Sami Dridi

• University of Arkansas at Fayetteville

Water scarcity and rising global temperatures are two of the greatest current and future threats to poultry sustainability. Therefore, selection for water efficiency (WE) and heat resilience are of vital importance. Additionally, intestinal integrity is of critical importance under challenging conditions to maintain nutrient absorption and therefor...

The woody breast (WB) myopathy poses significant economic and welfare concerns to the poultry industry, however, there is no effective strategy to mitigate this pathology due to its unknown etiology. After showing previously that hypoxia is a key factor in WB progression, we used here various techniques demonstrating dysregulated mitochondria (morp...

Heat stress (HS) induced by global warming is a real welfare, productivity, and economic burden of cattle production. However, some cattle breeds have superior physiological adaptive traits to others, yet the underlying molecular mechanisms are not fully defined. The present study aimed, therefore, to determine the expression profile of stress-rela...

In the broiler industry, intensive genetic selection has been placed on muscle growth which has undesirably led to increased fat accretion. Models of chicken preadipocyte differentiation in vitro have conventionally used incubators without the ability to control oxygen (O2) tension; thus, the cells are exposed to atmospheric (∼20-21%) O2, which is...

Poultry production is confronting real challenges, including a lofty projected high demand for animal proteins to feed the future, and the need to adapt to planetary boundaries (global warming) with limited natural resources (land, energy, water). Among the most challenging stressors to poultry production sustainability are heat stress (HS) and wat...

Divergent selection of broilers for water conversion ratio has established and high-(HWE) and low- water efficient (LWE) broiler lines. Two 2 × 2 factorial experiments were conducted to assess the gene expression profile of systems involved in renal water homeostasis. In Exp. 1, male and female HWE and LWE broilers were individually phenotyped betw...

Background Water scarcity is a current, significant global concern that will only increase under the pressure of climate change. Improving water efficiency of poultry is a new and promising area to help temper agriculture's future impact on fresh water availability. Here, we explored the effects of acute heat stress (HS) on circulating stress and i...

Novel biomaterials that bridge the knowledge gap in coupling molecular/protein signatures of disease/stress with rapid readouts are a critical need of society. One such scenario is an imbalance between bodily heat production and heat dissipation which leads to heat stress in organisms. In addition to diminished animal well-being, heat stress is det...

Poultry nutrition faces many challenges, including the need to meet the changing requirements of growing birds whilst also avoiding over-nutrition and nutrient losses which can be both environmentally and economically damaging. With the sector also facing increasing pressure to reduce its reliance on antibiotics, a greater understanding of the poul...

An imbalance between bodily heat production and heat dissipation leads to heat stress in organisms. In addition to diminished animal well-being, heat stress is detrimental to the poultry industry as poultry entails fast growth and high yield, resulting in greater metabolic activity and higher body heat production. When stressed, cells overexpress h...

Lameness due to bacterial chondronecrosis with osteomyelitis (BCO) is an infection of weak bone by opportunistic bacteria that infiltrate the circulation as a result of immune suppression or gastrointestinal deterioration. One mitigating strategy is the dietary inclusion of products to support overall broiler robustness and bone health. To test the...

Leg health is a significant economic and welfare concern for the poultry industry. Current methods of detection rely on visual assessment of the legs and gait scores and bone scoring during necropsy for full characterization. Additionally, the current scoring of femurs only examines the external surface of the femoral head. Through the use of the d...

A total of 720 male Cobb 500 broiler chicks were used in a 5 treatment and 8 replicate experiment to explore dynamic changes in blood metabolites in response to short-term nutrient depletion and repletion. Day old chicks were offered a corn and soybean meal-based common starter diet from d1 to 14 that was formulated to meet all nutrient requirement...

Heat stress (HS) and water scarcity are significant challenges to sustainable poultry production worldwide. It is, therefore, critical to identify effective strategies to prevent, withstand, or adapt to these challenges. After four generations of divergent selection for water efficiency, the present study was undertaken to determine the effect of H...

Powered by consumer taste, value, and preferences, natural products including phytogenics and algae are increasingly and separately used in the food systems where they have been reported to improve growth performance in poultry and livestock. The present study aimed to determine the effects of a new feed additive, microencapsulated NUQO© NEX, which...

The objective of the present study was to determine the effect of a novel (4th generation) phytase supplementation as well as its mode of action on growth, meat quality, and incidence of muscle myopathies. One-day old male broilers (n = 720) were weighed and randomly allocated to 30 floor pens (24 birds/pen) with 10 replicate pens per treatment. Th...

