Physiological Responses of Slow-Growing Chickens under Diurnally Cycling Temperature in a Hot Environment

Thermoregulatory Response, Growth Performance and Organ Weights of FUNAAB-Alpha Chicken Genotypes Administered Sweet Citrus Peel Powder

Thermoregulatory response and growth performance of FUNAAB-Alpha chickens administered sweet citrus peel powder (SCPP) were investigated in a twelve weeks experiment. A total of 360 1-day-old FUNAAB Alpha chicks were used for the study, comprising 120 birds per genotype: Normal feather (NF), Naked neck (NN) and Frizzle feather (FF). Birds were randomly allotted into 12 treatment groups: NF: 0 g, 3 g, 6 g and 9 g of SCPP, NN: 0 g, 3 g, 6 g and 9 g of SCPP, FF: 0 g, 3 g, 6 g and 9 g of SCPP. Each treatment was replicated thrice with 10 birds per replicate. No (p > 0.05) interactive and main effect of genotype and dosage of SCPP was observed on the Rectal temperature, Skin temperatures under wing and of the breast among the treatments. Similar (p > 0.05) interactive effect was observed on the respiratory rate (RR), however, higher (p < 0.001) RR was recorded in NN and FF compared with NF. Birds in the control group had the highest (p < 0.005) RR compared with birds administered 3 g and 9 g of SCPP/L of water. Interaction and main effect of SCPP dosage on heterophil (H), lymphocyte (L) and heterophil lymphocyte ratio (H/L) were not significant (p > 0.05) across the treatment groups. However, genotype significantly (p < 0.000) influenced H, L and H/L. The FF and NN had significantly (p < 0.000) lower H/L compared with the NF. Higher (p < 0.000) weight gain (WG) was observed in FF and NN compared to NF chickens. Significantly (p < 0.020) lower FCR was observed in 6 g/L (2.26), 3 g/L (2.65) and 9 g/L (2.66) of FF compared with NF on 9 g/L (4.03). Dosage of SCPP significantly (p < 0.001) influenced the relative weights of the intestine. In conclusion, lower H/L, higher WG and better FCR were observed in the NN and FF genotypes with the best FCR recorded at 6 g SCPP/L of water.

Effects of naked neck and frizzle genes on growth and egg-laying performance of chickens in the tropics in an era of climate change

In regions characterized by tropical and subtropical climates, the elevated ambient temperatures exert adverse effects on both broiler and laying chickens, impacting their growth and egg production performance. To mitigate the challenges posed by heat stress, genetic strategies aimed at reducing feather coverage have gained prominence in hot climate areas. Among these approaches, the naked neck (Na) and frizzle (F) genes have emerged as particularly noteworthy. The Na and F genes play a pivotal role in facilitating heat dissipation and temperature regulation. By decreasing feather insulation, these genes enable efficient heat dissipation through exposed areas of the chickens' bodies. This reduction in feather coverage leads to elevated body surface temperature, which, in turn, enhances the capacity for heat loss and contributes to overall body temperature reduction. A substantial body of literature underscores the well-established positive impacts of the naked neck and frizzle genes on growth and egg-laying performance. As a result, these genes hold significant potential for integration into broiler and layer production systems, especially in regions characterized by high tropical temperatures. In the context of broiler farming under challenging heat conditions, the Na and F genes have demonstrated favorable effects on crucial parameters such as feed conversion ratio, body weight gain, disease resistance, and carcass attributes. Likewise, layers exposed to elevated temperatures exhibit enhanced egg production, eggshell quality, fertility, hatchability, and resistance to diseases when these genes are incorporated. Given that the prevalence of the naked neck and frizzle genes is primarily observed in indigenous chicken populations, it becomes imperative to prioritize measures for their conservation due to their exceptional performance in heat-stressed environments. To unlock the full genetic potential of exotic poultry reared in hot and humid conditions, the integration of the Na and F genes is a strongly recommended strategy.

