By Connie Groop
Precision farming depends on precise placement of nutrients for growing seeds, but similar principles are also being applied to animal production at South Dakota State by investigating the precise feeding requirements of sows.
South Dakota Agricultural Experiment Station researcher Assistant Professor Crystal Levesque of the SDSU Department of Animal Science is in the second year of a $600,000 study entitled, “Evaluation of the dietary requirements of pregnant sows.” This research is funded through the New Innovator in Feed, Agriculture and Research award from the Foundation for Food and Agriculture Research.
“The study is progressing well; we’ve finished three research trials,” she said. “We will meet with those who have contributed and matched dollars for the project. We’ll decide the next steps in generating data on the amino acid requirements needed for sows in gestation.” The research is also supported by ADM Animal Nutrition, Evonik Nutrition & Care GmbH and Ajinomoto.
Under the bigger umbrella, Levesque focuses on precision livestock feeding, “We can feed protein and provide energy. We want to ensure all animals are getting the right amounts of amino acids and proteins at the right time to meet their needs with minimal excess.”
When feeding sows in a group, more aggressive animals will get more feed and smaller ones may get less. Those getting more end up larger or over-conditioned, which is not desired.
Equipment at the new SDSU Swine Education and Research Facility is helping Levesque find answers to her research questions. “One set of tools we have are electronic sow feeders,” Levesque said. “The feeders have the capacity to blend different diets and provide defined amounts of feed to each sow, minimizing competition between animals. This potential for phase feeding manages nutrients for all sows in a group. This is a real advantage from the cost perspective and environmentally. Wasted nutrients end up going into the (manure) pit. We capture benefits on all sides.”
At each stage of life, animals have different nutritional requirements to develop different tissues. Market hogs need to build muscle. Piglets need to grow bone structure. Gestating sows are complex as there is a need to keep the sow’s body in condition while building fetal tissue and mammary tissue. Each requires a unique proportion of amino acids.
Levesque’s study looks at the amino acids needed at different stages of pregnancy and the efficiency of tissue development. Models assume the needs stay the same. But Levesque said it depends on the gestational stage and the efficiency of nutrients being used in early and late gestation.
“If the assumption is incorrect, then this influences the accuracy of the prediction,” she said. “We are trying to add information to the models to become even more accurate in providing precision nutrition for each animal.
Besides changes in gestation, often sows having their first litter are not yet at full body size. They are trying to grow fetal tissue while their body demands nutrition. A gilt is bred when she reaches 210 days of age and 300 pounds, depending on her genetic make-up. However, her body will often not reach full maturity until she has produced three litters.
“The hierarchy of nutrient demand shifts during late gestation,” Levesque explained. “The developing fetuses become the primary target for dietary nutrients and the sow takes what’s left over.”
How then do the nutritional needs change for those sows that have had two or three litters? That's one of the questions that Levesque seeks to answer. An additional consideration is how nutritional needs vary from a sow that has a litter of 10 piglets versus 18 piglets.
“We expect that the parameters change. If we don’t match the sow’s diet with her nutrient requirements, she will compensate by robbing from her own body stores to take care of the fetuses,” Levesque said. “What if we are not quite meeting the nutrition needed for her and the piglets and what if that happens repeatedly? Does she have lesser quality piglets in the future? Those are the questions we’re pecking away at in small pieces. Overall, we want to determine the feed needed for optimal sow performance and to produce high-quality piglets.”