FEEDING pigs more fiber may lead to less aggression and improved gut health while maintaining performance. However, fiber type and feeding level are important factors influencing these effects.
According to Wageningen University & Research researcher Carol Souza da Silva, "Fiber gives restricted-fed pigs more satiety, whereas ad libitum-fed growing pigs compensate for the lower energy in fibrous diets by increasing intake."
Souza da Silva tested different types of fiber in her research but found that feeding fermentable fibers — "such as cassava roots or raw potatoes" — was best for pigs.
The aim of her research was to determine how and which types of fibers influence satiety to prevent pigs from becoming hungry between meals, thereby improving their welfare.
In her research, she noticed that pigs fed resistant starch maintained a feeling of fullness for more than seven hours after their meal.
"The pigs were less hungry, which was also reflected in their behavior. Moreover, resistant starch was found to change gene expression patterns and microbiotica composition in the hind gut, reflecting improved gut health and stabilized glucose levels," Souza da Silva said.
Feeding sows more fiber prevents them from feeling hungry, which can reduce behavioral problems. More fiber in the ration is also good for finishing pigs, according to the researcher.
"Their energy system can, to a large extent, adapt to this reduced-energy ration. They compensate for this by increasing their intake; consequently, growth is then similar to fiber-free rations. In the future, our research will focus on the body composition after slaughter, which is influenced by fibrous diets," she said.
During her research, Souza da Silva collaborated with human nutrition researchers who have "similar questions about satiating effects of fiber" and its role in preventing obesity. "The digestive physiology of pigs and humans is very similar," she added.
Bioactive ingredients from industrial hemp will be used in new research to optimize diets for sows and piglets, thus reducing postweaning diarrhea, the use of antibiotics and piglet mortality.
Researchers with Aarhus University in Denmark will be testing a new strategy in an effort to reduce mortality and enhance animal welfare.
It is the industrial variety of hemp that scientists and a number of industrial partners are putting their faith into with the aid of a grant from the Green Development & Demonstration Program under Denmark's Ministry of Food, Agriculture & Fisheries.
Hemp contains protein, fiber and fatty acids of a very high nutritional value plus some potentially immuno-modulating substances that present a hitherto untapped bioactive resource for pigs, the announcement said.
"In the project, we will focus on the potential of using protein and oil from industrial hemp as a special feed and feed supplement for piglets and sows. The cold-pressed therapeutic hemp seed oil and protein may help solve the production challenges of postweaning scours and early mortality due to their unique ingredients," explained Charlotte Lauridsen, project leader and section manager at the Aarhus department of animal science.
The motivation for the project came about due to the positive experience on a pig farm where a hemp oil product was added to the diets of piglets and nursery pigs. This led to a marked improvement in piglet survival that the project participants hope to replicate.
Before the effect of the hemp products can be tested in the project, processes need to be developed to remove tetrahydrocannabinol — the psychoactive substance that is found only in low concentrations in industrial hemp and is, therefore, useless for recreational purposes — so that the hemp can be used for animal feed.
The project will look at the effect of hemp on piglet survival. This will be done by supplementing hemp to the lactation diet for sows, which, via the colostrum, will provide energy and vitamin E to piglets and raise their concentration of immunoglobulin and, thus, their resistance to infections.
The project will also explore the effect of substances in hemp on postweaning diarrhea and the growth potential of piglets, the announcement said.
"Fatty acid composition, protein allocation and the content and composition of fibers are important for intestinal health and immune response in pigs during the critical postweaning period. The hemp plant contains substances with therapeutic properties that are of interest for the control of inflammation of the intestines due to infection," Lauridsen said.
Project participants estimate that the commercial utilization of hemp products can reduce piglet mortality by 1.5 pigs per litter and that the incidence of postweaning diarrhea can likewise be reduced, along with the consumption of antibiotics.
"Escherichia coli is the leading cause of diarrhea in the first few weeks postweaning, and we expect that hemp products can reduce mortality. At the same time, it is estimated that the majority of the antibiotics consumed are used to treat gastrointestinal disorders in pigs, and these disorders are, therefore, the major causes of the use of antibiotics in pig production," Lauridsen said. "Supplementation with hemp products will hopefully result in fewer outbreaks of postweaning diarrhea and will improve the health of the gastrointestinal tract in piglets, which, in turn, will lead to a reduced need for antibiotic treatment."
