Seasonal patterns in the farrowing distribution of two Iberian pig varieties (Retinto and Entrepelado) and its environmental and genetic sources of variation were analyzed within the context of a von Mises circular mixed model solved through Bayesian inference. Estimates about the dispersion parameter supported a low seasonal pattern for both Entrepelado and Retinto varieties with the farrowing peak located between March and April. Nevertheless, seasonality was corroborated by the deviance information criterion when comparing against a uniform circular model by the deviance information criterion (DIC); the uniform model increased more than 100 DIC units in both Iberian pig varieties. Regarding systematic effects, only the parity number of the sow had a relevant impact on farrowing distribution, advancing the farrowing peak in gilts and old sows. Genetic variability was only suggested in the Retinto population although with a small estimate, which would indicate little chance to modify farrowing distribution by genetic selection in the Iberian pig.

在通过贝叶斯推断求解的冯·米塞斯圆形混合模型的背景下，分析了两个伊比利亚猪品种（雷丁托和恩特佩拉多）的产仔分布的季节性模式及其环境和遗传变异源。色散参数的估计值支持Entrepelado和Retinto品种的低季节性模式，分娩高峰位于3月和4月之间。尽管如此，当通过偏差信息准则（DIC）与统一的圆形模型进行比较时，偏差信息准则证实了季节性）; 在两个伊比利亚猪品种中，统一模型增加了100多个DIC单位。关于系统性影响，只有母猪的胎次数对产仔量有相关影响，从而使母猪和老母猪的产仔高峰提前。遗传变异性仅在Retinto种群中提出，尽管估计值很小，这表明通过遗传选择伊比利亚猪的产仔分布的机会很小。