الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Effect of Thermal Environment on Plasma luteinizing Hormone (lH), Prolactin {PRll, Hypothalamic Vasoactive Intestinal Peptide (VIP) and Gonadotropin Releasing Hormone I and II (GnRH-1 and GnRH-11) of Turkey Hens.
Three experiments were conducted to determine the effect of constant 10°C or 32°C and the shifting from 32°C to 10°C or 10°C to 32°C on ovariectomized (OVX) and/or photostimulated {photo)-turkey hens induced alterations in plasma LH and PRL levels. In Exp. 1, the photo-induced rise in plasma LH was similar in hens maintained for 4 wk at 10°C and 32 °e. Hens shifted from 10°C to 32 °e on the day of photo showed a delay in the LH rise. The photo-induced increase in PRL was greater (p < 0.05) in the 32°C birds as compared to 10°C birds. A decline in PRL levels occurred when hens were shifted from 32°C to 10°C, whereas the reverse response occurred as hens were shifted from 10°C to 32°C. In Exp. 2, when photo hens were OVX, the increase in plasma LH was greater for hens maintained at 32 ° e as compared to those at 10°C. Shifting hens from 10°C to 32 °e on the day of OVX enhanced LH as well as PRL rises.ln Exp. 3, Hens were OVX on the same day of photo. The combined effects of photo and OVX on LH was not altered by rearing turkeys at 10°C or 32 °e. However, shifting hens from 10°C to 32 °e on the day of OVX-photo enhanced the LH response. Similar changes were observed for PRL. In Exp. 2 and 3, OVX reduced (P < 0.05) hypothalamic GnRHHI and II content; However no such effect was found in Exp. 1. Hypothalamic
VIP content was elevated (P < 0.05) in response to elevated temperature and OVX. These findings indicate that high ambient temperature has an augmentative effect on plasma LH and PRL. Acute high temperature exposure increased LHl?> mRNA abundance in OVX hens compared to their corresponding SHAM birds (Exp. 2 and 3). The hypothalamic VIP increased significantly in OVX under high acute temperature (Exp.2 and 3). The study indicate that PRL mRNA increased in response to elevated temperature from 1 DoC to 32°C in sham and OVX hens (Exp. 2 and 3). In all OVX hens there was a reduction in PRL gene expression in resr?0nse to reduced temperature from 32°C to 1 DoC, but it was not significant in any experiment.
Section two: Management and Well-Being of Market Turkeys.
A comparison was made in a factorial manner to examine the effect of strain (Nicholas, British United Turkey (BUT) and Hybrid), toe-nail trimming method (conventional vs microwave), lighting environment and dust control on the performance of male market turkeys. 368 poults of each strain were started. The lighting programs were intermittent light at 4(2L:4D) or (8L:4D: 2L:4D: 2L:4D). In each lighting program the product Dust-Off (Leslie Salt CO., Newark, CA 94560) containing magnesium chloride was applied to the litter in each pen at a rate of 2.18L 1m2 and compared to rooms where water was applied at a rate equivalent to the water content of the dust-Off (1 .44m2). Body weights at 18 weeks of age were similar for all Lighting program, strains and toe nail trim methods, and averaged 12.93 kg. Incidence of leg problems