Impacts of Strain Variation on Response to Heat Stress and Boldo Extract Supplementation to Broiler Chickens

Changes in Core Temperature of Cyan-Shank Partridge Chickens Exposed to Continuously Increased Ambient Temperature at Different Relative Humidity Levels

(1) Background: This study aimed to investigate the changes in core temperature of Cyan-shank partridge chickens with continuously increased ambient temperature at different relative humidity (RH) levels. (2) Methods: Thirty birds were selected at the age of 35 days and randomly divided and housed in three artificial climate chambers. Each chamber was set at one of three different RH levels (50%, 65%, and 80%), and the ambient temperature was increased by 1.0 °C per 0.5 h from 24.0 to 34.0 °C. The core temperature was tested at 1.0 h intervals, and the ambient temperature in the chambers was recorded using mini temperature data loggers. Data were collected continuously for three days at the ages of 35, 42, and 49 days. The broken-line model (BLM) was used to calculate the inflection point temperature (IPT) and basal core temperature (constant). (3) Results: Both RH and age had no significant influence on the IPT. With increasing ambient temperature, the average IPT values of birds measured at the three ages were 26.52, 27.02, and 26.71 °C at the RH levels of 50%, 65%, and 80%, respectively. A significant downward trend in basal core temperature was observed as the birds aged from 35 to 42 days (p < 0.05). (4) Conclusions: the core temperature of the chicken gradually decreased as the age increased. During the hot summer months, it is better to keep the ambient temperature less than 26.5 °C to avoid the excessive increase in core temperature in Cyan-shank partridge chicken at the ages from 35 to 49 days.

Effects of different environmental enrichment tools to improve behavior, welfare, and growth performance of broiler chickens

This study was performed to evaluate the effect of various environmental enrichment (EE) tools on broiler growth, welfare, behavior, carcass, and meat quality. A total of 300 commercial broilers were randomly divided into 05 treatments. The treatments include various EE tools such as perches, balls, hanging bottles, and laser lights placed for birds and a control group. The birds kept with perches and hanging bottles had the lowest feed intake, while the birds in the control group showed the poor feed conversion ratio compared to all EE treatments. Broilers raised under different EE were more active and exhibited frequent maintenance behavior (i.e., walking, jumping, running, wing flapping and aggressiveness) than the control group which spent more time in feeding and drinking. Moreover, the birds with EE had reduced incidence of toe injuries and footpad dermatitis than those in the control group. Birds reared with perches had higher meat lightness, whereas meat from the birds in the control group had lower cooking loss and shear force. It can be concluded that the use of various EE tools improved the welfare and behavior of the birds without affecting bodyweight of the birds. Furthermore, the use of hanging bottles and placing perches reduced feed intake and improved feed conversion ratio.

Terminalia bellirica and Andrographis paniculata dietary supplementation in mitigating heat stress-induced behavioral, metabolic and genetic alterations in broiler chickens

BACKGROUND

Heat stress (HS) is one of the most significant environmental stressors on poultry production and welfare worldwide. Identification of innovative and effective solutions is necessary. This study evaluated the effects of phytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata on behavioral patterns, hematological and biochemical parameters, Oxidative stress biomarkers, and HSP70, I-FABP2, IL10, TLR4, and mTOR genes expression in different organs of broiler chickens under chronic HS conditions. A total of 208 one-day-old Avian-480 broiler chicks were randomly allocated into four treatments (4 replicate/treatment, 52 birds/treatment): Thermoneutral control treatment (TN, fed basal diet); Thermoneutral treatment (TN, fed basal diet + 1 kg/ton feed PHY); Heat stress treatment (HS, fed basal diet); Heat stress treatment (HS, fed basal diet + 1 kg/ton feed PHY).

RESULTS

The findings of the study indicate that HS led to a decrease in feeding, foraging, walking, and comfort behavior while increasing drinking and resting behavior, also HS increased red, and white blood cells (RBCs and WBCs) counts, and the heterophile/ lymphocyte (H/L) ratio (P < 0.05); while both mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were decreased (P < 0.05). In addition, HS negatively impacted lipid, protein, and glucose levels, liver and kidney function tests, and oxidative biomarkers by increasing malondialdehyde (MDA) levels and decreasing reduced glutathion (GSH) activity (P < 0.05). Heat stress (HS) caused the upregulation in HSP70, duodenal TLR4 gene expression, and the downregulation of I-FABP2, IL10, mTOR in all investigated tissues, and hepatic TLR4 (P < 0.05) compared with the TN treatment. Phytogenic feed additives (PHY) effectively mitigated heat stress's negative impacts on broilers via an improvement of broilers' behavior, hematological, biochemical, and oxidative stress biomarkers with a marked decrease in HSP70 expression levels while all tissues showed increased I-FABP2, IL10, TLR4, and mTOR (except liver) levels (P < 0.05).

CONCLUSION

Phytogenic feed additives (PHY) containing Terminalia bellirica and Andrographis paniculata have ameliorated the HS-induced oxidative stress and improved the immunity as well as the gut health and welfare of broiler chickens.

