Gut agility – How do your birds respond to stressors?

It matters how your birds respond to nutritional and environmental stressors. The ability to control the response can make a difference to consistency in bird performance and wellbeing. Understanding how birds respond to stressors can help to find solutions to take control of their response.

Response to stressors at the cellular and gut level

In poultry the gut is highly responsive to stressors from the feed and the environment. High ambient temperatures, flocking density, dietary changes, mycotoxins in feed all challenge the bird and impact performance. The underlying causes to reduced performance are stress reactions at the cellular and gut level, which reduce feed intake and/or increase maintenance energy requirements.

Oxidative stress is one of the most common stress reactions at the cellular level in the animal. It is characterized by excess production of free radicals (ROS), which exceeds the ability of the bird’s antioxidant defence system to neutralise them. This is often associated with an increase in inflammatory responses and reduced gut integrity further down the line.

Building resilience to environmental and nutritional stressors in poultry

Environmental and nutritional challenges are a given for birds under commercial conditions. What matters to performance and wellbeing is how the birds respond and this is determined by their adaptive capacity and resilience.

However, continued selection for greater performance in the absence of consideration for the ability to cope with stressors has been shown to result in greater susceptibility to stressors. As a result, several research groups around the world are now putting more emphasis on finding ways of improving resilience by genetic selection in poultry. They characterize resilience as the capacity of the animal to return rapidly to its pre-challenge state following short-term exposure to a challenging situation.

Identifying relevant biomarkers in animals capable of maintaining high levels of productivity when exposed to stressors such as high ambient temperatures will help to breed for more resilient animals.

Nutrition to support a more efficient response in your birds

Research into the physiological changes accompanying the exposure to environmental and nutritional stressors is increasing the understanding of the mechanisms that the animal uses to accomplish the necessary functions efficiently. This is also helping to find ways to support a more efficient response by nutritional means to minimize the impact of those stressors on performance.

More recently attention has been paid to the transcription factor NrF2 and scientific data indicate that Nrf2 activation is one of the most important mechanisms to prevent/decrease stress-related detrimental changes at the cellular and gut level.  Nrf2 is a transcription factor that responds to oxidative stress by binding to the antioxidant response element (ARE), which initiates the transcription of antioxidant enzymes, such as superoxide dismutase, glutathione, and catalase.

Research carried out by the University of Athens reported that adding a gut agility activator to the diet of broilers up-regulated gene expression of antioxidative enzymes belonging to the Nrf2/ARE pathway and down regulated NF-kB1 expression. This coincided with increased levels of total antioxidant capacity in the gut and liver.

The results suggest that adding a gut agility activator to poultry diets, could form part of feeding strategies to support the adaptive capacity of birds to take greater control of the impact of potential environmental and nutritional challenges the bird may face, enabling birds to attain their performance potential.

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Anco in top 5 startups in animal nutrition

Anco was named as one of the top 5 startups in Animal Nutrition, among 1457 globally analyzed startups.

Anco discovered by StartUs Insights

The innovation intelligence company StartUs Insights analyzed 1457 startups and scaleups globally to compose a global startup heat map on the animal nutrition sector. The analysis was data-driven using the big data and artificial intelligence powered by the discovery platform developed by StartUs Insights.

Anco was named as one of the 5 food tech startups in animal nutrition that were handpicked by StartUs Insights as a result of their analysis.  The innovation that Anco contributed to the global animal nutrition industry is the gut agility activator product line Anco FIT.

Anco Animal Nutrition Competence is an Austrian startup and was founded in late 2015. The company went operational in 2016 and rapidly expanded its sales in the global animal feed industry. In 2019 the company was awarded the Austrian Born Global Champion prize, which recognized Anco’s success in rapid global expansion.

Today the company is selling Anco FIT gut agility activators in more than 35 countries around the world, helping livestock producers to improve the adaptive capacity and resilience of their farm animals for more competitive and more resilient sustainable livestock production.

