Restricted Feeding Research Articles

Effects of time restricted feeding combined with Lacto Ovo vegetarian diet on metabolic associated fatty liver disease management: a randomized clinical trial

Metabolic Associated Fatty Liver Disease (MAFLD) is becoming a major global health concern due to its links with obesity, insulin resistance, and cardiovascular risk. This randomized clinical trial assessed the effects of combining time-restricted feeding (TRF; 16/8) with a Lacto-Ovo-Vegetarian (LOV) diet on various factors in overweight and obese patients with MAFLD. Forty-six participants were randomly assigned to either the intervention group (TRF with LOV diet) or the control group, with 21 participants completing the 12-week study in each group. The intervention group showed significant reductions in weight (-8.07 ± 4.31 kg), BMI (-2.70 ± 1.32 kg/m2), waist circumference (-8.00 ± 4.06 cm), as well as ALT (-17.14 ± 14.33 U/L), GGT (-21.09 ± 24.06 U/L), Fatty Liver Index (-26.90 ± 15.81), insulin levels (-3.89 ± 4.69 mU/L), and TNF-α (-11.85 ± 12.52 pg/mL) compared to the control group (all P < 0.05). Lipid profiles also improved with a reduction in triglycerides (-46.85 ± 54.55 mg/dL) and an increase in HDL-C (3.91 ± 5.07 mg/dL) in the intervention group compared to the control group (P < 0.05). These findings imply that TRF combined with a LOV diet enhances metabolic markers, liver health, and weight loss, thus potentially offering a practical dietary approach for managing MAFLD. Further long-term studies are necessary to validate these results and investigate their clinical applications.

Interaction between feeding regimen, NSPase enzyme and extent of grinding of barley-based pelleted diets on the performance, nutrient digestibility and ileal microbiota of broiler chickens

ABSTRACT 1. The effects of feeding regimen, NSPase, extent of grinding and their interaction on the performance, digestive tract characteristics and ileal microbiota were studied. Eleven-day-old Ross 308 male broilers were given ad libitum (ADL) or intermittent (INT) access to finely (FG) or coarsely (CG) ground barley-based pelleted diets, with or without NSPase in a replicated pen trial. All birds had 4 h darkness separated with 1 h light periods with feed access. In addition, INT birds had access to feed through three 1 h feeding periods and one 2 h feeding period, with 3 h feed restriction periods between. 2. The INT feeding decreased weight gain (p < 0.001) but did not affect FCR. Supplementation with NSPase increased (p = 0.018) weight gain, but there was a tendency (p = 0.063) for it to be improved in INT-fed birds only. Including NSPase improved FCR, but only with FG diets (p = 0.037) and in INT group (p = 0.033). 3. The CG diet significantly reduced (p = 0.044) pH of the gizzard contents and increased (p = 0.035) gizzard relative weight compared to FG. Addition of NSPase (p < 0.001) or FG (p = 0.049) reduced jejunal digesta viscosity. The FG diet improved (p = 0.019) starch digestibility compared to CG. In NSPase-supplemented diets, CG increased ileal protein digestibility compared to FG in birds fed ADL only, resulting in a three-way interaction(p = 0.012). 4. The FG diet increased ileal concentration of total eubacteria and Lactobacillus spp. (p = 0.049), whilst INT feeding increased ileal concentration of Streptococcus spp. (p = 0.001). In NSPase-containing diets, FG increased ileal density of Enterococcus spp. in INT-fed birds (p = 0.027). 5. In conclusion, finely-ground barley in pelleted diets responded better to SPase enzymes than coarsely ground, particularly under INT feeding.

Caloric Restriction Preserves BBB Integrity After Transient Focal Cerebral Ischemia Through Reducing Neutrophil Infiltration.