Effect of wet feeding on performance, blood plasma indices, intestinal histomorphometry, and economics of broiler chickens under hot climatic conditions

The study aimed to investigate the impact of wet feeding on broiler chicken performance and intestinal histomorphometry. The research was conducted at the Veterinary College, Udaipur, India, using 144 commercial broiler chicks from day 1 to 6 weeks of age. The chicks were divided randomly into three experimental groups, each with four replicates comprising 48 birds. The control group (G1) was fed dry; while, group 2 (G2) received wet feed supplemented with 1.00 g water per g of feed and group 3 (G3) received wet feed supplemented with 1.20 g water per g of feed. Results revealed that G3 had significantly superior feed conversion ratios, lower feed intake, and increased body weight and weight gain compared to G2 and G1. Among the three treatment groups, there were no variations in blood plasma indicators. In comparison with G1, duodenum and ileum in G2 had higher villus height. The G3 revealed higher net profit margins and 18.89% saving of feed compared to G1, suggesting that it may be a valuable tool for lowering chicken feed costs.

Effectiveness of probiotics and clove essential oils in improving growth performance, immuno-antioxidant status, ileum morphometric, and microbial community structure for heat-stressed broilers

Recently, interest has increased in using bio-additives, herbs, and their extracts as feed additives because of their potential role in improving chick's health and productivity, especially during stress. Thus, our aim in this study is to examine whether nutritional supplementation (probiotics and clove essential oils) will help mitigate the negative effect of heat stress on the bird by modifying the microbial content, boosting immunity, oxidative status, metabolic, and growth. In this study, three hundred one-day-old broiler chicks (Ross 308) were fed the following experimental diet: (CON) basal diet (control diet); (CEO) CON with clove essential oils (300 mg/kg); (PRO) CON with probiotics (2 g/kg); (PC) CON with probiotics and clove essential oils. Our results showed a significant improvement (P < 0.05) in body weight gain, feed conversion ratio, nutrient digestibility, and digestive enzymes activities in broilers fed on PC, CEO, and PRO compared to the control group. Moreover, a significant decrease was recorded in the abdominal fat content and an increase in the relative weight of bursa of Fabricius, and higher antibody levels against Newcastle disease virus, as well as, there was an increase (P < 0.05) in interleukin 10 (IL-10) in all treated groups. Meanwhile, there was a decrease in tumor necrosis factor-α (TNF-α) in all supplemented groups compared with the control group. Serum triglycerides, cholesterol, low-density lipoprotein concentrations, and alanine aminotransferase activities were significantly lower in the treated groups. Superoxide dismutase and glutathione peroxidase levels were elevated (P < 0.05) and the malondialdehyde level value significantly decreased in all supplemented groups. The treated groups enhanced the ileum structure by increasing Lactobacillus, decreasing E. coli, and improving the morphometrically (P < 0.05). This study strongly suggests that clove essential oil and probiotic mixture can be used as a feed supplement to reduce the effects of heat stress by improving the growth performance and enhancing immuno-antioxidant status, ileum morphometric, as well as modifying the microbial community structure of the ileum of broilers.

Blood hematology and biochemical of four laying hen strains exposed to acute heat stress

This study is aimed at defining physiological responses to heat stress (HS) in four different lines to better understand the underlying mechanisms of various responses in these genotypes when exposed to heat for a short period. At the age of 30 weeks, 176 laying hens (44 each from the Fayoumi, Golden Sabahia, White Leghorn, and Lohman Brown) were allotted to 2 groups (thermoneutral temperature (26.0 ± 1 °C) and HS (35 ± 1 °C) with relative humidity 55 ± 5% for 6 h/day). Blood samples were collected after 6 h of heat. According to the findings of this study, acute HS increased the concentration of LH in hens by 20.2% while decreasing the concentration of FSH by 4.24. Genotype was found to have a significant effect on blood hematology and most blood biochemical. Significant differences were found between heat stress and genotype in most of the blood parameters. Golden sabahia laying hens had significantly higher WBC, IgY, and LH levels than other groups under HS. The findings of the current study suggested that Lohman Brown was less tolerant to acute HS than another genotype.

Effect of L-serine on circadian variation of cloacal and body surface temperatures in broiler chickens subjected to feed restriction during the hot-dry season

The study aimed to evaluate the effects of L-serine on circadian variation of body temperatures in feed-restricted broiler chickens during the hot-dry season. Day-old broiler chicks of both sexes served as subjects; comprising four groups of 30 chicks each: Group A: water ad libitum + 20% feed restriction (FR); Group B: feed and water ad libitum (AL); Group C: water ad libitum + 20% feed restriction + L-serine (200 mg/kg) (FR + L-serine); Group D feed and water ad libitum + L-serine (200 mg/kg) (AL + L-serine). Feed restriction was performed on days 7-14 and L-serine was administered on days 1-14. Cloacal and body surface temperatures, recorded by digital clinical and infra-red thermometers, respectively, and temperature-humidity index were obtained over 26 h on days 21, 28 and 35. Temperature-humidity index (28.07-34.03) indicated broiler chickens were subjected to heat stress. L-serine decreased (P < 0.05) cloacal temperature in FR + L-serine (40.86 ± 0.07 °C), compared to FR (41.26 ± 0.05 °C) and AL (41.42 ± 0.08 °C) broiler chickens. Peak cloacal temperature occurred at 15:00 h in FR (41.74 ± 0.21 °C), FR + L-serine (41.30 ± 0.41 °C) and AL (41.87 ± 0.16 °C) broiler chickens. Fluctuations in thermal environmental parameters influenced circadian rhythmicity of cloacal temperature; especially the body surface temperatures, positively correlated with CT, and wing temperature recorded the closest mesor. In conclusion, L-serine and feed restriction decreased cloacal and body surface temperatures in broiler chickens during the hot-dry season.

