Hens That Exhibit Poorer Feed Efficiency Produce Eggs with Lower Albumen Quality and Are Prone to Being Overweight.

Abstract

Simple SummaryThe contemporary hybrid layer is an efficient producer of eggs, which is a source of high-quality nutrients. However, there is a lack of scientific knowledge on how feed efficiency (FE), an important measure of hen productivity, differs between individual hens during laying life and its association with other hen performance and egg quality traits. This study sought to investigate the production traits, egg composition and quality of laying hens in mid-lay when ranked based on FE in early-lay. The results showed that feed to egg conversion ratios (FCR) exhibited in early-lay were maintained until at least 40 weeks, with feed intake being the major driver of the difference in FE, not the mass of the egg. Further, hen and egg quality traits are associated during mid-lay, with high feed efficient hens having a lower body weight but producing eggs whose albumen has a higher height, Haugh unit and amino acid concentration. These results may provide important information to poultry breeders and egg producers towards improving the economics of egg production and generally improve management decision making, which is usually made based on accepting the expected average performance of a cohort of animals.Feed efficiency (FE) is an important measure of productivity in the layer industry; however, little is known about how FE differs between individual hens during the egg-laying cycle and the implications for egg quality parameters. Individual 25-week-old ISA Brown hens were observed for 42 days, ranked into three FE groups (n = 48 per High (HFE), Medium (MFE) and Low (LFE) FE groups and then monitored later in the laying cycle from 35–40 weeks. The groups exhibited different feed to egg conversion ratios (p < 0.001) from 35–40 weeks. Average daily feed intake and body weight were highest (p < 0.001) in the LFE group compared to the MFE and HFE groups, while albumen height, Haugh unit and amino acid concentrations of the albumen were significantly higher in the HFE groups compared to the LFE cohort (p < 0.001). This study concludes that FE status established in early lay is a stable variable until at least 40 weeks of age, and overweight, mid-laying hens that had poor FE produced inferior egg albumen quality measurements and composition. The distinct traits of the highly efficient hens and the poor feed efficient hens may provide important information to improving productivity in egg production.