As restrictions increase on the use of antibiotics in animals amid concerns about antimicrobial resistance, there is a growing interest in evolved management practices, including the use of non-drug specialty feed ingredients that may help to support the animal’s immune system, optimise their physiology and ensuing performance.

by Sarah Cooper, Business Development Manager, Pichia Yeast, published in International Pig Topics

One of the feed ingredients of interest are yeasts. Yeast cell walls contain various bioactive components such as b-glucans and mannan oligosaccharides, which have been demonstrated to have beneficial impacts across various species. Several studies have shown that dietary b-glucans interact with intestinal cells effecting modulation of the intestinal immune response.

Mannan oligosaccharides have been demonstrated to bind and limit the colonisation of intestinal pathogens with beneficial consequences related to gastrointestinal health and performance.

P. guilliermondii is a novel yeast with unique morphology, structure and distribution of cell wall components, and consequent activity. The function of P. guilliermondii and associated influence on physiological and performance parameters have been assessed across a variety of animal species.

This body of research has focused on looking at the impact that may be associated with P. guilliermondii on the immune system, pathogen load, gastrointestinal health and performance, especially during stress and pathogenic challenges.

It has been well established that stress of various sources, commonplace in sow production, can seriously impact sow reproduction.  Maternal stress and foetal programming is well researched in human health and is an emerging theme in swine research efforts.

Foetal programming refers to acute or chronic stimuli impacting the foetus in utero, which may establish a permanent response within the foetus that impacts its physiologic function later in life. Therefore, the physiological status or wellness of the sow during gestation may influence her reproductive performance and the health of her piglets.

A series of peer-reviewed studies involving P. guilliermondii fed to sows during gestation and lactation have been performed looking at associated impacts on various parameters in sows and their offspring.

These studies demonstrate that supplementing the gestation and lactation diets of sows and gilts with an inactivated P. guilliermondii-based specialty feed ingredient promotes sow reproductive parameters, the performance of the sow’s offspring post-weaning and delivers profit.

Pichia supplementation

Reproductive performance in sows supplemented with P. guilliermondii during gestation and lactation has been assessed in numerous peer- reviewed studies in both research and commercial facilities, in the Unites States (US) and Europe.

Carry-over effects

A recent peer-reviewed study looked at commercial swine production facility in the US where 1,260 pigs were followed during the nursery, grow-finish phases. They were grouped according whether or not their sow has received 0.1% P. guilliermondii during gestation and lactation. Pigs weaned from sows that had received P. guilliermondii supplementation tended to have greater livability during both the nursery and grow-finish phases (Fig. 2) and finished significantly heavier compared to pigs weaned from sows that did not receive P. guilliermondii.

Consistent impacts

In order to more objectively assess the effects seen when P. guilliermondii is added to the gestation and lactation diets of sows, a meta-analysis was performed. The above-mentioned four peer- reviewed studies plus an additional four studies – a total of 1,446 sows – were included in the analysis of reproductive performance at birth until weaning.

The P. guilliermondii supplementation ranged from 0.1% to 0.2% and did not influence the effect of the product on the outcomes. Overall, P. guilliermondii supplementation in the sows was associated with an increased number of piglets born alive per sow (+3.5%, P<0.01; F).

When considering piglet survival before and after cross-foster, this resulted in more piglets weaned per sow (+5.3%, P<0.001; Fig. 5). In the assessment of the post-weaning phase, pigs weaned from sow supplemented with P. guilliermondii during gestation and lactation tended to have greater livability (Fig. 6) and significantly greater average daily gain (+5.7%, P=0.038;).

Pichia, Performance, Profit

The beneficial impact of P. guilliermondii supplementation in sows during gestation and lactation on litter size and weaned pig output has been demonstrated consistently across several studies and assessed through meta-analysis. The modes of action by which P. guilliermondii may impact sow litter size and weaned pig output are yet to be elucidated. It may be the case that P. guilliermondii, through its proposed modes of action, may promote resilience in the sow to overcome stressors, counteracting the negative effects of stress on reproduction, impacting foetal programming and consequent performance of offspring during lactation and post- weaning.

P. guilliermondii is commercially available as an inactivated specialty feed ingredient. Its inclusion in the gestation and lactation diets of sows and consequent impact on litter size and number of pigs weaned may facilitate improved swine production efficiency and profit.

Resilience in pigs has been described as the ability of pigs to cope and recover from stressors and is on the cusp of becoming a new benchmark in pig production.

by Gwendolyn Jones, Product Manager Gut Agility Activators, published in 2020

Studies have shown that pigs within a commercial grow-finish environment only achieve 70% of their growth potential compared to pigs reared in a less challenging and unrestricted research environment. Researchers have highlighted this 30% gap in pig performance as a key area for improvement using both management and genetic selection to reduce the impact of stressors on pigs reaching their genetic potential under commercial conditions. There are indications that improving the ability of pigs to cope with stressors may be a better way of improving pig performance than selecting only for increased growth potential from pig genetics researchers.

