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.”

Best Practices to manage seasonal infertility

Summer is here and for swine producers, this can be the start of seasonal infertility which is characterized by decreased breeding and farrowing performances in swine usually occurring in late-summer and/or early fall. How can it be prevented?

Boyer NHF seasonal infertility 2017.gif

Dr. Perle Boyer from the University of Minnesota compiles in this month’s column for the National Hog Farmer the measures you can take to minimize seasonal effects on reproductive performances.

Seasonal infertility can affect both males and females. We tend to focus on the dam but boars should also be monitored during summer as the consequences of heat stress on semen quality can last up to several weeks in some cases.

Among the 5 tips in the list, keeping the pigs cool during the warmer month is certainly a priority. Remember that an adult neutral temperature is between 64F and 68F. Above that, heat stress can impair the animals’ performances. Additionally, making sure that the sows keep eating both during the lactation and during the days post-weaning has yield positive results for the following pregnancy.

Further advice can be found in the full article on seasonal infertility.

 

 

Metabolites, antibiotimicrobials, and gut microbiome

salmonella.jpg
Salmonella Bacteria, Source: NIAID

In this article published by the National Hog Farmer, nutritionists and microbiome analysts from the University of Minnesota discuss what consequences antimicrobials can have on the gut 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.

The purpose of this research program is to study the effects antimicrobials can have on the bacterial populations present in the gut and how those changes influence the metabolites present in the pig.

What is a metabolite?

Metabolites are usually small molecules and are created by enzymatic reactions happening through the natural life of a cell or organism.

One of the effects of administering tylosin to pigs was the increased growth of bacteria producing short-chain fatty acids in the intestinal flora. The use of this antimicrobial also led to the development of Lactobacillus in the gut.

Relating changes in metabolites to the gut microbiome allows for a more complete understanding and investigation of the impact that antibiotics have in enhancing growth. Without completely understanding the mechanism of increased growth, antibiotic alternatives could be used inappropriately without much added benefit.

Link to the full paper

What does antimicrobial-resistant bacteria really mean?

Antimicrobial resistance is an expression that everyone in swine production has heard at least once but what does it really mean?  How are you as a producer or veterinarian affected?

Villalta NHF antimicrobial resistance 2017.gif

In this column for the National Hog Farmer, Dr. Carles Vilalta explains that beyond the definition of a bacterium that is not affected by an antimicrobial, there are two different approaches to think about resistance:

  • One is determined by the Minimal Inhibitory Concentration or MIC, which records the minimum medicine concentration required to stop the growth of the bacteria.
  • The other focuses on the presence of genes enabling the bacterium to counteract the effect of the antimicrobial.

These genes are usually present in a sub-population of bacteria called mutants. The video below created by Harvard Medical School shows how these mutants can develop, adapt, and survive the highest antimicrobial concentrations. (video length < 2min)

 

 

Ionophore intoxication in swine

In this month column of the National Hog Farmer, Dr. Albert Rovira from the University of Minnesota is reviewing the cases of intoxication due to ionophores, these antibiotics given through the feed to control bacterial and coccidial infections in swine.Clinical signs are non-specific. Indeed, pigs become weak and stop eating but do not have a fever. In more severe cases, neurological signs can be noted. However, histological lesions are striking with a dramatic change of the muscle structure as is shown in Figure 1 below.

ionophore-intoxication

There are three main causes of ionophore intoxication in swine:

  1. Dosage error in the diet: the optimal concentration is very small, between 15 and 30 parts per milliom.
  2. Mixing ionophore and tiamulin: Tiamulin prevents the ionophore from being excreted by the body, leading to toxic blood levels.
  3. Inclusion of ionophores designed for another species. Usually, the levels are incorporated at a concentration higher than the toxic level.

In conclusion although cases of ionophore intoxication are rare in swine, it may become more prevalent starting in 2017, with the approval of the only swine ionophore as a growth promotant.

Link to the full article