Doctoral researcher Kaitlyn Sommer, a member of the local workgroup and the study’s lead author. To get there, she studied the effects of two different feeding strategies on the growth rate of infant pigs. Their experiment involved 85 piglets fed ad libitum, meaning the animals were given continuous access to food. They pitted this free-feeding approach against a highly controlled feeding regimen that was strictly tailored to an individual pig’s body weight. We know that the entire study lasted just 15 days. Its aim was to link agricultural research with biomedical innovation.
These piglets were weaned at two days of age and individually raised on a complete milk replacer. One group ate as much milk as they wanted, while the other’s consumption was carefully controlled to match the amounts they might get from sucking on a sow. This focused feeding was designed to give a better understanding into the relationships between feeding behaviors and growth and development of young pigs.
Study Design and Methodology
Sommer’s experiment included 85 piglets, who were randomly assigned to either the treatment or control group for the experimental phase. One of these groups had ad libitum access to milk, permitting them to drink it whenever they wanted. By comparison, the second group of dogs was given precise doses calculated according to their body weight.
The measured doses aimed to mimic the frequency and quantity of milk that a piglet would receive from its mother. Piglets in the ad libitum group consumed more milk, total. This doesn’t mean they did it more often, though. Piglets given the regulated regimen had less volume per meal, but they ate more frequent meals during the day.
The study focused on a few important metrics. This involved measuring changes in the pigs’ body weight, behavioral observation, and monitoring insulin levels in the pigs’ blood. Insulin is a key hormonal regulator in directing amino acids that are building blocks for protein growth in piglets.
“Insulin is a big part of directing amino acids, which are the building blocks of protein,” – Ryan Dilger
At the end of the experiment, researchers observed piglets in the ad libitum group had higher total weight gain. To their surprise, they did not observe significant differences in soft tissue composition between the two feeding styles by the end of the study.
Behavioral Observations
Through behavioral analysis, behavioral changes were measured and observed providing fascinating findings into the piglets’ interactions with their feeding environments. Piglets that adhered to the suggested feeding protocol spent significantly more time in front of the milk bowl. They engaged in greater anticipatory feeding behaviors than the freely-fed controls.
Sommer noted that piglets formed bonds with enrichment objects they were given, including toys and towels. She shared about their powerful emotions when these things were taken away to be cleaned on a temporary basis.
“This suggests that the extra time artificially-reared pigs spend near the feeding bowl, and display behaviors like rooting or nosing, might be driven by their natural instinct to nose and suckle at the sow’s teat—an action known to encourage milk production,” – Sommer
This attachment highlights the positive effect of environmental enrichment on piglet welfare and development.
“They’d snuggle up with them, and get upset when we took them out for cleaning,” – Sommer
On the whole, these findings of the study have important implications for new livestock management practices. Sommer noted that learning how to better manage pigs in early life will help promote their development and ultimately productivity.
Implications for Agricultural Practices
Co-researcher Ryan Dilger thought it was exciting that the insights gained from this study help address larger questions related to agriculture and biomedicine.
“But, every piece brings us closer to understanding how management practices early in life can help piglets thrive, and get them started in the right direction,” – Sommer
This study has revealed how growth rates differ, depending on chosen feeding methods. The general body composition remains the same throughout. The Institute for Transportation & Development Policy continues to conduct research in this emerging area. It is sure to result in model practices that advance raising healthy animals and increasing animal welfare.
“Every study opens the door to new questions. What really stood out in this work is just how much the way we feed pigs can influence everything else we’re trying to measure,” – Dilger
The results of this study suggest that while growth rates may differ based on feeding methods, overall body composition remains consistent. As research continues in this area, it is likely to inform best practices for raising healthy livestock while also addressing animal welfare concerns.