Castration is a widely practiced management strategy that results in temporary pain with adverse effects on growth performance. Therefore, humane alternatives must be investigated. Male beef calves (n = 81) were stratified by weaning weight and allocated to 1 of 8 pens. Pens were assigned randomly to treatment: 1) banded (B; n = 42) or 2) a 1 mL in...

With climate change, selection for water efficiency and heat resilience are vitally important. We undertook this study to determine the effect of chronic cyclic heat stress (HS) on the hypothalamic expression profile of water homeostasis‐associated markers in high (HWE)‐ and low (LWE)‐water efficient chicken lines. HS significantly elevated core bo...

Dilated cardiomyopathy (DCM) is a disease of the heart muscle resulting in decreased myocardial function and is the second most common myopathy in canine. Previously, canine dilated cardiomyopathy was considered to be an inherited disease among large and giant breeds, however, recent reports suggest a possible link between certain grain-free diets...

Modern broilers, selected for high growth rate, are more susceptible to heat stress (HS) as compared to their ancestral jungle fowl (JF). HS affects epithelia barrier integrity, which is associated with gut microbiota. The aim of this study was to determine the effect of HS on the cecal luminal (CeL) and cecal mucosal (CeM) microbiota in JF and thr...

Simple Summary Water scarcity is an increasing problem facing the global agricultural industry, particularly livestock production. The poultry industry is actively seeking opportunities to reduce the use of water for cooling broiler houses during hot summer months. We investigated a sprinkler system combined with a cool cell system and a cool-cell...

New initiatives are required to meet the future grand demand for affordable, high quality, and nutritious animal-derived proteins under planetary boundaries and already limited natural resources. The objective of the present study was to determine the effect of a novel (4th generation) phytase supplementation as well as its mode of action on growth...

This experiment determined the effects of different HS models and pair-feeding (PF) on nutrient digestibility and markers of stress, inflammation, and metabolism in broilers. Birds (720 total) were allocated into 12 environmentally controlled chambers and reared under thermoneutral conditions until 20 d. Until 41 d birds were exposed to 4 treatment...

Simple Summary The adverse effects of heat stress on poultry production sustainability are well known, however, there is still a paucity of information regarding its effect on meat quality. Here, we report the effect of heat stress and supplementation of exogenous phytase on growth performances, muscle myopathy incidence, and meat quality as well a...

Simple Summary As it is the first limiting amino acid, the use of DL-methionine in poultry diet formulation is critical for poultry growth, yet its mode of action is not fully defined. In this study, we conducted two peripheral and central feeding trials to determine the effect of DL-methionine and its analog HMTBa on growth performance, plasma met...

Femur head necrosis (FHN), also known as bacterial chondronecrosis with osteomyelitis (BCO), has remained an animal welfare and production concern for modern broilers regardless of efforts to select against it in primary breeder flocks. Characterized by the bacterial infection of weak bone, FHN has been found in birds without clinical lameness and...

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a specific cause of lameness in commercial fast-growing broiler (meat-type) chickens and represents significant economic, health, and wellbeing burdens. However, the molecular mechanisms underlying the pathogenesis remain poorly understood. This study represents the first comprehensive character...

Visfatin and adiponectin are two adipokines known to regulate energy homeostasis and stress response within different peripheral tissues. Their role and regulation in highly metabolically active tissue such as the muscle is of particular interest. As modern poultry exhibit insulin resistance, obesity, and hyperglycemia along with a lack of insight...

Mitigating the negative effects of heat stress (HS) is a critical challenge for the global poultry industry. This study evaluated the thermoregulatory potential of 3 in ovo delivered bioactive substances using selected gut health parameters. Eggs were incubated and allotted to 5 groups, and respective bioactive substances delivered. These groups in...

Although broiler (meat-type) chickens are one of the most efficient protein sources that supports the livelihoods and food security of billions of people worldwide, they are facing several challenges. Due to its unknown etiology and heavy economic impact, woody breast (WB) myopathy is one of the most challenging problems facing the poultry industry...

The present study aimed to determine the socio-economic and morpho-biometric characteristics of the local population of chickens in North Africa. A total of 250 chickens were sampled in three regions of the country of Tunisia. A complete description by direct observation, individual weighing, and body parts measurements were determined. The results...