Caloric restriction is a health-promoting lifestyle that has been reported to protect both white and gray matter in cases of ischemic stroke. This study will explore the underlying mechanism of restricted feeding (RF) and provide a theoretical basis for precise clinical treatment of stroke. In this study, we pretreated C57BL/6J mice with 70% RF for a continuous 28-day period prior to 60 min of transient focal cerebral ischemia (tFCI). Histological staining, diffusion tensor imaging (DTI), and behavioral assessments were used to assess RF's neuroprotection following tFCI. Immunofluorescence staining, quantitative real-time PCR, and flow cytometry were conducted to evaluate brain inflammation post-tFCI. Western blot, immunofluorescence staining, tracers, and electric microscopy were used to assess the blood-brain barrier (BBB) integrity. Peripheral neutrophils were cleared by administrating an anti-Ly6G antibody. Initially, DTI, NeuN staining, and a batch of behavioral tests verified that RF significantly mitigated both gray/white matter injury and neurological deficits in the short- and long-term following tFCI. RF mice showed more anti-inflammatory microglia in their brains, along with reduced inflammatory cytokines, and chemokines. Interestingly, RF significantly reduced the neutrophils and macrophage infiltration. Subsequently, we observed that RF mice exhibited better BBB integrity following tFCI, with reduced neutrophil infiltration and matrix metalloprotein-9 release. Furthermore, the clearance of neutrophils with anti-Ly6G antibody in adlibitum feeding mice (LF-Ly6G) elicited comparable neuroprotective effects to those observed in RF, including improvements in neurological deficits, reductions in infarct volume, and mitigation of BBB damage. In summary, our findings suggest that RF maintains the BBB integrity following ischemic stroke at least partially by reducing neutrophil infiltration, thereby alleviating both neurological and histological impairments.

Lactational high weight loss impairs follicular development by causing mitochondrial dysfunction of ovarian cells in sows and mitigated by butyrate supplement.

In modern sows, lactational high weight loss (HWL), caused by the large litter size and inadequate feed intake, has a negative effect on follicular development after weaning, resulting in poor reproductive performance in the subsequent parity. However, the underlying mechanism remains unclear. This research aimed to explore the mechanism that sows HWL during lactation damages follicular development and attempt to improve the reproductive function by treating with butyrate. Four multiparous sister sows were chosen to build a HWL model for lactating sows through feed restriction during the final week of a 21-day lactation. Spatially transcriptomics (ST) and tissue immunofluorescent staining were then utilized for the antral follicles in the ovarian surface to search for differentially expressed genes and proteins among different cell types. Subsequently, the mouse assay, including immunofluorescent staining, transmission electron microscopy, hormone detection and western blot, were conducted to verify the findings in sows and investigate the effect of butyrate on the follicular development in HWL mice. Based on the transcriptomic analysis, differentially expressed genes in granulosa cells, theca cells, and ovarian stromal cells were examined. The findings revealed that HWL disturbs the mitochondrial electron transport chain and steroidogenesis in all three cell types by downregulating the expression of NDUFB3, SDHB, CYCS, COX8A and CYP19A1, as well as upregulating the expression of STAR, CYP11A1 and CYP17A1. Furthermore, results from mouse assays demonstrated that HWL causes apoptosis and alters sex hormone secretion by impairing mitochondrial function and disordering the expression of steroidogenesis key enzymes in ovarian cells, while these effects were partially mitigated by butyrate. The mitochondrial dysfunction and abnormal steroidogenesis induced by HWL during lactation in ovarian cells harm the follicular development of weaning sows, which could be alleviated by butyrate.

Research Note: Do broiler breeder hens use hypothermia to cope with cold environments and feed restriction?

Research Note: Do broiler breeder hens use hypothermia to cope with cold environments and feed restriction?

Parental Weight Stigma Associated with Self-Directed Weight Talk and Use of Health-Related Restrictive Feeding Practices.

