Poultry

Infectious bursal disease (IBD), caused by an Avibirnavirus, belonging to the family Birnaviridae, is an immunosuppressive disease that affects 3–6-week-old chickens, resulting in clinical or subclinical infection. Although clinical disease occurs in chickens, turkeys, ducks, guinea fowl, and ostriches can be also infected. IBD virus (IBDV) causes lymphoid depletion of the bursa, which is responsible for the severe depression of the humoral antibody response, primarily if this occurs within the first 2 weeks of life. IBD remains an issue in chicken meat production due to economic losses caused by the spread of variants or subtypes, resistant to the most common vaccines, responsible for a subclinical disease characterized by reduced growth performance and increased susceptibility to secondary infections. Very virulent strains of classical serotype 1 are also common in several countries and can cause severe disease with up to 90% mortality. This review mainly focuses on the immunosuppressive effect of the IBDV and potential vaccination strategies, capable of overcoming challenges associated with the optimal time for vaccination of offspring, which is dependent on maternal immunity and IBDV variant occurrence. Full article

Peptides produced from food sources possess numerous bioactivities that make them useful in improving human health and preventing diseases. Although many studies related to egg protein hydrolysis are available, little work has been conducted on the production of bioactive peptides from apo-ovotransferrin (OTF) using two-step enzyme hydrolysis. The objectives of this study were to produce bioactive peptides from OTF using two enzymes and to determine their functional properties. Lipolyzed OTF was prepared at a concentration of 20 mg/mL and treated with protease (3 h at 55 °C), papain (3 h at 37 °C), elastase (24 h at 25 °C), and α-chymotrypsin (3 h at 37 °C) as the first enzyme treatment. The hydrolysates from the first step of hydrolysis were treated with the above enzymes in different combinations and incubated for 24 h at their optimum temperatures, followed by heat inactivation at the end of each treatment. Based on 15% SDS-PAGE results, the nine best enzyme combinations were selected for further analysis. Papain + protease (PapPro, 0.0075 ± 0.004 malondialdehyde (MDA) mg/kg), α-chymotrypsin + papain (ChyPap, 0.081 ± 0.003 MDA mg/kg), and elastase + α-chymotrypsin (ElaChy, 0.083 ± 0.015 MDA mg/kg) showed strong antioxidant activity. PapPro showed the highest Fe-chelating activity (5.40 ± 0.85%) but lacked Cu-chelating activity. In conclusion, PapPro, ChyPap, and ElaChy treatments of OTF produced peptides with strong antioxidant and Fe-chelating activities but lacked Cu-chelating activity. Thus, ovotransferrin hydrolysates produced using PapPro, ChyPap, and ElaChy treatments have the potential to reduce oxidative stress in the body. Full article

This review analyzes the processes of phenotypic and morpho-biometric characterization of West African local chicken. Data were collected on a set of 44 articles, and other reference documents were used to analyze and discuss the data collected. Existing studies on the phenotypic and molecular characterization of local chicken populations in West Africa indicate the presence of a wide variety of plumage colors and conformations, and intra-population genetic diversity. However, none of these studies have been able to identify the existence of a differentiated subpopulation that can be assimilated into a distinct race. The conclusions of this studies are not sufficient to ensure the non-existence of “race” in West Africa because many of these studies focus only on the phenotypic aspect, while molecular characterization makes it possible to identify differentiated populations with certainty. Additionally, the populations studied are often small in size, though remaining within the FAO recommendation standards. The spatial distribution used to compare the subpopulations was based on agroecological zones with strong interconnections to and shared with West African human populations, to the detriment of socio-cultural realities. In order to be more effective and conclusive, characterization work could consider the spatial distance of subpopulations in a comparison and the levels of exchange between the human communities from which these chicken subpopulations originate. Full article

