Influência do tempo gestacional de matrizes suínas sobre o número e peso dos leitões ao nascimento.

Abstract

Modern pig farming constantly seeks to optimize its productive and reproductive indexes, especially regarding reproductive efficiency and piglet viability at birth. Among the factors that influence the reproductive performance of sows, gestation length stands out for its impact on birth weight, stillbirth rate and the occurrence of mummified piglets. This study evaluated the relationship between gestation length and the reproductive performance of sows, focusing on piglet birth weight, farrowing duration and the number of stillborn and mummified piglets. The study was carried out at a Piglet Production Unit located in Monte Alegre de Minas, Minas Gerais, Brazil, involving 74 HS (Hiper Sadia) sows. A total of 74 farrowings occurring in March 2025 were analyzed. Females were monitored exclusively at the time of farrowing, with data obtained from the farm’s computerized system (S2) and by direct collection during farrowings. The experimental design was completely randomized. Data were assessed for normality and homogeneity of variance; analysis of variance (ANOVA) followed by Tukey’s test (P < 0.05) was applied to parametric variables, and the Wilcoxon test to non-parametric variables. Correlations were calculated using Pearson’s or Spearman’s coefficients according to data distribution, using the RStudio software (R Core Team, 2023). A total of 1,041 piglets were born, of which 930 were liveborn, 77 stillborn and 34 mummified. Sows with gestation length ≤115 days had a higher total number of piglets (15.53 ± 4.02) but lower mean birth weight (1.40 ± 0.26 kg), whereas sows with gestation length >115 days had fewer piglets (13.27 ± 4.60) but higher mean birth weight (1.56 ± 0.34 kg) (P < 0.05). The number of liveborn piglets was negatively correlated with mean birth weight (r = –0.60; P < 0.05), indicating that larger litters tend to produce lighter piglets. It is concluded that gestation length directly influences piglet birth weight and viability and should be considered in sow reproductive management. These findings provide support for adopting management and selection strategies that balance prolificacy and birth weight, contributing to higher productivity and profitability of the system.