Efeito dos diferentes tipos de alojamento no pré-parto sobre o desempenho reprodutivo de matrizes suínas e a ocorrência da síndrome do segundo parto

Abstract

Swine production is a growing sector, essential for animal protein supply. With advancements in the field, highly technological systems have become predominant, where individual gestation crates for sows can compromise animal welfare and lead to health issues, such as hoof injuries and physical discomfort. Alternatively, group housing for pregnant sows has gained traction as a recommended practice, driven by demands for improved living conditions and animal welfare. However, it presents challenges such as controlling feed intake and managing social hierarchy among females. The second parity syndrome (SPS) is another significant concern, linked to nutritional and reproductive deficiencies that result in reduced sow productivity during the second cycle. This study aimed to evaluate the effects of different housing systems (group pens and individual crates) during gestation on reproductive indices such as the number of live-born, stillborn, and mummified piglets, gestation length, farrowing duration, and litter weight, as well as the incidence of SPS. The research was conducted at a Piglet Production Unit (PPU) located in Monte Alegre, Minas Gerais, Brazil. Data were collected from second-cycle sows, including 59 housed in group pens and 32 in individual crates, and an additional 58 females housed in group pens were evaluated across their first and second cycles. The analyzed data included gestation length, farrowing duration, live-born, stillborn, and mummified piglets, and litter weight. Data analysis was performed using R software version 4.3.1, applying the MannWhitney test for housing comparisons, the Wilcoxon test for second parity syndrome analysis of non-normally distributed variables, and paired t-tests for normally distributed variables. The results demonstrated that group housing provided significant benefits, such as a reduction in the number of mummified piglets. Statistical analyses revealed that, although some indices did not show significant differences, productive performance remained comparable to that achieved with individual crates. Additionally, second parity syndrome, once a critical concern, has become less pronounced in current sows, suggesting favorable genetic adaptations for reproductive performance over cycles, as well as improved nutrition and operational management. It is concluded that group housing during gestation is a promising alternative that does not compromise reproductive or health outcomes, demonstrating the feasibility of implementing animal welfare practices without productivity losses.