Determining the quality of palatability enhancers often requires verification through animal trials, and during these trials, it’s crucial to follow the experimental procedures meticulously. The trial designs include animal preference tests and growth performance tests. Preference tests serve as the primary method for evaluating the effectiveness of flavoring agents in attracting animals to consume feed.
Preference tests involve placing two or more diets in the experimental pens, allowing pigs to freely choose among them. The animals complete the test under fully ad libitum feeding conditions, and on the following day… 200g The leftover materials mentioned above. In actual production, since the experimental pigs used primarily for flavoring agents are mostly newly weaned piglets—whose gastrointestinal systems and other physiological functions are still developing—they need time to adapt from nursing milk to a complete feed. Introducing free access to feed immediately at this stage could lead to diarrhea due to the sudden increase in feed intake. Therefore, during this critical period, it’s advisable to adopt a strategy of feeding smaller, more frequent meals with increased feeding frequency. 3 During the pre-feeding period, if diarrhea is observed, it should be promptly recorded and treated. Testers are required to carefully monitor the feed intake at each feeder and check for any signs of feed spillage. If spillage occurs, it must be addressed immediately. Additionally, all test feeders should be identical in shape and size to ensure uniformity, preventing variations that could influence the pigs' feeding behavior. To avoid bias caused by the pigs' preference for specific feeders or orientations, the placement of the test feeders should be rotated daily. This practice ensures that the experimental results remain accurate and unbiased. 8 When dispensing the diet, ensure that all diets are distributed simultaneously. Whenever possible, add each type of diet at the same time as well. Trials have shown that animals exhibit a clear preference for the diet introduced first. For collecting daily leftover feed, choose an electronic scale with the highest possible precision—ideally accurate to the gram. After gathering the leftovers, thoroughly clean any residual odors remaining in the feeding trough, ensuring that the trough is spotless and tidy before resuming the daily feeding process.
The growth performance trial typically lasts one month, with pigs weighed every two weeks. During weighing, efforts should be made to minimize stress on the animals. Use a dedicated pig scale—drive the pigs into the weighing crate and, once the display stabilizes, carefully record their exact weight.
Additionally, daily record each group’s feed intake, ensuring that leftover feed is collected even if the same amount of feed is provided daily. After all, daily feed consumption patterns can reveal important insights into the pigs’ eating habits over time.
Don’t forget to document the pigs’ daily health status, as well as environmental factors like temperature and humidity, and any vaccination details.
Finally, any leftover feed from the trial must not be reused, as its aroma and nutritional value may have already diminished after being placed in the feeding trough. For the trial, select healthy pigs that are similar in terms of body weight, age, and gender—and ensure there are at least 4 One or more repeated trials are required. In summary, there are numerous factors influencing animal-free-choice method experiments; even minor oversights in detail can lead to experimental results that differ dramatically from the true data, potentially resulting in incorrect conclusions. Therefore, when conducting animal experiments, efforts should be made to minimize experimental errors. (Text/DDC Wanrui)