 

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Discover 5 top food tech startups providing animal nutrition here

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Animal welfare – why it is a top priority to farmers

When it comes to animal welfare consumers are most concerned about animal health according to recent studies, but so are farmers. The long-term success of farming relies on healthy animals. On National Farmers’day let’s not forget, behind every healthy animal is a strong farmer.

Caring for animals is at the heart of livestock farming

The problem is people often have very different perceptions of what animal welfare means. Studies  have shown that in the members of the public this is influenced by the situation in question, the context of the animal and personal characteristics.

Most farmers choose farming as a career, because they care deeply about animals. On top of that the farm’s economic success depends on healthy animals. For those reasons, farmers in collaboration with their veterinarians and nutritionists take many measures to make sure their animals are happy, comfortable and above all healthy.

Modern farms also employ AI assisted digital tools and sensors that pretty much allow them to monitor their animals 24/7 very closely and individually on top of their daily routine check-ups.

animal welfare . national farmersday 2021

Providing continuous feedback, based on real-time data, this enables the farmer to make better and more timely management decisions to address health needs and minimize health issues for his/her animals in care.

With accurate and real-time data at their fingertips, farmers can also be more selective with supplies and resources and as a result reduce emissions and environmental impact.

What is driving consumer viewpoints and choices?

A 2021 study by the international food and information council on consumer viewpoints and purchasing behaviors regarding animal and plant protein revealed that despite capturing widespread interest, animal welfare and environmental sustainability are the least prioritized purchase drivers.

What is driving purchasing decisions in consumers of protein is firstly taste, then price, followed by type of protein and healthfulness.

When asked about the importance of food labels, top influences for animal protein decisions were “no antibiotics” (23%), “natural” (23%) and “no added hormones” (22%). These labels ranked much higher compared to “free range” (11%) or “cage free” (11%).

In the UK a study carried out by Vigors et al (2021) with a sample of members of the public representative of the UK population indicated that participants considered animal welfare to be most positive when both health issues are minimised and natural behaviours are promoted.

However, animal health had the greatest effect on participants’ judgements, explaining more of the variance in their assessments of animal welfare than any other factor. The researchers concluded that perspectives of animal welfare are more nuanced than previously thought, influenced by the context of the animal, the aspect of welfare in question and personal characteristics.

Relevant articles

Happy or healthy? How members of the public prioritise farm animal health and natural behaviours, 

Plant and Animal Protein Choices: Consumer Viewpoints and Purchasing Behaviors 2021 

Behind every healthy animal is a strong farmer

Take control of how your pigs respond to heat

The impact of high temperatures on pig production will become more important over the next decades. Therefore, it matters how your pigs respond to heat and the ability to control the response can make a difference. What are you doing to take control?

How do grow-finishing pigs respond to rising temperatures?

Due to climate change pigs will become exposed to ambient temperatures above their thermal comfort zone more often and for longer periods. High ambient temperatures strongly affect physiology behaviour and metabolic adaptations that have a negative effect on growth performance of growing pigs. Economic losses for the US pork industry due to heat stress have been estimated at $300 million a year, with $200 million associated with grow-finish production losses.

Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and find it more difficult to pant. The best indicators for assessing heat stress of finishing pigs are: increased respiration rate and water to feed ratio, followed by reduced feed intake, and increased rectal temperature. In heavier pigs, signs of heat stress are noticed at lower temperatures, also pigs with modern genetics are more susceptible to heat stress.

The primary consequence of heat stress is that animals reduce feed intake progressively with increased temperature, which will reduce performance.  A meta-analysis carried out by da Fonseca de Oliveira et al (2018) reported that high ambient temperatures reduced the values of average daily gain (654 vs 596 g/d) and feed intake (2.14 vs 1.88 kg/d) when compared with the thermoneutral group.  Others reported that whereas each degree increase in ambient temperature between 24 and 30 °C would induce a feed intake decrease of 50 g/day in pigs of 60 kg body weight, the corresponding decrease would average 80 g/day in pigs of 90 kg body weight.

However, increased ambient temperatures have also shown to have negative effects on gut function and gut integrity in growing-finishing pigs, which lead to increased levels of endotoxins in blood, as well as altered inflammation profiles. Other research has demonstrated that oxidative stress plays a role in compromising intestinal barrier integrity in heat-stressed pigs.

