Effects of Dietary Terramycin and Methionine Supplements on Fat and Protein Gains in Weanling Rats

• Published in: The Journal of nutrition Vol. 51; no. 2; pp. 205 - 218
• Main Authors: Hartsook, E.W., Johnson, B. Connor
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.1953
• Subjects: Animals; Diet; Dietary Supplements; Fats - metabolism; Methionine - pharmacology; Old Medline; Oxytetracycline - pharmacology; Proteins - metabolism; Rats; PROTEINS/metabolism; FATS/metabolism; OXYTETRACYCLINE/effects; METHIONINE/effects
• ISSN: 0022-3166
• DOI: 10.1093/jn/51.2.205

1.Four groups of 10 weanling, male, albino rats each were fed the following diets ad libitum for 45 days: group 1, the basal diet (approximately 19.9% protein, 0.30% methionine, and 0.12% cystine); group 2, the basal diet + terramycin; group 3, the basal diet + 0.4% methionine; and group 4, the basal diet + terramycin + 0.4% methionine.2.No statistically significant effect of methionine supplementation alone of the basal diet was observed.3.Terramycin supplementation alone of the basal diet: (a) increased carcass dry matter significantly (12.7%, p < 0.02), increased significantly the efficiency of dry matter utilization for carcass dry matter deposition (10.0%, p < 0.05), and increased dry matter intake almost significantly (3.8%, p > 0.1); (b) increased carcass N deposition non-significantly (1.6%, p > 0.5) and decreased the efficiency of N utilization almost significantly (5.2%, p ≅ 0.064); (c) increased carcass ether extract significantly (36.1%, p < 0.01) and increased significantly the efficiency of dry matter utilization for ether extract deposition (36.2%, p < 0.01). Therefore, one may conclude that terramycin alone increased carcass dry matter gains, mainly by enhancing fat deposition.4.The terramycin-methionine interaction: (a) increased carcass N deposition non-significantly (4.5%, p > 0.2) and increased the efficiency of N utilization significantly (10.7%, p < 0.01); (b) significantly decreased carcass ether extract deposition (30.8%, p < 0.05) and significantly decreased the efficiency of utilization of dry matter for carcass ether extract deposition (30.6%, p < 0.05). Thus one may infer that the terramycin-methionine interaction enhanced the efficiency of utilization of dietary N and depressed fat gains.5.Speculations as to the mode of action of antibiotics have been advanced.