In addition to the expected effects on mortality, postweaning diarrhea and animal welfare, the project participants believe the cultivation of hemp also offers environmental benefits since it does not require pesticides.
The project started on Jan. 1 and will run until 2017.
Porcine reproductive and respiratory syndrome (PRRS) is the most expensive and invasive disease for pig producers on a global scale. Although it is not occurring on every farm, it is the biggest disease problem in the pig industry, University of Illinois animal sciences researcher James Pettigrew said. E. coli has also been a problem historically and continues to be on an industry-wide basis.
"Either disease can sweep through a farm, so their alleviation would substantially reduce production costs. Even though many management practices have been used in the swine industry, these practices cannot guarantee freedom from disease for pigs," Pettigrew said.
Consumer concerns about bacterial resistance to antibiotics have prompted the swine industry to seek additional methods to protect the health of pigs, including special feed additives. This interest led Pettigrew and his team to explore the potential benefits of selected plant extracts.
The researchers conducted two experiments to test the beneficial effects of adding plant extracts to pig diets to combat PRRS and E. coli. In both experiments, researchers used four diets in weanling pigs, including a control diet and three additional diets that included garlic botanical extracted from garlic, turmeric oleoresin extracted from ginger or capsicum oleoresin extracted from pepper. In both experiments, half of the pigs in each dietary treatment were challenged with either E. coli or PRRS virus, while the other half of the pigs were not challenged.
"We've known for a long time that plant extracts, also called essential oils or botanicals, have certain biological actions," said Yanhong Liu, a doctoral student who led the studies. "For instance, they can act as antioxidants or as antimicrobials. We wanted to test whether we could get a benefit from feeding those products in very low doses to pigs that were challenged with these specific diseases."
E. coli, a bacterium that causes illness of the gut, is marked by diarrhea, decreased appetite, decreased bodyweight and, in some cases, a higher mortality rate. E. coli is especially dangerous postweaning as pigs adapt to new feed and new environments, Pettigrew said.
The pigs in the study challenged with E. coli that had been fed any of the three plant extracts had a lower frequency of diarrhea (20%) than the pigs fed the control diet (40%). The pigs fed plant extracts were more efficient (40%) in feed use than the pigs fed the control diet in the E. coli-challenged group, and challenged pigs fed plant extracts had sounder gut morphology compared with the challenged pigs fed the control diet.
Liu noted that even the pigs in the non-challenged group with a low frequency of mild diarrhea benefited from the plant extracts.
"Because there is a relatively high diarrhea rate in postweaning pigs as they are moved from the mom and started on all solid feed, the extracts could also be used to reduce its occurrence," she said.
Common symptoms of PRRS, a viral infection of the lungs, include fever, lethargy, trouble breathing, loss of appetite and decreased growth performance. The disease can also lead to spontaneous abortions and higher preweaning mortality rates in pigs.
After feeding the pigs challenged with the PRRS virus the three plant extracts, the researchers observed that the pigs were more efficient in week 1 (55%) and week 2 (40%) than the pigs fed the control diet. The pigs continued eating and gaining weight, especially those given turmeric, Liu said.
When they checked blood samples from the pigs with the PRRS virus, they found that the pigs fed plant extracts also had a lower blood viral load (13%) and lower concentrations of inflammatory mediators than pigs fed the control diet. These observations also suggest that feeding plant extracts could suppress ongoing inflammation and prevent secondary infections.
The researchers believe the benefits resulted from the effects on the pigs' immune systems because feeding plant extracts reduced the inflammation caused by E. coli and the PRRS virus.
"In production animals, inflammation is costly. Inflammation reduces feed intake, and it diverts nutrients away from growth to the immune system," Pettigrew said. "If we can bring that quickly back down to normal after a challenge, then that helps in production."
Although previous studies have looked at using plant extracts in pig diets, Pettigrew said Liu's study, which looked at the effects of three different extracts on two different diseases, had not been done previously. He added that the low concentration of the extracts used while still producing beneficial results also set this study apart from others.