Effects of supplemental different clay minerals in broiler chickens under cyclic heat stress

The objective of this study was to investigate the effect of supplementing clay minerals and organic chromium in feed on broiler chicken under heat stress (HS). A total of 90 one-day-old broiler chicken (Arbor Acres) with an initial body weight of 45.0 ± 0.2 g were assigned to five treatment groups (six replications, three birds each cage): 1) NC group, basal diet under room temperature environment; 2) PC group, basal diet under high temperature (HT) environment; 3) ILT group, basal diet + 1% illite + HT; 4) ZLT group, basal diet + 1% zeolite + HT; 5) OC group, basal diet + 400 ppb/kg organic chromium + HT. The ILT and ZLT groups had significantly higher body weight than the PC group in 4 weeks. Apparent total tract digestibility of gross energy was increased in the ILT, ZLT, and OC groups compared to the PC group. The NC group had lower foot-pad dermatitis score than other groups. Escherichia coli population in the cecum and feces was decreased in the ZLT group than in the PC group. Lactobacillus in cecum and feces was significantly increased in the ZLT group than in the PC group. Regarding blood profiles, blood cortisol was decreased in the NC and ILT groups compared to the PC group. Water holding capacity and pH were increased in the ZLT group than the PC group. In conclusion, according to the results of growth performance, nutrients digestibility, bacteria counts, and meat characteristics, supplementation of the ZLT in broiler diet can alleviate HS.

Dietary supplementation with chia polyphenols alleviates oxidative stress and improves egg nutritional quality in Japanese quails under heat stress

Heat stress in poultry is a major concern, especially in regions with hot summers and scarce cooling infrastructure. Dietary supplementation with antioxidants, such as polyphenols, has risen as a strategy to mitigate the physiological consequences of heat stress. A by-product of the extraction of oil from chia seeds, which is discarded if not used, could be a possible source of polyphenols. The aim of the present study was to evaluate the effects of dietary supplementation with polyphenols from defatted chia seed cake on the general performance, and oxidative status of Japanese quail exposed to heat stress. Furthermore, productive performance, egg quality and yolk fatty acid composition were also assessed. A total of 36 females (96 days of age) were randomly assigned to different diets: BASAL (control), LDCP (low dose of chia polyphenols), or HDCP (high dose of chia polyphenols). Half the animals in each diet group were exposed to 34 °C for 9 h a day (Heat Stress; HS), while the other half remained at the standard 24 °C (No Heat Stress; NHS). After 23 days of experimental conditions, animals under HS showed higher body temperatures and time spent panting, but lower egg laying rate. Moreover, HS modulated the activity of catalase and glutathione peroxidase enzymes, increasing lipid peroxidation in serum and liver; and increased saturated fatty acids in egg yolk. Supplementation with chia polyphenols helped to mitigate the HS effects, especially on glutathione peroxidase activity, decreasing lipid peroxidation. In addition, supplementation with HDCP showed the highest proportion of polyunsaturated fatty acids in liver and egg yolk. In conclusion, the use of defatted chia seed cake could represent a sustainable strategy to mitigate heat stress effects on Japanese quail, due to its capacity to decrease oxidative stress and improve the nutritional quality of egg, while decreasing the amount of waste generated by the food industry.

Prebiotics can restrict Salmonella populations in poultry: a review

Antibiotics were over the years, the common supplement used for poultry production. There is a global trend to lessen antibiotics' use due to the contamination of consumed meat with antibiotic residues. Also, there is a concern that human treatments might be jeopardized due to the emergence of antibiotic-resistant bacteria. Prebiotics are attractive supplements, particularly in poultry production, because of the diversity of their effects, including pH amendments, production of short-chain fatty acids (SCFA) and the inhibition of pathogens' growth. The commonly used prebiotics are carbohydrate sources that cannot be easily broken down by chickens. However, they can efficiently be utilized by the intestinal tract's microflora. Oligosaccharides, polysaccharides and lactose are non-digestible carbohydrate sources that are typically used in poultry diets as prebiotics. This review covers current applications and prospects for using prebiotics to improve poultry performance and reduce pathogens, particularly Salmonella, in gastrointestinal tract.

Effect of Dietary Ramie Powder at Various Levels on the Growth Performance, Meat Quality, Serum Biochemical Indices and Antioxidative Capacity of Yanling White Geese

To investigate the effects of different levels of ramie powder (Boehmeria nivea (L.) Gaudich.) (i.e., 0%, 6%, 12% and 24%) on the production performance, serum biochemical indices, antioxidative capacity and intestinal development of Yanling white geese, a total of 256 geese at 56 days of age were randomly divided into four groups and fed a control diet and the control diet supplemented with 6%, 12% and 24% ramie powder, respectively, for 42 days. The results show that dietary supplementation with 12% ramie powder significantly increased the average final weight (p < 0.05) and tended to improve the average daily gain (ADG) and feed/gain ratio (F/G) of the test geese (0.05 < p < 0.10). Moreover, the dietary inclusion of 12 and 24% ramie powder improved meat qualities by reducing the L* value (p < 0.05) and cooking loss (0.05 < p < 0.10) of thigh muscle. Compared with the control group, the ramie powder supplementation at different levels increased the serum activities of glutathione peroxidase and glutathione, promoting the antioxidative capacity of the body (0.05 < p < 0.10). This study demonstrates that moderate ramie powder is beneficial to the production performance of Yanling white geese and has the potential to be used as a poultry feed ingredient. In conclusion, 12% was the proper supplementation rate of ramie powder in Yanling white geese feed.

