Dietary effects on immune response of fast-growing chicks to inoculation of sheep erythrocytes and Escherichia coli

Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA.

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.

This article has been cited by other articles:

				H. Enting, W. J. A. Boersma, J. B. W. J. Cornelissen, S. C. L. van Winden, M. W. A. Verstegen, and P. J. van der Aar The Effect of Low-Density Broiler Breeder Diets on Performance and Immune Status of their Offspring Poult. Sci., February 1, 2007; 86(2): 282 - 290. [Abstract] [Full Text] [PDF]