ABSTRACT 1. This study evaluated carbohydrase supplementation on growth performance, metabolisable energy (ME) equivalence and body composition of broilers fed reduced-energy diets. A total of 1440 eight-day-old male Cobb 500 broilers were distributed in a completely randomised design with eight dietary treatments, nine replicates and 20 birds per replicate. Treatments consisted of a positive control (PC) diet meeting ME requirements, a negative control (NC) diet (with a reduction of 180 kcal/kg ME) and six (NC) diets supplemented with different carbohydrase complexes containing xylanase and β-glucanase (CBH1-6 at commercial inclusion levels). 2. Performance was evaluated at 21 and 35 d of age as body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). ME equivalence was estimated using regression equations from diets with graded ME levels and body composition was measured by dual-energy X-ray absorptiometry. 3. Broilers fed the NC diet had lower BWG (0.84 vs. 0.90 kg; p ≤ 0.001) and BW at 21 d (1.09 vs. 1.14 kg; p ≤ 0.001) compared with the PC. Supplementation with CBH3 restored BW and BWG to values similar to PC in the starter phase and resulted in the highest estimated ME equivalence (106.9 kcal/kg in the starter phase and 36.5 kcal/kg overall), followed by CBH6 (40.2 and 12.3 kcal/kg). 4. Feed intake increased only in NC+CBH3 (p ≤ 0.001), whereas FCR remained higher than PC in most treatments (p ≤ 0.005). No consistent effects were observed on lean tissue or bone mineral content, although fat was reduced in specific treatments (p ≤ 0.05). 5. Carbohydrase supplementation partially alleviated the effects of ME reduction, with responses depending on enzyme complex and production phase.

ABSTRACT 1. The Sonic Hedgehog (Shh) gene expresses a highly conserved signalling molecule essential for cell-to-cell communication, which regulates key biological processes, such as embryonic development (as embryo days; ED) and organogenesis. Although feathering is a critical aspect of skin development in poultry, particularly in Chinese indigenous breeds such as the Jilin white goose, its molecular mechanisms remain poorly understood. 2. In this study, 150 fertilised Jilin white goose eggs were analysed to investigate embryonic skin morphological changes. Immunohistochemistry (IHC) was applied to determine the localisation of Shh protein, while qPCR and Western blotting were conducted to examine the temporal dynamics of mRNA and protein expression. 3. The results revealed that Shh mRNA expression increased initially and then declined between ED8 and ED13, with the highest level observed at ED12. In contrast, Shh protein expression demonstrated a biphasic rise with an intervening decline, peaking at ED9. 4. In vitro skin tissue culture experiments indicated that Shh may contribute to feather bud initiation and development by modulating the WNT signalling pathway. 5. This study elucidated the temporal and spatial expression patterns of Shh and its interaction with the WNT signalling pathway during early embryonic skin development in Jilin white geese.

ABSTRACT 1. This study evaluated the effects of phytase superdosing in broiler chicken diets based on corn, soybean meal and meat and bone meal on performance, carcass yield, pectoral myopathies, bone mineral composition and the metabolisability of energy and nutrients. 2. Two experiments were conducted: one focused on performance and the other on nutrient metabolism. In both experiments, birds were randomly assigned to a completely randomised experimental design. The performance trial included 1600 male Cobb 500 broilers, whereas the metabolism trial included 480 birds of the same strain. In the performance trial, birds were allocated to one of eight treatments with 10 replicates of 20 birds per experimental unit from 1 to 42 d of age. In the metabolism trial, each experimental unit consisted of six birds. Linear and quadratic regression analyses were performed to estimate the optimal phytase supplementation level. 3. Higher phytase inclusion levels, particularly 2000 phytase units/kg feed, resulted in greater weight gain and better feed conversion ratio. Diets supplemented with 2000 and 2500 phytase units/kg caused the highest calcium and phosphorus concentrations in tibia bones. 4. In the nutrient metabolisability trial, phytase supplementation promoted linear increases in metabolisability coefficients for gross energy, organic matter and zinc, along with linear reductions in excreted mineral matter and zinc. 5. Overall, phytase superdosing, especially at 2000 and 2500 phytase units/kg, enhanced broiler performance, increased bone mineral deposition, improved nutrient metabolisability by 7 to 29% and reduced phosphorus excretion by up to 31.6%. 6. These findings demonstrated that high-dose phytase can be an effective strategy to improve feed efficiency and nutrient utilisation in broiler diets containing mixed phosphorus sources, including animal-derived ingredients.

