How piglets from nulliparous sows have their vitality and performance affected by farrowing kinetics and individual birth characteristics

• Grant number: 24/22521-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Cesar Augusto Pospissil Garbossa
• Grantee: Erich Herzogenrath Cavaca Inácio
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The high mortality rate and low vitality among piglets born from modern female pigs represent an economic and animal welfare issue in swine production. This problem may be associated with the individual characteristics of the piglets at birth, as well as with increased prolificacy of females, which leads to longer farrowing durations and a greater interval between births. During farrowing, uterine contractions can interrupt fetal blood flow by compromising the umbilical cord, subjecting piglets to hypoxia and accumulation of carbon dioxide and lactic acid, which may compromise their vitality and survival capacity. This study aims to evaluate the influence of farrowing kinetics in primiparous sows and the individual characteristics of their piglets at birth on vitality, colostrum intake, and piglet performance during the suckling period. Seventeen commercial-line gilts will be used for this study, housed in individual crates. The females will be transferred on the 110th day to farrowing crates in the maternity unit and subjected to a farrowing induction protocol on the 114th day of gestation. During the farrowing process, the total number of live-born, stillborn, and mummified piglets will be recorded; the time intervals for each piglet's birth until the last piglet is expelled; and the presentation position of the neonates. All piglets born will have their weight, time, and order of birth recorded. Live-born piglets will have their vitality assessed using APGAR score. These same piglets will undergo blood sampling for the evaluation of biochemical and metabolic parameters to estimate the severity of asphyxia experienced during farrowing. Circulatory alterations will be assessed through analysis of umbilical cord integrity (normal; edematous; congested; hemorrhagic). The rectal temperature of the piglets will be measured after the vitality assessment. All fetal attachments will be collected and weighed after the end of farrowing. The weight of the live-born piglets will be recorded again 24 hours after the onset of farrowing to determine their weight gain, which will be used to estimate individual piglet colostrum intake and female colostrum production. The weight of the piglets will continue to be recorded on predetermined days up to the 28th day of life. After 24 hours from the start of farrowing, piglets will be cross-fostered among females to ensure litter sizes are similar. After one week of life, the chosen teat of each piglet will be observed and recorded weekly. General health observations will be made daily, with any pathological changes and use of medications, as well as any deaths and their probable causes, being recorded.