3-Indolebutyric acid (IBA) is a synthetic hormone. It is used in propagation by cuttings. For root formation from shoots, it is an important component of nutrient media [1]. It can improve fertilized avian eggs. In the poor laying seasons, treatment with the invention of US 3088866 A can increase the average annual chick yield of eggs in a commercial hatchery from about 75% to about 85% [2].

The total yield of chicks during the good laying seasons of the year is about 80 to 85%, based on a high percent of hatchable eggs of about 80 to 90%. The total yield of chicks during the poor laying seasons of the year is about 50 to 55%, based on a high percent of hatchable eggs of about 60 to 65%. In well run commercial hatcheries, it is considered excellent that an average yield for any one year of the total number of incubated eggs is about 75% [2].

To eggs that was naturally fertilized and showed no sign of a living embryo prior, treatment with IBA in optimum amounts facilitated the live embryo formation in certain of the eggs. It further increased the chick yield of a given batch of eggs. In the life-giving cells of the blastoderm of the egg, IBA in optimum amounts stimulated the life growing activity of the cells and resulted in the formation of a live embryo, though the formation failed to show before treatment under the most careful candling [2].

To the live animal embryo of a fertilized avian egg, when IBA is made available, it stimulated the biological life-growing processes during incubation. In all cases, after the treatment of IBA, hatched chicks were healthy, viable and vigorous. They tended to be more resistant to disease than common chicks hatched from untreated eggs [2].

References:
[1].  J. Ivanicka, L. Pastyrik In: ISHS Acta Horticulturae 80: Symposium on Growth Regulators in Fruit Production, Wageningen, 1978. p. 83-85.
[2].  Pincus G, Wernicoff N; Vineland Poultry Lab. Improving fertilized avian eggs with 3-indolebutyric acid. US patent 3088866 A. 1963 May 7.