Building resilience to rising temperatures in pigs

Continued selection for greater performance in the absence of consideration for heat tolerance will result in greater susceptibility to heat stress. Not surprisingly, several research groups across the world are trying to find ways for enhancing the resilience of livestock to climatic variability and climate change. Resilience can arise due to lower sensitivity or better adaptability to a challenge.

Scientists are beginning to discover ways to influence the adaptive capacity of farm animals to mitigate the effects of heat stress and its negative consequences for animal welfare and farm profitability in response to rising temperatures. Identifying relevant biomarkers in animals capable of maintaining high levels of productivity during heat stress will also help to breed for climate resilient animals. The Nrf2-KEAP 1 pathway, appears to be particularly promising, as a regulatory mechanism to explore further at the cellular level, because of its dual influence on the antioxidative and anti-inflammatory response of animals.

Nutritional support to take the sting out of heat

Nutritional interventions supporting the efficiency of adaptive mechanisms represent a practical, adaptable and cost-effective strategy to mitigate the negative effects of heat stress and improve animal productivity.

Gut agility activators are feed supplements that were specifically formulated to enhance the resilience of animals, by supporting cellular defense systems and enabling animals to adapt with more efficient responses to stressors including rising temperatures thus mitigating the impact on performance.

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Impacts on performance of growing-finishing pigs under heat stress conditions: a meta-analysis (2018) 

Diurnal heat stress reduces pig intestinal integrity and increases endotoxin translocation 

 

How do your cows respond to mycotoxins?

Cows are more resilient to the impact of mycotoxins such as DON, because the rumen microflora can degrade DON to a non-toxic form. However, there are certain situations where even cows can become quite vulnerable to the effects of mycotoxins. It is important to know which ones they are and what you can do to have more control over the response in cows.

How do cows respond to the DON mycotoxin?

The first line of defense to DON is the rumen microflora. Rumen microbes effectively transform DON into non-toxic metabolites.

However, the detoxification capacity for DON by rumen bacteria can be compromised in high producing dairy cows, which are fed greater amounts of concentrates and where feed passage rate is high. Both conditions will affect rumen pH and the time available for rumen microbes to degrade DON into non-toxic metabolites.

DON that is not transformed into its non-toxic metabolites will increase the production of reactive oxygen species (ROS) at the cellular level, lead to oxidative stress, which eventually can also increase inflammatory responses in the cow. This again can affect milk quality and milk yields as well as the cows health. It has been demonstrated that dairy cows fed diets contaminated with DON, produce lower milk yields, decreased milk fat and have increased milk somatic cell counts. Furthermore they are also more likely to experience metabolic disorders in the transition period.

Factors that can exacerbate a negative response to DON

Other stressors can exacerbate the impact DON in diets can have on cows, as they will cause the same kind of stress reactions on the cellular level. In combination the effects on milk production and health will then likely be higher. These stressors include:

  • Transition period status
  • High milk yields
  • High concentrate diets
  • High ambient temperatures/ summer heat

Building resilience to mycotoxins in dairy cows

The above learnings highlight, that helping cows to better deal with stressors such as high productivity, transition period, high ambient temperatures and high concentrate diets, will ultimately reduce the vulnerability to the effects from mycotoxins such as DON.

Therefore, feeding for an optimum rumen pH and rumen microflora is the first step to a higher resilience to DON in dairy cows. Good management practices that help cows ease through the transition period and keep them cool during hot summer months, will further reduce the vulnerability of cows to the potential impact of DON on health and performance.

Nutritional support to disarm mycotoxins

Traditionally, feed additives have been developed to attack mycotoxins in the animal’s digestive tract directly to counteract harmful effects from mycotoxins in the animal. However, both mycotoxin binders and mycotoxin deactivators have their limitations. It is well known that adsorption is not an effective strategy for most mycotoxins. Only certain bentonites work well with aflatoxins and some yeast cell wall components have been proven to bind zearalenone, based on specific structural fits. For other types of mycotoxins, particularly DON, binding strategies do not work effectively.

