In the pork industry chain, the productive life of sows is undoubtedly a core indicator closely linked to economic benefits, and its length is deeply rooted in the selection of genetics and breeding systems. Studies have shown that genes play an important role in shaping sows' ageing patterns, weight regulation, and backfat ratio at first puberty, all of which are intrinsically linked to the sow's productive lifespan. For example, it has been found that specific genes have a significant impact on the sow's reach of mature age, weight standards, and fat reserves at the time of first breeding.
Cross-breeding, as an important means, has a substantial impact on the productive life of sows. Statistics show that with the right mix of crosses, hybrid sows generally produce more offspring when culled and are less risky than purebred sows in terms of early culling. A vivid example is that crossbred sows with 1/4 Meishan pigs have an average productive life of 778 days, significantly more than 1/8 or 1/4 Duroc bloodlines, which allows them to produce more litters per head on average when they are culled, and the overall number of piglets surviving is correspondingly higher.
Although the heritability of sows is estimated to be between 0.05 and 0.25, indicating that genetic selection is feasible to improve this trait, for more complex traits such as vitality and reproductive ability, the process of improvement by genetic selection alone will be slow. At this point, the concept of "retention" was introduced to describe the ability of a sow to reproduce again after giving birth to a litter, a parameter that helps us to better understand the longevity of a sow.
In addition to genetic direct influences, other production characteristics that are closely related to economic performance, such as growth and development speed, backfat thickness and hoof and leg robustness, may also indirectly affect the life span of pigs. For example, there is a positive correlation between longer productive life and higher litter size in one breed, but this relationship may be negative in another. In reality, the health of the hooves and legs is particularly critical, as it is the second most important factor in determining whether a sow retires early, especially for young sows with 1 to 3 parities, and whether the hooves and legs are strong or not is critical to whether they can successfully enter the next round of reproduction.
With the advancement of science and technology, molecular biology research has opened up new ways to optimize the productive life of sows. Studies have revealed a number of genes related to the longevity and survival of sows, such as CPT1A, CCR7, etc., which are like notes in the music of life, and through their identification and intervention, it is possible to adjust and optimize the viability and reproductive performance of sows.
In summary, through the precise selection of sow breeds with good genetic quality, the scientific construction of cross-breeding programs, and the timely application of advanced molecular biotechnology, we are expected to gradually improve the productive life of sows, so as to obtain higher efficiency and output in commercial production practice. At the same time, we need to be aware that the genetic characteristics of sows interact with environmental conditions, and different breeding environments may affect the emergence of sows' genetic characteristics, so environmental factors should be fully considered in practical operations to ensure that sows can show the best production potential in all environments.