The effects of mortality on pig feed efficiency

(Editor's note: This is part two of a three-part series on feed efficiency in pigs.)

Feed efficiency refers to the amount of feed consumed by a pig to produce a unit of weight gain, and it can be influenced by multiple factors, including genetics, nutrition, environment and health. A critical metric for pork producers, feed efficiency has a major impact on the profitability of a pig production system.

How does mortality affect feed efficiency?

One of the factors that can significantly affect feed efficiency is mortality. Pig mortality is one of the main challenges the pig industry faces today. It is a complex, multifactorial issue that affects most operations and can greatly affect the overall profitability of an operation. Mortality rates are widely dependent on each individual system but typically range 5–10% within wean-to-finish.

The effects of mortality on pig feed efficiency depend on several factors:

1. The main direct impact is a reduction in the number of pigs marketed, leading to an increased cost of production.

Obviously, when a pig dies before it reaches market weight, the revenue from that animal is completely lost and the cost of producing the pig up to that point cannot be recovered. It is clear, therefore, that mortality events in heavier pigs that were close to marketing have a significantly higher economic impact, as more resources were used and wasted. Additionally, the producer must spend additional funds to properly dispose of the dead animals. The revenue loss and added costs reduce the profitability of the operation.

2. Mortality can also have an indirect effect by affecting the pen’s social structure.

When one or more pigs dies, changes in the social structure of the group can lead to stress and increased aggression among the remaining pigs. This can lead to decreased feed intake, reduced growth rates, and increased susceptibility to disease.

3. Finally, mortality events can alter the performance and feed budgets, and consequently the feed costs, of the remaining pigs.

If a significant number of pigs die, the amount of feed available is now divided by a smaller number of animals. This means that more feed is provided, per pig, for a longer period. This can have both pros and cons. Typically, less-nutrient-dense feeds are provided as pigs get heavier, to account for changes in nutrient requirements and feed intake. Yet when extra feed is available due to mortality, the remaining pigs receive the more nutrient-dense diets for longer. This will typically improve feed efficiency, but feed cost per pig will be increased, which has a direct impact on the economic viability of the operation.

Strategies to tackle pig mortality

Fortunately, some strategies can be used to tackle this issue and promote health in the pork industry:

1. Biosecurity

Improving biosecurity practices is probably the most important aspect of preventing the introduction and spread of diseases in pig herds. These practices include controlled access to barns; cleaning and disinfection protocols; shower-in and shower-out protocols; and adequate quarantine procedures.

2. Vaccination

The implementation of a robust vaccination program that is tailored to the needs of a particular pig herd is also essential. Several options are available to prevent diseases such as porcine reproductive and respiratory syndrome (PRRS), porcine circovirus, and swine influenza. By following appropriate guidelines provided by veterinarians, producers can significantly reduce the mortality associated with preventable diseases.

3. Management

Management practices can have an important impact on pig health. Staff should be trained to conduct regular monitoring of health indicators, such as body condition and fecal quality, to detect early signs of disease. Hygiene practices, ventilation and adequate floor space play important roles in minimizing stress and disease spread. Additionally, it is critical to ensure that all pigs receive adequate nutrition and unlimited access to a clean and easily accessible water supply.

As always, treatment and prevention options are increasing as science advances. Researchers are currently studying the possibilities of genetic selection in producing pigs more resilient to certain diseases. This could be an invaluable tool to reduce mortality rates in the future.

In summary, mortality has profound direct and indirect impacts on feed efficiency and, therefore, on the profitability of any pork production system. Mortality is certainly a complex issue that requires concerted, multidisciplinary efforts, but it must be addressed for a more sustainable and profitable pork industry.

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