Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193, China.
Genet Sel Evol. 2022 Jun 3;54(1):41. doi: 10.1186/s12711-022-00733-7.
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.
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.
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.
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.
在禽类生产中，生育力持续时间（DF）是一个重要的经济性状，因为它对雏鸡产量有很强的影响。已经报道了各种评估个体母鸡 DF 的标准或性状，但它们受到许多非遗传因素的影响。因此，需要一个可靠的定义和相关的遗传参数。由于产蛋量在鸡的繁殖中也很重要，因此需要了解 DF 与产蛋性能之间的关系，以便设计选择计划。
我们使用了五个同时考虑生育力和胚胎存活率的性状来描述 DF。对 2094 只母鸡进行了表型和遗传分析，测量了 35 周和 60 周龄的 DF 以及 400 天产蛋量（HEP400）。评估了 DF 和 HEP400 的选择差异。
DF 在很大程度上独立于高峰期产蛋量的卵数，但产蛋量和 DF 都会随着年龄的增长而自然下降。五个 DF 性状的遗传力在 35 周龄时在 0.11 到 0.13 之间，在后期产蛋期略有增加，在 0.14 到 0.17 之间（除了有效持续时间，即从授精到第一枚未孵化卵的时间）。两个年龄段测量的给定性状的遗传相关性估计值适中（0.37-0.44），除了有效持续时间。然而，胚胎存活率强烈依赖于产蛋量。DF 日（FDD）在两个年龄段与 HEP 的遗传相关性估计值较弱。FDD 的选择改善了 DF，但对产蛋性能没有显著变化。选择增加 HEP400 并不能改善 DF。
尽管与 DF 相关的五个性状的遗传力估计值较低，但基于其中任何一个性状进行选择以改善 DF 是可能的。在这些性状中，FDD 是在授精后大约两周内收集鸡蛋时的有效选择标准。改善 DF 的最佳选择程序将涉及在不同年龄段进行多次测量。FDD 独立于产蛋性能，可以与产蛋性能一起纳入繁殖计划，以提高繁殖效率。