Effect of three different insect larvae on growth performance and antioxidant activity of thigh, breast, and liver tissues of chickens reared under mild heat stress

This study investigated the potential of insect-based diets to mitigate heat stress impact on broiler chickens, focusing on growth performance and antioxidant stability. Four dietary groups were examined, including a control and three treated groups with Tenebrio molitor (TM), Hermetia illucens (HI), and Zophobas morio (ZM) larvae, respectively, at a 5% replacement ratio. Temperature and relative humidity of the poultry house were monitored. Under heat stress conditions, the HI-fed group consistently exhibited the highest body weight, demonstrating their remarkable growth-promoting potential. TM-fed broilers also displayed commendable growth compared to the control. Insect larvae inclusion in the diet improved feed intake during early growth stages, indicating their positive influence on nutrient utilization. Regarding antioxidant stability, malondialdehyde (MDA) levels in the liver, an oxidative stress and lipid peroxidation marker, were significantly lower in the TM-fed group, suggesting reduced oxidative stress. While the specific insect-based diet did not significantly affect MDA levels in thigh and breast tissues, variations in the total phenolic content (TPC) were observed across tissues, with HI larvae significantly increasing it in the breast. However, the total antioxidant capacity (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) levels did not differ significantly among dietary groups in the examined tissues. Results suggest that insect-based diets enhance broiler growth and potentially reduce oxidative stress, particularly in the liver. Dietary presence of bioactive compounds may contribute to these benefits. Further research is required to fully elucidate the mechanisms underlying these findings. Insect-based diets seem to offer promise as feed additives in addressing the multifaceted challenges of oxidative stress and enhancing broiler health and resilience under heat stress conditions.

Physiological Response, Haematology and Stress Condition of Scavenging Chickens in Cement Production Areas

This study investigated the physiological and stress indices of scavenging chickens in LAFARGE and Dangote cement factories located at Ewekoro and Ibese, respectively and respective adjourning communities of Ogun State, Nigeria. One hundred adult scavenging chickens comprising of 25 from each location were used. The birds were caught at night on their perch and kept in furnished cages till the next morning. Data were collected on their rectal temperature, pulse rate, and respiratory rate . Also 5 mL blood was collected through the wing vein of each chicken. Highest (p < 0.05) pulse rate (215.64 beat/minute) and respiratory rate (19.90 breath/minute) were recorded among the chickens at LAFARGE area. Highest (p < 0.05) packed cell volume (28.06%), hemoglobin (4.01 g/dL), monocyte (4.28%) and glucose (256.53 g/dL) were recorded among ones at Ibese (Dangote). White blood cell (6488.89 × 103µL) was highest (p < 0.05) in chickens at Ewekoro (LAFARGE). The study concluded that cement factories infringe on health status of scavenging chickens in the domains. Effective environmental mitigation programme should be put in place for enhanced welfare of the birds.

Heat stress effects on the genetics of growth traits in Thai native chickens (Pradu Hang dum)

OBJECTIVE

The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens.

METHODS

A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters.

RESULTS

At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, -0.85, and -0.83 for BW, 0.17, -0.81, and -0.95 for ADG, 0.25, -0.61, and -0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to -9.30, -0.23, -15.21 (in males) and -6.04, -0.21, -10.10 (in females) gram per 1 level increase of THI from the THI of 76.

CONCLUSION

The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

Investigating the modulatory effects of Moringa oleifera on the gut microbiota of chicken model through metagenomic approach

Introduction

This study aimed to assess the effects of supplementing chicken feed with Moringa oleifera leaf powder, a phytobiotic, on the gastrointestinal microbiota. The objective was to examine the microbial changes induced by the supplementation.

Methods

A total of 40, one-day-old chickens were fed their basal diet for 42 days and then divided into two groups: SG1 (basal diet) and SG2 (basal diet + 10 g/kg Moringa oleifera leaf powder). Metagenomics analysis was conducted to analyze operational taxonomic units (OTUs), species annotation, and biodiversity. Additionally, 16S rRNA sequencing was performed for molecular characterization of isolated gut bacteria, identified as Enterococcus faecium. The isolated bacteria were tested for essential metabolites, demonstrating antibacterial, antioxidant, and anticancer activities.

Results and discussion

The analysis revealed variations in the microbial composition between the control group (SG1) and the M. oleifera-treated group (SG2). SG2 showed a 47% increase in Bacteroides and a 30% decrease in Firmicutes, Proteobacteria, Actinobacteria, and Tenericutes compared to SG1. TM7 bacteria were observed exclusively in the M. oleifera-treated group. These findings suggest that Moringa oleifera leaf powder acts as a modulator that enhances chicken gut microbiota, promoting the colonization of beneficial bacteria. PICRUSt analysis supported these findings, showing increased carbohydrate and lipid metabolism in the M.oleifera-treated gut microbiota.

