Relação entre a ordem de parto de porcas multíparas e a ordem cronológica de nascimento de leitões natimortos e mumificados em granja comercial.

Abstract

The increase in prolificacy in modern swine production systems has contributed to a rise in the number of piglets born per litter, creating increasing challenges related to neonatal survival and perinatal losses. Among these losses, the occurrence of stillborn piglets and mummified fetuses stands out, as these indicators are frequently used to evaluate the reproductive efficiency of sows in commercial farms. Physiological and productive factors, such as sow parity and the birth order of piglets during farrowing, may directly influence the occurrence of these losses. In this context, the present study aimed to analyze the relationship between the parity of multiparous sows and the chronological birth order of stillborn piglets and mummified fetuses in a commercial farm. Data from 198 farrowings of multiparous sows with parity ranging from the second to the eighth farrowing were evaluated. For analysis, the sows were grouped into three parity categories: group A (parities 2 and 3), group B (parities 4 and 5), and group C (parities 6, 7, and 8). For each farrowing, data were collected on the total number of piglets born, number of stillborn piglets, number of mummified fetuses, farrowing duration, and the chronological birth order of non-viable fetuses. Birth positions were grouped into three classes to evaluate the distribution of losses throughout the farrowing sequence: first to eighth, ninth to fourteenth, and fifteenth to twenty-fourth positions. Parity influenced only the total number of piglets born, with the highest mean observed in sows of the fourth and fifth parities (p < 0.001). No significant differences were observed for farrowing duration (p = 0.42), number of stillborn piglets (p = 0.10), or number of mummified fetuses (p = 0.98). Although a trend toward an association was identified between parity and the distribution of stillborn piglets throughout the birth sequence (p = 0.056), no significant association was observed for mummified fetuses (p = 0.100). Therefore, it was concluded that parity influences litter size but does not significantly affect the occurrence of stillborn piglets or mummified fetuses, although there is a tendency for an association between parity and the distribution of stillborn piglets throughout the birth sequence.