Resilience in dairy cows – feed for adaptability

It is possible to breed for resilience in dairy cows. But is it possible to feed for it? What are the nutritional options?

Farm resilience

Resilience is a concept that acknowledges unpredictability and emphasizes the need to enable adaptability and transformability of systems instead of optimizing them. A farm management approach based on resilience comes up with systems and solutions that can absorb and accommodate future events in whatever unexpected form they may come.  It follows that resources are allocated to strategies that allow reducing the impact of a wide variety of potential unknown events and on identifying emergent opportunities.

Farm resilience is characterized by the ability to:

(1) constantly evolve while protecting against shocks to the system

(2) readjust to adapt to stressors

(3) to implement strategies to take advantage of strengths

and (4) to continually adapt to the current situation (Darnhofer 2009)

Increasing diversity and adaptive capacity of farm systems have been highlighted as key drivers to improve farm resilience and the ability of farms to cope with different types of disruption and stressors.

Farm resilience starts in the cow

In a dairy production system, farm resilience also depends on how well cows can cope with unforeseen challenges in their feed and their environment. As the cow is an integral part of the system, she is expected to be resilient and less sensitive to stressors and sub-optimal circumstances. This is because less resilient cows will have greater fluctuations in their milk performance and quality leading to a decreased cost-effectiveness of dairy rations and a lower likelihood of reaching performance targets. Consequently, fluctuations in farm profits are bound to occur.

Lower resilience in cows can also lead to increased susceptibility of disease which can cause further losses in the long run. More resilient cows put fewer constraints on new farming systems and require fewer drugs, without compromising health or economic efficiency and are less likely to be prematurely culled. This again affects the sustainability and long-term profitability of the dairy sector.

Resilience in dairy cows – advantages

  • more flexibility and adaptive capacity for the farm system
  • greater consistency in milk production
  • greater consistency in milk quality
  • longer production lives, longevity
  • more stable farm incomes
  • fewer treatments and drugs
  • easier to manage cows and reduction in labour time
  • improved cow welfare

Resilience in dairy cows depends on adaptive capacity

Resilience is determined by how the cow responds and adapts to stressors or in other words by her adaptive capacity.  The transition period for instance is a critical time that requires a high capacity to adapt to lactation. But milk production and quality will also depend on how the cow responds to other stressors, such as heat and mycotoxins. Most stressors will provoke stress reactions in the form of reduced feed intake, oxidative stress, inflammatory responses or changes in rumen efficiency. The extent of these stress reactions is determined by the adaptive capacity of the cow, which again determines the impact stressors can have on key performance parameters, health and longevity of the cow and how quickly she recovers.

Gut agility – feeding for adaptive capacity

Nutrition can play an active role in management strategies designed to reduce the impact of stressors on dairy cow well-being and performance. New nutritional concepts, such as gut agility activators, are designed to support the adaptive capacity of dairy cows for improved resilience.

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Webinar for poultry farmers in Nigeria – register here

Together with our Anco FIT distributor for Nigeria, Caesar and Jones, we are organizing a free educational webinar for poultry farmers in Nigeria.

Nutritional options for more stable and longer productivity in poultry

25th of September 2020

10am Nigerian time

How to register

This webinar is for free and you can register at the link below to join. We look forward to your active participation.

What to expect

Stability in farm income and adaptive properties are two key factors that have been linked to high resilience of poultry farms in Nigeria.  But what can poultry farmers do to support this cost-effectively by nutritional means to stay competitive and reduce the need of antibiotic growth promotors?

In this webinar Dr. Gwendolyn Jones will be looking at how novel nutritional concepts can support current efforts to increase the adaptive capacity of farms for resilience in Nigerian poultry production. This includes adaptation strategies of poultry farmers to rising temperatures in Africa.

The adoption of existing and new technologies for adapting to climate change and variability is a high priority for many ecological regions in Nigeria. Adaptive capacity is the ability of individuals and communities to adjust to changes, to take advantage of opportunities or to cope with the consequences.