The avian inner perivitelline layer (IPVL), containing the zona pellucida (ZP) family of proteins, surrounds the ovulated ovum. Sperm binding at the germinal disc (GD) region of the IPVL initiates fertilization in avian species, and the amount of sperm binding at the GD reflects female fertility. RT-PCR and quantitative Western blot analyses were used to determine differences in ZP protein mRNA expression and protein concentration between GD and nongerminal disc (NGD) regions among four genetic strains of broiler breeders. Both the mRNA expression and protein concentration of chicken ZPB2 was greater in the GD region, compared to the NGD region, and ZPB2 protein was more abundant in the small prehierarchical follicles. Chicken ZPC mRNA, but not ZPC protein, was greater in the NGD region compared to the GD region, and hepatically expressed ZPB1 protein was more concentrated in the NGD region. Testosterone increased the expression of both ZPC mRNA and protein in cultured granulosa cells from prehierarchical follicles. The current research is the first to investigate the relative amount of ZP proteins between the GD region and NGD region in chicken IPVL. The results provide further evidence that ZPB2 may be critical for avian sperm binding at the GD region of the IPVL. Full article

The objective of this study was to evaluate whether probiotic supplementation to laying hens can improve the quality of eggs during storage. The trial was developed in a commercial farm, in which light-weight laying hens (36 weeks old) housed in cages were randomly selected for one of two different treatments: a control group fed non-supplemented diets, or birds fed with diets supplemented with 50 g/ton of probiotics. The trial lasted for 84 days, comprising three productive phases of 28 days each. The fresh egg quality was evaluated and then the eggs were stored and randomly separated for quality assessment at each storage interval (7, 14, 21, 28, 35, and 42 days). Means were compared using variance analysis considering differences at 5 and 10%. The probiotic was able to improve albumen weight, yolk length, yolk height, and yolk index (p < 0.05) during storage. Yolk color (fan) was also improved by 3.9% (p < 0.001), while increases of 1.35% (p < 0.001) in luminosity, 8.05% (p < 0.001) in red intensity, and 3.4% (p < 0.001) in yellow intensity were observed in comparison to the control group. Probiotic treatment was able to reduce by 2.03% (p < 0.001) yolk pH, and by 19.65% (p < 0.05) TBARS levels when compared to the control treatment. Therefore, the addition of probiotics to laying hen diets is an effective strategy to improve egg quality during storage. Full article

In this study, the effects of malted sorghum-based diets (MSBD) on carcass characteristics and meat quality were investigated in broiler chickens. Two-week-old Ross 308 broilers were randomly allocated to three groups (each with five replications) and were then reared on either 0 or 100% (red (Mr Buster) or white (Segaolane)) malted sorghum commercial diets. The highest (p < 0.05) slaughter weights, hot carcass weights, and cold carcass weights were observed for the broilers reared on the control diets. Broilers reared on MSBD had high (p < 0.05) drumstick–thigh and vertebrae weights. The broilers fed the malted red sorghum-based diet (MRSBD) had the longest (p < 0.05) small intestine and highest gizzard and liver percentage. The pHi of the broilers fed MRSBD was higher (p < 0.05) than the broilers on the control or malted white sorghum-based diet (MWSBD). Breast muscle crude fibre was the lowest (p ˂ 0.05) for the MRSBD and phosphorus was low (p ˂ 0.005) for MSBD broilers. The highest (p < 0.05) muscle potassium and magnesium was found in the control diet broilers. The carcass characteristics, internal organs, and meat quality traits of the broilers fed MSBD compared well to those fed the control diets. It is concluded that malted sorghum grains are a potential alternative energy source to maize for broiler diets and could reduce competition for maize grains between livestock and human use. Full article