Why resilience?

Average daily gain is a function of the pig’s production potential as well as the ability of the animal to cope with stressors and unforeseen challenges. Breeding and management strategies that result in more resilient pigs, will increase the capacity of pigs to reach their genetic potential under commercial conditions and improve production efficiency on farms in a sustainable way. Furthermore, it is expected that resilience research will benefit the health and welfare of pigs and reduce the use of antibiotics or treatments in general on pig farms. An economic value associated with improved resilience in pigs beyond reduction in production losses and health costs is a reduction in labour time and costs, as animals show less problems and become easier to manage.

The response of a pig to stressors in terms of minimizing the impact of a stressor and quickly recovering from it is defined as resilience. So, the capacity of the body to withstand challenges to its stability is considered as resilience.  There are many different types of stressors a pig can potentially encounter throughout its productive lifetime, which again can impact its performance. Quite often the first noticeable impact of stressors will be a reduction in feed intake in pigs. However, there are also reactions on the cellular and gut level of the pig, such as oxidative stress and inflammation in response to stressors, further reducing the available energy for growth, as those type of stress reactions will increase requirements for maintenance energy.

Ultimately the pig’s capacity to adapt efficiently will determine the extent of those stress reactions and the impact they will have on growth performance over time.  A meta-analysis study by Pastorelli et al (2012) across 122 published pig trials, studying the impact of selected stressors found under commercial conditions on reduction in average daily growth rate. The researchers also looked at how much of the reduction in growth rate was due to an increase in maintenance energy and how much was related to a reduction in feed intake.  According to this data some stressors, such as respiratory disease, lipopolysaccharides (LPS) and mycotoxins have a greater impact on feed intake than maintenance energy requirement. This might also be expected from heat stress. Whereas when it came to challenges associated with the gastrointestinal tract, a large part of the reduction in average daily gain was due to an increase in maintenance requirements. Other stressors which were not covered by this study are: human handling, vaccination, dust, ammonia or out of feed and water events, which can all also have an impact on performance of pigs to a greater or lesser extent.

Spotting resilience in pigs

Single time-point measurements have been said to be of limited value because they do not measure responses to and recovery from stressors. Although there are exceptions, such as productive longevity as it is a single measurement of the accumulated consequence of adaptive capacity and resilience. Otherwise repeated measurements over time have been found to be key to determine resilience in animals. This is where new technologies, such as automated monitoring, sensors and computer vision come into their own greatly facilitating the ability of producers to collect data from repeated individual measurements in pigs on farm. It is also making the recording of individual feed intake in group-housed pigs more accessible, which would otherwise be difficult to do on farms.

Recently several research groups have taken different approaches to measuring resilience in pigs, some using production data, some behavioural data and others are currently using artificial intelligence to monitor tail posture in pigs. But what they all have in common is, that they are looking at repeated observations to detect the number of fluctuations or deviations from an expected standard over time. Some suggest that the individual day-to-day variation in feed intake could be utilized to quantify resilience to heat stress, whereby pigs with more day-to-day variation in feed intake would indicate that pigs are less resilient.

Genetic researchers in the US confirmed that fluctuations in feed intake or duration at the feeder over time are indicators for resilience in pigs to a variety of stressors, including disease and can be used as heritable measures of general resilience in pigs. The variance of deviations in daily feed intake and deviations in daily duration at the feeder during the finishing phase were positively genetically correlated to mortality and number of treatments required in pigs. A pig welfare research group from the Netherlands are using the pig’s tail posture and intactness as the main indicator for resilience. The theory behind it being that more resilient pigs are less inclined to start tail biting and this is also related to tail posture – curly versus straight.

Managing for resilience in pigs

Geneticists have certainly started to pave the way to breed more resilient pigs by determining phenotypic parameters that are suitable as resilience indicators. Behavioural research is highlighting the opportunity to improve resilience in pigs through management practices, such as enriched housing. In piglets the location of sow feeders during lactation have been shown to matter in the piglet’s ability to adapt to the weaning process.

Nutritional solutions that help to build the adaptive capacity of the pig to stressors for more energy efficient responses could also play a role in managing resilience. For sure more research is underway to gain a better understanding of how nutrition and other management practices can effectively support pig resilience.

Closing remarks

The resilience approach requires us to make a shift in how we evaluate the impact of breeding and management strategies in pigs. While the proposed resilience indicators are not always easy to measure under commercial conditions using conventional practices, the development of new technologies helping farmers to monitor individual animals for precision livestock farming is certainly speeding up progress required to facilitate this.

This approach also highlights the need for adaptability to future events over optimization and improving efficiency under known conditions for pigs and farms.

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