The adaptive capacity of poultry farms starts in the bird. Find out how improving the adaptive capacity of the bird by nutritional means can lead to more stable incomes, maintain higher productivity for longer in laying hens and reduce the need for antibiotic growth promotors in broiler and egg production.

About the speaker

Gwendolyn is educated to PhD level in animal science in agriculture. For her animal science degree at the University of Edinburgh she carried out her undergraduate research project at the University of Zimbabwe, giving her exposure to challenges for animal nutrition in Africa. In addition, she gained a MBA from the University of Iowa in the US.

She brings 15 years commercial experience through a variety of roles she held in the animal feed industry with a global perspective on farming. Gwendolyn is passionate about contributing to agility and resilience for sustainable competitive animal production and food security globally.

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Egg production – Resilience for laying persistence

In egg production longer laying cycles can help to cut costs, so they are a promising solution in a tough economic climate. Plus, they can reduce the environmental impact of egg production. Therefore, there is an increasing focus on improving laying persistence and egg quality at the end of the laying cycle. However, due to increasingly intensive metabolism for egg formation, laying hens are more susceptible to diseases, which requires a shift in breeding and nutrition towards greater resilience of birds to improve laying persistence for longer laying cycles.

There is a fast decline in egg production after the hens reach 480 d of age leading to reduced commercial value of laying hens. Understanding the mechanisms of the deterioration of the laying performance can help to slow down the process. The ovary and the liver are key organs involved in egg production of the laying hen, which is why knowing how to support them effectively by nutritional means can make a difference to laying persistence.

Oxidative stress in aging organs

Ovarian aging is one of the highest risk factors that lead to the decline of ovarian functions and hence a reduction in egg production. Studies have shown that oxidative stress plays a driving role in ovarian aging. The antioxidant status of the ovary decreases with age (Figure 2) as a result of a reduction in antioxidant enzymes and antioxidants in the hen’s own defense mechanisms. Oxidative stress is initiated by the gradual accumulation of reactive oxygen species (ROS) in the ovary and a reduction of the antioxidative capacity during the aging process. This will be exacerbated through stressors, such as heat, mycotoxins, endotoxins and others, which increase the production of ROS in the hen on a cellular level. A growing body of evidence suggests that oxidative stress is involved in most of commercially relevant stresses in poultry production. Oxidative stress is defined as an imbalance between production of ROS and their elimination by protective mechanisms. This imbalance leads to damage of important biomolecules and cells, with potential impact on the whole organism. It can also lead to inflammatory responses which can affect energy efficiency of the laying hen.

Age-related changes in the antioxidative capacity of the hen’s liver, is an important factor that influences liver function. Studies have demonstrated that the total antioxidant capacity of the liver declines as the hen ages (Figure 2) and this has also been linked to a decrease in egg production and in the ability of yolk precursor formation.

Feeding for resilience in egg production

To extend the laying cycle of commercial flocks, long-term maintenance of organs involved in producing eggs is required. Feeding for antioxidative capacity in laying hens has been shown to retard the antioxidant decline of aging ovaries and can thus help to maintain functioning ovaries for longer. It is also known to maintain a healthy liver for longer. However, feeding to improve the adaptive capacity of birds to stressors helps to minimize stress reactions, such as oxidative stress, as well as inflammatory responses and reduced feed intake, which can further increase resilience in birds and reduce the potential for stressors to diminish the chances for producers to successfully extend the laying period. Animal resilience has been defined as “the capacity of the animal to be minimally affected by challenges or to rapidly return to the state pertained before exposure to a challenge.

The gut agility concept in Anco FIT Poultry was specifically developed to increase the capacity of the bird to adapt to challenges more efficiently and to reduces stress reactions that would otherwise reduce the hens performance and potential to sustain longer laying cycles. A trial carried out in a commercial laying hen flock in Brazil, demonstrates how Anco FIT Poultry improves the resilience of birds to stressors compared to birds on a control diet (Figure 3). The impact of stressors was smaller on egg production and birds recovered quicker from stressors leading to greater laying persistency and more eggs produced per hen over the trial period.

