The deep connections between gut health and livestock performance are undeniable. Being able to measure gut health could provide extremely valuable insight to producers, helping them assess their nutritional or management strategies and identify ways to support animals amid health challenges. Yet the gut is an enormously complex ecosystem; arming producers with the ability to interpret it is no small task.
In order to meet this challenge, animal nutrition expert AB Vista has been developing tools and protocols to measure the gut health status of pigs in commercial farms during the post-weaning transition. Today, we hear from AB Vista’s Global Service Manager, Dr Virginie Blanvillain about the biomarkers it is looking at, how they are being assessed, and what kinds of actionable insight can be derived from this exercise.
[Feedinfo] Can you explain AB Vista’s feed intelligence concept, and how analysing gut health biomarkers fits within it?
[Virginie Blanvillain] The feed intelligence concept is about combining our products, expertise and services to help customers achieve their goals. As part of this, we have developed a number of services over the years to support our customers with decision-making. With our NIR service, we have advised our customers on ingredient and feed quality. With the Emissions Reporting Service launched a few years ago, we can help customers identify areas in their production system to reduce carbon emissions in an economical and balanced way.
An efficient and sustainable production system needs to also consider the relationship between health and nutrition. Emphasis has been on gut health because the interaction between the host and the microbiota can drive changes in animal performance, and hence production cost. We know that the microbiome can support homeostasis and animal health. Many different modes of action are still to be uncovered, and it is a complex area. However, by incorporating the analysis of gut health biomarkers into our feed intelligence concept, we can help nutritionists, veterinarians and production managers to evaluate how different feeding or management strategies impact gut health, and eventually robustness and performance. So far, we have built a database for poultry and pigs, and we have gained some interesting insights into piglets in the post-weaning period.
[Feedinfo] Why is the post-weaning phase a particularly critical time for understanding piglet gut health?
[Virginie Blanvillain] The post-weaning phase is an important transition period in the production cycle of finisher pigs, because it is a time when piglets face numerous challenges associated with diet changes, transfer to a new environment and combination of multiple litters. In addition to the various stressors associated with weaning, the removal of prophylactic antibiotic use and the ban of pharmacological zinc levels in piglet feeds in some countries have made diarrhoea a common incidence during the first weeks post-weaning.
Diarrhoea is a symptom of dysbiosis. With the analysis of biomarkers in faecal samples – such as volatile fatty acids (VFA) and inflammation markers – we can provide additional information for decision-makers to identify or test solutions which support gut integrity and the resilience of the herd when facing challenges.
We believe that focusing on the post-weaning phase will also help understand how the suckling phase impacts the transition from a milk-based diet to a fibre-based diet after weaning. With the characterisation of gut health in the post-weaning transition, we also hope that we will be able to build correlations between the health status early on, and the performance of the pigs in the grower-finisher period.
[Feedinfo] Tell me about the sampling and testing protocols developed as part of this concept. What does this look like when applied in a commercial facility?
[Virginie Blanvillain] We have been working with Alimetrics Diagnostics, which has 20 years of experience in the analysis of markers of gut health. We have tested its technology, fine-tuning it for commercial conditions.
The transfer of Alimetrics technologies in commercial settings has been facilitated with the intervention of BioFreeze™. The BioFreeze™ kits consist of individual vials, which contain a buffer solution to interrupt biological reactions after sample collection. Sample stability with the BioFreeze™ kits is a great advantage, and it makes sample shipment very safe and convenient. Samples can also be collected easily by different personnel (even with limited training or experience).
Fresh faeces are collected from piglets between one and five weeks post-weaning, from individuals or from a group of piglets, with limited impact on animal welfare. On the one hand, sampling individual piglets allows us to look at inter-individual differences within a population and study the dynamic response to the different stressors. Pooled samples, on the other hand, provide an average picture of the herd. The decision on sample collection should be discussed together with the customers and adapted to their goals.
[Feedinfo] How are gut health biomarkers selected?
[Virginie Blanvillain] We know the microbiome is still a very complex area, and there is no defined ideal microbiota profile of good gut health. We have identified universal markers which can help characterise the functionality of the microbiome under different circumstances. Our aim is to have the capability to quantify minimum, maximum or optimal levels for each marker.
Our approach is not real-time, and we are not looking at running diagnostics on a herd with a specific challenge in a barn at one point in time. Our approach has been more focused on monitoring gut health over time, to evaluate or validate the impact of changes on gut integrity and animal robustness. To select an adequate set of markers, we must ensure our ability to detect differences and replicate results in other situations.
So far, we have focused on VFA and some key commensal bacteria, which are indicative of fibre and protein fermentation. We also found that, along with the quantification of pathogen load, measuring immunological markers can help understand how the animals respond to the post-weaning transition.
[Feedinfo] What can biomarkers such as fiber fermentation, protein fermentation, or pathogen load tell us about animal performance or resilience? Can you give any examples of practical, tangible insights which can follow on from that insight?
[Virginie Blanvillain] It is now clear that fibre fermentation plays a key role in improving gut health, particularly under antibiotic-free programs. The stimulation of fibre fermentation results in greater production of VFA. We measured the dynamic change in VFA concentration in fresh faeces of nursery pigs. Interestingly, we observed most of the changes occur in the first three weeks post-weaning, during which period faecal VFA concentration may double or triple in a single individual. It was also observed that butyrate is usually the main contributor of that shift, hence reinforcing the importance of stimulating fibre fermentation to support gut integrity.
Innate immune response is a natural mechanism for maintaining homeostasis. We have identified calprotectin as a functional inflammation biomarker in fresh faeces. For example, we have used calprotectin to demonstrate that, following a challenge, the recovery of the piglets was accelerated when providing the right combination of fibre and additives. These results supported the effectiveness of the tested feeding strategy.
Branched-chain fatty acids (BCFA) are known markers of proteolytic fermentation, and negative correlations with insoluble fibre have been demonstrated. We now know that getting undigested fibre down to the colon can help control BCFA production in humans and pigs. The BCFA are good markers because they can only result from the fermentation of branched-chain amino acids. Some pathogenic bacteria are known for their proteolytic activity, including E. coli, and Campylobacter spp. Our database confirmed a positive correlation between BCFA and E. coli. On the contrary, we find a negative correlation between BCFA and Bifidobacteria, with Bifidobacteria positively correlating with VFA and butyrate concentration.
These research activities described above provide valuable insights and open new opportunities in the gut health area. It is a key milestone in our gut health strategy, and we will keep learning and sharing this knowledge and our innovative solutions to support animal robustness and resilience in challenging times.
Published in association with AB Vista