The objective of the present study was to characterize the probiotic potential of nine strains of Lactobacillus spp. isolated from the gastrointestinal tract of Creole hens through in vitro and in vivo tests. The following parameters were evaluated in vitro: (1) growth at four pH levels, (2) resistance to four bile salt concentrations, (3) tolerance to four NaCl concentrations, (4) growth capacity in the culture medium, and (5) the antimicrobial activity against Escherichia coli, Salmonella, Klebsiella, and Staphylococcus aureus. The candidate LP-40 had significantly (p < 0.05) increased resistance to pH 3 and 0.3% bile salts and elevated antimicrobial activity in vitro compared to the other strains evaluated. This strain was identified as Lactobacillus salivarius by 16S rRNA sequencing. An in vivo experiment was conducted to assess the effect of LP-40 supplementation in the drinking water on 42-day performance parameters in broiler chickens as compared to a non-treated control or dietary treatment with enrofloxacin. The administration of LP-40 in the drinking water significantly (p < 0.05) improved body weight, feed conversion compared to the antibiotic-treated control. Thus, the in vitro and in vivo results suggest that Lactobacillus salivarius LP-40 demonstrates probiotic potential and, perhaps, could be utilized as an alternative to antibiotic treatment. Full article

Managing and controlling environmental temperature conditions using practical strategies is crucial to avoid the negative impacts of high environmental temperature, improving poultry production and welfare. High environmental temperature is one of the significant factors challenging poultry production during hot seasons or in tropical areas causing heat stress (HS). The detrimental effects of HS on broilers range from reduced growth performance to impaired poultry meat quality. HS impairs physiological responses caused by alteration in blood parameters, which could lead to impaired product quality by reducing moisture content and altering the production of antioxidant enzymes resulting in increased oxidative stress. There has been a focus on the use of nutritional supplements as a cost effective HS amelioration strategy, such as betaine and polyphenols. Supplementing broiler chicken’s diets with polyphenols aims to enhance growth performance via reduced levels of oxidative stress in tissues under HS conditions. Furthermore, using betaine as an osmolyte aims to protect tissues during osmotic stress conditions. The current review reveals that betaine and polyphenols are essential under crucial conditions such as HS to protect tissues from oxidative damage. Full article

Point-of-care analyzers such as the Vetscan VS2 (VS2) that provide fast results are becoming an important tool in a variety of clinical and research settings. Several studies have explored the use of the VS2 to evaluate blood chemistry values in chickens; however, the VS2 analyzer has not yet been tested in turkeys. The first objective of this study was to utilize the VS2 to evaluate possible time-dependent changes in biochemical blood analytes over time, such as glucose, calcium, or sodium. Blood samples from 30 turkeys were analyzed with the VS2 at three time points (0, 15–20, and 40–60 min post collection), and it was found that the blood biochemistry values were stable when stored at 4 °C and analyzed within 60 min of collection. Next, we assessed the agreement between the VS2 portable analyzer and the reference benchtop analyzer (Cobas c501) and found that all of the blood analytes were comparable between both analyzers. Finally, we determined reference intervals using 120 blood samples collected from turkeys in the brooding period (0–7 days) and 118 samples collected from turkeys in the growing period (1–12 weeks). Although the values were compared to the published data, the understanding of any observed differences was challenging because reference intervals for the biochemical values in turkeys are limited, and the origin of these interval values could not be traced. Significant differences in the whole blood analytes were noted between brooding and growing birds. This study offers reassurance of the validity of the use of portable analyzers in the field for turkey veterinarians. We conclude that the VS2 can be used to measure biochemical analytes in turkeys and provide the first reference intervals for brooding and growing turkeys using this instrument. Full article

Under commercial conditions, laying hen chicks are exposed to a range of stressful events immediately after hatch. Here, we studied whether environmental enrichment was able to reduce the stress sensitivity of these chicks. A total of 50 hatchery chicks (HC) and 50 control chicks (CC) were raised in enriched pens (E), while 53 HC + 53 CC were raised in standard non-enriched floor pens (NE). HC weighed less on day one, but there was no effect of hatchery treatment at later ages. HC were more pessimistic in a cognitive judgement bias test and emitted more distress calls when socially isolated, indicating that hatchery stress affected behaviour and stress sensitivity. However, enrichment did not affect the behaviour in any of these tests. We found no effects of hatchery stress in a novel environment, but indications that enrichment may have increased fearfulness of HC. The sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis was reduced in HC-E compared to HC-NE, indicating that enrichment buffered the physiological stress sensitivity in HC; however, the opposite pattern was found in CC. In conclusion, our results show complex and somewhat contradictory effects on the ability of enrichment to buffer the consequences of stress in commercial hatcheries. Full article

