#### § 558.311 Lasalocid.

(a) *Specifications.* Each pound of Type A medicated article contains 68 grams (15 percent), 90.7 grams (20 percent), or 150 grams (33.1 percent) lasalocid as lasalocid sodium activity. A minimum of 90 percent of lasalocid activity is derived from lasalocid A.

(b) *Sponsor.* See No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)).

(c) *Related tolerance.* See [§ 556.347 of this chapter](/on/2024-09-17/title-21/section-556.347).

(d) *Special considerations.*

(1) Type C cattle and sheep feeds may be manufactured from lasalocid liquid Type B feeds which have a pH of 4.0 to 8.0 and bear appropriate mixing directions as follows:

(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.

(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) A physically stable lasalocid liquid feed will not be subject to the requirements for mixing directions prescribed in [paragraph (d)(1)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(1)) of this section provided it has a pH of 4.0 to 8.0 and contains a suspending agent(s) sufficient to maintain a viscosity of not less than 300 centipoises per second for 3 months.

(3) If a manufacturer is unable to meet the requirements of [paragraph (d)(1)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(1)) or [(d)(2)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(2)) of this section, the manufacturer may secure approval of a positionally stable liquid feed by:

(i) Either filing a new animal drug application for the product or establishing a master file containing data to support the stability of its product;

(ii) Authorizing the agency to reference and rely upon the data in the master file to support approval of a supplemental new animal drug application to establish physical stability; and

(iii) Requesting the sponsor of an approved new animal drug application to file a supplement to provide for use of its lasalocid Type A article in the manufacture of the liquid feed specified in the appropriate master file. If the data demonstrate the stability of the liquid feed described in the master file, the supplemental new animal drug application will be approved. The approval will provide a basis for the individual liquid feed manufacturer to manufacture under a medicated feed license the liquid mediated feed described in the master file. A manufacturer who seeks to market a physically unstable lasalocid liquid feed with mixing directions different from the standard directions established in [paragraph (d)(1)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(1)) of this section may also follow this procedure.

(4) If adequate information is submitted to show that a particular liquid feed containing lasalocid is stable outside the pH of 4.0 to 8.0, the pH restriction described in [paragraphs (d)(1)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(1)) and [(d)(2)](/on/2024-09-17/title-21/section-558.311#p-558.311(d)(2)) of this section may be waived.

(5) Required label statements:

(i) For liquid Type B feed (cattle and sheep): Mix thoroughly with grain and/or roughage prior to feeding. Feeding undiluted, mixing errors, or inadequate mixing (recirculation or agitation) may result in an excess lasalocid concentration which could be fatal to cattle and sheep. Do not allow horses or other equines access to Type A articles or Type B feeds containing lasalocid as ingestion may be fatal. Safety of lasalocid for use in unapproved species has not been established.

(ii) For Type A articles or Type B feeds (cattle and sheep): Feeding undiluted or mixing errors may result in an excess lasalocid concentration which could be fatal to cattle and sheep. Do not allow horses or other equines access to Type A articles or Type B feeds containing lasalocid as ingestion may be fatal. Safety of lasalocid for use in unapproved species has not been established.

(iii) For Type A articles, Type B or Type C feeds (cattle): A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal.

(6) Lasalocid Type A medicated articles containing lasalocid dried fermentation residue are for use in cattle and sheep feed only.

(7) Each use in a free-choice Type C cattle feed as in [paragraphs (e)(3)(vi)](/on/2024-09-17/title-21/section-558.311#p-558.311(e)(3)(vi)) through [(e)(3)(viii)](/on/2024-09-17/title-21/section-558.311#p-558.311(e)(3)(viii)) of this section must be the subject of an approved NADA or supplemental NADA as provided in [§ 510.455 of this chapter](/on/2024-09-17/title-21/section-510.455).

(e) *Conditions of use.* It is used as follows:

(1) The conditions of use for chickens are:

| Lasalocid in grams/ton | Combination in grams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (i) 68 to 113 | | Broiler or fryer chickens: For prevention of coccidiosis caused by *Eimeria tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima.* | Feed continuously as the sole ration. | 054771 |
| (ii) 68 | Bacitracin methylenedisalicylate, 10 to 50 | Broiler chickens: For prevention of coccidiosis caused by *Eimeria tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima;* and for increased rate of weight gain and improved feed efficiency. | Feed continuously as the sole ration. Bacitracin methylenedisalicylate provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |
| (iii) 68 to 113 | Bacitracin methylenedisalicylate, 4 to 50 | Broiler chickens: For prevention of coccidiosis caused by *Eimeria tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima;* and for improved feed efficiency. | Feed continuously as the sole ration. Bacitracin methylenedisalicylate provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |
| (iv) 68 to 113 | Bacitracin zinc, 4 to 50 | Broiler chickens. For prevention of coccidiosis caused by *Eimeria tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima;* and for increased rate of weight gain and improved feed efficiency. | Feed continuously as the sole ration. Bacitracin zinc provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |
| (v) 68 to 113 | Bambermycins, 1 to 2 | Broiler chickens: For prevention of coccidiosis caused by *Eimeria tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima;* and for increased rate of weight gain and improved feed efficiency. | Feed continuously as sole ration. Bambermycins provided by No. 016592 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 016592 |

(2) The conditions of use for turkeys are:

| Lasalocid in grams/ton | Combination in grams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (i) 68 to 113 | | Growing turkeys; For prevention of coccidiosis caused by *Eimeria meleagrimitis, E. gallopavonis,* and *E. adenoeides.* | Feed continuously as sole ration. | 054771 |
| (ii) 68 to 113 | Bacitracin methylenedisalicylate, 4 to 50 | Growing turkeys: For prevention of coccidiosis caused by *E. meleagrimitis, E. gallopavonis,* and *E. adenoeides;* and for increased rate of weight gain and improved feed efficiency. | Feed continuously as the sole ration. Bacitracin methylenedisalicylate as provided by No. 054771 in [§ 510.600(c)](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) in this chapter. | 054771 |
| (iii) 68 to 113 | Bacitracin zinc, 4 to 50 | Growing turkeys: For prevention of coccidiosis caused by *E. meleagrimitis, E. gallopavonis,* and *E. adenoeides;* and for increased rate of weight gain and improved feed efficiency. | Feed continuously as the sole ration. Bacitracin zinc as provided by No. 054771 in [§ 510.600(c)](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) in this chapter. | 054771 |

(3) The conditions of use for cattle are—

| Lasalocid amount | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- |
| (i) 10 to 30 grams/ton of feed | Cattle fed in confinement for slaughter: For improved feed efficiency. | Feed continuously in complete feed to provide not less than 100 milligrams (mg) nor more than 360 mg of lasalocid sodium activity per head per day. | 054771 |
| (ii) 25 to 30 grams/ton of feed | Cattle fed in confinement for slaughter: For improved feed efficiency and increased rate of weight gain. | Feed continuously in complete feed to provide not less than 250 mg nor more than 360 mg of lasalocid sodium activity per head per day. | 054771 |
| (iii) Not less than 60 mg or more than 300 mg of lasalocid per head per day | Pasture cattle (slaughter, stocker, feeder cattle, and beef replacement heifers): For increased rate of weight gain | Feed continuously at a rate of not less than 60 mg or more than 300 mg of lasalocid per head per day when on pasture. The drug must be contained in at least 1 pound of feed. Daily intakes of lasalocid in excess of 200 mg/head/day have not been shown to be more effective than 200 mg/head/day | 054771 |
| (iv) 1 mg lasalocid per 2.2 pounds (lb) body weight per day | Cattle up to 800 lb: For control of coccidiosis caused by *Eimeria bovis* and *E. zuernii.* | Hand feed continuously at a rate of 1 mg of lasalocid per 2.2 lb body weight per day to provide not more than 360 mg of lasalocid per head per day. | 054771 |
| (v) 1 mg lasalocid per 2.2 lb body weight per day | Replacement calves: For control of coccidiosis caused by *E. bovis* and *E. zuernii.* | In milk replacer powder, hand feed at a rate of 1 mg of lasalocid per 2.2 lb body weight per day. A withdrawal period has not been established for lasalocid in pre-ruminating calves. Do not use in calves to be processed for veal. | 054771 |
| (vi) 1,440 grams/ton | Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): For increased rate of weight gain. | As a free-choice Type C medicated loose mineral, feed continuously at a rate of not less than 60 mg nor more than 200 mg of lasalocid per head per day. | 012286 |
| (vii) 1,440 grams/ton | Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): For increased rate of weight gain. | As a free-choice Type C medicated mineral block, feed continuously at a rate of not less than 60 mg nor more than 200 mg of lasalocid per head per day. | 017800 |
| (viii) 300 grams/ton | Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): for increased rate of weight gain. | As a free-choice Type C medicated protein block, feed continuously at a rate of not less than 60 mg nor more than 200 mg of lasalocid per head per day. | 067949 |
| (ix) 60 to 300 mg of lasalocid per head per day | Growing beef steers and heifers on pasture (stocker, feeder, and slaughter) and replacement beef and dairy heifers on pasture: For increased rate of weight gain | Feed continuously as a Type C free-choice medicated feed at a rate of 60 to 300 mg of lasalocid per head per day. Daily intakes of lasalocid in excess of 200 mg/head/day have not been shown to be more effective than 200 mg/head/day | 054771 |