Parents are important conduits of weight- and health-related messaging. Weight-related communication and approaches to child feeding used by parents may reflect their past experiences with weight stigma and are understudied pathways through which intergenerational weight stigma may be transmitted. To examine how experienced and internalized weight stigma among parents of children with higher weights are associated with weight-related communication and the feeding practices they use. The Listening to Parents study is a cross-sectional study of 103 parent-child dyads who completed in-person study visits at the University of Michigan in Ann Arbor, Michigan between November 2022 through June 2023. Participants were parents of children (ages 6 to 14 years, identified by parents as "heavier or overweight") who completed the Stigmatizing Situations Inventory Brief (SSI-B) and Weight Bias Internalization Scale-Modified (WBIS-M), as well as questions about weight-related communication and the Comprehensive Feeding Practices Questionnaire (CFPQ). Outcomes included 5 items corresponding to parental weight-related communication (self-directed, other-directed, and child-directed weight talk, child-directed weight teasing, and child-directed encouragement to lose weight) and 3 CFPQ subscales (Monitoring, Restriction for Health, and Restriction for Weight Control). Linear regression models were used to examine associations between mean scored parent- experienced and parent-internalized weight stigma and weight-related communication and feeding practices. Models were adjusted for child gender, parent-perceived child weight status, parental race/ethnicity, parental body mass index, and household income-to-needs ratio. In covariate-adjusted models, parent-internalized weight stigma was positively associated with self-directed weight talk (β=0.20, SE=0.078, p=0.01) and greater use of health-related restrictive child feeding practices (β=0.16, SE=0.070, p=0.02). No other significant associations in covariate-adjusted models were observed. While parents with greater internalized weight stigma may engage in more self-directed weight talk, they may also be more attuned to the harms of weight stigma and seek to minimize child-directed weight talk and weight teasing.

Effects of restricted feeding rates on growth, production, and economics of Nile tilapia (Oreochromis niloticus) and giant freshwater prawn (Macrobrachium rosenbergii) polyculture in pond-based biofloc and traditional grow-out system

Effects of restricted feeding rates on growth, production, and economics of Nile tilapia (Oreochromis niloticus) and giant freshwater prawn (Macrobrachium rosenbergii) polyculture in pond-based biofloc and traditional grow-out system

The research progress and prospects of circadian rhythm in obesity: a bibliometric analysis.

Numerous studies have shown a link between circadian rhythms disruptions and a higher risk of obesity. This article aims to conduct an extensive bibliometric analysis to deepen our understanding of the relationship between circadian rhythms and obesity. The literature related to the circadian rhythm of obesity, published from the inception of the Web of Science Core Collection (WoSCC) until June 30, 2024, was extracted from the WoSCC databases (SCIE, SSCI, ESCI). Using CiteSpace, Vosviewer, WPS, and other software, this paper examines the publication trends, including the number of papers, countries/regions, institutions, authors, journals, references, and keywords. A total of 2,870 articles were included in this analysis, revealing a consistent year by year increase in research on the circadian rhythm of obesity. These publications originate from 460 institutions in 88 countries. Among the authors analysis, Garaulet, Marta was the most prolific, and Turek FW was the most co-cited. Proceedings of the National Academy of Sciences of the United States of America emerged as the journal with the highest number of publications, and American Journal of Physiology had the highest centrality. The most frequently used keywords were "obesity," "circadian rhythm," "circadian clock," "metabolic syndrome," "metabolism." Additionally, research areas involving intermittent fasting, restricted feeding, and gut microbiota were rapidly developing and represented the forefront of research on circadian rhythms and obesity. Our study demonstrates that research on circadian rhythms in obesity has been rapidly expanding, with increasingly in-depth exploration of the topic. It is recommended to strengthen cooperation between countries and institutions to jointly promote research in this field. The gene expression of obesity is an early hotspot in the study of circadian rhythm and obesity, and emerging research areas such as intermittent fasting, restricted feeding, endothelial nitric oxide synthase and gut microbiota will become significant hotspots and trends in the field of circadian rhythm and obesity. These findings provide researchers critical directions for future studies and may have significant implications for clinical practice and public health policy.

Feed efficiency and resilience in dairy ewes subjected to a nutritional challenge.