 

Published in International Poultry Production by Gwendolyn Jones

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Summer heat stress in cows – better milk quality with Anco FIT

Summer heat stress in cows is known to reduce milk yields and milk quality, reducing the profitability of dairy farms, which is why it is important to find ways to effectively manage it on farms.

Higher producing cows are more sensitive to heat stress

Lactating dairy cows prefer ambient temperatures of between 5 and 25 °C, the “thermoneutral” zone. At ambient temperatures above 26°C, the cow reaches a point where she can no longer cool herself adequately and enters heat stress. Whereas the upper critical limit of the thermoneutral zone for dairy cattle is between 25 °C and 26 °C, the, the temperature-humidity index (THI) is below 72.

Higher producing cows, and thus multiparous cows, are more sensitive to the effects of heat stress compared to lower producing or primiparous cows. As milk yield increases from 35 to 45 kg/d, the heat stress threshold is decreased by 5°C. Recent studies show that modern cows become heat-stressed starting at an average THI of 68 with the levels of stress increasing with increasing THI values.

Higher-producing cows exhibit more signs of heat stress than lower-producing cows because higher-producing cows generate more heat as they eat more feed for higher production. They must get rid of the extra heat generated due to metabolizing more nutrients in the feed. As a result, much of the reduction seen in milk production is due to lower feed intake by the cow. Feed intake in lactating dairy cows starts to decline at around 25°C and drops more rapidly above 30°C.  High producing dairy cows also have a higher metabolic heat load produced through processes such as lactogenesis and milk secretion. Consequently, as milk production and metabolic heat production rise genetically, heat stress will increasingly limit the expression of genetic potential in the future.

The stage in the lactation curve at which the cow experiences heat stress is another important factor for the total lactation yield. Cows are less able to cope with heat stress during early lactation and heat stress has the biggest impact during the first 60 days of lactation. This is because cows are in negative energy balance and make up for the deficit by mobilizing body reserves in this early part of lactation. Catabolic processes are associated with heat production.

Summer heat stress in cows affects milk quality

Milk quality is important for producers to earn monetary bonuses through lower somatic cell counts and increased butterfat/protein, increasing farm profitability.

Controlling somatic cell count (SCC) is a year-round challenge for most dairy producers, and hot humid weather intensifies this challenge. Heat stress generally increases the production of free radicals or reactive oxygen species (ROS). This can lead to oxidative stress, which again has been associated with increased SCC in milk.

Results from studies on the impact of heat stress on milk components are inconsistent, however several studies have reported reduced milk fat and protein levels in response to heat stress. Some researches argue that fat yield decreases could be explained by a decrease in forage intake with low fiber levels, and protein decreases could be attributed to reduced DMI and energy intake when the animal is under heat stress. Other research has shown that milk fat depression during heat stress can be linked to depressed rumen health. Therefore, supporting optimal rumen function by nutritional means may help to reduce the negative impact of heat stress on milk fat.

Strategies to mitigate the negative effects of summer heat stress in cows

Cool water

It is highly important that cows are provided cool water during periods of high temperature. Water is the primary nutrient needed to make milk and cows drink up to 50 percent more water when the temperature-humidity index is above 80. Water should be easily accessible to cows and located in a position such that cows do not have to cross areas of hot sun.

Commercial trial with Anco FIT in cows during summer heat

Gut agility activators, such as Anco FIT and Anco FIT Farm are designed to support the cow to adapt to challenges including heat stress more efficiently by minimising stress reactions including oxidative stress at the cellular level, shifts in the rumen balance and reduced feed intake.

Feedback from a commercial dairy farm with 750 cows in Germany during months where temperatures were recorded above 26°C included that SCC over a period of 3 months were reduced by 13% and milk fat and protein levels increased by 3%. Furthermore, treatments for high SCC were reduced from 5 treatments/week to 1-2 treatments per week. Cows were fed a ration based on corn silage, grass silage, soya and grains, where Anco FIT was added at 30g/cow/day and received a milking concentrate in the milking robot.