Long-Lasting Effects of Incubation Temperature During Fetal Development on Subcutaneous Adipose Tissue of Broilers

Increasing evidence indicates that fetal programming may cause permanent effects on offspring adipose tissue and body composition. Previous study showed reduction in newly-hatched broiler chick adiposity by manipulating incubation temperature during fetal development. The present study examined whether incubation temperature during fetal development has long-term effects on post-hatching fat deposition in broilers. Broiler breeder eggs (Cobb-500^®) were incubated under constant low (36°C, LT), control (37.5°C, CT) or high (39°C, HT) temperature from day 13 onward, giving to eggshell temperature of 37.3 ± 0.08°C, 37.8 ± 0.2°C, and 38.8 ± 0.3°C, respectively. Male chicks were reared under recommended temperatures until 42 days old. LT 21 days old broilers exhibited higher blood cholesterol than CT broilers, and higher triglycerids, VLDL, and LDL, and lower HDL than CT and HT broilers. LT broilers presented higher liver cholesterol than CT broilers and lower ether extract percentage than CT broilers. Adipocyte count was lower in the abdomen than in the thigh. Until day 21 of age, feed intake was higher in LT than in HT broilers. At day 42 of age, blood cholesterol and LDL were higher in HT broilers than in CT and LT broilers. Liver cholesterol was higher in LT than in HT broilers. LT treatment reduced neck and increased thigh adipocyte size compared to CT treatment, while the HT treatment reduced abdomen and neck adipocyte size compared to other two treatments and in the thigh compared to LT treatment. In CT broilers, thigh adipocytes were smaller than abdomen and neck adipocytes. HT treatment increased adipocyte number per area in the neck compared to LT and CT treatment, and LT and HT treatments reduced adipocyte count in the thigh compared to CT treatment. CT broilers presented higher adipocyte count in the thigh than the abdomen and neck, while HT broilers presented higher adipocyte count in the neck than the abdomen and thigh. Cell proliferation was lower in the abdomen than in the thigh. The results show incubation temperature manipulation during fetal development has long-term and distinct effects on regional adiposity, and can be used to modulate broiler fat deposition.

Potential ameliorative role of Spirulina platensis in powdered or extract forms against cyclic heat stress in broiler chickens

Global warming has become intensified and widespread, threatening the world with causing acute heatwaves that adversely affect poultry production and producers' profitability. Spirulina platensis is a precious and promising mitigating strategy to combat the detrimental impacts of heat stress due to its high contents of nutrients and bioactive components. The current study was designed to compare the incorporation impact of S. platensis powder or aqueous extract on the growth and physiological responses of heat-stressed broiler chicks. Six hundred 1-day-old Ross 308 male broiler chicks were allocated into five experimental groups with six replicates of 20 chicks each. The control group fed the basal diet without additives, SPP1 and SPP2 groups fed the basal diet with 1 g/kg and 2 g/kg S. platensis powder, respectively, while SPE1 and SPE2 groups received 1 ml/L and 2 ml/L S. platensis aqueous extract in the drinking water, respectively. All birds were exposed to cyclic heat stress (34 ± 2 °C for 12 h) for three successive days a week from day 10 to day 35. In vitro analysis showed that total phenols, flavonoids, and antioxidant activity of S. platensis were remarkably decreased (P < 0.001) in the aqueous extract compared to the powder form. Body weight, weight gain, and feed conversion ratio were improved (P < 0.001) in all treated groups, while carcass yield and dressing percentage were increased only in SPP1 and SPP2. Feed and water intake and blood biochemical parameters were not affected. Both forms of S. platensis enhanced the lipid profile, redox status, and humoral immune response of heat-stressed chicks superior to the powder form. Conclusively, the powder form of S. platensis was more effective in enhancing the productivity of broilers and alleviating the negative impacts of heat stress than the aqueous extract form.

Effects of Dietary Chromium Picolinate on Gut Microbiota, Gastrointestinal Peptides, Glucose Homeostasis, and Performance of Heat-Stressed Broilers

The current research was devoted to evaluating the effects on gut microbiota, gastrointestinal peptides, and glucose homeostasis of chromium picolinate applied to heat-stressed broilers. In a 14 d experiment, 220 28-day-old AA broilers were randomly assigned into one thermal-neutral and three high-temperature groups dietary-supplemented with 0, 0.4, or 0.8 mg/kg of chromium as chromium picolinate. The temperature for the thermal-neutral group was set at 21 °C, while that for the other three groups (high temperature) was set at 31 °C. The results showed that the average daily gain and average daily feed intake of the 0.4 mg/kg chromium-supplemented group significantly increased compared with the high-temperature groups (p < 0.05). The content of cholecystokinin in the 0.4 mg/kg group significantly decreased, and the gastric inhibitory polypeptide level was significantly elevated in jejunum (p < 0.05). The cecal microbiota of heat-stressed broilers was substantially different from that of the thermal-neutral group. After diet-supplemented chromium, compared to the high-temperature groups, the 0.4 mg/kg chromium supplemented group was characterized by a reduction of Actinobacteriota and Proteobacteria at the phylum level. The Bacilli were elevated, while proportions of Coriobacteria and Gammaproteobacteria were reduced significantly at the class level. The proportions of Lactobacillaceae, Christensenellaceae, and Erysipelotrichaceae were elevated significantly, while that of Clostridiaceae was reduced significantly at the family level. The proportion of Turicibacter was elevated significantly and the proportions of Olsenella and Ruminococcus were reduced significantly at the genus level (p < 0.05). Compared to the high-temperature groups, in the 0.4 mg/kg chromium-supplemented group, the insulin concentration and insulin resistance index were reduced (p < 0.05), and sodium-glucose transporter 1 expression was up-regulated in jejunum (p < 0.05). Performance, microbiota, gastrointestinal peptides, or serum parameters of the 0.8 mg/kg group were almost unaffected by chromium compared with the high-temperature groups. In conclusion, diet supplemented with 0.4 mg/kg Cr improved performance, insulin resistance and sodium-glucose transporter 1 expression and altered gut microflora structure and secretion of gastrointestinal peptides, thus showing that supplementation with chromium is beneficial to maintain glucose homeostasis and alleviate heat stress.