Lameness is a leading cause of animal welfare and production concerns for the poultry industry as fast-growing, high-yielding broilers seem more susceptible to bone disease and infections. A major limitation to the study of these disorders is the lack of a chicken immortalized chondrocyte cell. Primary cell isolation is a valid and complex method f...

We received funding for a USDA SAS project that began in September (2019) that involves 7 institutions and approximately 30 faculty. Overarching goals of the project are to improve the system wide efficiency of nutrient and water use in broiler production through a) a better understanding and manipulation of the host physiology and microbial influe...

With the growing global demand for animal protein and rising temperatures caused by climate change, heat stress (HS) is one of the main emerging environmental challenges for the poultry industry. Commercially-reared birds are particularly sensitive to hot temperatures, so adopting production systems that mitigate the adverse effects of HS on bird p...

Heat stress (HS) compromises the yield and quality of poultry products and endangers the sustainability of the poultry industry. Despite being homeothermic, chickens, especially fast-growing broiler lines, are particularly sensitive to HS due to the phylogenetic absence of sweat glands, along with the artificial selection-caused increase in metabol...

Heat stress (HS) is devastating to poultry production sustainability due its detrimental effects on performance, welfare, meat quality, and profitability. One of the most known negative effects of HS is feed intake depression, which is more pronounced in modern high-performing broilers compared to their ancestor unselected birds, yet the underlying...

Simple Summary Heat stress (HS) represents an environmental and socio-economic burden to the poultry industry worldwide. However, the underpinning mechanisms for HS responses are still not well defined. Here, we used a high-throughput analysis to determine the metabolite profiles in acute and chronic heat-stressed broilers in comparison with thermo...

This experiment compared the effects of 2 chronic heat stress (HS) models, constant (coHS) and cyclic (cyHS), on broiler performance, carcass characteristics and meat quality. A total of 720 male chicks from a Cobb 500 line were placed in 12 environmentally controlled chambers divided into two pens of 30 birds. Before the experimental HS models wer...

Background Heat stress (HS) has negative effects on poultry productivity, health and welfare resulting in economic losses. Broiler chickens are particularly susceptible to HS due to their high metabolic rate and rapid growth. The commensal intestinal bacterial populations have an important physiological role in the host and could ameliorate the neg...

Neuropeptide Y (NPY) is one of the most abundant and ubiquitously expressed neuropeptides in both the central and peripheral nervous systems, and its regulatory effects on feed intake and appetite- have been extensively studied in a wide variety of animals, including mammalian and non-mammalian species. Indeed, NPY has been shown to be involved in...

‘Woody breast’ (WB) and ‘white striping’ in broiler meat is a global problem. With unknown etiology, WB negatively impacts bird health, welfare and is a significant economic burden to the poultry industry. New evidence has shown that WB is associated with dysregulation in systemic and breast muscle-oxygen homeostasis, resulting in hypoxia and anaem...

Originally named for its expression in the posterior hypothalamus in rats and after the Greek word for “appetite”, hypocretin, or orexin, as it is known today, gained notoriety as a neuropeptide regulating feeding behavior, energy homeostasis, and sleep. Orexin has been proven to be involved in both central and peripheral control of neuroendocrine...

Commercial broilers have been selected for high growth rate and productivity; however, this has negatively impacted their susceptibility to heat stress (HS). Insight into the molecular mechanisms underlying this vulnerability can help design targeted strategies for improvement of HS tolerance. Red blood cells (RBC) and white blood cells (WBC) were...

Autophagy is a cell survival and homeostasis mechanism involving lysosomal degradation of cellular components and foreign bodies. It plays a role in bone homeostasis, skeletal diseases, and bacterial infections as both a cell-survival or cell-death pathway. This study sought to determine if autophagy played a role in bacterial chondronecrosis with...

Reproductive behavior refers to the orderly sequence of behavioral events that are associated with reproduction, and it includes courtship, copulation, nest building, oviposition, incubation, and parental behavior. Reproductive behavior in vertebrates is thought to have evolved long before the ascent of birds. Presumably, as a result of this ancien...

Technological advances in the field of proteomics have enabled researchers to visualize and characterize diverse physiological states in organisms. In the field of avian research, the proteome responsible for egg composition, embryonic development, behavior, and plumage has been further expounded. In addition, production traits of the modern broile...

The biology of growth of avian species is discussed. The growth of birds follows a sigmoid curve and can be described using various mathematical models including Logistic equations or the Gompertz model. The growth rate of extant birds is high with altricial birds growing at faster rates than precocial birds but slower grow rates in early avian spe...