It was concluded that feeding Anco FIT to dairy cows during hotter months helped the cows to cope with the heat better and reduce some of the stress reactions that would otherwise impact milk quality and cow wellbeing.

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Anco Brazil poultry webinar has attracted great interest

In July Anco Brazil hosted a poultry webinar in co-operation with our distributor Evance, which caught the attention of an engaged audience in the Brazil poultry industry. The webinar aimed to provide inspiration for cost-effective poultry production in times of crisis.

Dr. Marco Aurelio Nunes, Technical Manager at Anco presented strategies to reduce production costs with the least possible impact on production indexes. This included nutritional solutions that can be used to increase resilience in birds and mitigate the impact of stressors on performance in poultry. He also shared some simple evaluation tools that can help egg producers determine, which strategy would be most cost-effective, based on their individual circumstances.

Marcelo Blumer, executive director at Anco Brazil commented: “We are excited about the amount of interest we could generate with our webinar and that attendees were fully engaged. The questions and answer session at the end showed us that people were following the webinar closely and were eager to learn more. As a result of the success, we are already thinking of a topic for a second webinar which we are planning for later this year. This is an important time to make every effort to stay connected, collaborate and to keep learning, so we can find ways to adapt quickly and together for profitable animal production.”

Contact Anco Brazil to find out more Anco Brazil Contact

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Heat stress in sows – Better lactation performance with Anco FIT

Heat stress in sows can compromise lactation performance, as it generally reduces feed intake in sows. The gut agility activator Anco FIT was tested in sow feed for maintaining sow lactation performance despite heat stress during the summer months in Argentina.

Heat stress in sows

In sows, temperatures above 25c can cause heat stress. In lactating sows this is generally associated with reduced feed intake, resulting in reduced milk production, with the knock-on effect on piglet growth. The modern lactating sow is particularly at risk of heat stress, as it has been heavily selected for increased productivity including litter size and litter weaning weight, which comes with increased heat production.

Trial design

The trial was carried out on a commercial farm with 1500 sows in Cordoba, Argentina. The trial period was during the summer months in Argentina from February 29th to 9th of April. Temperatures ranged between 26 and 29C, with a humidity of around 75% and it was expected that sows were experiencing some degree of heat stress.

100 sows were split into 2 groups: 1) control group fed corn-soybean diet, specified to sow requirements in gestation and lactation 2) trial group fed the control diet supplemented with 1 kg of Anco FIT per ton of feed. The trial started two weeks before farrowing and ended with the weaning of pigs at 21 days of lactation.

Cross-fostering was performed within 24 h post-farrowing and litters of piglets were adjusted to 12-13 piglets within the same treatment. The average daily feed intake of the sows during lactation was recorded. Piglets received no creep feed during the lactation period.

Results

Sow feed intake in lactation was significantly increased in Anco FIT vs control sows (5.29kg/d vs 4.39 kg/d, P<0.01). Piglet mortality was significantly reduced in sows fed Anco FIT and litter weight gains significantly increased vs control (42.26kg vs 36.55kg, P<0.01).

Conclusion

Adding Anco FIT to sow diets at 1kg/t increased sow feed intake and lactation performance under summer heat stress in commercial sow farm conditions.

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Farm resilience starts in the bird – feed for adaptability

Farm resilience is emerging as a key success factor in times of great uncertainty. Farming deals with a lot of uncertainties and change at its best. However, adding factors like climate change, the Covid 19 crisis and rapid changes in consumer demand into the mix exacerbates the need for the capacity of farms to adsorb shocks and adapt to change quickly to survive economically in the long-term.

Farm resilience versus farm optimization

Resilience thinking highlights that in the long run for a farm to persevere optimising resource allocation under known conditions will not be enough. Resilience is a concept that acknowledges unpredictability and emphasizes the need to enable adaptability and transformability of systems instead of optimizing them.

A farm management approach based on resilience comes up with systems that can absorb and accommodate future events in whatever unexpected form they may come. It follows that resources are allocated to strategies that allow reducing the impact of a wide variety of potential unknown events and on identifying emergent opportunities. However, fewer resources are spent on improvements in efficiency.