Effect of Dietary Ramie Powder (Boehmeria nivea) at Various Levels on Growth Performance, Carcass and Meat Qualities, Biochemical Indices, and Antioxidative Capacity of Linwu Ducks

Current experiment was designed to check the effect of dietary supplementation of ramie powder on the growth performance, carcass and meat qualities and antioxidative capacity of Linwu ducks. A total of 312 ducks at 21-day-age were equally divided into 4 groups, fed with control diet, control diet supplemented of 3, 6, or 12% ramie powder, respectively. The results showed that dietary supplementation of 6 and 12% ramie powder increased the final weight and daily body weight gain (P < 0.05), and dietary supplementation of 6% ramie improved the cooking loss of the leg meat 45-mins-postmortem compared with the control group (P < 0.05). Moreover, dietary supplementation of 6% ramie powder promoted the antioxidative capacity of the ducks by increasing the serum activities of superoxide dismutase and glutathione (P < 0.05), as well as the mRNA expressions of glutathione peroxidase 1 in the breast meat and superoxide dismutase 1 in the leg meat (P < 0.05). This experiment demonstrated that dietary supplementation of ramie powder showed beneficial efficacy on the growth performance of Linwu ducks. It corroborated the potential of dietary ramie being used as poultry feed ingredient and suggested that 6% was the proper supplementation rate of ramie powder in Linwu ducks' feed.

Synergistic effect of Spirulina platensis and selenium nanoparticles on growth performance, serum metabolites, immune responses, and antioxidant capacity of heat-stressed broiler chickens

This study examined the effects of dietary Spirulina platensis (SP) at levels of 0, 5, and 10 g.kg-1 and selenium nanoparticles (SeNPs) at 0, 0.1, and 0.2 mg.kg-1, individually and in combination, on heat-stressed broiler chickens for 5 weeks. Four hundred fifty one-day-old Ross-308 chicks were allocated to 9 dietary groups with 5 replicates (10 chicks each). The control diet was consisted of corn-soybean-based basal diet. The obtained results displayed a significant increase in final body weight (p = 0.005) and weight gain during the periods from 22 to 35 days (p = 0.002) and 1 to 35 days (p = 0.005) in birds fed supplemented diets compared to those fed control diet, with the highest being in birds fed with both 10 g SP and 0.1 mg SeNPs. Feed conversion ratio was also improved in birds fed supplemented compared to control group. Dietary supplements significantly improved carcass dressing (p < 0.001), carcass yield (p = 0.001) percentages, and blood lipid profile. Blood triiodothyronine was higher (p = 0.005) with all treated diets except that contain 5 g SP compared to the control, with the highest being in birds fed diet contains 5 g SP + 0.2 mg SeNPs. Immunoglobulin subclasses IgG, IgM, and IgA were higher in birds fed supplemented diets compared to the control group. Antibody titers to Newcastle disease, avian influenza, and infectious bursal disease were numerically increased with dietary supplementation compared to the control group. Dietary treatments increased (p < 0.001) glutathione peroxidase and superoxide dismutase (SOD) levels, except diet contains 5 g SP for SOD level and decreased (p < 0.001) malondialdehyde level. It is concluded that dietary inclusion of SP and SeNPs, particularly their combination at levels 5 g SP plus 0.2 mg SeNPs kg-1 and 10 g SP plus 0.1 mg SeNPs kg-1, improved growth performance, carcass yield, immunity, and antioxidant capacity of heat-stressed broilers.

Meta-Analysis and Systematic Review of the Thermal Stress Response: Gallus gallus domesticus Show Low Immune Responses During Heat Stress

Heat stress, which affects broiler growth performance and immunity, is a major concern in the poultry industry. This meta-analysis aimed to demonstrate the significant effect of heat stress on broiler mass gain and immunoglobulin levels, which regulates the mortality rate of broilers. A total of 2,585 studies were downloaded from PubMed, Web of Science, and Google Scholar from January 1, 2015, to September 1, 2021. Eventually, 28 studies were selected based on specific criteria. The results for body mass gain, total mass of immune organs (thymus, spleen, and bursa of Fabricius), immunoglobulin (IgA, IgG, and IgM) levels, and mortality rate were analyzed using odds ratio or the random-effects model (REM) at a confidence interval (CI) of 95%. Compared to the control, heat stress significantly decreased body mass gain (10 trials: REM = 1.35, 95% CI: 1.21, 1.50). Compared to that in the control, heat stress significantly increased immunoglobulin levels: IgA (7 trials: REM = 1.69, 95% CI: 0.90, 3.16), IgG (6 trials: REM = 1.24, 95% CI: 0.85, 1.81), IgM (8 trials: REM = 0.69, 95% CI: 0.44, 1.08), and heat stress also increased the broiler mortality rate (6 trials: REM = 0.06, 95% CI: 0.01, 0.27). However, there were no significant changes in the immune organs between the control and heat-stressed groups. In conclusion, heat stress remarkably alters the mass gain and immunoglobulin levels of broilers, which may be a cause of the high mortality rate.

