Gilt management for improved sow lifetime productivity

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This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing a report by Drs. Patterson and Foxcroft about gilt management. Previously, we shared the recording of her presentation during the 2018 Leman conference. Below is an update on her work at the University of Alberta.

Key Points

  • Successful replacement gilt management starts at birth
  • A low individual birth weight and a “Low litter birth weight sow phenotype” are key factors determining the efficiency of replacement gilt production
  • Good gilt selection and pre-breeding programs remove early culling for reproductive problems as a factor in sow life time productivity

Gilt are the foundation of good production (Tubbs, 2015) and drive farm success (Ketchem and Rix, 2015).Low individual gilt birth weights have
been linked to increased preͲweaning mortality (Magnabosco et al., 2015), poor growth until finishing, compromised ovarian and uterine development (Deligeorgis et al., 1985), fewer pigs produced over three parities and earlier removal from the herd (Magnabosco et al. 2016). At sow level, a low litter “birth weight phenotype“(BWP) carries all the same risks as a low individual birth weight, but as a “litter” trait. As part of a National Pork Board-funded project to investigate links between litter BWP and sow lifetime productivity (SLP) conducted in collaboration with Holden Farms Inc., litter BWP was determined over at least two successive parities.

Multiplication sows (n = 651) were then classified as having either a low (L, < 1.18 kg, n=63), lowͲmedium (LM,> or = 1.16 to < or = 1.36 kg, n=281), medium-high (MH, > 1.36 and < or =1.6 kg, n=254) or high (H, > 1.6 kg, n=53) average litter BWP. Low BWP sows produced progeny with limited survivability after birth, poor retention during gilt development, and overall had a lower efficiency of replacement gilt production. Although BWP had a significant effect on weight and growth rate at the time of Pre-Selection (170 days), when puberty stimulation commenced at around 182 days of age, BWP did not affect the days to recorded first estrus.

Therefore, the growth performance of even the lighter gilts born did not delay the onset of pubertal estrus. Furthermore, for those low birth
weight pigs that survived and were selected as replacements on the basis of a recorded pubertal estrus event, a low BWP did not affect total pigs
born over four parities, or longevity in the sow herd. In contrast, gilts born in litters with a high BWP had lower retention rates in the sow herd.

Take home messages

Low birth weights affect the efficiency of replacement gilt production because these gilts either die, or are voluntarily non-selected because of relatively poor growth performance: However, if they survive, they have an equal chance of being bred and have better performance in the breeding herd that had high birth weight gilts.

Irrespective of gilt origin, earlier maturing gilts that have a recorded standing heat (HNS) within 30 days of starting boar exposure are the premium “Select” gilt population. They are inseminated earlier, have fewer non-productive days (NPD), are culled less due to reproductive problems, have higher farrowing rates, have more pigs born alive and are culled later (see Patterson and Foxcroft, 2019).

To be reliable and cost-effective, the stimulation program must involve daily direct contact between the gilts and high libido boars: This maximizes the “boar effect” and drives the efficiency in the gilt development unit (GDU). Adequate resources need to be allocated to the GDU (staffing, facilities, focus and time) and daily records of GDU performance should drive key management decisions (e.g. PG600 intervention). Only breeding-eligible gilts with a recorded HNS should be delivered to the sow farm or moved to the pre-breeding area. Breeding gilts at 2nd or 3rd estrus, at a target body weight of 135-150 kg, and after utilizing at least a 14-day pre-breeding “acclimation period” during which gilts are essentially on full feed, are the next crucial steps in optimizing SLP.

Take home message

Individual recording of gilt performance in the GDU is as critical as, and has longer-lasting consequences than, individual recording of breeding sow performance after weaning.

References are available on the original document.

Piglet gut microbiota: a potential determinant for M. hyopneumoniae susceptibility

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing a report by the MycoLab regarding piglet microbiota and its potential influence of M.hyopneumoniae susceptibility.

