title: Further investigation of the dietary protein and monensin level interrelationship in broiler chicks: influence of Eimeria acervulina infection, increased dietary protein, and level of feed intake.
abstract: Three experiments were conducted to evaluate the influence of several dietary factors on the monensin response in commercial broiler chicks fed corn-soybean meal diets varying in crude protein (CP). All experiments were conducted between 8 and 22 days posthatching. Trial 1 had a 2 X 2 X 2 factorial design wherein diets containing 16 or 24% CP and 0 or 121 mg/kg monensin were fed in the presence and absence of Eimeria acervulina infection. The monensin-induced growth depression was greater at 16% CP than at 24% CP. Coccidial infection had no effect on the monensin X protein level interaction. Monensin supplementation markedly improved performance of chicks infected with E. acervulina. Trial 2 was conducted to determine if the monensin-induced depression in performance caused by feeding a high level of monensin (140 mg/kg) could be moderated by feeding a high protein diet. Monensin supplementation reduced growth rate 18 and 10% in chicks fed 20 and 24% CP, respectively. Increasing CP to 28% alleviated the adverse effects of monensin on weight gain. Pair-feeding was used in Trial 3 to determine the extent to which the monensin-induced growth depression observed in chicks fed low protein diets was due to reduced feed intake. As expected, reducing the dietary CP from 24 to 16% resulted in a marked increase in the growth depression caused by 121 mg/kg monensin. Pair-feeding indicated that most of monensin's adverse effects in low protein diets could be attributed to its anorexic properties.
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D002645:Chickens / Q000254:growth & development* / Q000469:parasitology; D003048:Coccidiosis / Q000378:metabolism / Q000503:physiopathology / Q000662:veterinary*; D004044:Dietary Proteins / Q000494:pharmacology*; D005247:Feeding Behavior; D008297:Male; D008985:Monensin / Q000494:pharmacology*; D011201:Poultry Diseases / Q000378:metabolism / Q000469:parasitology* / Q000503:physiopathology
chemical_list: D004044:Dietary Proteins; D008985:Monensin