Sow Udder Health: How Morphology Impacts Piglet Survival

Sow maternal ability is crucial because genetic selection for traits like feed conversion and growth rate has inadvertently increased piglet mortality around farrowing. Enhancing sow maternal ability, particularly through traits influencing nursing piglets, is essential to improve overall production and welfare. While the specific components of maternal ability weren't detailed beyond udder characteristics, factors like mothering instinct and milk production also play significant roles. Addressing these factors can reduce piglet losses and improve farm efficiency. Note that maternal ability improvements are relevant for other livestock sectors as well.

The traits measured in Meidam sows included teat length, teat diameter (DIA), interteat distance within the same row (SAMER), teat distance from the abdominal midline (AML), udder development score (DEV), the proportion of teats oriented perpendicular to the udder, and the proportion of nonfunctional teats. These measurements directly influence a piglet's ability to effectively nurse and receive colostrum, which is vital for their early survival. For example, adequate teat length and diameter are needed for piglets to latch on, while interteat distance affects competition among piglets. The article did not specifically quantify the impact of each trait on piglet survival but implied that optimizing these traits through breeding can enhance maternal performance and reduce mortality.

The heritability estimates, ranging from 0.10 to 0.56 for udder morphology traits and 0.35 for colostrum IgG concentration, indicate that these traits can be effectively improved through genetic selection. Teat diameter (DIA) showed the highest heritability (0.56), suggesting it would respond well to selection. The proportion of teats oriented perpendicular to the udder had the lowest heritability (0.10), meaning environmental factors might play a larger role in this trait. The moderate heritability of colostrum IgG concentration (0.35) suggests that selecting for higher IgG levels in colostrum is possible, improving piglet immunity. Although the specific selection methods are not mentioned, genomic selection or traditional pedigree-based selection could be used.

Swine breeders can incorporate udder quality traits into their breeding goals, weighting them appropriately with other important traits like growth rate and feed efficiency. This balanced approach ensures that improvements in production traits don't compromise maternal performance. Selecting for traits like optimal teat length, teat diameter (DIA), interteat distance (SAMER), and udder development score (DEV) can enhance a sow's ability to nurse piglets effectively. Additionally, selecting for higher colostrum IgG concentration can improve piglet immunity. The development of a comprehensive udder evaluation score would further aid breeders in identifying superior animals. The economic implications of these breeding strategies could be significant, potentially reducing piglet mortality and increasing the number of piglets weaned per sow.

Further research should focus on developing comprehensive udder evaluation scores that integrate multiple udder traits into a single, easily assessed metric. It is also essential to explore the relationships between specific udder traits and piglet outcomes, such as piglet growth rate, pre-weaning mortality, and overall health, across different farming systems. Additionally, investigating the genetic correlations between udder traits and other economically important traits, such as sow longevity and litter size, is needed to avoid unintended consequences of selection. These research efforts should lead to more targeted breeding strategies and improved management practices, ultimately enhancing piglet survival and farm profitability. More information is needed as to what defines the different farming systems.