N.Y. Comp. Codes R. & Regs. tit. 1, § 6.10 – Frequency of testing of universal samples.

(a) Testing of universal samples taken from a dairy farm from which milk is picked up on an every-other day basis. A tester shall test not less than three universal samples taken during a month, and shall test at least one universal sample taken during each 10-day period of the month. In lieu of the foregoing, a tester shall test not less than four universal samples taken during a month, and shall test at least one universal sample taken during each seven-day period of the month commencing at the beginning of the month.
(b) Testing of universal samples taken from a dairy farm from which milk is picked up on a daily basis. A tester shall test not less than six universal samples taken during a month, and shall test at least two universal samples taken during each 10-day period of the month. In lieu of the foregoing, a tester shall test not less than eight universal samples taken during a month and shall test at least two universal samples taken during each seven-day period of the month commencing at the beginning of the month.
(c) Notwithstanding the provisions of subdivisions (a) and (b) of this section, a tester shall test additional universal samples, when required to do so by the provisions of section 6.15 of this Part and when a particular test indicates that the amount of milk component in the universal sample tested cannot be accurately determined, as set forth in section 6.11(c) of this Part.