Conclusion

This study indicates that supplementing chicken feed with Moringa oleifera leaf powder as a phytobiotic enhances the gut microbiota in chicken models, potentially improving overall health. The observed changes in bacterial composition, increased presence of Bacteroides, and exclusive presence of TM7 bacteria suggest a positive modulation of microbial balance. The essential metabolites from isolated Enterococcus faecium bacteria further support the potential benefits of Moringa oleifera supplementation.

Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.

Genetic Effect and Growth Curve Parameter Estimation under Heat Stress in Slow-Growing Thai Native Chickens

Heat stress is becoming a major problem because it limits growth in poultry production, especially in tropical areas. The development of genetic lines of Thai native chickens (TNC) which can tolerate the tropical climate with the least compromise on growth performance is therefore necessary. This research aims to analyze the appropriate growth curve function and to estimate the effect of heat stress on the genetic absolute growth rate (AGR) in TNC and Thai synthetic chickens (TSC). The data comprised 35,355 records for body weight from hatching to slaughtering weight of 7241 TNC and 10,220 records of 2022 TSC. The best-fitting growth curve was investigated from three nonlinear regression models (von Bertalanffy, Gompertz, and logistic) and used to analyze the individual AGR. In addition, a repeatability test-day model on the temperature-humidity index (THI) function was used to estimate the genetic parameters for heat stress. The Gompertz function produced the lowest mean squared error (MSE) and Akaike information criterion (AIC) and highest the pseudo-coefficient of determination (Pseudo-R²) in both chicken breeds. The growth rates in TSC were higher than TNC; the growth rates of males were greater than females, but the age at inflection point in females was lower than in males in both chicken breeds. The THI threshold started at 76. The heritability of the AGR was 0.23 and 0.18 in TNC and TSC, respectively. The additive variance and permanent environmental variance of the heat stress effect increased sharply after the THI of 76. The growth rate decreased more severely in TSC than TNC. In conclusion, the Gompertz function can be applied with the THI to evaluate genetic performance for heat tolerance and increase growth performance in slow-growing chicken.

Comparison of Performance, Egg Quality, and Yolk Fatty Acid Profile in Two Turkish Genotypes (Atak-S and Atabey) in a Free-Range System

Simple Summary

In recent years, consumers have shown increased interest in healthy and safe food produced under improved animal welfare standards. Therefore, production systems proving outdoor access have gained popularity, increasing the need for knowledge on genotypes suitable for free-range systems. This study aimed to investigate the suitability of two Turkish layer genotypes, Atak-S (brown) and Atabey (white), in a free-range system. We evaluated laying performance, egg quality parameters, and yolk fatty acid profile. The egg production was higher in Atabey than Atak-S, whereas the eggs from Atak-S hens tended to be heavier and had a stronger shell structure than eggs from Atabey hens. Furthermore, eggs from Atabey hens had improved egg yolk and albumen content compared to eggs from Atak-S hens. The total saturated fatty acid content in yolk was higher in Atabey eggs than in Atak-S eggs at 56 weeks of age, whereas a higher yolk color score was observed in Atak-S eggs than in Atabey eggs. Our results could help free-range egg producers to improve production, as well as satisfy consumer demands regarding egg quality in organic production.

Abstract

Consumer interest in buying eggs from animal welfare-friendly systems with outdoor access is increasing, leading to an increase in the need for knowledge on genotypes suitable for free-range systems. Two Turkish laying hen genotypes, Atak-S (brown, n = 210) and Atabey (white, n = 210), were reared in a free-range system from 19–72 weeks of age, and their suitability for the system was assessed based on laying performance, egg quality, and yolk fatty acid profile. Mean hen-day and hen-housed egg production were found to be higher in Atabey than Atak-S (p < 0.01). The brown eggs from Atak-S hens tended to be heavier than the white eggs from Atabey hens (p < 0.01). Brown eggs obtained from Atak-S hens had a stronger shell structure (p < 0.01), while white eggs from Atabey hens had higher mean yolk index, albumen index, and Haugh unit than brown eggs (p < 0.05). At 56 weeks of age, total saturated fatty acid content in yolk was higher in white eggs than in brown eggs (p < 0.01). These findings related to genotype could help free-range egg producers in their choices for more profitable production and for meeting consumer demands on egg quality and egg yolk fatty acid levels.