ABSTRACT 1. This study determined the pre-caecal digestibility of crude protein (CP), amino acids (AA), gross energy, phosphorus (P) and pre-caecal phytate (InsP6) disappearance of a dehulled and ethanol-extracted rapeseed kernel meal (RKM) without and with exogenous phytase in broiler chickens. 2. The experiment utilised a 3 × 2 factorial design with the factors RKM inclusion (0, 12.5 or 25%) and phytase supplementation (0 or 1500 FTU/kg). Diets were fed to Ross 308 broiler chickens from 16 to 21 d of age raised in floor pens (seven per diet). 3. The RKM inclusion decreased the digestibility of certain AA (p < 0.05) and phytase increased the digestibility of CP and all AA in the diets (p < 0.05). CP digestibility in RKM, calculated by linear regression, was 75% without and 80% with phytase and Lys digestibility was 81% without and 85% with phytase. There was no significant phytase effect on the slopes of regression lines. 4. With increasing RKM inclusion, pre-caecal InsP6 disappearance decreased without phytase and increased with phytase (RKM × phytase: p < 0.010). Increased RKM inclusion reduced the amount of digestible P without phytase, whereas with phytase, the amount of digestible P increased with RKM inclusion (RKM × phytase: p < 0.001). 5. Pre-caecal gross energy digestibility decreased with RKM inclusion (p < 0.001) and increased with phytase supplementation (p < 0.05). Crude protein and AA digestibility of the RKM was high and increased with phytase supplementation. The P from RKM was not digestible without phytase.

ABSTRACT 1.This study investigated antimicrobial resistance and virulence factors in Salmonella enterica subsp. enterica serovar Thompson (SET) isolates from broilers in the Brazilian poultry industry. 2. Among 44 isolates, 18.18% showed phenotypic resistance, with tetA, sul1 and sul2 genes frequently detected, while sul3 was absent. Two isolates carried clinically relevant resistance genes: blaCTX-M-1 (ESBL) and OXA-48 (carbapenemase). 3. The PFGE analysis revealed five distinct clusters with low genetic diversity, which suggested a clonal dissemination pattern. One strain from cluster E showed the highest pathogenicity in broilers, underscoring the need for continued molecular surveillance in poultry production.

ABSTRACT 1. The nutritional potential of Faba bean (Vicia faba L.) is limited by the presence of phytate, which reduces phosphorus (P) digestibility and the bioavailability of other minerals. This study evaluated the effect of autoclaving and phytase on the P digestibility of broiler chickens. 2. Diets were formulated to include faba beans (FB) or autoclaved FB (AFB), with or without 1,000 FYT/kg phytase, in a 2 × 2 factorial arrangement. Broiler chickens were fed a similar starter diet until d 18, after which 256 chickens were weighed and assigned to four diets in a randomised complete block design, with body weight as the blocking factor (eight replicates of eight birds per cage). 3. Phytase increased the apparent total tract digestibility of P (p < 0.01), with an interaction between autoclaving and phytase on AID of P (p < 0.01); the AID of P increased to a greater extent when phytase was added to non-autoclaved FB than to autoclaved FB. Additionally, ileal digestible P and retainable P intake increased with phytase supplementation (p < 0.01).