It is currently uncertain how selection of more efficient animals might impact other traits such as resilience (which, in this context, is defined as the ability of an animal to sustain or revert quickly to its previous production level and health status after a disturbance), especially in small ruminants. However, improving, or at least maintaining, resilience is of utmost importance to ensure livestock production in the face of external perturbances, which are expected to become more prevalent in the near future due to climate change and global instability. This study was conducted to investigate whether a nutritional challenge consisting of animals receiving only 70% of their voluntary feed intake (DMI) for 26 d, might differentially affect the response of high- and low-feed efficiency (FE) sheep. To meet this aim, residual feed intake (RFI), as a proxy of FE, was calculated in 40 lactating ewes fed a total mixed ration ad libitum. Using the RFI values, the ewes with the highest (H-FE; n = 8) and the lowest (L-FE; n = 8) FE were selected and subjected to the nutritional challenge. After the feed restriction, all sheep were again fed ad libitum for a further 25 d. Temporal patterns of variation in animal performance, ruminal fermentation and blood and milk metabolites in response to, and recovery from, the underfeeding were examined in H-FE versus L-FE. More efficient ewes (H-FE) tended to eat less than less efficient ewes (L-FE) for the same level of production. Linear regressions for DMI and milk yield data showed that time-series response to the challenge was comparable in L-FE and H-FE. Despite temporal changes due to underfeeding, both FE divergent groups displayed a similar response to, and recovery from, the challenge with no significant differences in the temporal patterns of variation of the parameters analyzed, except for a tendency to higher plasma glucose in the L-FE ewes. These results challenge the general hypothesis that more efficient animals would be less resilient, but further research is still needed on the relationship and possible trade-offs between high efficiency and resilience.

Maternal circadian rhythms during pregnancy dictate metabolic plasticity in offspring.

Tissue-level oscillation is achieved by tissue-intrinsic clocks along with network-dependent signals originating from distal organs and organismal behavior. Yet, it remains unexplored whether maternal circadian rhythms during pregnancy influence fetal rhythms and impact long-term susceptibility to dietary challenges in offspring. Here, we demonstrate that circadian disruption during pregnancy decreased placental and neonatal weight yet retained transcriptional and structural maturation. Intriguingly, diet-induced obesity was exacerbated in parallel with arrhythmic feeding behavior, hypothalamic leptin resistance, and hepatic circadian reprogramming in offspring of chronodisrupted mothers. In utero circadian desynchrony altered the phase-relationship between the mother and fetus and impacted placental efficiency. Temporal feeding restriction in offspring failed to fully prevent obesity, whereas the circadian alignment of caloric restriction with the onset of the active phase virtually ameliorated the phenotype. Thus, maternal circadian rhythms during pregnancy confer adaptive properties to metabolic functions in offspring and provide insights into the developmental origins of health and disease.

Responses of Poultry to Heat Stress and Mitigation Strategies During Summer in Tropical Countries: A Review&lt;b&gt;&lt;/b&gt;

The poultry industry faces increasing challenges from heat stress caused by global warming, particularly in tropical regions. Heat stress, caused by rising environmental temperatures, undermines the health and productivity of poultry, resulting in significant economic losses. This review comprehensively addresses the physiological and behavioural responses of poultry to heat stress and explores the key mitigation strategies, categorized under genetics, management and feeding. Genetic approaches, like utilizing specific genes in breeding, show promise but require wider adoption. Management practices such as housing design, including orientation, insulation and ventilation, controlled lighting and thermal manipulation are critical to maintaining poultry in their thermoneutral zone. Furthermore, feeding strategies like feed restriction, dual feeding and nutritional manipulation have shown promise in reducing heat stress effects. In addition to feeding strategies, water management is also crucial for mitigating heat stress, especially in tropical areas. Ensuring sufficient water space, maintaining operating waterers, and keeping water cool are essential to encourage adequate drinking. Despite progress, further investigation is required to explore the synergistic effects of combined strategies to improve the resilience of poultry. This review highlights the urgent need for comprehensive approaches to mitigate heat stress in poultry to ensure sustainable productivity under the challenges of global warming

Time restricted feeding with or without ketosis influences metabolism-related gene expression in a tissue-specific manner in aged rats.

