Abstract: Porcine prolactin (pPRL) is administered to poultry in dosages of from about 1-500 ug/kg/day, preferably 10-100 ug/kg/day, to promote growth by improving the rate of weight gain and/or increasing feed utilization efficiency.

Abstract: A process for promoting growth and feed efficiency in food producing mammals is provided by administering to such mammals, growth promoting amounts of a zinc complex of a polyether antibiotic selected from the group consisting of monensin, nigericin, salinomycin, narasin, noborotomycin A and B, SY-1, grisorixin, X-206, lonomycin, laidlomycin, mutalomycin, alborixin, lasalocid and lysocellin.Zinc complexes of this type are prepared by adding soluble zinc salt to a fermentation beer containing a polyether antibiotic to thereby form an insoluble, recoverable biomass containing the desired growth-promoting zinc complex for use in the process herein.

Abstract: A composition for promoting the growth or feed conversion efficiency of meat-producing animals which contains growth-promoting amounts of growth hormone and a zearalin.

Abstract: A method of administering micronutrients to animals over extended periods by subcutaneous implant. Important micronutrients, including iron, copper, selenium, zinc, manganese, cobalt, molybdenum, chromium, silicon, iodine, biotin, vitamins E and B.sub.12 are supplied conveniently, and in positive, predetermined amounts by means of subcutaneously implanted pellets containing the micronutrient and a suitable excipient to provide controlled release of the micronutrient over an extended period of time. One example comprises iron dextran in combination with a lactose, fibrin, or other suitable excipient, in the form of a pellet which is subcutaneously implanted behind the ear of piglets to supply sufficient iron for optimum growth and to avoid iron-deficiency anemia. Important trace elements which may also be administered in carefully controlled amounts in suitable salt forms by the method of this invention include nickel, tin, vanadium, fluorine and arsenic.

Abstract: Nitrohydroxyalkylquinoxaline-1,4-dioxides represented by the formula ##STR1## where R is hydrogen, lower alkyl of 1-3 carbon atoms, hydroxymethyl or acetoxymethyl and R' is hydrogen or lower alkyl of 1-2 carbon atoms or R and R' taken together can be alkylene of 5 carbon atoms and alkanoic acid esters thereof. The compounds are useful for promoting growth rate of animals and improving their feed efficiency.

Abstract: A composition represented by the formula ##STR1## where R and R.sup.1 can be hydrogen, methyl, ethyl or hydroxymethyl and can be the same or different. The compounds are useful for promoting the growth of animals.

Abstract: Compounds represented by the formula: ##STR1## where R and R' collectively are (a) .dbd.NOCH.sub.2 COOCH.sub.3, ##STR2## or R is hydroxyl or alkoxy and R' is ##STR3## (h) --NHOH, or (i) --NHNHCO.sub.2 CH.sub.3. The compounds promote the growth rate of animals and improve the feed efficiency.

Abstract: A method of promoting the growth and improving the feed efficiency of animals using substituted quinoxalines represented by the formula: ##STR1## where R is hydrogen or lower alkyl of 1 to about 4 carbon atoms.