摘要
Montbeliarde dairy cattle were introduced in Ecuador with the aim of ameliorating the production performance of other cattle breeds. The aim was to analyze the reproductive performance, demographic structure, inbreeding, and genetic diversity of Montbeliarde cattle obtained by absorption crossing. Official pedigree records from the Ecuadorian Montbeliarde Association were used. The total population was divided into seven populations: (i) historical (all individuals), (ii) 1999–2003, (iii) 2004–2008, (iv) 2009–2013, (v) 2014–2018, (vi) 2019–2023 (current), and (vii) reference (individuals with known parents). Demographic structure variables analyzed: pedigree completeness index (PCI), number of equivalents (GEqu), complete (GCom) and maximum (GMax) generations, and generation interval (GI). Inbreeding-derived variables analyzed: inbreeding (F), inbreeding increment (ΔF), average relatedness (AR), co-ancestry (C), non-random mating (α), effective population size (Ne), and genetic conservation index (GCI). Gene origin probability/genetic diversity variables analyzed: number of founders (f), effective number of founders (fe) and ancestors (fa), number of equivalent genomes (fg), fe/fa and fg/fa ratio, and DG losses. The databases were analyzed by ENDOG, POPREP, and CPC software. PCI in the historical population compared to the current population decreased from 72.95 to 65.87% (sire/dam pathway), while the GI decreased from 7.17 to 3.08 years when the historical and current populations were compared. Dam reproductive efficiency increased over time. Moreover, F = ~1%, AR = 2.06%, ΔF = 0.22%, C = 1.03%, α = −0.0077, GCI = 3.12, and Ne = 58 values were obtained. Gene origin probability in the reference population was f = 439, fa = 37, fe = 71.64, fg = 23.43, and fg/fe = 0.33, showing a GD loss due to unequal contribution of founders (0.55%) and bottleneck and genetic drift (4.25%). In conclusion, the Ecuadorian Montbeliarde cattle population displayed a relatively low diversity and high genetic relationship. Inbreeding levels increased while Ne values decreased over time. The introduction of new purebred bloodlines could be important to minimize the inbreeding levels ensuring the long-term conservation of this breed and minimizing GD loss.
摘要译文
在厄瓜多尔引入了蒙贝利亚尔德奶牛，目的是改善其他牛品种的生产性能。目的是分析通过吸收交叉获得的蒙贝利亚尔德牛的生殖性能，人口统计结构，近交和遗传多样性。使用了厄瓜多尔蒙贝利亚德协会的官方血统记录。总人口分为七个人群：（i）历史（所有个人），（ii），1999- 2003年，（iii），2004- 2008年，（iv）2009-2013，（v），（v）2014-2018，（vi），2019-2023（vi）2019-2023（当前）（当前）和（vii）和（vii）参考（伴有知名父母）。分析的人口统计结构变量：谱系完整性指数（PCI），等效数（GEEM）的数量，完整（GCOM）和最大（GMAX）世代以及生成间隔（GI）。分析的近亲衍生变量：近交（f），近交次增量（ΔF），平均相关性（AR），共同处理（C），非随机配对（α），有效的人口大小（NE）和遗传保护指数（GCI）。分析的基因起源概率/遗传多样性变量：创始人的数量（F），有效数量的创始人（FE）和祖先（FA），等效基因组的数量（FG），Fe/FA和FA和FG/FA比率以及DG损失。数据库由Endog，Poprep和CPC软件分析。与当前人口相比，历史人口中的PCI从72.95下降到65.87％（父亲/大坝途径），而GI比较了历史和当前人口的7.17年减少到3.08年。大坝生殖效率随着时间的推移提高。此外，F = 〜1％，AR = 2.06％，ΔF= 0.22％，C = 1.03％，α= -0.0077，GCI = 3.12，并且获得了NE = 58值。参考人群中的基因起源概率为F = 439，Fa = 37，Fe = 71.64，Fg = 23.43和Fg/Fe = 0.33，显示创始人（0.55％）和瓶颈和遗传漂移（4.25％）的不平等贡献（0.55％），GD损失。总之，厄瓜多尔的蒙贝利亚尔德牛群的多样性相对较低和遗传关系较高。近亲繁殖水平增加，而NE值随时间下降。引入新的纯种血统对于最大程度地降低近交水平可能很重要，从而确保该品种的长期保护并最大程度地减少GD损失。
Luis F. Cartuche-Macas (https://orcid.org/0000-0003-3278-1238) [1];Oscar J. Guaman Ilvay (https://orcid.org/0009-0000-2166-6678) [2];Edilberto Chacón (https://orcid.org/0000-0001-9590-6451) [3];Miguel A. Gutierrez-Reinoso [4];Manuel Garcia-Herreros (https://orcid.org/0000-0002-0911-6689) [5];. Reproductive Performance, Inbreeding, and Genetic Diversity in Montbeliarde Dairy Cattle Obtained by Absorption Crossing[J]. Animals, 2025,15(3): 322