NHF: Enteroids as in vitro model for ileitis

Our new contribution to the National Hog Farmer was written by Dr. Talita Resende, a PhD candidate at the University of Minnesota under the supervision of Dr. Connie Gebhart. Talita’s research focuses on swine ileitis and models to better understand its pathogen: Lawsonia intracellularis. Today, she explains how she uses enteroids.

The small intestine is largely responsible for nutrient digestion and absorption in the gastrointestinal tracts of pigs, but it is also an ideal colonization site for enteric pathogens. The investigation of the interactions between host and enteric pathogens can be conducted in vivo, or in vitro, with advantages and disadvantages for each of the models. Enteroids, small intestinal organoids, represent a new in vitro approach to investigate those interactions. But why are enteroids a new approach and what are their advantages in comparison to the current models?

Enteroids are three-dimensional structures originated from embryonic stem cells, induced pluripotent cells or adult stem cells from intestinal tissue. Therefore, they present all the cell types and a structural organization similar to crypts and villi found in the small intestine. This complex structure offers ideal conditions to investigate the mechanisms by which Lawsonia intracellularis causes proliferative enteropathy – also known as ileitis – in pigs.

Swine microbiome studies: Why, how and where are we going?

There is no Science Page this week; we will return to our normal schedule next week. In the meantime,  you may read our previous publications on our website.

Today, we will be talking about swine microbiome studies. Dr. Andres Gomez, expert in microbiome, who joined the University as part of the new AGREETT positions wrote an article for the National Hog Farmer about research on swine microbiome.

What does microbiome mean?

Microbiome refers to all of the microbes present in an area. For example, gut microbiome is the entire population of microorganisms (most of the time bacteria) present in the intestinal tract.

Microbes have been traditionally viewed through a lens of distrust, as pathogens affecting health. However, molecular and computational breakthroughs to study microbial diversity and function by sorting DNA sequences have presented a novel concept of an animal “flora” that acts as a friend as opposed to a foe.

Characterizing the microbiome to improve nutrition

Characterizing the specific microbes that increase or decrease in abundance upon pharmaceutical or dietary interventions is critical to determine precise dose-response relationships and to potentially reduce feed costs while achieving desired improvements in pig health and productivity.

Defining “healthy” microbiomes to identify poor-doing pigs

Regular “microbiome snapshots” along the most critical stages of pig growth (e.g., pre- and post-weaning), can be used to predict health and potential pathogen threats for disease by early identification of bacteria in slow-growing pigs or those that are at most risk of infection. This would allow producers to make early decisions on therapeutic or dietary interventions to enhance performance and health.

swine gut microbiome
 1) nutrients and feed additives modulate gut microbiomes to impact health and performance, 2) microbiomes across the pig anatomy are accurate biomarkers of stress such as diseases, early weaning, and heat, and 3) microbiomes in manure can be modulated to mitigate harmful gases.

Enhancing the protective microbiome

The microbiome in the gut or respiratory tract is a protective layer against infectious diseases. Thus, with microbiome research, we can determine how novel feed additives and management interventions work, by either enhancing the abundance of microbes that promote health and/or displacing those that cause disease.

Microbiome beyond pork production

For instance, specialized bacteria and fungi can degrade otherwise underutilized natural resources to maximize pig productivity, while decreasing the environmental footprint. Additionally, specialized microbial communities can also mitigate the production of dangerous gases  produced in manure pits.

NHF: Coping with shortage of vitamins A and E in swine diets

This month, the swine nutritionist team at the University of Minnesota share in the National Hog Farmer, how to cope with the shortage of vitamins A and E in swine diets.

Usually, vitamins A and E are added to swine diets at up to 4 times the recommendation made by the National Research council. This is due in part to the variability of requirements in swine. However, a system-wide approach could help the industry to cope with the increase in price and the limited supply.

A wide range of alternatives are proposed to make up for the shortage:

  • Rely on body reserves
  • Add ingredients with high levels of vitamins
  • Remove vitamins A and E from finishing diets 35 days before harvest (it has no effect on their performances)
  • Minimize storage time to avoid degradation
  • Avoid low-quality oils to increase vitamin E absorption by the liver
  • Polyphenols and carotinoids can be used as alternatives
  • Strategically use injectable form

In addition to those strategies, farm personnel needs to be vigilant and look for signs of deficiency like impaired reproductive performances and Mulberry Heart Disease.

Alternatives to vitamin A and E in swine diets.jpg

NHF: Processing fluids are effective for PRRSV diagnostics

This month in the National Hog Farmer, Drs. Carles Vilalta, Juan Sanhueza, and Montse Torremorell share a project instigated by the late Dr. Bob Morrison regarding the use of processing fluids to make a PRRSV diagnosis.