A more cost-effective strategy to counteract mycotoxins focuses on disarming mycotoxins by supporting the animal’s resistance to the harmful effects of mycotoxins. This strategy empowers animals to respond more efficiently to DON by reducing the extent of the stress reactions generally seen in response to them. For example, adding plant extracts to the diet that are known to upregulate adaptive mechanisms for the antioxidative defense of the animal and downregulate inflammatory responses, as well as maintain efficient rumen fermentation can support a more favourable response to nutritional challenges such as mycotoxins.

Relevant articles

Aflatoxins: Did you know that in high yielding dairy cows the carry-over rate into milk is greater?

How to support dairy cows in their defense against DON

Effects of oxidative stress in response to mycotoxins in dairy cows

Egg quality – what to feed to make it last

Egg quality generally deteriorates with hen age and storage time. Novel feeding strategies in laying hens can support extended productivity of high egg quality that persists longer during storage.

Benefits of extended laying cycles

Extending laying cycles to up to 90-100 weeks has financial as well as environmental benefits. This stems from the fact that longer laying cycles reduces the number of breeding birds and feed required for egg production. However, a decline in egg numbers combined with a deterioration in egg quality are the main reasons for replacing flocks at or around 72 weeks of age. The financial and environmental benefits of extended laying cycles call for strategies to increase laying persistence and stability in egg quality. These strategies need to involve the long-term maintenance of the tissues and organs involved in producing eggs.

 Factors affecting egg quality parameters

Typical egg quality parameters are shell strength, albumen height and Haugh units (HU). Generally, it is known that these parameters can be affected by hen age, genetics and nutrition.

Albumen height and HU are important parameters for albumen quality and indicate egg freshness. The Haugh unit is the standard selection measurement for albumen quality. The higher the value of the Haugh unit, the better the quality of eggs. Classification of eggs by HU according to the United States Department of Agriculture (USDA): AA (100 to 72), A (71 to 60), B (59 to 30) and C (below 29).

Studies have shown that Haugh units deteriorate with hen age from an average 89.6 to 68.8 over the laying period. Egg shell strength and albumen height are also known to be lower in older laying hens compared to younger laying hens.

Storage time is an additional factor that can affect several egg quality parameters. It has been shown to have a significant negative effect on albumen height, HU and yolk colour. The effect of storage time on egg quality can be further exacerbated by temperature. Eggs stored refrigerated can maintain quality for a longer period compared to eggs stored at room temperature.

Can we slow down the aging process of ovaries in laying hens?

Ovarian aging is characterized by a gradual decrease in both the quantity and the quality of oocytes and is related to the age of the laying hen. One of the most important factors inducing ovarian aging is oxidative stress. Oxidative stress is caused through the accumulation of reactive oxygen species (ROS) generated during metabolic activity, which can be exacerbated in periods of high productivity or when the bird is challenged by stressors, such as heat, mycotoxins and flocking density.

The birds antioxidative capacity relies on a complex antioxidant system, which makes use of biological antioxidants and enzymes. However, the antioxidative capacity decreases during the aging process. Nuclear factor erythroid 2-related factor 2 (NrF2) is well established as a critical transcription factor that regulates antioxidant genes and is responsible for the induction of various cellular defense mechanisms, including antioxidative enzymes, against oxidative stress.

Recent research has shown that the Nrf2/KEAP pathway in ovaries gets down-regulated in the aging process of laying hens (Liu et al 2018). Furthermore, the dietary supplementation of certain phytogenic molecules demonstrated the potential to naturally slow down the aging process of ovaries, since it reduced oxidative stress by activating the Nrf2/KEAP pathway in ovaries.

Feeding strategies to make egg quality last longer in production and storage

Recent research studies investigating the effects of feeding the gut agility activator Anco FIT Poultry in laying hens have shown that it improves albumen height and Haugh units during the laying production cycle and extended egg storage life based on these egg quality parameters.