Dietary inclusion of the vitamin D3 (D3) metabolite, 25-hydroxycholecalciferol (25OHD3), was demonstrated to improve broiler growth performance and breast meat yield. To assess the effect of combined maternal (MDIET) and post-hatch (PDIET) dietary 25OHD3 inclusion on broiler growth performance and carcass characteristics, a randomized complete block design experiment with a 2 × 2 factorial treatment structure was conducted. From 25 to 38 weeks of age, broiler breeder hens were provided with 1 of 2 MDIET formulated to contain: 5000 IU D3 (MCTL), or 2240 IU of D3 + 2760 IU of 25OHD3 per kg of feed (M25OHD3). Their chick offspring (n = 448; 224 per MDIET) hatched from eggs collected from 37 to 38 weeks of age were reared in 16 replicate pens with 7 birds per pen and fed 1 of 2 PDIET in 3 phases up to day 40 formulated to contain: 5000 IU of D3 per kg of feed (PCTL), or 2240 IU of D3 + 2760 IU of 25OHD3 per kg of feed (P25OHD3). No additive or synergistic effects of combining 25OHD3 inclusion in MDIET and PDIET were observed. Broilers from 25OHD3-fed hens (M25OHD3) were heavier on day 40 than those from hens fed only D3 (MCTL; 2.911 vs. 2.834 kg; p = 0.040). Tender weight (123 vs. 117 g) and yield (5.63 vs. 5.44%) were greater in the M25OHD3 broilers than the MCTL broilers (p = 0.006). Broilers fed 25OHD3 (P25OHD3) tended to have heavier breasts (637 vs. 615 g; p = 0.050), bone-in wings (215 vs. 210 g; p = 0.070), and boneless thighs (279 vs. 270 g; p = 0.078) compared with those fed only D3 (PCTL). Neither MDIET nor PDIET altered the severity of Wooden Breast and White Striping (p ≥ 0.106). Overall, including 25OHD3 in either the maternal or broiler diet increased broiler meat yield. Full article

Avian pathogenic E. coli (APEC) can cause avian colibacillosis, an economically important disease that contributes to bird mortality and the high costs associated with prevention and treatment. Little is known about APEC in the context of Australian conditions. The current study aimed to estimate the prevalence of APEC and determine the risk factors associated with cloacal carriage of APEC among commercial healthy meat chickens in Queensland. Cloacal swabs were collected at slaughter from 400 healthy meat chickens (ten per farm) originating from 40 farms. A total of 2200 E. coli isolates were selected from cultured swabs and screened for the presence of five APEC-associated virulence genes (VGs). Farm-level data were collected using a questionnaire. Binominal general linear models were used to identify farm-level risk factors associated with bird-level APEC prevalence. Thirty-four per cent of the cultured E. coli isolates (n = 751) were classified as APEC, with all farms testing positive for APEC, and the overall bird-level prevalence of APEC was 63.0%. Higher APEC within-farm bird-level prevalence was positively associated with the usage of well water as a source of drinking water (OR = 6.2, 95% CI: 2.3, 16.5, p < 0.001); not having shower facilities available for farm visitors (OR = 3.6, 95% CI: 1.8, 7.1, p < 0.001); distances greater than 20 m between the car park and the poultry shed (OR = 2.2, 95% CI: 1.4, 3.4, p = 0.001); not applying water line disinfection after each flock cycle (OR = 2.2, 95% CI: 1.4, 3.5, p = 0.001); the presence of wild birds within 50 m of the poultry shed (OR = 2.3, 95% CI: 1.4, 3.7, p = 0.001). Chlorine combined with automatic drinking water filtration reduced within-farm bird-level APEC prevalence (OR = 0.07, 95% CI: 0.02, 0.34, p = 0.001). This study identified a number of important factors associated with APEC and showed that improving biosecurity and water treatments might reduce the prevalence of APEC. The notable high APEC prevalence on all farms requires further epidemiological investigations. Full article

