Broiler chicks hatched from egg weight extremes and diverse breeder strains

Events following the hatching of chicks have lately gained increased intere st by the poultry industry. Research evaluating composition of eggs and yol k sacs of chicks from different sources and their effects on early chick de velopment is scarce. In this research broiler hatching eggs were obtained f rom breeder flocks of four diverse strains, then categorized as "heavy" or "light" to represent the top and bottom one-third weights from each populat ion. Heavy eggs typically had a greater proportion of albumen and less yolk than small eggs, and these differences were similarly expressed among stra ins. Influence of the egg source on hatched chicks differed with the carcas s and yolk sac. Egg weight and strain affected chick weight but not its com position, whereas the yolk sac was consistent in proportion to the chick bu t varied in composition. Overall differences in weight, proximate to the ch ick but varied in composition. Overall differences in weight, proximate ana lysis, amino acid, and mineral compositions of eggs and chicks appear to be small, and possible nutrient accommodation in the first feed to improve pe rformance seems unnecessary.