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Mcfarlane, James Michael 2014-12-15T21:01:11Z 2014-12-15T21:01:11Z 10000-01-01 1987 1987 Whether concurrent stressors synergize in affecting chicks was studied. Results suggest stressors affected chicks in similar fashion when acting singly or together; i.e., effects were additive. Experiment I. New Hampshire x Columbian chicks were studied via 2$\sp{4}$-factorial of aerial ammonia (A, O or 125 ppm), beak-trimming (B, sham or trimmed trial d 1), coccidiosis (C, O or 4 $\times$ 10$\sp{5}$ sporulated E. acervulina oocysts d 1), and heat (H, air 30.4 or 36.5 C). Five 7-d trials had 15 6-chick replicates of 16 treatments. All stressors decreased chick weight gain (G), feed intake (F), and G/F, except B for G/F; A x C for G was only interaction. A, C, and H increased s$\sp{2}$/x for G among chicks in treatment groups (CV-G). As stressor number (order) rose from 0 to 4, G, F, and G/F fell, and CV-G rose, linearly. D-7 heterophil %/lymphocyte % (h/l) rose due to all stressors and linearly with order. Only C affected blood total-cell fraction. Experiment II. Hubbard chicks were studied via 2$\sp{6}$-factorial of A and B (as Exp. I), C (0 or 6 $\times$ 10$\sp{5}$ oocysts as Exp. I), random electric shock (E, O or 3-10 mA), H (air 30.4 or 34.8 C), and continuous white noise (N, 80 or 95 dB). Four 7-d trials had 6 3-chick replicates of 64 treatments. All stressors but N decreased G, F, and G/F and increased CV-G; few interactions were found. As order rose from 0 to 6, G, F, and G/F fell linearly. No treatment affected d-7 plasma corticosterone. C increased carcass-water content and decreased chloroform/methanol-extract, A increased crude-protein, and C decreased carcass-energy; few interactions were found. Order did not affect composition. C increased standing and eating, H decreased drinking, times; few interactions were found. C damaged kidneys and duodenal mucosa; H mitigated the lesions. N caused, and synergized positively with C for, duodenal lesions. A caused, but H mitigated, hepatic lesions. Order affected no lesion score. Made available in DSpace on 2014-12-15T21:01:11Z (GMT). No. of bitstreams: 1 8721710.pdf: 12706415 bytes, checksum: 177ec9b87bcb90b9199f6c6badc06bd5 (MD5) Previous issue date: 1987 Embargo set by: Seth Robbins for item 70217 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 376 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987. http://hdl.handle.net/2142/70051 (UMI)AAI8721710 Agriculture, Animal Culture and Nutrition Linear Additivity of Multiple Concurrent Environmental Stressors' Effects on Chick Performance, Physiology, Histopathology, and Behavior text Animal Sciences Animal Sciences University of Illinois at Urbana-Champaign Dissertation Ph.D.