Table 1.
Biologics injected | Reference | Stage of incubationa | Location of injection | Results |
---|---|---|---|---|
Carbohydrates | (51, 66, 113–115) | Late stage | Amniotic fluid | Trophic effects on small intestine and effects on goblet cell activity; effects on embryonic metabolism and body weight |
Amino acids | (116–118) | Late and early stage | Amniotic fluid, yolk sac, air cell, site not specified (needle length and narrow/broad end of egg given) | Effects on chick-to-egg ratio, body weight, bursal weight, and thymus weight; effects on body weight in relation to location and day of injection; effects feed intake, feed conversation ratio, and immune response |
Hormones | (119–121) | Late and early stage | Albumen | Effect on muscle content; effects on body weight, skeletal growth, feed efficiencies, and adipose tissue development |
Prebiotics, probiotics, synbiotics | (122–125) | Early stage | Air cell, amnion | Effects on muscle fibers and histology; effects on Salmonella colonization; effect on final body weight gain and pancreatic enzyme activity; effect on number of bifidobacteria in feces |
Proteins (antibodies) | (126, 127) | Late and early stage | Yolk sac, albumen, amniotic fluid | Effects on body weight and muscle mass varied among injection locations; effects on antibiotic residue detection |
Immunostimulants | (128–130) | Late stage | Amniotic fluid | Effects on in vitro bactericidal activity of heterophils and protection against Salmonella invasion; effect on macrophage and antibody response |
aDay of incubation, early stage = 0–12 days of incubation; late stage = 13–21 days of incubation; see reference for exact day of incubation.