Effect of diet supplemented with graded levels of garlic (Allium sativum L.) powder on growth performance, carcass characteristics, blood hematology, and biochemistry of broilers

Background

Recently, attention has been paid to using plants with medicinal efficacy as alternates to antibiotics and growth promoters. Garlic is a traditional plant used as a spice and herb in broilers.

Aim

To investigate the effect of garlic powder on broiler performance, carcass characteristics, blood hematology, and biochemistry.

Method

A total of 240 1-day-old broiler chicks (Cobb500) were purchased from a local hatchery and randomly distributed into four dietary treatments. Each treatment comprised 5 replicates with 12 chicks each. Garlic powder (Allium sativum) was supplemented as follows: 0.0%, 0.1%, 0.2%, and 0.3%. The diets were formulated to be approximately isocaloric and cover all nutrient requirements for broilers throughout two stages of growth periods: starter diets (1-21 days) and finisher diets (22-42 days). At the end of the experiment, one bird was chosen from each replicate to measure the carcass characteristics and blood was collected.

Results

The findings showed that birds fed a diet supplemented by 0.3% garlic powder was significantly (p < 0.05) better in terms of body weight, body weight gain, and feed conversion ratio compared to those birds fed 0%, 0.1%, or 0.2% garlic powder. In addition, feeding 0.1% or 0.2% garlic powder significantly increased (p < 0.05) packed cell volume, total white blood cells, neutrophil, eosinophil, monocyte, and lymphocyte compared to the control group. Furthermore, garlic supplementation led to a decrease in alanine aminotransferase, total cholesterol, triglycerides, and low density lipoprotein compared to the control. At the same time, high density lipoprotein was significantly increased (p < 0.05) by garlic supplementation.

Conclusion

It can be concluded that the supplementation of 0.3% garlic powder as a growth promoter leads to reducing the cost of production through improving growth performance and enhancing birds' health.

Soybean Oil Replacement by Poultry Fat in Broiler Diets: Performance, Nutrient Digestibility, Plasma Lipid Profile and Muscle Fatty Acids Content

Simple Summary

The effect of partial or complete substitution of soybean oil (SO) by poultry fat (PF) on growth, nutrient digestibility, plasma lipids, and the pectoral muscle content of fatty acids (FAs) was examined in this study. Dietary PF supplementation improved breast muscle FA profile but did not affect muscle vitamin E content and liver thiobarbituric acid reactive substances (TBARS). By adding PF to the diet, economic efficiency was greatly improved in a dose-dependent manner. Therefore, the results of this study revealed that PF could be used as a partial or total replacement of SO in broiler nutrition without affecting their performance or physiological response with a tendency to improve their meat products.

Abstract

Continuous genetic improvements of commercial broiler strains has led to the necessity of using fats in their rations to fulfill a large portion of the energetic requirements. Several fat sources have been introduced in poultry nutrition, such as rendering poultry fat (PF) an available and cheap lipid source compared to conventional sources such as soybean oil (SO). The present study investigated the effect of partial or full replacement of SO by PF on performance, nutrient digestibility, blood lipids, and fatty acids (FAs) content of pectoral muscle. Four hundred and eighty one-day-old male Ross-308 chicks were distributed into four experimental groups (12 replicates each): the first group (control) was fed a diet formulated with soybean oil as a fat source while the second to fourth groups (PF25, PF50, and PF100) were fed diets formulated with 25, 50 and 100% of PF as a fat source instead of SO. Results revealed no synergistic effect between SO and PF in any of the studied parameters. Replacing SO by PF did not alter birds’ growth, carcass characteristics, and plasma indices of birds. Abdominal fat% was increased (p < 0.01) in PF50 and PF100. Dry matter digestibility was improved (p < 0.05) in PF50 and PF100, while crude fat and protein digestibility was not affected. Contents of palmitic and docosahexaenoic acids in the pectoral muscle of PF50 and PF100 were reduced (p < 0.01) while concentrations of oleic and linolenic acids, total unsaturated FAs, and polyunsaturated FAs/Saturated FAs ratio were elevated (p < 0.05) in the same groups. Liver thiobarbituric acid reactive substances (TBARS) and muscle vitamin E contents were not altered. The dietary addition of PF greatly improved economic parameters. In conclusion, PF can be used as a lipid source in broiler diets to produce inexpensive meat while maintaining its growth performance.

Comparative evaluation of single or combined anticoccidials on performance, antioxidant status, immune response, and intestinal architecture of broiler chickens challenged with mixed Eimeria species

