Effect of Germ-Free Environment on Ca47 Metabolism ,

Comparative biology of germ-free and conventional poultry

“…However, a selection of additional relevant work did not fit conveniently into these categories. For example, Edwards and Boyd (1963) noted that following oral delivery of Ca 47 , GF had higher tibia and whole blood calcium ( Ca ) than CV birds, but no such differences were evident when the Ca 47 was administered intraperitoneally. This work suggests that the microbiome may play a role in Ca metabolism, perhaps via changes in intestinal pH, absorption, solubility or via indirect mechanisms involving vitamin D or phosphatase and phosphorus absorption.…”

“…However, GF chicken research was not widely used until the pioneering research of Reyniers and colleagues from the University of Notre Dame ( Reyniers et al, 1950 ). Subsequently, the GF chick model has been used extensively to explore the mode of action of antibiotics ( Forbes and Park, 1959 ; Coates et al, 1963 ), nutrient digestion and absorption ( Edwards and Boyd, 1963 ; Boyd and Edwards, 1967 ; Campbell et al, 1983 ), coccidiosis ( Radharkrishnan and Bradley, 1973 ; Gaboriaud et al, 2021 ), gastrointestinal development ( Cook and Bird, 1973 ; Ford, 1974 ; Corring et al, 1981 ; Philips and Fuller, 1983 ; Furuse and Yokota, 1984a ; Furuse and Okumura, 1994 ), protein metabolism ( Salter and Coates, 1971 ; Salter et al, 1974 ; Coates et al, 1977 ; Okumura et al, 1978 ; Furuse and Yokota, 1985 ; Furuse et al, 1985 ; Muramatsu et al, 1985 ; Muramatsu et al, 1987 ; Yokota et al 1989 ; Muramatsu et al, 1993b ), metabolic rate ( Harrison and Hewitt, 1978 ; Muramatsu et al, 1988 ), energy metabolism ( Coates et al, 1981 ; Hedge et al, 1982 ; Furuse et al, 1991b , c ; Muramatsu et al, 1992 ) and feed additive efficacy ( Furuse et al, 1991a ; Muramatsu et al, 1993a ; Langhout et al, 2000 ; Drew et al, 2003 ; Cheled-Shoval et al, 2014 ). The entire body of work from 1950 to 2022 (approximately 40 independent studies) on germ-free chickens gives considerable insight into the role of the microbiome in development of the intestine and support organs, the ability of the chick to extract nutrients from the feed, development of immune function, retention of protein and nonprotein nitrogen ( N ), energy metabolism, metabolic rate, and disease resilience.…”