(4) The conditions of use for minor species are:

| Lasalocid in grams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- |
| (i) 20 to 30 | Sheep maintained in confinement: For prevention of coccidiosis caused by *Eimeria ovina, E. crandallis, E. ovinoidalis (E. ninakohlyakimovae), E. parva,* and *E. intricata.* | Feed continuously in complete feed to provide not less than 15 milligrams (mg) nor more than 70 mg of lasalocid sodium activity per head per day depending on body weight. | 054771 |
| (ii) 113 | Chukar partridges: For prevention of coccidiosis caused by *E. legionensis.* | Feed continuously as sole ration up to 8 weeks of age. | 054771 |
| (iii) 113 | Rabbits: For prevention of coccidiosis caused by *E. stiedae.* | Feed continuously as sole ration up to 6 1/2 weeks of age | 054771 |

(5) It is used as a free-choice mineral Type C feed as follows:

(i) *Specifications.*

| Ingredient | Percent | International feed No. |
| --- | --- | --- |
| Defluorinated phosphate (20.5% Ca, 18.5% P) | 35.9 | 6-01-080 |
| Sodium chloride (salt) | 20.0 | 6-04-152 |
| Calcium carbonate (38% Ca) | 18.0 | 6-01-069 |
| Cottonseed meal | 10.0 | 5-01-621 |
| Potassium chloride | 3.0 | 6-03-755 |
| Selenium premix (0.02 percent Se)1 | 3.0 | |
| Dried cane molasses (46% sugars) | 2.5 | 4-04-695 |
| Magnesium sulfate | 1.7 | 6-02-758 |
| Vitamin premix1 | 1.4 | |
| Magnesium oxide (58% Mg) | 1.2 | 6-02-756 |
| Potassium sulfate | 1.2 | 6-06-098 |
| Trace mineral premix1 | 1.04 | |
| Lasalocid Type A medicated article (68 g/lb)2 | 1.06 | |
| | | |
| --- | --- | --- |
| 1 Content of the vitamin and trace mineral premixes may be varied; however, they should be comparable to those used by the firm for other free-choice feeds. Formulation modifications require FDA approval prior to marketing. Selenium must comply with [21 CFR 573.920](/on/2024-09-17/title-21/section-573.920). Ethylenediamine dihydroiodide (EDDI) should comply with FDA Compliance Policy Guides Sec. 651.100 (CPG 7125.18). | | |
| 2 To provide 1,440 g lasalocid per ton, use 21.2 lbs (1.06%) of a lasalocid Type A medicated article containing 68 g/lb. If using a lasalocid Type A medicated article containing 90.7 g/lb, use 15.88 lbs per ton (0.794%), adding molasses. | | |

(ii) *Amount.* 1,440 grams per ton.

(iii) *Indications for use.* Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): for increased rate of weight gain. Intakes of lasalocid in excess of 200 mg/head/day have not been shown to be more effective than 200 mg/head/day.

(iv) *Limitations.* For pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers); feed continuously on a free-choice basis at a rate of 60 to 300 milligrams lasalocid per head per day.

(v) *Sponsor.* See No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)).

(6) It is used as a ruminant free-choice liquid Type C feed as follows:

(i) *Specifications.*

| Ingredient | Percent | International feed No. |
| --- | --- | --- |
| Cane molasses | 55.167 | 4-13-241 |
| Condensed molasses fermentation solubles | 24.0 | |
| 50% Urea Solution (23% N) | 12.0 | |
| Ammonium polyphosphate solution | 1.0 | 6-08-42 |
| Phosphoric acid (54%) | 3.0 | 6-03-707 |
| Xanthan gum | 0.05 | 8-15-818 |
| Water | 4.0 | |
| Trace mineral premix1 | 0.5 | |
| Vitamin premix1 | 0.2 | |
| Lasalocid liquid Type A medicated article (90.7 g/lb)2 | 0.083 | |
| | | |
| --- | --- | --- |
| 1 Content of the vitamin and trace mineral premixes may be varied; however, they should be comparable to those used by the firm for other free-choice feeds. Formulation modifications require FDA approval prior to marketing. Selenium must comply with [21 CFR 573.920](/on/2024-09-17/title-21/section-573.920). Ethylenediamine dihydroiodide (EDDI) should comply with FDA Compliance Policy Guides Sec. 651.100 (CPG 7125.18). | | |
| 2 To provide 150 gm lasalocid per ton, use 1.652 lb (0.083%) of a lasalocid liquid Type A medicated article containing 90.7 g/lb. If using a dry lasalocid Type A medicated article containing 68 g/lb, use, use 2.206 lbs per ton (0.111%), replacing molasses. If using a dry lasalocid Type A medicated article containing 90.7 g/lb, use 1.652 lbs per ton (0.083%), adding molasses. | | |

(ii) *Amount.* 150 grams per ton.