Proteins are of critical importance in birds, as in mammals, for their roles including in ensuring structures (such as collagen) and maintaining sophisticated control systems responsible for readily reversible oxygen carrying capacity, nuclear functioning, enzymatic, signal transduction mechanisms, defense against pathogens, and responses to other...

Meeting the challenge of optimizing productive efficiency, product quality and animal health and well-being requires a thorough understanding of the mechanisms that regulate and coordinate feed intake and energy metabolism. The regulation of feed intake consists of several overlapping neural and endocrine pathways involved in negative and positive...

Heat stress (HS) has been increasingly jeopardizing the sustainability of the poultry production. Moreover, modern high-performing chickens are far less able to withstand HS than their predecessors due to higher growth rate and metabolic rates. Performance losses caused by HS are mainly ascribed to decreases in feed consumption. Since feed intake i...

Heat stress has strong adverse effects on poultry production and, thereby, threats its sustainability, which energized scientists to search for innovative and effective solutions. Here, we undertook this study to evaluate the effects of in-feed herbal adaptogen (stress response modifier) supplementation on growth performances, meat quality, and bre...

Complex disease states, like bacterial chondronecrosis with osteomyelitis (BCO), not only result in physiological symptoms, such as lameness, but also a complex systemic reaction involving immune and growth factor responses. For the modern broiler (meat-type) chickens, BCO is an animal welfare, production, and economic concern involving bacterial i...

Heat stress (HS) has been reported to disrupt nutrient digestion and absorption in broilers. These effects may be more prominent in fast-growing chickens due to their high metabolic activity. However, the underlying molecular mechanisms are not yet fully elucidated. Hence, the current study aimed to evaluate the effect of chronic HS on jejunal nutr...

Muscle development during embryonic and early post-hatch growth is primarily through hyperplastic growth and accumulation of nuclei through satellite cell contribution. Post-hatch, muscle development transitions from hyperplasia to hypertrophic growth of muscle fibers. Commercial selection for breast yield traditionally occurs at ages targeting hyp...

Simple Summary Broilers are especially heat sensitive because of the absence of sweat glands and their elevated metabolism. Under commercial conditions, extremely high temperatures (heat stress) reduce their performance. This research aimed to assess spray-dried feeding plasma (SDP) during constant heat stress (HS) on the performance, intestinal pe...

This study was conducted to distinguish the effects of heat stress (HS) and feed intake (FI) on broiler chicken’s physiological responses. Day-old male Cobb 500 broilers (n = 672) were allocated to three treatments: (1) control (CTL): birds raised under normal temperature (23°C) from day 29 to 42; (2) cyclic heat stress (CHS): birds exposed to high...

Proteins are considered the most expensive nutrients in commercial modern broiler production, and their dietary inclusion at low levels is pivotal to minimize feed costs and reduce nitrogen waste. The quest for an environmentally friendly source of proteins that favor the formulation of low protein diets without compromising broiler health, welfare...

Neuropeptide Y (NPY) is a highly conserved 36-amino acid neurotransmitter, which is primarily expressed in the mammalian arcuate nucleus of the hypothalamus. It is a potent orexigenic neuropeptide, stimulating appetite and inducing feed intake in a variety of species. Recent research has shown that NPY and its receptors can be expressed by peripher...

Simple Summary The use of essential oils in animal feeding has been practiced for their role as antibacterial, antiviral, antifungal, antioxidant, digestive stimulants, immunomodulators, hypolipidemic agents, and heat stress alleviators. The objective of the present research was to assess dietary supplementation of three formulations of essential o...

Simple Summary Global concern around and heightened sensitivity to emerging drug-resistant superbugs have energized scientists to search for new alternatives to in-feed antibiotics. Powered by consumer demand for natural products and due to their beneficial effects on growth performances, phytogenics have become very popular and favorable alternati...

Woody breast (WB) condition has created a variety of challenges for the global poultry industry. To date, there are no effective treatments or preventative measures due to its unknown (undefined) etiology. Several potential mechanisms including oxidative stress, fiber-type switching, cellular damage, and altered intracellular calcium levels have be...

