Researchers tested whether different types of fat in chicken feed could help prevent Salmonella bacteria from spreading inside chickens. They fed 1,152 baby chickens four different diets with various fat sources and then exposed them to Salmonella. They checked for the bacteria in chicken litter, organs, and meat over six weeks. The study found that all four fat types worked similarly—the bacteria naturally cleared from chicken organs over time, but it survived longer in the litter on the ground. This suggests that the type of fat in feed doesn’t significantly affect how quickly chickens clear Salmonella from their bodies, though bacteria in litter could still contaminate meat during processing.

The Quick Take

  • What they studied: Whether different types of fat added to chicken feed could help chickens fight off Salmonella bacteria better than others
  • Who participated: 1,152 day-old baby chickens divided into four groups of 48 pens each, all given the same Salmonella bacteria on day 7 of life
  • Key finding: All four fat types performed equally well—none was better at helping chickens clear Salmonella from their bodies. By day 42, the bacteria had mostly disappeared from chicken organs in all groups, but it stuck around in the litter
  • What it means for you: If you eat chicken, the type of fat in chicken feed doesn’t appear to affect your food safety risk from Salmonella in the meat itself. However, keeping chicken litter clean remains important since bacteria can survive there and contaminate meat during processing

The Research Details

Scientists divided 1,152 baby chickens into four equal groups, with each group eating feed containing a different type of fat: soybean oil, poultry fat, soap stock (a byproduct from oil processing), or palm oil. On day 7, all chickens were given a mixture of two common Salmonella bacteria types to simulate a real infection. The researchers then tested for bacteria in chicken litter (using special boot swabs), internal organs (spleen, liver, and intestines), and meat surfaces at different time points over six weeks. They used standard laboratory methods to count and identify the bacteria, then compared results between groups using statistical analysis.

This research design is important because it mimics real-world conditions where chickens might get infected with Salmonella. By testing multiple time points, researchers could see how quickly each group cleared the infection. Testing both internal organs and litter helps identify where bacteria survives longest, which is crucial for food safety planning.

This was a controlled experiment with a large sample size (1,152 birds), which makes the results more reliable. The researchers used proper randomization and tested multiple time points, which strengthens confidence in the findings. However, the study was limited to laboratory conditions and may not perfectly reflect what happens on real farms. The results were consistent across treatments, suggesting the findings are fairly robust.

What the Results Show

When researchers checked chickens on day 14 (one week after infection), Salmonella bacteria were found in the livers of 50-83% of chickens across all four fat groups, with no significant differences between groups. By day 42, the bacteria had almost completely disappeared from livers in all groups—only one chicken in the soybean oil group still had it. In the intestines (cecal contents), bacteria were present in 83-92% of chickens on day 14, but by day 42, direct detection methods found no bacteria in any group. However, when using more sensitive testing methods, 25-45% of chickens still showed signs of Salmonella in their intestines by day 42. The key finding was that all four fat sources produced nearly identical results—no fat type was better or worse at helping chickens clear the infection.

When researchers tested chicken meat surfaces after processing (day 43), they found Salmonella on 81-100% of carcasses across all groups. The soybean oil, poultry fat, and soap stock groups all had 100% contamination, while the palm oil group had 81%. This suggests that even though internal organs cleared the bacteria, the meat could still become contaminated during processing, likely from contact with contaminated litter or equipment.

Previous research has suggested that certain dietary components might help chickens fight infections, but this study found that fat source alone doesn’t significantly impact Salmonella clearance. The natural clearing of bacteria from organs over time aligns with what scientists know about how chicken immune systems work. The persistence of bacteria in litter is consistent with other studies showing that Salmonella can survive in poultry environments for extended periods.

This study was conducted in controlled laboratory conditions, which may not perfectly represent what happens on actual farms where multiple factors affect bacteria survival. The researchers only tested two types of Salmonella bacteria, so results might differ with other strains. The study focused on broiler chickens (meat chickens) and may not apply to other chicken types. Additionally, the researchers couldn’t determine exactly why bacteria survived longer in litter—other factors like moisture, temperature, or bedding type might play a role.

The Bottom Line

Based on this research, changing the type of fat in chicken feed is unlikely to significantly reduce Salmonella risk in poultry products. Instead, focus on other proven food safety measures: proper cooking of chicken to safe temperatures (165°F), good kitchen hygiene, and preventing cross-contamination. For the poultry industry, maintaining clean litter and processing environments appears more important than fat source selection. Confidence level: Moderate—this is one study in controlled conditions.

Poultry producers and food safety professionals should note that fat source selection won’t solve Salmonella problems alone. Consumers should understand that this doesn’t change food safety recommendations for handling chicken. People with weakened immune systems, young children, and elderly individuals should continue following standard food safety practices regardless of how the chicken was fed.

In this study, chickens naturally cleared most internal Salmonella within 4-6 weeks. However, this timeline applies to controlled conditions and may vary on real farms. Consumers won’t notice any difference in food safety based on chicken feed fat type—proper cooking remains the most reliable protection.

Want to Apply This Research?

  • Track daily chicken consumption and cooking methods (temperature reached, cooking time) to correlate with any gastrointestinal symptoms. Users can log: date, chicken type, cooking method, internal temperature reached, and any symptoms in following 48 hours.
  • Use the app to set reminders for proper chicken handling: thaw in refrigerator (not counter), cook to 165°F internal temperature, and wash hands/surfaces after handling raw chicken. Create a checklist for food safety steps before cooking.
  • Track food safety practices weekly and correlate with any illness symptoms. Set monthly reminders to review proper chicken storage temperatures and cooking guidelines. Monitor for any gastrointestinal symptoms and their timing relative to chicken consumption to identify patterns.

This research examines how different chicken feed fats affect Salmonella in poultry production and does not change food safety recommendations for consumers. Proper cooking of chicken to 165°F internal temperature remains the most effective way to prevent Salmonella infection. This study was conducted in controlled laboratory conditions and may not reflect real-world farm conditions. Always follow USDA food safety guidelines for handling and cooking poultry. If you experience symptoms of food poisoning, consult a healthcare provider. This information is for educational purposes and should not replace professional medical or food safety advice.