(iii) *Indications for use.* Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): for increased rate of weight gain. Intakes of lasalocid in excess of 200 mg/head/day have not been shown to be more effective than 200 mg/head/day.

(iv) *Limitations.* For pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers). Feed continuously on a free-choice basis at a rate of 60 to 300 milligrams lasalocid per head per day.

(v) *Sponsor.* See No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)).

(7) It is used as a free-choice, loose mineral Type C feed as follows:

(i) *Specifications.*

| Ingredient | Percent | International feed No. |
| --- | --- | --- |
| Monocalcium phosphate (21% P) | 57.70 | 6-01-082 |
| Salt | 17.55 | 6-04-152 |
| Distillers dried grains w/ solubles | 5.40 | 5-28-236 |
| Dried cane molasses (46% Sugars) | 5.20 | 4-04-695 |
| Potassium chloride | 4.90 | 6-03-755 |
| Trace mineral/vitamin premix1 | 3.35 | |
| Calcium carbonate (38% Ca) | 2.95 | 6-01-069 |
| Mineral oil | 1.05 | 8-03-123 |
| Magnesium oxide (58% Mg) | 1.00 | 6-02-756 |
| Iron oxide (52% Fe) | 0.10 | 6-02-431 |
| Lasalocid Type A medicated article (68 g/lb)2 | 0.80 | |
| | | |
| --- | --- | --- |
| 1 Content of the vitamin and trace mineral premixes may be varied; however, they should be comparable to those used by the firm for other free-choice feeds. Formulation modifications require FDA approval prior to marketing. Selenium must comply with [21 CFR 573.920](/on/2024-09-17/title-21/section-573.920). Ethylenediamine dihydroiodide (EDDI) should comply with FDA Compliance Policy Guides Sec. 651.100 (CPG 7125.18). | | |
| 2 To provide 1,088 g lasalocid per ton, use 16 lbs (0.80%) of a lasalocid Type A medicated article containing 68 g/lb. If using a lasalocid Type A medicated article containing 90.7 g/lb, use 12 lbs per ton (0.6%), adding molasses. | | |

(ii) *Amount.* 1,088 grams per ton.

(iii) *Indications for use.* Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers): For increased rate of weight gain. Intakes of lasalocid in excess of 200 mg/head/day have not been shown to be more effective than 200 mg/head/day.

(iv) *Limitations.* Feed continuously on a free-choice basis at a rate of 60 to 300 mg lasalocid per head per day.

(v) *Sponsor.* See No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)).

(8) Lasalocid may also be used in combination with:

(i) Chlortetracycline as in [§ 558.128](/on/2024-09-17/title-21/section-558.128).

(ii) Chlortetracycline and sulfamethazine as in [§ 558.140](/on/2024-09-17/title-21/section-558.140).

(iii) Lincomycin as in [§ 558.325](/on/2024-09-17/title-21/section-558.325).

(iv) Melengestrol as in [§ 558.342](/on/2024-09-17/title-21/section-558.342).

(v) Oxytetracycline as in [§ 558.450](/on/2024-09-17/title-21/section-558.450).

(vi) Tylosin alone or in combination with melengestrol acetate as in [§ 558.625](/on/2024-09-17/title-21/section-558.625).

(vii) Virginiamycin as in [§ 558.635](/on/2024-09-17/title-21/section-558.635).

[[41 FR 44382](https://www.federalregister.gov/citation/41-FR-44382), Oct. 8, 1976]

###### Editorial Note

#### Editorial Notes:

1. For Federal Register citations affecting [§ 558.311](/on/2024-09-17/title-21/section-558.311), see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at *[www.govinfo.gov](http://www.govinfo.gov).*

2. At [79 FR 13545](https://www.federalregister.gov/citation/79-FR-13545), Mar. 11, 2014, [§ 558.311](/on/2024-09-17/title-21/section-558.311) was amended; however, the amendment could not be incorporated because of the inaccurate amendatory instruction.