Poultry production faces several threats and challenges, one of the most important of which is avian coccidiosis which causes annual losses exceeding US$ 3 billion. Discovering new drugs or combinations of existing anticoccidials has become inevitable to overcome the emergence of coccidiosis resistance. This study evaluated a new combination of maduramicin and diclazuril in comparison to the well-known product Maxiban72 which consisted of narasin and nicarbazin, and the single effect of monensin as treatments for avian coccidiosis. A total of 750 1-day-old Indian River broiler chicks were allocated equally into 5 experimental groups with 6 replicates each as follows: 1) negative unchallenged control group (NC) fed the basal diet; 2) positive control group (PC) received the basal diet and inoculated with Eimeria; 3) PC + 100 mg monensin sodium (Atomonsin)/kg diet (MS); 4) PC + 5 mg maduramicin ammonium (Madramycin) + 2.5 mg diclazuril (Atozuril)/kg diet (MMD); and 5) PC + 40 mg narasin + 40 mg nicarbazin (MaxibanT72)/kg diet (NN). Anticoccidials improved (P < 0.01) growth performance, dressing (%) and carcass yield of inoculated birds compared to untreated-inoculated ones. Erythrogram and leukogram parameters were affected by Eimeria challenge. Total protein, globulin, cholesterol, triglycerides, superoxide dismutase and glutathione peroxidase levels in PC birds' serum were reduced (P < 0.05) while their values of liver enzymes, malondialdehyde and catalase were elevated (P < 0.01) when compared to NC ones. Serum immunoglobulin A, and jejunal gene expressions of interleukin-6 and interferon gamma were increased (P < 0.05) in PC group compared to NC group. Anticoccidial drugs restored values of the aforementioned biomarkers near to those of NC. Jejunal architecture in inoculated birds was improved by the anticoccidial treatments in MS, MMD, and NN. Fecal oocyst counts were significantly reduced in MMD, NN, and MS groups compared to PC group. Conclusively, although all examined anticoccidial drugs were effective in treating Eimeriosis, the anticoccidial combinations in MMD and NN groups were more effective than the single administration of MS in treating avian coccidiosis.

Nutritional manipulation to combat heat stress in poultry - A comprehensive review

Global warming and climate change adversely affect livestock and poultry production sectors under tropical and subtropical conditions. Heat stress is amongst the most significant stressors influencing poultry productivity in hot climate regions, causing substantial economic losses in poultry industry. These economic losses are speculated to increase in the coming years with the rise of global temperature. Moreover, modern poultry strains are more susceptible to high ambient temperature. Heat stress has negative effects on physiological response, growth performance and laying performance, which appeared in the form of reducing feed consumption, body weight gain, egg production, feed efficiency, meat quality, egg quality and immune response. Numerous practical procedures were used to ameliorate the negative impacts of increased temperature; among them the dietary manipulation, which gains a great concern in different regions around the world. These nutritional manipulations are feed additives (natural antioxidants, minerals, electrolytes, phytobiotics, probiotics, fat, and protein), feed restriction, feed form, drinking cold water and others. However, in the large scale of poultry industry, only a few of these strategies are commonly used. The current review article deliberates the different practical applications of useful nutritional manipulations to mitigate the heat load in poultry. The documented information will be useful to poultry producers to improve the general health status and productivity of heat-stressed birds via enhancing stress tolerance, oxidative status and immune response, and thereby provide recommendations to minimize production losses due to heat stress in particular under the growing global warming crisis.

Effect of acute heat stress on cognitive performance of chickens in a feed-related discriminant task

Little is known about immediate and long-lasting effect of acute heat stress on chicken cognition. Thirty-five, 9-week-old birds were trained to differentiate two cone colours; white (rewarded, R; with feed underneath) and black (unrewarded, UR; empty). The sixteen birds that learnt the task were randomly assigned to three temperature regimens (TR: 22-24 °C (control), 30-32 and 36-38 °C for 3h/day) for three consecutive days during which rectal (RT), wing (WT) and eye (ET) temperatures were monitored. After the 3 h of exposure, birds were allowed to rest for 1 h before the commencement of the discriminant task. The latencies to open the cones (R and UR) and proportion of cones opened were recorded. A long-lasting effect was tested a week after exposure to TR. TR had a significant effect on RT, WT and ET. The motivation to turn over R cones was weaker in birds exposed to 36-38 °C than birds exposed to 22-24 °C. Also, the proportion of R cones opened were fewer in birds that experienced TR of 36-38 °C compared to birds exposed to 22-24 °C and 30-32 °C specifically on two out of the three cognitive test days (Days 1 and 3). Latency and proportion of UR cones opened was not affected by TR. RT, WT and ET were all negatively and significantly correlated with latency to open the UR cones. Previous exposure of birds to three TR had no effect on the latency to open both cones but the proportion of R cones opened was greater in birds exposed to 30-32 °C compared to the 22-24 °C birds. In conclusion, an immediate (36-38 °C) and long-lasting effect (30-32 °C) of acute heat stress was associated with a weak motivation to perform feed related discrimination task.

Impact of multi-strain probiotic, citric acid, garlic powder or their combinations on performance, ileal histomorphometry, microbial enumeration and humoral immunity of broiler chickens

Heat stress, one of the critical obstacles to poultry sector in subtropical and tropical countries, reduces performance, immune response, and animal welfare. This study examined the effect of dietary inclusion of probiotic (PRO), citric acid (CIT), garlic powder (GAR) or their combinations on growth, blood constituents, ileal microflora and morphology and humoral immunity of broiler chickens subjected to cyclic heat stress. Four hundred ninety one-day-old Ross-308 broiler chicks were randomly allocated to 7 groups with 7 replicates of 10 birds each as follows: control (C) group received the basal diet without supplements, PRO, CIT and GAR groups supplemented with 0.5 g kg^-1 multi-strain probiotic mixture (MPM), citric acid and garlic powder, respectively. PRO-CIT and PRO-GAR groups treated with 0.5 g kg^-1 MPM, and 0.5 g kg^-1 citric acid and garlic powder, while CIT-GAR group fed diet with 0.5 g kg^-1 of citric acid and garlic powder. Results revealed that dietary supplements and their combinations improved (P < 0.001) growth performance and decreased abdominal fat of heat-stressed birds. Dietary supplements decreased (P < 0.01) serum concentrations of cholesterol, triglycerides and LDL, while HDL was elevated (P < 0.05). Feed additives reduced (P < 0.01) ileal enumeration of Escherichia coli and total coliform while Lactobacillus count was increased (P < 0.05) only in MPM-enriched groups. Supplementation of these natural products improved (P < 0.01) ileal architecture while humoral immune response was not significantly influenced except antibody titre against Newcastle disease virus which was increased (P < 0.05) in MPM-supplemented groups. Conclusively, addition of the dietary supplements and their combinations, particularly, probiotic and citric acid combination can improve productive performance, and intestinal flora and histomorphometry of broilers exposed to cyclic heat stress.

