Inheritance of the duration of fertility in chickens and its correlation with laying performance

Abstract

Background Duration of fertility (DF) is an important economic trait in poultry production because it has a strong effect on chick output. Various criteria or traits to assess DF on individual hens have been reported but they are affected by many nongenetic factors. Thus, a reliable definition and associated genetic parameters are needed. Because egg production is also vital in chicken breeding, knowledge of the relationship between DF and laying performance is needed for designing selection programs. Methods We used five traits that consider both fertility and embryonic livability to delineate DF. Phenotypic and genetic analyses were completed for 2094 hens, with measurements of DF at 35 and 60 weeks of age and hatching egg production at 400 days of age (HEP400). The selection differentials for DF and HEP400 were evaluated. Results DF is largely independent of the number of oviposited eggs in the peak laying period but both egg production and DF naturally decline with age. The heritability of the five DF traits ranged from 0.11 to 0.13 at 35 weeks of age and increased slightly in the later laying period, ranging from 0.14 to 0.17 (except for efficient duration, time between insemination and the first unhatched egg). Estimates of the genetic correlation for a given trait measured at the two ages were moderate (0.37–0.44), except for efficient duration. However, number of viable embryos depends strongly on egg production. Estimates of genetic correlations of fertility duration day (FDD) at both ages with HEP were weak. Selection for FDD improved DF but without a significant change in laying performance. Selection for increased HEP400 did not contribute to DF improvement. Conclusions Although estimates of heritability of the five traits related to DF were low, selection to improve DF based on any one of them is possible. Among these, FDD is an effective selection criterion when the eggs are collected for approximately two weeks after insemination. The best selection procedure for DF improvement would involve multiple measurements at various ages. FDD is independent of laying performance and can be incorporated into a breeding program with egg production to improve reproductive efficiency.

Genetic improvement of duration of fertility in chickens and its commercial application for extending insemination intervals

“…The determination of DF is typically based on the number of days after insemination when hens lay fertilized or hatched eggs. Considering that the DF naturally declines with age ( Gumulka and Kapkowska, 2005 ; Wen et al, 2022 ), the measurements were carried out during 2 specific stages of the hen's reproductive cycle: the peak laying period (∼35 wk of age) and the late laying period (∼60 wk of age).…”

“…Consequently, in most commercial chicken production systems of developed countries like the United States, AI programs have not been commonly implemented due to the prohibitively high labor costs involved in large-scale commercial operations. On the other hand, developing countries like China ( Wen et al, 2020 ; Wen et al, 2022 ) and India ( Singh, 1999 ) have widely embraced AI for its benefits in breeding and commercial purposes. With advancements and improvements in technology, there is potential for the cost of artificial insemination to become more economically favorable, leading to an increase in its commercial implementation globally.…”

“…In a typical poultry breeding program, selective improvement of specific traits within dedicated male and female pure lines is a common practice ( Wolc et al, 2009 ). The DF exhibits significant variation among hens, with heritability estimates ranging from 0.11 to 0.17 ( Wen et al, 2022 ), indicating the need for greater selection pressure on the trait to achieve faster genetic progress. Previous studies conducted on chicken ( Brillard et al, 1998 ) and duck ( Cheng et al, 2009 ; Liu et al, 2015 ) have demonstrated the viability of genetic selection for a longer DF to enhance the overall reproductive performance of breeder flocks.…”

Paternity bias and cryptic female choice in chickens

“…Investigating the molecular characteristics of CFC is vital to both scientific advancements and applications in animal production. Avian species, being typical oviparous animals, offer a unique advantage for exploring the potential mechanisms of CFC due to the abundance of fertilizer available and the ease of assessing paternal bias by embryo ( Wen et al, 2022 ). Traditionally, the proof of sperm transport in the oviduct has been considered as a race toward the eggs, favoring the fastest and highest quality sperm for fertilization ( Holt and Fazeli, 2016a ).…”

Curcumin Attenuates Damage to Rooster Spermatozoa Exposed to Selected Uropathogens

“…This will in turn decrease production costs by reducing the number of roosters, thereby saving space, feed, maintenance, and operating expenses [ 1 ]. Nevertheless, it must be acknowledged that the success of AI is fundamentally dependent on semen quality, which is needed to maximize reproductive output while minimizing the wastage of an animal’s investment in producing male gametes [ 3 ]. In the meantime, extended ejaculates may be affected by a vast array of endogenous and exogenous factors, including bacterial contamination, which may compromise the shelf life of insemination doses, fertility rates and hatchability [ 4 , 5 ].…”