Key points

  • Early life gut microbiota could be a potential determinant in modulating susceptibility to chronic respiratory diseases such as enzootic pneumonia in pigs.
  • Increased abundance of short‐chain fatty acid producing bacteria in piglet gut was associated with decreased M. hyopneumoniae respiratory lesions.  
  • Understanding the function and composition of a ‘healthy’ pig gut microbiota would aid to successfully implement novel disease control strategies.
Continue reading “Piglet gut microbiota: a potential determinant for M. hyopneumoniae susceptibility”

Risky pigs: Moving weaned pigs during an FMD outbreak – part 1

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Key points

  • Foreign animal diseases like FMD, ASF, and CSF are a threat to the global swine industry.
  • The response to a foreign animal disease usually involves the establishment of disease control areas within which there will be movement restrictions put in place in an attempt to stop disease spread between farms.
  • Allowing movement from a disease control area of pigs with no evidence of infection can be done without spreading disease if science-based risk mitigation measures are put in place.
Continue reading “Risky pigs: Moving weaned pigs during an FMD outbreak – part 1”

Predicting the monthly risk of PRRS in Minnesota counties using past MSHMP surveillance data

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, we are sharing a report from recent PhD graduate Kaushi Kanankege about predicting the monthly risk of PRRS.

Key points

  • High risk of PRRS occurrence was observed in counties where >25% of MSHMP farms were fully or partially air-filtered, have high number of hog farms, and have farms belonged to multiple production systems.
  • PRRS occurrence association with air filters may be due to attempts to mitigate risk in prevalent areas.
  • Further research is required to understand the space-time association of the windborne local spread of the virus and the installation of air filters.
Continue reading “Predicting the monthly risk of PRRS in Minnesota counties using past MSHMP surveillance data”

The Resistome: What is it, and why should I care? Part 2

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Last week, we talked about the resistome – what it is, and what it could mean for livestock production and public policy. If you need a quick reminder, check back to last week’s MSHMP report before continuing.

This week, we continue our list of five emerging trends about the resistome:

3. Growing animals experience dramatic changes in their resistome, even in the absence of antibiotic drugs. This is also true for human babies and children.In fact, the scientific literature is clear on this: the resistome (and also the microbiome!) of rapidly growing livestock animals is dynamic. For the swine world, this means that most of our antibiotic treatments are being given to animals whose resistance (and microbiome) profiles are already in a baseline state of flux. Contrast this to human medicine, where we have the luxury of studying resistance in very mature, stable populations; not so in swine medicine. While that means that our task might be more challenging, I am optimistic that it also presents exciting opportunities. Given that the microbiome (and resistome) of growing animals is already changing dramatically, do we have an opportunity to “nudge” it in one direction or the other? There is some evidence that the microbiomes of adult humans are surprisingly resilient, i.e., they may shift transiently but often return to their “normal” state. This resilience might be a good thing for most of us, but it makes it challenging to change our microbiomes permanently if we need to. Perhaps because growing animals’ microbiomes are not so stable, we can more easily nudge them towards a beneficial state, i.e., with more metabolically- and inflammatory-friendly microbes and fewer resistance genes? We don’t know yet, but it’s an intriguing question.

4. Resistance is even more complex than we realize, and this is a good thing. Given everything I’ve outlined above, it should be no surprise that some of our assumptions about antibiotic resistance are being challenged. This is a good thing, and I’m hopeful that eventually this newfound knowledge will allow us to protect antibiotic efficacy in the long-term. Bacteria will always find a way to resist our treatments, and therefore the antibiotic pipeline must run continually to keep up.If there are ways that we can manipulate bacterial populations to slow down their evolution towards resistance, this prolongs the efficacy of antibiotics that are already on the market. I think that the complex resistome dynamics that we can now leverage are likely to hold some solutions in this regard.

5. Resistome (and microbiome) data is exploding – faster than we can keep up. Given the relative ease with which we can now generate DNA sequence data, we are experience a “data deluge”. While data generation is a necessary step towards knowledge discovery, it is not a sufficient step. We need to make sure that we are taking the laborious and resource-intensive measures needed to turn this data into information, and then finally into applied benefit. This transformation requires a dedicated team of extremely diverse skillsets – and that team includes producers and veterinarians who can help us ask the right questions of the data, and can then help us turn the resulting information into on-farm benefit.

I’m sure this science report is a bit different than what you expected to read, but I hope it was a helpful essay on the resistome and all of its complexities.

If you want to read some of our livestock-related scientific literature that utilizes a resistome approach, I would encourage you to read the following research summaries:

Summary 1

Summary 2

There are also some podcasts and blogs about our work, which can be found here: podcast and blog post.

And finally, you can always see our latest research publications and activities at our website and Twitter accounts: www.thenoyeslab.org and @noelle_noyes

Thanks for reading!