Managing the Prenatal Period to Enhance the Physiology and Productivity of Poultry

Abstract

The present study was carried out in Poultry Physiology Research Lab at Faculty of Agriculture, Ain Shams University, from April 2021 to July 2021 under the Egyptian environmental conditions. The study aimed to decrease the detrimental effects of long broiler breeder eggs storage period by using Short Period of Incubation During Egg Storage Period (SPIDES) technique, with or without late prenatal thermal conditioning on egg quality, hatchability, post-hatch productive and immune performance, some physiological traits, some histocytological observation of breast muscles and exploring the molecular mechanism of the hepatic expression of heat shock proteins (hsps), antioxidant enzymes and mitochondrial related genes of broiler under heat stress conditions. Eight hundred Ross broiler eggs were divided into four main groups control kept in the storage room conditions, the 1st (S0) group was maintained under the optimal egg storage room conditions for 20 d, while The 2nd (S1),3rd (S2) and 4th (S3) were subjected in a separate room to SPIDES for 5 h at 37.8○C ± 0.1 once at day 5 , two times at day 5 and 10; and three times at day 5, 10 and 15 d after egg collection, through same period of storage. At the 14th day of incubation, the main groups were randomly divided into two equal main subgroups, the control kept under the optimal conditions (TC0) and the thermal conditioned exposed to prenatal thermal conditioning (TC1) at 39.5 ○C ± 0.1 for 6h/ d from the 14th to the 18th embryonic day resulting finally in eight experimental sub-groups (S0TC0, S1TC0, S2TC0, S3TC0, S0TC1, S1TC1, S2TC1 & S3TC1). The egg quality, embryo temperature, hatchability percentage, early, mid and late embryonic mortalities, post-hatching performance, post-hatching immunocompetence, some blood biochemical constituents, T3 plasma level, mRNA expression of Heat shock proteins' gene of liver, mRNA expression of mitochondrial related genes and mRNA expression of hepatic antioxidant enzymes related genes in liver, histocytological measurements of pectoral muscles and liver histology were estimated.