Characteristics of Piglets Born by Two Highly Prolific Sow Hybrids

Area of Science:

• Animal Science
• Reproductive Biology
• Veterinary Medicine

Background:

• High piglet mortality is a significant welfare and economic issue in Danish organic pig production, with nearly one-third of piglets not surviving to weaning.
• Piglet survival is influenced by characteristics like birth weight, rectal temperature, and intrauterine growth restriction (IUGR).
• Differences in breeding goals between sow hybrids (DanBred and Topigs Norsvin) may lead to variations in these critical piglet characteristics.

Purpose of the Study:

• To investigate and compare piglet characteristics between two highly prolific sow hybrids: DanBred and Topigs Norsvin.
• To determine the extent to which piglet characteristics (birth weight, rectal temperature, IUGR) affect piglet mortality in outdoor farrowing systems.

Main Methods:

• Forty-nine sows (22 DanBred, 27 Topigs Norsvin) were monitored over their first two parities in an outdoor farrowing system.
• Piglets were individually marked, weighed, and scored for IUGR on day 1 postpartum (pp).
• Rectal temperature and weight were recorded again on day 3 pp. Principal component analyses were used to explore variable relationships.

Main Results:

• Topigs Norsvin piglets were significantly heavier and had higher rectal temperatures on days 1 and 3 pp compared to DanBred piglets.
• Early piglet death was associated with IUGR, lower rectal temperature, and lower weight on day 1 pp.
• Late mortality was linked to larger litter size and the DanBred hybrid, while Topigs Norsvin was associated with higher rectal temperature, longer crown-to-rump length, and higher weight.

Conclusions:

• Significant differences exist in piglet characteristics between DanBred and Topigs Norsvin hybrids, impacting piglet mortality.
• Piglet weight on day 1 pp and rectal temperature on day 1 pp are critical factors influencing stillbirth and live-born mortality.
• Utilizing sows that produce heavier, smaller litters may be a viable strategy to mitigate piglet mortality in outdoor farrowing systems.