The purpose of this trial was to evaluate the effects of Punica granatum L. and Allium cepa L. peels aqueous and cyclodextrin extracts on broiler chicks’ performance and welfare status, as well as on the meat chemical composition and oxidative stability. A total of 120 one-day-old male Ross-308 chicks were randomly allocated to three treatments with four replicate pens (10 chicks per pen). Broiler chicks in the control group were fed typical commercial rations in mash form, based on maize and soybean meal. The rations of the other two treatments were further supplemented with the mixture of Punica granatum and Allium cepa aqueous and cyclodextrin extracts at the level of 0.1% of the feed, respectively. At the end of the trial (day 35), tissue samples were collected for analysis. Body weight (BW), feed intake (FI), average daily gain (ADG) and the feed conversion ratio (FCR) during the period of 1–10 days, 11–24 days, 25–35 days and 1–35 days were evaluated. Litter score, dry matter in litter, pododermatitis and feather score were also assessed at the end of the trial. Data were analyzed with ANOVA using SPSS v25 software. The results showed that BW, FI and FCR values did not differ among the groups. Scoring of pododermatitis, diarrhea, feather, fecal moisture, wooden breast and white stripping did not differ (p ≥ 0.05) among the groups. Punica granatum and Allium cepa aqueous and cyclodextrin extracts favorably affected (p < 0.05) meat composition, color parameters, TBARS and protein carbonyls. Diet supplementation also increased (p < 0.05) ∑n-3 fatty acids as well as ∑n-6 fatty acids in the thigh meat. The cis-4,7,10,13,16,19-Docosahexaenoic acid fatty acids in the breast meat of broilers fed with diets supplemented with the aqueous pomegranate and onion peel extracts were found to be higher (p < 0.05), while these fatty acids in the thigh meat were found increased (p < 0.05) in the cyclodextrin group. Aqueous and cyclodextrin pomegranate and onion peel extracts may provide a promising additive to the broilers diet with functional properties, in the absence of stressful conditions. Full article

Research on the impact of supplementing additional dietary choline to modern, large-frame broiler chickens is limited, and current choline recommendations are outdated. The objective of this study was to determine the effect of additional dietary choline chloride supplementation on growth performance and carcass characteristics of modern broilers reared to 32 days of age. Corn and soybean meal-based diets were formulated to contain an additional 0, 400, 800, 1200, 1600, or 2000 mg of choline chloride per kg of feed above the choline present in the basal diet ingredients. As-hatched Ross 708 × Yield Plus broiler chicks (n = 2160; 30 birds per pen; 44 ± 0.2 g initial BW) were randomly allotted to the experimental diets, reared for 31 days, and processed at day 32. Growth performance, carcass yield, and breast myopathy incidence were not impacted by supplemental choline. However, abdominal fat pad weight tended to diminish with increasing dietary choline, and drumstick yield was reduced in birds fed over 800 mg per kg of feed. These results indicate feeding additional choline does not impact growth performance but may result in changes in carcass characteristics of modern, high-yielding broilers reared for 32 days. Full article

