a parah begins only after the slaughtering and he explains it based upon the first Rav Chayim that it only is considered a korban after the slaughtering and that is when the mielah will start because the sifri learns the law of mielah from that it’s called a chatas; hence it is dependent upon the shem korban.  (If the parah is bedek habais why does the sifri need a derasha that there is mielah on the parah, every bedek habyis has mielah?  See Tosfos Menachos 51b, Kesef Mishne ibid, see Sfas Emes there that will work with this Rosh,  ודו"ק.)  This Rosh is not like the Rambam that says the mielah starts from the time of the hekdesh.  So, it would seem that the Rambam holds that it is a korban already from the time that it is hukdash not like the Rav Chayim cited in Briskor Rav.  

However, Rav Chayim on the Rambam has a different interpretation of that Rambam that the mielah on the parah stems from the din of bedek habayis and the derasha of it being a chatas tells us that mielah no longer applies after it is burnt (עיי"ש.)  [However, the Rav Chayim (stencil) no longer has a proof from here that it is considered a korban from the time it is designated as a parah adumah according to what Rav Chayim on the Rambam writes.]