Heat stress management in poultry

High ambient temperature is one of the major causes of economic losses in the livestock industry. The poultry industry is an integral part of the livestock industry. It faces severe losses due to heat stress (HS). The adverse effects of HS can be seen on production performance, body temperature, intestinal health, appetite hormone regulation, immune responses and oxidative characteristics. It is important to monitor these parameters to identify the HS possessions during rearing so that timely action can be taken to minimize the adverse effects of high ambient temperature. Furthermore, the application of productive methods on farms is equally important. Several strategies have been suggested by researchers. Providing a suitable environment with selective rearing systems along with proper ventilation and hygiene is the basic requirement for all types of livestock reared for animal protein. Supplementation of appropriate feed additive could be useful for improving intestinal absorption and minimizing adverse effects of HS. Selection for breeding heat resistant birds also provide merits for improving the germplasm of the strains. Early age thermal conditioning also helps in developing resistance for HS. The most recent advancement is the supplementation of active substances during incubation. It is expected that these methods may have a potential impact on the poultry industry for creating thermotolerance in the newly hatched chicks. This review highlights the major issues concerning chicken health and suggests the measures to be adopted following the increase in environmental temperature.

Assessment of Stocking Rate and Housing System on Performance, Carcass Traits, Blood Indices, and Meat Quality of French Pekin Ducks

Commercial practice in poultry production management has been susceptible to increased problems, driven by concerns about safety of food and animal welfare. Thus, the main proposal of the present study was to evaluate the influence of different stocking densities on performance, blood, and carcass traits of Pekin ducklings reared on two different floor types (wood shaving litter, WSL or plastic slatted floor, PLS). A total of 450 one-day-old ducklings were randomly allocated into six equal experimental groups stocking density (nine, 15 and 21 birds/m2 during the first 14 d and three, five and seven birds/m2 until 49 days) reared on two floor types (WSL and PLS), five replicate pens each. Increased stocking density reduced body weight (BW), weight gain (WG), and feed conversion ratio (FCR) values and increased feed intake (FI) in both floor types at 14 days old. At 49 days old, reared ducklings on PLS type verified higher BW and WG and reduced FCR values. Moreover, increasing stocking density in both floor types significantly reduced the breast, thigh, and left fillet percentages. Conversely, reared birds floored on PLS system decreased the triglycerides (TG) and increased the total cholesterol (TC) serum content. Furthermore, the meat contents of TG and TC were decreased in birds reared on higher stocking density but not affected by floor type. Further, serum antioxidant indices were reduced in PLS birds on low stocking densities. In conclusion, housing Pekin ducklings on PLS improved their growth performance, carcass traits, meat cholesterol, and antioxidant status, particularly at stocking density of three and five birds/m2.

Assessment of Laying Hens' Thermal Comfort Using Sound Technology

Heat stress is one of the most important environmental stressors facing poultry production and welfare worldwide. The detrimental effects of heat stress on poultry range from reduced growth and egg production to impaired health. Animal vocalisations are associated with different animal responses and can be used as useful indicators of the state of animal welfare. It is already known that specific chicken vocalisations such as alarm, squawk, and gakel calls are correlated with stressful events, and therefore, could be used as stress indicators in poultry monitoring systems. In this study, we focused on developing a hen vocalisation detection method based on machine learning to assess their thermal comfort condition. For extraction of the vocalisations, nine source-filter theory related temporal and spectral features were chosen, and a support vector machine (SVM) based classifier was developed. As a result, the classification performance of the optimal SVM model was 95.1 ± 4.3% (the sensitivity parameter) and 97.6 ± 1.9% (the precision parameter). Based on the developed algorithm, the study illustrated that a significant correlation existed between specific vocalisations (alarm and squawk call) and thermal comfort indices (temperature-humidity index, THI) (alarm-THI, R = -0.414, P = 0.01; squawk-THI, R = 0.594, P = 0.01). This work represents the first step towards the further development of technology to monitor flock vocalisations with the intent of providing producers an additional tool to help them actively manage the welfare of their flock.