Anco FIT Poultry is specifically designed to boost the adaptive capacity of birds by upregulating efficient adaptive mechanisms at the gut and cellular level.  Research trials have proven that this gut agility activator upregulates cytoprotective factors in the NRF2-KEAP pathway in poultry and increases the antioxidative capacity in tissues and organs vital for productivity of the bird.

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Quantifying the resilience to DON mycotoxin in pigs

Recent studies have shown that resilience indicators based on monitoring voluntary feed intake in pigs also have the potential to demonstrate the resilience to DON mycotoxin in pigs.

Impact of DON on feed intake in pigs

Mycotoxins in pig feed are known to influence pig performance negatively. Studies have shown that the magnitude of the effects varies with the type and concentration of mycotoxin, sex, age of the pig as well as nutritional factors.

When it comes to the mycotoxin deoxynivalenol (DON), meta-analysis studies have highlighted that the greater part of the variation in weight gain was related to the variation in feed intake, more than compared to other mycotoxins (Andretta et al 2011). Some studies reported that DON can induce the release of satiety hormones from endocrine cells found in the gut and others reported that the pro-inflammatory cytokine produced upon exposure to DON can also participate to the observed anorexia.

There are also other responses to DON in pigs, such as oxidative stress and inflammation on the cellular and gut level, which can play an additional role in the impact on pig growth performance as they affect energy maintenance requirements. In contrast to ruminant and poultry, pigs are more sensitive to DON because they have a low ability to detoxify DON to less toxic products.

In a study by Serviento et al (2018) evaluating short- and longterm effects of DON-contaminated diets on the feeding behaviour of finishing pigs (99 to 154 days of age) average daily feed intake was reduced on average by 26% to 32% when compared to the control groups. This was found to be related to a reduction in the rate of feed intake and the meal frequency.  Previous DON exposure did not make the pigs resistant to a second interrupted DON challenge. However, based on the faster retrieval rate in feed intake, this previous experience seemed to improve pig response to a repeated DON challenge. The adaptive mechanism of pigs to DON has not been fully understood.

Feed intake as a resilience indicator in pigs

Improving resilience is starting to gain interest for breeding programs. But before we can improve something, we also need to know how to measure it. Several research studies have been underway in different parts of the world to determine what can be measured as a good indicator for resilience in pigs.

The response of a pig to a challenge or perturbation can be characterized by the resistance and resilience potential of the pig. Although the origin of perturbations may not be known, their effect on animal performance can be observed, through changes in voluntary feed intake. The resistance trait describes the immediate reduction in daily feed intake to minimize the impact at the start of the disruption while the resilience trait describes the capacity of the pig to adapt to the perturbation through compensatory feed intake to quickly return to the target trajectory of feed intake.

Feed intake can be very informative about the health and welfare status of the animal and modern monitoring technologies are facilitating the recording of individual feed intake in group-housed pigs.

Nguyen-Ba et al (2020a) developed a modelling and data analysis methodology to quantify the feed intake in response to perturbations in terms of resistance and resilience using voluntary feed intake as a response criterion. The methodology has been employed successfully to identify the target trajectory of feed intake (amount of feed that a pig desires to eat when it is not facing any perturbations) in growing pigs and to quantify the pig’s response to a perturbation in terms of traits related to resistance and resilience.

Measuring resilience to DON mycotoxin in pigs

In a second study Nguyen-Ba et al (2020b) applied the methodology mentioned above to quantify the feed intake response in pigs exposed to DON in the diet. The results showed that the methodology based on measuring feed intake in pigs was able to indicate relatively accurately when the pigs were exposed to DON in the feed by detecting deviations from the target cumulative feed intake resulting from the exposure to a DON-contaminated diet.

Furthermore, results demonstrated that the response of pigs to DON-contaminated diet is influenced by age or body weight as well as previous exposure to the DON-contaminated diet. The researchers thought that this indicates that the adaptation of pigs relies more on resilience than on resistance mechanism.

Older pigs recovered faster than the younger pigs from the DON challenge. Researchers concluded that the greater compensatory feed intake for the heavier pigs is related to the fact that they have a greater gut capacity, as gut capacity increases with body weight.