A crisis, such as Covid 19, may be a trigger for transformational change, since it is more likely that new alternative organizational forms will be considered.

Feeding birds for resilience

In a poultry production system, farm resilience also depends on how well birds can cope with unforeseen challenges in their feed and the environment. This is because less resilient birds will have greater fluctuations in their performance leading to a decreased cost-effectiveness of poultry feeds and a lower likelihood of reaching performance targets. With poultry feed representing around 70% of the total cost of poultry production systems it also means more variability in farm profits. Lower resilience in birds can also lead to increased susceptibility of disease which can cause further losses in the long run.

Research has shown that certain feed supplements can play a role in management strategies designed to reduce the impact of stressors on poultry well-being and performance. The gut agility activator Anco FIT Poultry was proven to improve the capacity of broilers and laying hens to cope with stressors under commercial conditions and enhance the birds endogenous defense mechanisms to buffer stress reactions on the cellular level more efficiently in a research environment.

More resilience means less need for antibiotics

Feeding birds for adaptability to increase resilience can also help to reduce the need for antibiotics. Minimizing stress reactions, such as reduced gut integrity and oxidative stress, by nutritional means also helps to reduce the susceptibility of birds to disease that may otherwise require the need for treatments with antibiotics or the use of antibiotic growth promotors in the feed.

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Heat stress in pigs – nutritional interventions that work

Heat stress in pigs puts an economic strain on pig production in many countries of the world and the current climate changes have increased the prevalence and intensity of heat stress. Nutritional interventions supporting resilience mechanisms represent a practical, adaptable and cost-effective strategy to mitigate the negative effects of heat stress and improve animal productivity.

Economic losses from heat stress in pigs

Compared to other animals, pigs are more sensitive to heat stress due to their high metabolic heat production, quick fat deposition, and lack of sweat glands. Heat stress-induced economic losses result from reduced and inconsistent growth, poor sow performance and increased mortality and morbidity. In the US alone heat stress is costing pig farmers around $50 to $60 per pig each year. Regions around the world most affected by climate change are likely to see an increase in the detrimental effects of heat stress on animal production and welfare in the future. On top of that genetic selection for increased litter size and leaner phenotypes leads to an increase in thermal sensitivity in pigs, due to increased basal heat production.

Summer heat stress in sows

Sows suffer from heat stress in environmental temperatures above 25°C. Heat stress in sows has been shown to reduce feed intake, from 655 g/day to more than 2 kg per day, with subsequent negative consequences for reproduction, milk production and piglet growth. If the sow is maintained under heat stress conditions for a long period, there is a risk that the animal will overheat, which can lead to death via hyperthermia. In countries with tropical conditions such as Brazil this is very common. According to researchers in Brazil, lactating sows of some genetic lines can have up to 15% mortality during Brazilian summers due to heat stress conditions. In gestating sows there is some evidence that heat stress during pregnancy can have in utero negative effects on the offspring’s thermoregulatory capabilities.

Heat stress in fattening pigs

Research has shown that it only takes 2-6 hours of heat stress (37C and 40% humidity) to compromise feed intake and intestinal integrity in growing pigs. Studies in finishing pigs have also shown oxidative stress in the liver in response to chronic heat stress at 30 °C. The drop in feed intake in response to heat stress increases as the body weight increases in pigs. Pigs of 60-100kg raised in Brazil during the summer months have been reported to have a reduction in growth rates of around 15% compared to pigs raised during the winter.

Management interventions for heat stress in pigs

Flexible, affordable management approaches to immediately decrease heat stress susceptibility without negatively influencing traditional production traits are of great value to pig production. However, the input cost for optimal cooling technology is very costly and often too expensive for smaller producers.

Dietary supplementation and modifications are less costly easily adjustable tactics and are suitable for all production systems.

