1. (a) Specifications. Type A medicated articles containing 50 grams laidlomycin propionate potassium per pound.
2. (b) Sponsor. See No. 054771 in § 510.600(c) of this chapter.
3. (c) Tolerances. See § 556.346 of this chapter.

4. (d) Special considerations.

   1. (1) Laidlomycin propionate potassium Type B liquid medicated feeds may be manufactured from dry laidlomycin propionate potassium Type A medicated articles. The Type B liquid medicated feeds must have a pH of 6.0 to 8.0, dry matter of 62 to 75 percent, and bear appropriate mixing directions as follows:

      1. (i) For liquid feeds stored in recirculating tank systems: Recirculate immediately prior to use for no less than 10 minutes, moving not less than 1 percent of the tank contents per minute from the bottom of the tank to the top. Recirculate daily as described even when not used.
      2. (ii) For liquid feeds stored in mechanical, air, or other agitation type tank systems: Agitate immediately prior to use for not less than 10 minutes, creating a turbulence at the bottom of the tank that is visible at the top. Agitate daily as described even when not used.
   2. (2) The expiration date of the Type B liquid medicated feed is 21 days after date of manufacture. The expiration date for the dry Type C medicated feed made from the Type B liquid medicated feed is 7 days after date of manufacture.

   3. (3) Labeling for all Type B medicated feeds (liquid and dry) and Type C medicated feeds containing laidlomycin propionate potassium shall bear the following statements:

      1. (i) Do not allow horses or other equines access to feeds containing laidlomycin propionate potassium.
      2. (ii) The safety of laidlomycin propionate potassium in unapproved species has not been established.
      3. (iii) Not for use in animals intended for breeding.

5. (e) Conditions of use. It is used in growing beef steers and heifers fed in confinement for slaughter as follows:

   Laidlomycin propionate potassium in grams per ton	Combination in grams/ton	Indications for use	Limitations	Sponsor
   (1) 5		For increased rate of weight gain and improved feed efficiency	Feed as the sole ration Type C medicated feeds to provide 30 to 75 mg laidlomycin propionate potassium per head per day	066104
   (2) 5-10		For improved feed efficiency	Feed as the sole ration Type C medicated feeds to provide 30 to 150 mg laidlomycin propionate potassium per head per day	066104

6. (f) Laidlomycin propionate potassium may also be used in combination with chlortetracycline as in § 558.128.

[59 FR 18297, Apr. 18, 1994, as amended at 60 FR 53509, Oct. 16, 1995; 62 FR 9929, Mar. 5, 1997; 63 FR 27845, May 21, 1998; 66 FR 46706, Sept. 7, 2001; 68 FR 13839, Mar. 21, 2003; 68 FR 42590, July 18, 2003; 69 FR 30198, May 27, 2004; 79 FR 13545, Mar. 11, 2014; 81 FR 95005, Dec. 27, 2016; 86 FR 14823, Mar. 19, 2021; 91 FR 20343, Apr. 16, 2026; 91 FR 33072, June 3, 2026]