Many of the 'hallmarks of aging' involve alterations in cellular and organismal metabolism. One pathway with the potential to impact several traditional markers of impaired function with aging is the PI3K/AKT metabolic pathway. Regulation of this pathway includes many aspects of cellular function, including protein synthesis, proliferation and survival, as well as many downstream targets, including mTOR and FOXOs. Importantly, this pathway is pivotal to the function of every organ system in the human body. Thus, we investigated the expression of several genes along this pathway in multiple organs, including the brain, liver and skeletal muscle, in aged subjects that had been on different experimental diets to regulate metabolic function since mid-life. Specifically, rats were fed a control ad lib diet (AL), a time restricted feeding diet (cTRF), or a time restricted feeding diet with ketogenic macronutrients (kTRF) for the majority of their adult lives (from 8-25 months). We previously reported that regardless of macronutrient ratio, TRF-fed rats in both macronutrient groups required significantly less training to acquire a biconditional association task than their ad lib fed counterparts. The current experiments expand on this work by quantifying metabolism-related gene expression across tissues and interrogating for potential relationships with cognitive performance. AKT expression was significantly reduced in kTRF fed rats within liver and muscle tissue. However, AKT expression within the perirhinal cortex (PER) was higher in kTRF rats with the best cognitive performance. Within CA3, higher levels of FOXO1 gene expression correlated with poorer cognitive performance in ad libitum fed rats. Together, these data demonstrate diet- and tissue-specific alterations in metabolism-related gene expression and their correlation with cognitive status.

Both Feed Restriction and Transition Period Suppressed Adipose Tissue MRNA Abundance of Genes Involved in Lipogenesis and Lipolysis in Fat-Tailed Ewes.

This study sought to investigate the consequences of the induced feed restriction during the transition period on the mRNA abundance of genes entangled in lipogenesis and lipolysis in the tail adipose of fat-tailed sheep. Twenty fat-tailed ewes were randomised into the control (Control; n = 10) and restriction (Restriction; n = 10) groups. Control animals were fed 100% of the balanced diet pre-(Week -5 to parturition) and post-partum (parturition to Week 5). Restriction ewes received equivalent 100%, 50%, 65%, 80%, and 100% of the balanced ration at Weeks -5, -4, -3, -2, and -1 relative to parturition, respectively. After parturition, the latter group received the equivalent of 100%, 50%, 65%, 80%, and 100% of the diet recommendation at weeks 1, 2, 3, 4, and 5, respectively. At the end of weeks -3 and 3, tail adipose were sampled under local anesthesia. Fatty acid synthase, acetyl-CoA carboxylase, carnitine palmitoyltransferase I and II, and acyl-CoA synthase long-chain family member-1 mRNA abundances were measured using the TaqMan quantity real-time PCR. A mixed model procedure of SAS software was used to evaluate the results. Feed restriction downregulated target genes' mRNA abundance during both pre- and post-partum. Parturition suppressed the mRNA abundance of measured genes in both groups. Established on the outcomes, lipogenesis, and lipolysis of the adipose tissue would be influenced by metabolite and hormone instability during the transition period and feed restriction. The lessening of adipose tissue lipogenesis and lipolysis might be a hemostatic response to cope with the energy insufficiency for fetal growth and the onset of lactation and also prevent the induction of inflammation, metabolic disorders, and infectious diseases during feed restriction or transition period.

Time-Restricted Eating and Cancer: Lessons Learned and Considerations for a Path Forward.

Time-restricted eating (TRE) is a type of intermittent fasting (IF). Food can be consumed as desired during the eating period, but not during the remainder of the day. Studies suggest that many of the health benefits of fasting may not simply be the result of weight loss, but also due to the body's responses to the fasting that lead to improved metabolic functioning. While animal studies are convincing regarding the benefits of time restricted feeding, human (TRE) studies are less consistent and generally short term (< 1 year). In 2020, the National Cancer Institute (NCI) funded five IF studies, four of which focused on TRE, which addressed the question "How does intermittent fasting affect cancer incidence, treatment response, or outcome?" NCI sponsored a webinar in 2023 featuring investigators of the funded studies in which they discussed challenges as well as their thoughts regarding the most important TRE topics that should be addressed going forward. Six areas were identified, which are discussed below as well as in a recently published NOT-CA-24-073: Factors impacting how Time-Restricted Eating (TRE) influences cancer-related outcomes. Moving the science forward will allow the scientific community to better understand TRE's potential. This potential includes the development of targeted TRE interventions to optimize long-term adherence to the intervention, which is required to better understand fully explore its potential benefits in cancer risk, increased response to cancer treatment, as well as improved quality and quantity of life among cancer survivors.