Nutrition
• Consider the thermal effect of feed and reduce fibres and crude proteins, which generate a lot of heat.
• Increase the fat content of the diet
• Feed pigs during the cooler hours of the day
• Provide pigs with unlimited access to cool and fresh drinking water
• Adapt vitamin, mineral and amino acid levels in feed to the pig requirements under heat stress

Supporting resilience mechanisms by nutritional means

Research increasing the understanding of the molecular mechanisms involved in heat stress induced inflammation and intestinal barrier disruption paves the way to nutritional strategies to preserve the physiological performance of the gut. Many of the negative consequences that heat stress has on pig health and productivity are mediated by reduced intestinal barrier integrity, which is followed by inflammatory responses.

At the cellular level, hyperthermia leads to disruption of intestinal epithelial integrity, by affecting tight junctions. Damage to tight junctions facilitates the transfer of toxins and pathogens from the gut through the epithelial barrier, contributing to an exaggeration of inflammatory responses, which can further worsen the intestinal damage. Hyperthermia provokes the production of reactive oxygen species (ROS). However, it can also directly impair the antioxidant defence system of the animal, which eventually leads to oxidative stress and intracellular damage. Studies in growing pigs have shown an inverse relationship between oxidative status and growth performance, whereby pigs with a higher oxidative stress status had poorer performance.

Nutritional solutions which have the capacity to preserve cellular homeostasis by enhancing cellular defense systems, thereby reducing oxidative stress and inflammation, as well as maintain intestinal integrity are considered to be able to help protect animals against the adverse effects of heat stress.

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

Sow trial with Anco FIT during summer months

A recent sow lactation trial carried out in the summer months in Argentina, showed increased feed intake (21%) and improved lactation performance in sows fed the gut agility activator Anco FIT compared to sows on a control diet.

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Don’t let summer heat stress spoil poultry appetite

Summer is just around the corner and it is time to prepare strategies to manage the impact of summer heat stress on poultry production efficiency.

Effect of heat stress on feed intake in poultry

Modern poultry is particularly sensitive to temperature-associated environmental challenges, due to their metabolic activity. Decreased feed intake in response to heat stress is the starting point for decreased body weight gain, feed efficiency, egg production and quality. Research has shown that a 12-day heat stress period in laying hens decreases feed intake by 29 g/bird, resulting in a 28.8% decrease in egg production. Others reported that for every 1◦C increase in temperature between 21◦C and 30◦C, appetite decreases by 1.5%, and for every 1◦C increase in temperature between 32◦C and 38◦C, the reduction is about 4.6% in laying hens. Studies in broilers have shown that birds reared in temperatures between (35 and 38 C) had significantly lower feed intakes and growth rates compared to birds reared in optimal temperatures.

Underlying mechanisms

There is general agreement that gut peptide hormones like Cholecystokinin (CCK) and Ghrelin have a role to play in appetite regulation in chicken. However, the role of these gut peptides in appetite regulation is not fully understood for poultry yet and there is some controversy around how their physiological roles may differ between birds and other vertebrates.

There is little information available on the underlying mechanisms for a reduction in feed intake in response to heat stress in poultry. One study investigating the effect of heat exposure on gene expression of various appetite regulating peptides in laying hens reported an upregulation of ghrelin mRNA in the hypothalamus as well as in the glandular stomach and jejunum. Suggesting that one of the pathways for the negative impact on feed intake of high ambient temperature in laying hens might be mediated by its effects on the hypothalamic and gastrointestinal ghrelin signals.

Supporting feed intake under summer heat stress

New nutritional concepts, such as gut agility activators, are designed to support the adaptive capacity and hence resilience of the bird by nutritional means. They help the bird to adapt to stressors by minimizing stress reactions including reduced feed intake. The gut agility activator Anco FIT Poultry has been shown to maintain higher feed intakes in broilers and layers compared to control animals in commercial conditions under summer heat stress. This was associated with higher weight gains and end weights

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Feeding cows for adaptive capacity in the transition period

The adaptive capacity of the cow determines transition success. When dairy cows fail to adapt physiologically to the demands of calving and the onset of milk production, the resulting metabolic stress leads to transition cow disorders with negative consequences for milk production, reproduction efficiency and longevity. The high prevalence of metabolic disorders and production disease around calving highlight the fact that many farm systems do not provide adequate solutions and are overstretching the adaptation capacity of their cows. Understanding the underlying mechanisms and factors exacerbating metabolic stress during transition can help to find nutritional solutions that enhance the adaptive capacity in transition dairy cows.

