title: Dietary effects on immune response of fast-growing chicks to inoculation of sheep erythrocytes and Escherichia coli.
abstract: Responses to SRBC and Escherichia coli inoculations were measured during the early posthatch period in broiler cockerels fed diets differing in nutrient density. Diet A consisted of 20% protein and 2,685 kcal ME/kg and Diet B consisted of 24% protein and 3,146 kcal ME/kg. There was no effect of diet on antibody response of chicks inoculated at 10 d of age with 0.25, 2.50, 5.00, or 25.00% suspensions of SRBC. A significantly larger proportion of chicks, however, produced antibody at the 25.00% than at the 0.25% dosage of SRBC. When inoculated at 15 d of age with 10(-6), 10(-4), or 10(-2) dosage of E. coli, there were no significant diet by dosage interactions for lesion scores, or relative change in BW 24, 48, and 120 h after inoculation. There were differences among E. coli dosages for severity of lesions and mortality, with rankings being 10(-2) > 10(-4) > 10(-6). Lesion scores and mortality were higher for the chicks fed Diet B than those fed Diet A. Also, deleterious effects of E. coli on BW 24, 48, and 120 h after inoculation were greater for chicks fed Diet B than for chicks fed Diet A. Responses to inoculations of SRBC and E. coli of broilers fed a diet with a lower nutrient density were equal or superior to those of broilers fed a diet with a higher nutrient density.
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA.
authors.forename: N K
authors.initials: NK
authors.lastname: Praharaj
authors.forename: E A
authors.initials: EA
authors.lastname: Dunnington
authors.forename: W B
authors.initials: WB
authors.lastname: Gross
authors.forename: P B
authors.initials: PB
authors.lastname: Siegel
mesh_terms: D000821:Animal Feed; D000818:Animals; D000917:Antibody Formation; D001835:Body Weight; D002645:Chickens; D004044:Dietary Proteins; D002149:Energy Intake; D004912:Erythrocytes / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D007114:Immunization; D008297:Male; D012756:Sheep
chemical_list: D004044:Dietary Proteins