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.

Effect of Feeding Wet Feed or Wet Feed Fermented by Bacillus licheniformis on Growth Performance, Histopathology and Growth and Lipid Metabolism Marker Genes in Broiler Chickens

The present study evaluated the effect of three feeding methods (dry feed, wet feed or wet feed fermented with Bacillus licheniformis) on the growth performance, intestinal histomorphometry and gene expression of the lipid metabolism- and growth-related genes of broiler chickens. A total of 360 one-day-old Cobb-500 broiler chicks were randomly allotted into three groups containing four replicates with 30 birds each. The first group (control) was fed a dry mash basal diet. The second and third groups were fed wet feed and fermented wet feed. The final body weight and weight gain were reduced (p < 0.01) in the wet feed group, while they did not differ between the fermented wet feed and dry feed groups. Feed intake was not altered, and feeding on wet feed significantly (p < 0.01) increased the feed-to-gain ratio compared to the remaining groups. No differences between the three feeding methods in carcass characteristics, blood biochemistry and nutrient digestibility were observed except for crude protein digestibility, which was increased (p < 0.01) in the fermented wet feed group. Duodenal and ileal villi heights were elevated in birds fed fermented wet feeds, while crypt depth was not altered. The expression fold of IGF-1, GH and m-TOR genes in the pectoral muscle of birds fed wet feed was decreased (p < 0.05), while myostatin gene expression was elevated. Feeding on wet feed reduced the hepatic gene expression of PPARγ and increased that of FAS. In conclusion, wet feed negatively affected the broiler chickens' efficiency under heat stress; however, fermenting the wet feed with Bacillus licheniformis improved feed utilization and birds' performance compared to the dry feed group.

Provision of Additional Cup Drinkers Mildly Alleviated Moderate Heat Stress Conditions in Broiler Chickens

Sixty-four broilers of a commercial strain in a 2 × 2 factorial design with two environmental conditions: normal (N; 20°C, 50% RH) or MHS (30°C, 70% RH for 6 h/day for 3 consecutive days), and two drinker treatments; standard (B; a bell drinker/pen) or additional (A; as B + two cup drinkers). Each treatment had 16 birds with half of them implanted with temperature-ID chips to estimate the change in core body temperature (ΔCBT). Comb (CT) and feet (FT) temperatures were measured with atemperature probe, behavior was recorded with digital cameras, daily weight gain, feed intakes and litter moisture content (LMC) were also monitored. Data were subjected to General Linear Model (GLM) analysis. MHS broilers had greater ΔCBT, CT, and FT and more time spent panting and drinking compared to N broilers. Provision of additional cup drinkers reduced ΔCBT but enhanced heat loss from the comb and feet. At 6HS, MHS birds showed a tendency to spend more time drinking from the cup drinkers compared to N birds without compromising LMC. MHS suppressed feed intake and not weight gain.

The role of polyphenols in poultry nutrition

In the last two decades, poultry and animal industries became increasingly interested in using plant-based feed supplements, herbs and their derivatives to retain or enhance their health and productivity. These health benefits for the host mainly attributed to the secondary plant metabolites, namely polyphenols. Polyphenols are renowned for their antioxidant, immunomodulatory, anti-mutagenic and anti-inflammatory properties. However, despite these advantages of polyphenols, they have been characterized by poor absorption in the gut and low concentration in target cells that compromise their role as effective antioxidants. The low bioavailability of polyphenols necessitates the need for further investigations to harness their full potential in poultry farms. This review is existing evidence about the bioavailability of polyphenols and their antioxidant, immunomodulatory, antimicrobial, detoxification properties and their impacts on poultry performance.

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.

The Influences of Various Housing Systems on Growth, Carcass Traits, Meat Quality, Immunity and Oxidative Stress of Meat-Type Ducks

The present study aimed to investigate the effect of different housing systems on Pekin ducks. A total of 300-day old Pekin ducklings were randomly divided into four experimental groups; the first housed in a closed house (CH), the second in closed house with open yard (HY), the third group in closed house with swimming pool (CHSP) and the fourth in a closed house with swimming pool and yard (HYSP). Results indicated that the HYSP and CHSP produced higher body weight comparing to the other groups. However, the HYSP gave the highest body weight followed by CHSP then HY and CH. The same trend was observed regarding weight gain and feed-conversion ratio (FCR). Moreover, HYSP, HY and CHSP showed higher dressing percentage, breast muscles and thighs and lower abdominal fat than the CH group. Serum protein was significantly higher in HYSP and HY than that of the closed house. While, lipids, cholesterol and triacylglycerol were significantly lower in groups housed in HY than that of CH. Meat cholesterol and triacylglycerol reduced in groups reared in HY. Housing ducklings in yards and using swimming pools significantly improved the general immunity (phagocytic index and activity and differential leucocytes count), and also improved the oxidative stress parameters. In conclusion, results confirmed that housing ducks in a house supplied with yard and swimming pool can improve its productivity, carcass traits, meat quality, blood lipid profile, immunity and antioxidative status.