Poultry, Volume 1, Issue 2 (June 2022) – 7 articles

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