The improvement of sampling and diagnostics techniques has made sampling on the farm an easier task with the use of pooled serums or oral fluids samples for example.

One of the ways to get cheaper, more sensitive and quicker techniques would be to use routine chores, such as piglet processing, since castration and tail docking are part of the regular procedures in sow farms.

The goal of this study was to evaluate the accuracy of the processing fluids (the liquid accumulated at the bottom of the pail when farmers collect tails and testicles during routine procedures) by real-time polymerase chain reaction to assess PRRSV status in a sow herd.

The key points from the studies were:

 

Flu control: it’s all about the piglet

Our latest collaboration with the National Hog Farmer was written by Drs. Montse Torremorell and Marie Culhane from the University of Minnesota.

Flu never seems to go away in some herds and that is because there are groups of pigs, or subpopulations, that are able to maintain and spread the flu virus.

One of the most important subpopulations that have been identified as sources of virus on a farm is the piglets. Piglets may be infected, but may not show any signs of disease, and as a result, are silent spreaders of flu. Then, at weaning, a small, but significant, percentage of the piglets can be subclinically infected with flu, meaning they appear healthy but are shedding flu at the nursery or wean-to-finish site.

This causes a challenge for producers because even though piglets are born free of flu, they tend to be contaminated by the dam during their second week of like. The peak of flu-positive piglets occurs at weaning when piglets are moved to a nursery where they may be put in contact with naive piglets from another source and therefore become a major source of infection.

We need to understand how piglets become infected in the farrowing room in order to prevent it. Sow vaccination is a tool commonly used to protect piglets via the transmission of antibodies through the colostrum or maternal immunity. It has been shown to decrease the prevalence of flu-positive piglets at weaning but is insufficient to constantly wean negative animals.

“At the University of Minnesota, we have been measuring the impact of piglets on the spread of flu for years. We found, in a study by Allerson of 52 swine breeding herds in the United States, 23 herds (44%) tested IAV RT-PCR positive at least once during a six-month study period. Groups of piglets from those herds also tested positive for flu at weaning about 25% (75 of 305) of the time.

Along those same lines, Chamba and partnering sow farms reported that out of the 34 farms studied for more than five years, all sow farms tested positive for flu at one time or another and the level of flu infection in the groups of weaned pigs ranged from 7% to 57%. More importantly, in this study, approximately 28% (427 of 1,523) of groups of pigs tested positive at weaning. […]

Ultimately, the successful control of on-going flu infections in growing pigs will depend on the sow farm’s ability to wean a negative pig […]”

Click to read the entire article on the National Hog Farmer website.

NHF: Here’s how co-opetition fits in thriving pork industry

Our latest collaboration with the National Hog Farmer develops the concept of co-opetition and how it fits in the pork industry. Dr John Deen, professor at the University of Minnesota explains what co-opetition with the following:

“With co-opetition, the argument is that the best businessperson is one that does not only excel at production but also works cooperatively with competitors to address common opportunities.”

NHF Deen coopetition swine industry

The article develops two examples for which co-opetion can be useful, one of them being infectious diseases. The Morrison’s Swine Health Monitoring Project is a clear example of a successful initiative in this regard, with competing production systems voluntarily sharing information on their farms’ health status.

More importantly, co-opetition is happening in a variety of productions. Dr. Rebecca Liu from Lancaster University compared cooperation and competition with co-opetition, and how it helped other industries to thrive during her keynote presentation the 2017 Allen D. Leman swine conference. To listen to Dr. Liu’s talk, click on the image below.

Liu Coopetition keynote 2017 Leman.gif

 

Senecavirus A is still with us!

We are continuing our series on Senecavirus A this week with the latest paper written in our rubric for the National Hog Farmer.

Senecavirus is still with us NHF sept 17

More than 230 Senecavirus outbreaks have been confirmed after July 2015 in the United States and this is why it is important:

“The clinical signs in pigs infected with vesicular disease caused by SVA are variable and can range from no outward signs, to nonspecific signs such as decreased appetite or fever, or pigs may develop vesicles, or blisters, on the skin or in the mouth.[..]

While SVA continues to plague U.S. and global pork producers, it is important to be reminded of and understand some basic characteristics and behavior of this virus. SVA causes vesicular lesions affecting the skin, mouth and feet of pigs of all ages and has been associated with increased neonatal mortality which may be accompanied by neonatal diarrhea. If vesicular disease is present, your state animal health official must be notified in order to rule out other foreign animal diseases, such as FMD. The virus can be detected in multiple sample types but there is variability in the amount of time for which each sample type can be used for detection. Finally, SVA is extremely stable and contaminated facilities, transport vehicles and fomites are concerns for possible virus transmission but several disinfectants have been shown to be effective at neutralizing the virus.”