Climatic Change and Chicken Immunity
515
As the temperature rises, the birds undergo many changes—increased water consumption, respiration rate, body temperature, inferior egg quality and susceptibility
to diseases.
In particular, the highly specific adaptive immune mechanisms are affected by heat
stress. In more specific, heat stress deteriorates the cell mediated immune responses.
This reveals that heat stress needs to be considered as an important factor compromising chicken’s health. As a result of heat conditioning, biochemical and physiological
mechanisms were induced to cope with heat stress; this induction may have delay
production of additional acute phase proteins to protect the cells from damage. The
stress hormones—cytokine interactions are responsible for altered immune functions
during heat stress. Modern day molecular biology tools can help in understanding
various cellular and molecular mechanisms involved in the production, physiological and immunological aspects of the poultry birds, which in turn can help in the
development of breeds more adapted to the climate changes.
Heat stress is one of the most important environmental stressors challenging poultry production worldwide. The negative effects of heat stress on broilers and laying
hens range from reduced growth and egg production to decreased poultry and egg
quality and safety. However, a major concern should be the negative impact of heat
stress on poultry welfare.
Finally, it is important to mention that intervention strategies to deal with heat
stress conditions including environmental management (such as facilities design,
ventilation, sprinkling, shading, etc.), nutritional manipulation (i.e., diet formulation according to the metabolic condition of the birds), as well as inclusion of feed
additives in the diet (e.g., antioxidants, vitamins, minerals, probiotics, prebiotics,
essential oils, etc.) and water supplementation with electrolytes. Over the past fifty
years the global poultry production experienced leaps and bounces to accommodate rising demand. On the other hand, popular demand and scientific interest for
organic poultry production, particularly feeding with medicinal botanicals, has considerably increased in recent years. Many studies have clearly established the fact
that herbal plants and their derivatives have potential as immune modulators. Both,
the innate and adaptive components of the immune system are stimulated by phylogenic. Moreover, most studies have exercised herbal extracts rather than the purified
compounds. Therefore, there is still distrust concerning the efficacy and optimum
dosage of herbal plants and their derivatives as immune stimulators. Hence, more
research is required for scientific validation of herbal plants as potent chicken immune
stimulators. Nevertheless, the effectiveness of most of the interventions has been variable or inconsistent. More recently, two innovative approaches have been explored,
including early-life conditioning (i.e., prenatal heat acclimation) and genetic selection of breeds with the increased capacity of coping with heat stress conditions (i.e.,
increased heat tolerance). However, these potential opportunities, although promising (particularly, for poultry production in hot climatic regions), still require further
research and development.
515
As the temperature rises, the birds undergo many changes—increased water consumption, respiration rate, body temperature, inferior egg quality and susceptibility
to diseases.
In particular, the highly specific adaptive immune mechanisms are affected by heat
stress. In more specific, heat stress deteriorates the cell mediated immune responses.
This reveals that heat stress needs to be considered as an important factor compromising chicken’s health. As a result of heat conditioning, biochemical and physiological
mechanisms were induced to cope with heat stress; this induction may have delay
production of additional acute phase proteins to protect the cells from damage. The
stress hormones—cytokine interactions are responsible for altered immune functions
during heat stress. Modern day molecular biology tools can help in understanding
various cellular and molecular mechanisms involved in the production, physiological and immunological aspects of the poultry birds, which in turn can help in the
development of breeds more adapted to the climate changes.
Heat stress is one of the most important environmental stressors challenging poultry production worldwide. The negative effects of heat stress on broilers and laying
hens range from reduced growth and egg production to decreased poultry and egg
quality and safety. However, a major concern should be the negative impact of heat
stress on poultry welfare.
Finally, it is important to mention that intervention strategies to deal with heat
stress conditions including environmental management (such as facilities design,
ventilation, sprinkling, shading, etc.), nutritional manipulation (i.e., diet formulation according to the metabolic condition of the birds), as well as inclusion of feed
additives in the diet (e.g., antioxidants, vitamins, minerals, probiotics, prebiotics,
essential oils, etc.) and water supplementation with electrolytes. Over the past fifty
years the global poultry production experienced leaps and bounces to accommodate rising demand. On the other hand, popular demand and scientific interest for
organic poultry production, particularly feeding with medicinal botanicals, has considerably increased in recent years. Many studies have clearly established the fact
that herbal plants and their derivatives have potential as immune modulators. Both,
the innate and adaptive components of the immune system are stimulated by phylogenic. Moreover, most studies have exercised herbal extracts rather than the purified
compounds. Therefore, there is still distrust concerning the efficacy and optimum
dosage of herbal plants and their derivatives as immune stimulators. Hence, more
research is required for scientific validation of herbal plants as potent chicken immune
stimulators. Nevertheless, the effectiveness of most of the interventions has been variable or inconsistent. More recently, two innovative approaches have been explored,
including early-life conditioning (i.e., prenatal heat acclimation) and genetic selection of breeds with the increased capacity of coping with heat stress conditions (i.e.,
increased heat tolerance). However, these potential opportunities, although promising (particularly, for poultry production in hot climatic regions), still require further
research and development.