Hi Christina,
This not my product/process area so somewhat speculative.
May need to differentiate “VA” and “TACCP”. These terms have acquired a variety of meanings. BRC, I think, closely follows GFSI’s VA definitions.
afaik BRC’s interpretation of VA in 5.4.2 is aimed at validating authenticity of the “raw material” (RM) in respect to the sold product, ie checking for substitution/adulteration (S/A) in the “raw material” "supply chain".
afaik, It is not related to process stages for the finished product other than the detection capability for (S/A) at the initial RM reception stage.
I presume the raw material here is live chicken, finished product unknown, and the VA refers to possible substitution/adulteration (S/A) of RM. An analysis for (S/A) would presumably depend on the precise specification of the finished product/labelling, eg the nature, variety, quality ( species ?, Organic? etc). Clauses 5.4.(1, 3-6) are also relevant.
Offhand, if the above interpretation correct and based on the OP’s stated integration, the VA should not be particularly difficult but the vulnerability possibilities/history (if any), of this product/process unknown to me.
The actual presentation of the various stages of generic VA’s has been detailed in previous threads here.
I assume “TACCP” as applied to the site activities is “equivalent” to BRC’s food defense clause.