The effect of different dietary manipulations on haematological properties in Japanese quail

Quantitative and qualitative dietary conditions are crucial for physiological functions. Blood haematology, the indicator of immune regulation, is critically affected by dietary conditions. Despite their importance, the effect of macro- and micronutrient manipulation remains unknown. We used feed restriction, energy or protein restriction, and supplementation of leucine, methionine, or both on top of restricted-feeding to study the effect on haematological properties in Japanese quail. Fifty-six birds of six weeks of age were distributed into seven treatments; control, 20% feed restriction, 20% energy restriction, 20% protein restriction, supplementing 20% leucine, 20% methionine, or both on top of restricted feeding. Haematological properties, including white blood cell count, number and percent of lymphocytes, mid-range (eosinophil + basophil), granulocytes, red blood cell count, haemoglobin levels, packed cell volume, mean corpuscular volume, and mean corpuscular haemoglobin were analysed. We found that quantitative feed restriction, energy restriction, and amino acid supplementations showed no significant effect compared to the control group. However, protein restriction reduced all indices, suggesting the importance of proteins in maintaining leukocyte and erythrocyte indices. The present study revealed that neither moderate calorie restriction nor moderate specific amino acid supplementation have an impact on blood haematology, while 20% protein restriction has a notable effect.

Avifaunal diversity of Daranghati Wildlife Sanctuary, India

Abstract Birds are among the most charismatic animals on our planet. Worldwide, there are about 11,000 different avian species. BirdLife International (2024) has listed 1,211 bird species that occur in India, demonstrating its immense diversity. Of these species, the majority (about 80%) are restricted to the Himalayas. To contribute to our knowledge on avian diversity in India, we conducted avifaunal surveys in the Daranghati Wildlife Sanctuary, located in Shimla district of Himachal Pradesh, India. A total of 76 species of birds, representing 11 orders, 32 families, and 59 genera, were recorded. Passeriformes dominated the avifauna with 56 species. Muscicapidae was the most abundant family enumerating 12 species. The second largest family was Fringillidae including 6 species, closely followed by Paridae and Phasianidae, with 5 species each. Of the 76 species recorded, 22 (28.95%) were classified as very common, 25 (32.90%) as common, 21 (27.63%) as uncommon, and 8 species (10.52%) as rare. The Western Tragopan (Tragopan melanocephalus) is a vulnerable species and the Himalayan Griffon (Gyps himalayensis) is listed as a near-threatened species as per IUCN Red List. Around 30% of the species belong to very narrow and restricted feeding guilds. The study also revealed the presence of 21 bird species with a decreasing population trends as provided by the global IUCN population assessments, thereby highlighting the importance and imperative of conservation measures in this Wildlife Sanctuary.

Untargeted urine metabolomics suggests that ascorbic acid may serve as a promising biomarker for reduced feed intake in rabbits

Feed restriction is a common nutritional practice in rabbit farming; however, decreased feed intake can also signal potential digestive disorders at an early stage. This study endeavors to investigate the impact of feed restriction on selected productive traits and the urinary metabolome of juvenile rabbits across diverse genetic backgrounds. Our objective is to identify potential biomarkers capable of detecting periods of fasting. A total of 48 growing rabbits were used from two genetic types: Prat line (selected for litter size at weaning, n = 24) and Caldes line (selected for post-weaning growth rate, n = 24). At 60 days of age, a digestibility trial was carried out. Changes in productive traits (through bioelectrical impedance analysis, live weight control, average daily gain, energy, and protein retention) were evaluated when the animals were fed ad libitum from 60 to 64 days of age and when the same animals were subjected to feed restriction (50% of maintenance energy requirements) from 70 to 74 days of age, in a split-plot trial. In addition, untargeted urine metabolomics analysis was performed at both periods (ad libitum vs. restricted). Although some differences between genetic lines were observed in the animals’ performance traits (average daily gain and retention of energy and protein), no differences in the urine metabolome were found between genetic types. However, feed restriction caused notable changes in the metabolome. When the animals were subjected to feed restriction, they had higher levels of ascorbic acid (P = 0.001) and p-cresol sulphate (P = 0.058) and lower levels of pyrocatechol sulphate/hydroquinone sulphate (P < 0.001), resorcinol sulphate (P = 0.002), enterolactone sulphate (P < 0.001), enterolactone (P < 0.001), kynurenic acid (P = 0.0002), proline betaine (P < 0.001), pipecolic acid betaine (P < 0.001), xanthurenic acid (P < 0.001) and quinaldic acid (P < 0.001) than the same animals when they were fed ad libitum. This study proposes urine ascorbic acid as potential biomarker for fasting events in rabbits. As urine ascorbic acid is the sole metabolite that significantly increases in the restricted group, it offers promising indicator for early detection and targeted management of digestive disorders in rabbits.