Relevant articles

Resilience in pigs – new benchmark to reach genetic potential 

How to prepare a plan for mycotoxin risk management 

Mycotoxin kinetics – did you know how quickly mycotoxins disappear? 

Nguyen-Ba et al (2020a). A procedure to quantify the feed intake response of growing pigs to perturbations. Animal, 14(2)

Nguyen-Ba et al (2020b). Modelling the feed intake response of growing pigs to diets contaminated with mycotoxins. Animal, 14(5)

 

Optimizing cow longevity by managing for resilience

Cow longevity is the second most economically important trait in dairy cows. Cows with a high longevity, i.e. long productive life span typically exhibit good reproductive performance, few health problems and consistent milk production. However, production efficiency, herd profitability and welfare are less dependent on the longest life than on the optimum length of productive life.

The drive to increase the sustainability of the dairy industry is further intensifying the need for dairy farmers to improve their ability to optimize cow longevity. More recent research highlights possibilities to identify metrics earlier in the life of the cow to enable better decision making in culling cows and manage for resilience to increase the chance of reaching the optimum productive life span. Pilot studies are also revealing the potential to support resilience in dairy cows by nutritional means.

Impact of cow longevity on sustainability

Short longevity poses a threat to the three pillars of sustainable agriculture: economic profit, environmental impact, and social concerns. It is associated with financial losses on farms, increased environmental footprint of milk production, and welfare issues for the animals. Short longevity indicates that animals are not expressing their maximum potential for productivity and profitability due to the high costs associated with rearing cows until they reach the productive stage.

Improved longevity means higher profit per cow, as the income from the productive stage of life pays off the investment made in raising replacement heifers. Mature cows have a higher milk yield than younger cows. As a result, greater longevity increases the proportion of high-yield cows in the herd and fewer cows are needed to sustain a given level of production.

Reducing the number of cows required to produce a given quantity of milk required to produce a given quantity of milk improves environmental sustainability of a dairy enterprise by reducing the carbon footprint per kilogram of milk produced. Therefore, improving dairy cow longevity contributes to a more sustainable dairy industry.

Cow longevity is determined by farmer decisions

The moment and reason a cow is culled, is determined by decisions made by dairy farmers, unless the cow was removed from the herd because of death. Therefore, cow longevity is the outcome of decisions by the dairy farmer throughout the life of the animal.  Culling decisions are the result of cow factors such as health, milk production, and reproductive status, as well as the availability of replacement heifers, parlour capacity and prices. Cows with higher genetic merit, greater production capacity, or better resilience against premature culling are more valuable to dairy farmers.

Genetic opportunity cost is the loss from keeping older, less genetically improved cows in the herd instead of younger, more genetically improved cows. Genetic opportunity cost favours a younger herd, which may trigger greater cow culling to capture genetic improvement and replace cows that are less valuable. However, it needs to be balanced against the benefits of lower culling rates for production costs and environmental effects. A herd with a high proportion of young animals emits more methane and excretes more phosphorus in the environment per unit of milk compared with a herd with a greater proportion of multiparous cows.

This highlights the need to optimize longevity rather than increase longevity in dairy herds. More recent studies and simulation models aim to determine the culling rate that will maximize the profit from genetic gain while minimizing the costs of turnover.  Improvement of culling decision support tools will help to optimize the economically optimal productive lifespan for individual cows based on the conditions they are being reared in. Ultimately, they will help to improve profitability and social acceptability of dairy production.

Relationship between longevity and resilience

Collaborative research across several research institutes in Europe is paving the way to early identification of dairy cows with a high probability of completing several lactations. In the long run there is hope that this will help to significantly improve the optimization of farm-individual management with respect to longevity.

Initial studies revealed the potential for high-frequency milk yield and activity sensor data to rationalize evidence-based culling decisions as early as after the first lactation. The research highlights the relationship between cow resilience and longevity and indicated that a higher resilience score generally corresponded with a higher final lactation number in dairy cows.