Heat stress (HS) is devastating to the poultry industry due to its adverse effects on animal well-being and performance. The effects of heat stress are typically measured using a portable i-STAT blood analyzer that quantifies circulatory hemoglobin concentration and other blood chemistry parameters. Here, we used diffuse reflectance spectroscopy (D...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

A leading cause of lameness in modern broilers is bacterial chondronecrosis with osteomyelitis (BCO). While it is known that the components of BCO are bacterial infection, necrosis, and inflammation, the mechanism behind BCO etiology is not yet fully understood. In numerous species, including chicken, mitochondrial dysfunction has been shown to hav...

Published literature elucidating dietary valine (Val) requirements for female broilers is limited and lacks data for the finisher phase. Three experiments (Exp) were conducted to determine the Val requirement for Cobb MX × 500 females during the grower (Exp 1; 14 to 28 days), finisher (Exp 2; 28 to 42 days), and withdraw periods (Exp 3; 42 to 56 da...

In an effort to understand the apparent trade-off between the continual push for growth performance and the recent emergence of muscle pathologies, shotgun proteomics was conducted on breast muscle obtained at ~8 weeks from commercial broilers with wooden breast (WB) myopathy and compared with that in pedigree male (PedM) broilers exhibiting high f...

the PDF can be download freely on pubmed. https://pubmed.ncbi.nlm.nih.gov/33634751/

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...

Neuropeptide Y (NPY) is a highly conserved 36-amino acid neurotransmitter, which is primarily expressed in the mammalian arcuate nucleus of the hypothalamus. It is a potent orexigenic neuropeptide, stimulating appetite and inducing feed intake in a variety of species. Recent research has shown that NPY and its receptors can be expressed by peripher...

The research-teaching nexus is the pinnacle of academic activity. As a scientist and educator, my overall objective is to give students access to cutting-edge research and help them develop high order inquiry skills. In addition, as research and thesis writing frequently involves the development of new complex reading skills associated with compreh...

Lipid metabolism in avian species places unique demands on the liver in comparison to most mammals. The avian liver synthesizes the vast majority of fatty acids that provide energy and support cell membrane synthesis throughout the bird. Egg production intensifies demands to the liver as hepatic lipids are needed to create the yolk. The enzymatic r...

The phytogenic AV/HGP/16 premix (AVHGP), superliv concentrate premix (SCP), and bacteriostatic herbal growth promotor with essential oils (BHGP)-enriched diets have been shown to improve feed efficiency (FE) in broilers. This FE improvement was achieved via modulation of hypothalamic neuropeptides, which results despite feed intake reduction, in in...

To determine how soy protein isolate (SPI) ameliorated liver steatosis in male obese Zucker rats, we conducted global transcriptomic expression (RNAseq) analysis on liver samples of male rats fed either the SPI or a control casein (CAS)-based diet (n = 8 per group) for 16 weeks. Liver transcriptomics were analyzed using an Ilumina HiSeq system with...

Bacterial chondronecrosis with osteomyelitis (BCO) is one of the leading causes of lameness and welfare concerns in the modern broiler. The avian bone physiology and remodeling process is complex and dependent on numerous bone and vascular cell types and pathways working harmoniously. The rapid growth rate of the leg bones in the modern broiler cou...

Chickens provide models for human physiology research, as their normal physiological status mimics mammalian obesity and human Type II diabetes. Metformin is a common medication used to treat Type II diabetes. Prior studies have demonstrated metformin’s ability to induce the “browning” phenomenon of white adipose tissue and promote non-shivering th...

In general, upstream regulator predictions indicate that processes associated with anti-inflammation were present in livers of rats fed with Soy Protein Isolate, whereas processes of inflammation were observed in the livers of rats fed with Casein as control.

Orexins are originally characterized as orexigenic hypothalamic neuropeptides in mammals. Subsequent studies found orexin to be expressed and perform pleiotropic functions in multiple tissues in mammals. In avian (non-mammalian) species, however, orexin seemed to not affect feeding behavior and its physiological roles are poorly understood. Here, w...

Heat stress (HS) is a critical concern to the poultry industry, as it affects both productivity and wellbeing. Various managerial and nutritional strategies have been proposed to mitigate the negative effects of HS in chickens, with plant-based additives showing promise. Recently, we reported the positive effect of a phytogenic feed additive (PFA)...

The mechanisms leading to sarcopenia, the main cause for frailty in older adults, are still unclear. Autophagy and the ubiquitin-proteasome system (UPS) may play a role in mediating muscle protein breakdown related to sarcopenia. In addition to loss of muscle mass, compromised muscle performance observed in sarcopenic patients has been linked to mu...