Effect of Dietary Calcium Stress on Plasma Vitamin D3 Metabolites in the Egg-Laying Japanese Quail

D. M. KAETZEL, J. H. SOARES
1985 Poultry Science  
An experiment was conducted to elucidate the effect of short-term exposure of japanese quail eggs to high incubation temperature on the ability to cope with the heat stress during laying period. A total number of 998 fertile Japanese quail eggs were divided into two groups; the first one was maintained at the recommended incubation temperature (37.5°C), while the second was exposed to 39.5°C for two hours at days 3, 7 and 13 of embryogenesis. At laying period, quails from each incubation
more » ... h incubation temperature were randomly assigned to four dietary treatments, control; high-energy diet (+ 150 Kcal ME/ Kg diet more than the recommended level); high-lysine (10 % more) and vitamin C supplemented diet. Blood metabolites and histological sections for the lymphoid organs and for tibiae of laying quails were examined. Results showed that plasma total protein was insignificantly lower. Also, plasma calcium and phosphorus levels did not significantly influenced by treatments. Histological examination of spleen sections showed considerable variations related to treatments. Both heat exposure and high-lysine diets caused a reduction in lymphocytes number and size. Caecal tonsil sections showed a pronounced effect of early heat exposure on the general developmental patterns of crypts of Lieberkuhn either in their size or number. Harderian gland histology reflected the presence of several lymphocytic cells in the stroma of the gland. Tibia bone sections showed normal appearance of the compact bone layer concomitant by an obvious hypertropic proliferation of bone cells. Based on the present results, it could be concluded that pre-hatching exposure of quail eggs to high temperature and feeding of a high-energy or vitamin C supplemented diets during laying period could be recommended for maintaing the physiological homeostasis of quails during heat stress.
doi:10.3382/ps.0641121 pmid:3839307 fatcat:ovgw62r67zed5atuxalltzhzzy