Resilience can be described as the capacity of the animal to be minimally affected by a disturbance or to rapidly return to the initial state that pertained before exposure to a disturbance. In the studies mentioned above dairy cows with a high lifetime resilience were defined as animals that avoid early culling by coping well with the farm’s management conditions and having a high adaptability to imposed challenges, whilst reproducing easily and producing consistently, resulting in a long productive life span on commercial farms. The idea is to eventually develop a tool that enables farmers to rank their cows according to resilience scores based on readily available farm data.

Feeding for resilience

A recent pilot study investigating the impact of the gut agility activator Anco FIT on the resilience of dairy cows under practical conditions indicated the potential for this animal feed solution to influence proven resilience indicators in dairy cows, such as reduced fluctuations in milk yield, which warrants further research. The insights of this study were derived from frequent measurements collected via sensors and an automatic milking system in a commercial environment.

by Gwendolyn Jones, published in International Dairy Topics, by Positive Actions Publications

Relevant articles

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Resilience in dairy cows – feed for adaptability

 

Scientific abstract – Feed conference 2021

Effect of a gut agility activator on underlying mechanisms for adaptive capacity of organs vital for resilience in chickens

Scientific abstract published in the proceedings of the Feed Conference 2021, 23-24th June 2021

Authors: Jones, G.M. and Mountzouris, K.C.

Adaptive mechanisms on the cellular level in the gut and liver of broilers were investigated in response to a gut agility activator (GAA) comprising a botanical formula.

One-day-old male Cobb broilers (n=500) were allocated to 4 different treatments diets with 0, 750, 1000 and 2000 mg/kg GAA (Anco FIT Poultry) for 42 days. Each treatment was replicated 5 times with 25 birds each. Birds were euthanized at 42 days and tissue samples of liver and mucosa along the intestine were taken from 10 chickens per treatment for analysis of gene expression and 20 birds per treatment for biochemical analysis. Data were analysed by ANOVA and significant effects (P≤0.05) were compared using Tukey HSD test. Polynomial contrasts tested the linear and quadratic effect of GAA inclusion levels.

Total anti-oxidative capacity (TAC) was improved in the liver (P=0.040) and at 1000 g/kg intestinal TAC was higher in the duodenum (P=0.011) and the ceca (P=0.050) compared to the control. Furthermore, critical genes for enzymes belonging to the Nrf2/ antioxidant response element (ARE) pathway (SOD1, GPX2, HMOX1, NQO1, Nrf2 and Keap1) were upregulated in the duodenum and the ceca mainly in a quadratic way (P ≤ 0.05) compared to the control. Increasing GAA downregulated genes for NF-KB1 in a quadratic pattern and TLR4 and HSP70 linearly in the duodenum and ceca.

The data indicates that the GAA is positively impacting underlying adaptive mechanisms at the cellular level in the liver and certain parts of the gut which could play a role in modulating the response of birds to stressors and thus increase resilience. The effects were dependent on GAA inclusion level. Commercial applications using the effective inclusion levels of this experiment showed a positive effect on performance in the face of stressors such as heat and mycotoxins in broilers and increased laying persistence in layers at the later stages of the laying cycle. Establishing standards to evaluate resilience in poultry along with further research using the GAA under stress-challenge environments are warranted.

Relevant links

Feed conference 2021

Experience with Anco FIT Poultry is growing globally

Managing oxidative stress in sows for better returns

Increased oxidative stress can quietly eat away at returns in sow production, as it is a factor that impairs milk production, reproductive performance and longevity of the sow. Indirectly it will also negatively impact the health and growth of nursing piglets. The problem gets exacerbated in hyper-prolific sows and by challenges such as heat, mycotoxins and obesity. The ability to measure oxidative stress efficiently and knowing how to develop effective strategies to help prevent excessive oxidative stress in sows will go a long way towards supporting high returns on sow farms.

Oxidative stress explained

Oxidative stress describes an imbalance between the production of reactive oxygen species (ROS) in the pig and the ability of the pig’s antioxidant defense mechanisms to neutralize them. Accumulation of ROS results in oxidative damage to lipids, proteins and DNA in cells and consequently tissue damage. It can also induce damage in the intestinal tissue, compromise gut integrity in pigs and leads to an increase in inflammatory responses. Therefore, oxidative stress has been associated with impaired health status and reduced energy available for productive purposes. For instance, under oxidative stress and inflammation 30% of the performance drop is explained by the catabolism and feed conversion needed to manage inflammation.