High fiber levels (165 g neutral detergent fibre (NDF)/kg DM) in Moringa oleifera leaf powder (MOLP) could limit its utilization as a nutraceutical source in Jumbo quail diets. Pre-treating MOLP with exogenous fibrolytic multi-enzymes could reduce the nutrient-encapsulating effect of non-starch polysaccharides and subsequently increase nutrient and bioactive compound utilization. Thus, this study investigated the effect of pre-treating dietary MOLP with an exogenous fibrolytic enzyme mixture on some physiological parameters and meat quality characteristics in Jumbo quail. A total of 396 Jumbo quail were randomly distributed to 6 experimental diets, with 6 replicate pens each and 11 birds per replicate. The experimental diets were: CON = a standard grower diet (156.5 g NDF /kg) without MOLP; ENZ0 = CON + 10% MOLP; and CON + MOLP pre-treated with 0.25% (ENZ25), 0.50% (ENZ50), 0.75% (ENZ75) and 1% (ENZ100) fibrolytic enzymes. There were no significant linear or quadratic effects on growth performance parameters and carcass characteristics in response to incremental levels of fibrolytic enzymes. However, neutrophils linearly increased, while breast meat lightness and 24 h hue angle linearly declined with enzyme levels. Quadratic effects were observed on gizzard weights and 1 h hue angle in response to enzyme levels. All the hemato-biochemical values fell within the normal ranges for healthy quail. It was concluded that the maximum fibrolytic multi-enzyme application rate of 1% may not have been adequate to enhance feed utilization and positively affect weight gain in Jumbo quail, thus higher levels may need to be investigated further. Full article

This study evaluated the effects of feeding varying levels of dietary DL-methionine (MET) supplementation on breast meat (BM) quality of broilers of different sex. The 1-day-old, sexed chicks (Ross 708, 1552) were randomly allocated into four groups (each with 4 replicates) and were raised with diets supplemented with 0, 0.5, 1, or 2 g MET/kg of feed to a common weight (2.72 kg). Color, pH, drip loss (DL), water-holding capacity, moisture uptake, cooking yield (CY), texture, total antioxidant capacity (TAC), and lipid oxidation (LO) were determined using BM samples harvested 24 h postmortem. The male BM had higher redness, TAC, firmness, and toughness but lower yellowness (p < 0.01) than the female BM. In both sexes, birds fed 0.5 g/kg MET had lower DL (p < 0.01) than those fed 1 and 2 g/kg MET. For storage up to 3 days, MET suppressed LO in cooked BM (p < 0.01) and suppression increased as MET increased. CY for 1 and 2 g/kg MET were higher (p < 0.01; 79.04 and 78.60%, respectively) than CY for 0 and 0.5 g/kg MET (66.18 and 68.03%, respectively). These results suggest that MET supplementation at 1 g/kg or higher for broilers can improve oxidative stability, muscle functionality, and breast meat CY. Full article

This research evaluated the influence of kudzu leaf meal particle size on body weight, feed consumption, feed conversion, breast weight, and organ weights of broilers. Treatments (4) included a control and kudzu leaf meal added to replace 2.5% soybean meal in a broiler starter diet at three particle sizes (1.00, 2.00, and 3.35 mm). Dietary treatments were fed to 240 male broilers over a 21 day grow out. Overall, there were no significant treatment effects for body weight, feed consumption, breast weight, or organ weights. There were no treatment effects for day 1 to 7 feed conversion (p > 0.05). There tended to be treatment differences for day 1 to 14 feed conversion (p = 0.052) and a significant effect between day 1 to 21 (p = 0.002). Feed conversion between day 1 to 21 was depressed at the 1.00 mm kudzu particle size. Based on this study, kudzu remains a viable protein source for inclusion in broiler diets and a particle size of 2 to 3 mm would be recommended. Full article

The purpose of this study was to investigate the effects of high levels of Tenebrio molitor dietary inclusion (15%) on molecular mechanisms that influence poultry health in a broiler chicken diet. The global gene expression of four tissues (breast, liver, jejunum, and caecum) was evaluated using the RNA-Seq approach. The analysis of differentially expressed genes suggested that the use of Tenebrio molitor leads to the overexpression of genes related to protein elongation required for tissue growth and development in the gut and liver. It would also appear to contain nutrients that reduce the expression of genes related to the immune system and inflammation of the mucosa. The dietary inclusion of Tenebrio molitor in poultry could also lead to a possible inactivation of the growth factor and a reduction of tissue free-radicals. No genes alterations have been detected in liver RNA expression that would discourage the use of larvae in feeding broilers. Full article