Mode of Action of Antibiotics in Stimulating Growth of Chicks

Coates, Michael I.; Dickinson, Cecilia D.; Harrison, G. F.; Kon, S. K.; Cummins, Saoirse; Cuthbertson, William

doi:10.1038/168332a0

Cited by 67 publications

(10 citation statements)

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“…[16] who found t h a t you ng co n v en tio n al chickens orally tre a te d w ith penicillin a t n u tritio n a l levels d isp lay , am o n g o th ers, a " th in n e r tu n ic a p ro p ria la y e r" in th e duod en u m th a n th o se birds w hich ditl not receive th e a n tib io tic . T hese findings, in cid en tally , fit in well w ith th e original th esis o f Coates et al [3] who p o in te d out th e overall im p o rta n c e o f th e in d ire ct (flora) effects o f an tib io tics w hen fed to th e host at n u tritio n a l levels. In an a tte m p t to place all these re su lts on a com m on d e n o m in a to r, it can te n ta tiv e ly be sta te d t h a t th e presence o f th e flora in th e in testin al lum en o f th e co n v en tio n al host im p a rts elem ents o f a mild (" physiological" ) in flam m ation to th e w all o f th e in te stin e .…”

Section: Discussionsupporting

confidence: 59%

Effects of the Normal Microbial Flora on Various Tissue Elements of the Small Intestine

Gordon

Bruckner-Kardoss²

1961

Cells Tissues Organs

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Section: Discussionsupporting

confidence: 59%

Effects of the Normal Microbial Flora on Various Tissue Elements of the Small Intestine

Gordon

Bruckner-Kardoss²

1961

Cells Tissues Organs

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“…Coates et al found that environmental factors also influence the response to antibiotics (18). Chicks kept in a new or clean environment did not benefit from dietary antibiotics.…”

Section: Discussionmentioning

confidence: 99%

The Mode of Action of Antibiotics in Stimulating Growth of Chicks

Eyssen

Somer

1963

The Journal of Experimental Medicine

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A study was made of the effect of antibiotics on growth of chicks and on intestinal absorption of fats and carbohydrates. Around the 8th day of life, chicks fed an antibiotic-free casein-sucrose diet developed a transitory syndrome of malabsorption of fats and carbohydrates, associated with disturbance of the efficiency of feed utilization and poor weight increase. Administration of virginiamycin, at a level of 20 ppm, suppressed this period of malabsorption and resulted in improved feed conversion and increased weight gain. The temporary growth depression and malabsorption were not observed in disinfected rooms in new quarters. Under these conditions virginiamycin did not stimulate growth nor was the efficiency of feed utilization improved by the antibiotic. However, the growth-depressing flora could be introduced to the new quarters by feeding each bird 50 mg of fresh feces collected from chicks in old quarters. Both the intestinal absorption and the growth-promoting effect of virginiamycin were influenced by the type of carbohydrate in the basal diet, and have been found to be most pronounced when sucrose was fed as the sole source of carbohydrate. The malabsorption was less obvious when cornstarch was substituted for sucrose. In this case virginiamycin had only a limited effect on growth and on feed conversion. The present investigations suggest that antibiotics stimulate growth of chicks by their antibacterial action against Gram-positive microorganisms which interfere with the absorption of nutrients. Furthermore, the growth-promoting effect seems to be most pronounced during a limited period of a few days around the 8th day of life.

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“…It has been known since the late 1940s that feeding sub-therapeutic concentrations of antibiotics to livestock causes them to grow bigger, faster, and less expensively (Coates et al, 1951;Elliott, 2015;Moore et al, 1946;Sneeringer et al, 2015;Stokstad and Jukes, 1950). The mechanism of this effect remains unclear after more than 60 years.…”

Section: Antibiotic Usage On the Farmmentioning

confidence: 99%