Research Note: In ovo and in-feed probiotic supplementation improves layer embryo and pullet growth

Probiotics are widely used as feed supplements in the poultry industry to promote growth and performance in chickens. Specifically, this supple-mentation starts around the time of lay and continues through the production cycle in laying hens. However, the embryonic period is critical to the growth and development of metabolically active organs thereby influenc-ing subsequent health and productivity in adult birds. Therefore, the present study investigated the potential use of probiotics to promote embryonic growth in layers. Further, a pilot grow-out study was conducted to evaluate the effect of in ovo and in-feed probiotic application on pullet growth. For the study, fertile White Leghorn eggs were sprayed with phosphate buffered saline (control, CON) or probiotic cocktail (in ovo only, IO; Lactobacillus paracasei DUP 13076 and L. rhamnosus NRRL B 442) prior to and during incubation. The embryos were sacrificed on d 7, 10, 14, and 18 of incubation for embryo morphometry. On d 18, remaining eggs were set in the hatcher to assess hatch-ability and hatchling morphometry. For the pullet trial,hatchlings were raised on feed with or without probiotics until wk 5. Pullets were sacrificed weekly, and morphometric parameters were recorded. Results of our study demonstrate that in ovo probiotic application significantly improved relative embryo weight, crown -rump length, hatchability, and hatchling weight when compared to the control (P < 0.05). Further, this enhanced embryonic development was associated with a concomitant increase in posthatch growth. Specifically, pullets raised from probiotic-sprayed eggs had significantly improved crown-rump length, tibial length, tibial bone weight, and body weight when com-pared to the control (P < 0.05). Moreover, among the different treatment schemes employed in this study [CON (no probiotics), in-feed only (IF), IO only, and in ovo and in-feed probiotic supplementation (IOIF)], sustained probiotic supplementation (IOIF) was found to be the most effective in promoting growth. There-fore, in ovo and in-feed probiotic supplementation could be employed to promote embryo and pullet growth to support subsequent performance in layers.

Automated summary

The study investigated the use of probiotics in promoting embryonic and pullet growth in laying hens. The application of in ovo probiotics significantly improved embryo weight, length, hatchability, and hatchling weight. Additionally, sustained probiotic supplementation was found to be the most effective in promoting growth.