Transition failures

The transition period is a demanding time for dairy cows and around 30% to 50% of dairy cows are affected by some form of metabolic or infectious disease, around the time of calving. This includes milk fever ketosis, retained placenta and mastitis. A declining availability of qualified dairy staff is likely to exacerbate this, as it means that cows are receiving less individual attention to identify and respond to health issues. When disorders occur, it is a demonstration that cows have difficulties in coping with external and internal conditions, endangering their own capacity to survive. It shows that the cows are failing to adapt to changes, stressors and gaps between nutrient supply and demand.

During the transition period dairy cows must adjust metabolically to a dramatic increase in energy and nutrient requirements needed for foetal growth and onset of milk production, exceeding the amount of energy the cow receives from dietary sources. This makes the cow susceptible to a negative energy balance. A negative energy balance initiates lipid mobilization, which again leads to high concentrations of non-esterified fatty acids (NEFAs). Metabolism of large amounts of NEFAs to ketone bodies induces an increased production of reactive oxygen species (ROS), which can eventually lead to oxidative stress in the liver of dairy cows.

Increased oxidative stress in dairy cows is recognized as an underlying factor of dysfunctional inflammatory responses and it has been linked to the occurrence of transition disorders. Oxidative stress in the liver is known to cause inflammatory damage of the liver, which impairs the metabolic function of liver cells and promotes the development of ketosis. In the mammary gland it has been associated with increased somatic cell counts in milk and the incidence of mastitis. Overall, these findings lead to the assumption that the underlying mechanisms that exacerbate metabolic stress and cause health disorders in transition dairy cows are combined effects of altered nutrient metabolism, oxidative stress and dysfunctional inflammatory responses.

Transition success

Successful adaptation avoids metabolic disorders in the transition period. Overall dairy cows are more likely to succeed in adaptation in the transition period when the gap between nutrient demands and supply is limited. However, there are also indications in the literature that even when cows had comparable energy balance, there is considerable individual variation of the adaptive ability of cows during early lactation based on metabolic and endocrine variables. Therefore, another approach is to find ways to support the cow in her ability to cope with nutritional and metabolic challenges, which would actually help the cow’s adaptability for transition success.

This amongst other things requires the identification of relevant markers that enable the measurement of achieving improved adaptability. One obvious marker for oxidative stress is the level of reactive oxygen species (ROS). However, more recent research suggests that the oxidative stress index (OSi) predicts oxidative status more accurately. The OSi is the ratio between ROS and serum antioxidant capacity.  The researh shows that the OSi is significantly increased in dairy cows around calving, compared to levels at dry-off and at 30 days post calving. So one way of identifying improved adaptive capacity of cows in the transition period could be to measure the oxidative stress index in response to nutritional interventions.

Nutritional support for adaptive capacity

Researchers report that genetic selection for increased milk yield has decreased the adaptability of modern dairy cows. However, a better understanding of the underlying mechanisms for adaptability in dairy cows is helping the development of nutritional solutions to enhance the cow’s ability to cope more efficiently with nutritional and metabolic challenges.

For instance feeding plant extracts with high antioxidative powers can help to increase the level of antioxidative enzymes and antioxidants to support the cow’s own antioxidative defense in the liver. Feeding those type of components can give the liver a better chance of fighting ROS produced in the transition period and thus minimize the negative consequences from oxidative stress on liver function. A large part of the capacity of the adaptation of ruminants to dietary challenges is allowed by the rumen, so feed supplements designed to help maintain rumen efficiency are also going to ease the transition to lactation. However, attempts to reduce the prevalence of metabolic disorders and associated production diseases should rely on continuous and comprehensive monitoring with appropriate indicators on the farm level.

Published in International Dairy Topics by Gwendolyn Jones

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