When are sows most vulnerable to oxidative stress?

The findings of previous studies showed that oxidative stress levels increased during late gestation and lactation. This was associated with sows being under severe catabolic status during late ges­tation and lactation. Catabolic conditions increase the production of reactive oxygen species. Lymphocyte DNA damage was significantly increased during late gestation compared to day 30 of pregnancy. Changes in concentrations of lipid and protein peroxidation products indicate, that during the periparturient period, especially around farrowing and the first week of lactation, the oxidative/antioxidative balance is disturbed, which leads to oxidative stress. Extended catabolic condition during lactation can be a cause of further oxidative stress negatively affecting productivity and longevity of sows.

Factors increasing oxidative stress

External factors such as environmental stressors and social stress can lead to increased oxidative stress in sows. Studies have reported that sows showed increased oxidative stress by increased lipid peroxidation, protein oxidation and oxidative DNA damage in a hot environment under heat stress, compared with sows in a thermal neutral environment. Oxidative stress indicators in the hot environment were negatively correlated with number of piglets at birth and weaning, as well as litter weight gain. Reduced litter size of sows under heat stress could be due to increased oxidative stress during the period of embryonic implantation causing increased embryonic death. Feed quality is another important factor affecting levels of oxidative stress. For example, mycotoxins can play a role even at low to moderate levels of contamination. A factor that is less well known is sow body condition. Recent studies have shown that higher backfat thickness in sows is associated with enhanced oxidative stress, increased expression of pro-inflammatory cytokines and inhibited a healthy placenta development relative to sows with moderate backfat thickness. Levels of ROS and malondialdehyde (MDA), a lipid peroxidation marker, were increased in the placenta of sows with increased backfat thickness . This may also affect fetal development, as lipid oxidation can influence placental development, lipid metabolism and transport. The above stresses the importance of closely controlling body condition in sows.

Advances in measuring oxidative stress

The intensity of oxidative stress can be monitored with several biomarkers including antioxidative enzymes and non-enzymatic antioxidants, as well as end products or intermediates of peroxidative processes of lipids and proteins. Up until very recently biomarkers for oxidative stress have been measured in serum/plasma samples of pigs. Anybody that has taken blood samples from pigs knows that it can be very stressful to the pig and it is unknown how this may impact on levels of the different oxidant biomarkers. More recent studies evaluated the possibility of measuring oxidative stress biomarkers in saliva of pigs. Saliva as material to evaluate stress conditions has several advantages over blood in pigs, since collecting saliva is easy, non-invasive and leads to minimal discomfort in the animal. It therefore represents an ideal sample in pigs and makes salivary markers very attractive. The findings of the study confirmed that salivary biomarkers for oxidative stress are valid and reliable. On top of that the salivary biomarkers showed significant changes in a situation of oxidative stress such as lactation in sows. This means that future trials designed to measure oxidative stress in pigs would be a lot easier to conduct if salivary biomarkers are used.

Feed for antioxidative capacity

A better understanding of the factors causing oxidative stress in sows and improved capabilities of measuring oxidative stress in sows is paving the way to take control of oxidative stress more actively to minimize the impact on the sow. Feed additives that have proven capabilities for antioxidant capacity can help to support the antioxidative capacity of sows. Formulating diets accordingly, particularly for production phases where the sow is more vulnerable to oxidative stress can thus prevent excessive oxidative stress in sows.

Many herbs and spices contain high levels of components with strong antioxidative power, such as alkaloids and polyphenolic compounds including different types of phenolic terpenes, phenolic acids and flavonoids. New research methodologies are increasing the understanding of how bioactive substances from herbs and spices work alone and in concert at the cellular level in animals. This is helping companies working in this field to design products and efficacy trials to maximise the potential benefits from these substances in animal nutrition.

Published in International Pig Topics by Gwendolyn Jones, May 2021

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