Impact of Growth Rate on the Welfare of Broilers.

Selection for the more efficient production of broilers has resulted in rapid growth rates. The aim was to review the existing knowledge on the effect of growth rate on broiler welfare. Genotypes with faster growth rates consistently demonstrate poorer gait scores and increased prevalence of disorders affecting their legs than slower-growing genotypes. Reduced mobility places faster-growing broilers at an increased risk of developing contact dermatitis, as they spend increased durations sitting in contact with litter. Poor walking ability, heavy body weights, and conformational differences such as proportionally larger breast muscle in genotypes with faster growth can impact a bird's ability to walk and navigate the environment, making it difficult to access resources and express natural behaviors. Faster growth has also been associated with poor cardiovascular health, increased susceptibility to heat stress, increased prevalence of mortality, ascites, as well as multiple breast muscle myopathies. Feed restriction, a practice associated with hunger and frustration, may be used to control the growth of broiler breeders, with birds having higher growth potential typically experiencing higher restriction levels. Overall, there is strong evidence that fast growth rates negatively impact welfare, and that slower-growing genotypes show significantly improved welfare. Furthermore, some evidence suggests that even minor reductions in growth rate can lead to welfare improvements.

Probiotic post feed restriction supplementation on realimentation performances, carcass characteristic, gut morphology and gut microbes of broiler chicken

Probiotic post feed restriction supplementation on realimentation performances, carcass characteristic, gut morphology and gut microbes of broiler chicken

Hepatic Transcriptomics of Broilers with Low and High Feed Conversion in Response to Caloric Restriction.

In broiler chickens, the efficient utilization of macro- and micronutrients is influenced by various metabolic pathways that are closely linked to feed efficiency (FE), a critical metric in poultry industry, with residual feed intake (RFI) as the preferred proxy. Feed restriction is considered an approach to address the underlying molecular mechanisms of feed conversion. We hypothesized that broiler chickens with divergent RFI subjected to quantitative feed restriction differ in their pattern of molecular pathways for efficient nutrient utilization in liver as post-absorptive tissue. Cobb 500FF broiler chickens divergent for RFI (n = 112) were feed-restricted from day 9 until market weight at day 33-37 post-hatch. Based on a previous trial, feed restriction levels were set at 92% (low-RFI birds) and 80% (high-RFI birds) relative to the control groups. Transcriptomic analyses of the liver were conducted. Due to the interaction of the RFI group and feeding regimen, a total of 140 to 507 differentially expressed genes were identified for the respective contrasts, with implications for hepatic metabolism and cellular stress response. Although the broilers did not realize their full growth potential under restrictive feeding (12.4% reduced body weight vs. controls, p = 0.094), the gene expression patterns indicate a lower susceptibility to blood coagulation (KNG1, FGG, and FGB), suggesting that controlled and mild feed restriction could lead to health benefits in less feed-efficient broilers. Moreover, FE traits are shown to be linked to cellular detoxification processes (MGST3 and CYP2AC2) and triacylglycerol syntheses (MOGAT1 and LPIN1). Divergent transcriptional profiles between broiler groups under varied caloric conditions indicate potential for optimizing nutritional management strategies.