ABSTRACT 1. Apoptosis is suppressed in the formation of goose fatty liver, which may be a protective mechanism. The objective of this study was to elucidate the mechanism by which apoptosis is inhibited in goose fatty liver. 2. Twenty, male, Landes geese were selected and randomly divided into a control group and an overfed treatment. Additionally, the primary hepatocytes were isolated from the goose embryos and treated with glucose. 3. The geese in the overfed group had higher liver weight, body weight and liver:body weight ratio than that in the control (p < 0.05). No significant difference on inflammation, fibrillation, or apoptosis level was observed from the staining of liver sections between the control and overfed group. 4. Neither the protein level of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) in liver nor the malondialdehyde concentration and manganese superoxide dismutase activity in liver mitochondria was altered in these two treatments (p < 0.05). Compared with the control group, the overfed treatment had decreased reduced glutathione (GSH) and increased glutathione reductase activity in liver mitochondria (p < 0.05). 5. There was no significant difference in apoptosis level, Bcl-2 and Bax protein level and Bcl-2/Bax ratio was found in hepatocytes treated with 20, 40 or 60 mM glucose when compared with the control group (p < 0.05). However, treatment with 40 or 60 mM glucose tended to increase the MDA concentration in hepatocytes (p = 0.055 and p = 0.091, respectively). The hepatocytes in 40 or 60 mM glucose treatment had decreased GSH concentration in comparison to the control (p < 0.05). 6. These findings suggested that apoptosis inhibition in goose fatty liver may be mediated through maintenance of Bcl-2/Bax ratio. Additionally, the increased antioxidant ability in tissue and mitochondria of goose fatty liver may contribute to resistance of apoptosis.

ABSTRACT 1. Although the anti-inflammatory drug Ketoprofen has been used in ducks, there has been no research on its pharmacokinetics. This study examined the disposition kinetics and bioavailability of Ketoprofen in Pekin ducks after intravenous (IV), intramuscular (IM) and oral administration for the first time. 2. A total of 18 ducks were split into three equal groups (n = 6) and were given a single dose of Ketoprofen (5 mg/kg) via IV, IM or oral routes. Blood samples were collected at 16 different time points up to 24 h post‐administration to determine the change in Ketoprofen plasma concentration over time by high-performance liquid chromatography with ultraviolet detection. 3. Following IV injection, total clearance, volume of distribution at steady state and elimination half‐life were 0.31 l/h/kg, 0.32 l/kg and 0.95 h, respectively. Following IM and oral administrations, peak plasma concentrations of 13.82 and 6.76 μg/ml were attained at 0.34 and 0.48 h, respectively. Bioavailability was 106 and 63% for IM and oral route, respectively, and average plasma protein binding was 98.8 ± 2.4%. 4. Ketoprofen showed small volume of distribution and rapid elimination in Pekin ducks. The IM injection resulted in higher plasma concentration and bioavailability than oral administration. This information contributes to the use of Ketoprofen in ducks in an appropriate dosage regimen, but efficacy needs to be demonstrated in experimental inflammation models.

ABSTRACT 1. This study investigated the effects of Aronia melanocarpa pomace (AP) supplementation on serum variables, egg quality, laying performance, nutrient utilisation and gut microflora in late-stage laying hens. 2. A total of 288 Hy-Line Brown hens (60 weeks old) were randomly allocated to one of four groups: a control (basal) or the basal diet supplemented with either 1% AP (APL), 2% AP (APM), or 3% AP (APH) for 20 weeks. Each group contained six replicates of 12 hens. 3. Egg production, egg mass and shell thickness increased with AP supplementation, peaking in the 3% AP group (p < 0.05). The AP supplementation significantly reduced serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and aspartate aminotransferase (ALT) concentrations, with the greatest reductions observed in the 3% AP group (p < 0.05). Linear decreases in TG, TC and LDL-C were more pronounced in the 2% and 3% AP groups (p < 0.05). Linear improvements in calcium metabolism were observed in AP groups compared to the control group (p < 0.05). 4. Crypt depth decreased in the duodenum, jejunum and ileum (p < 0.05), while the villus height-to-crypt depth ratio increased in the duodenum and ileum (p < 0.05), with a similar trend for the jejunal samples (p = 0.092). The AP supplementation increased beta diversity of caecal microbiota. At the genus level, Megamonas and Olsenella spp. abundance rose (p < 0.05), while Barnesiella spp. decreased (p < 0.05). 5. Supplementation with 3% AP enhanced laying performance and egg quality in late-stage hens by improving lipid metabolism, calcium utilisation and gut microbiota composition. These findings highlighted AP as a functional feed additive for sustainable poultry production.

ABSTRACT 1. Pendulous crop is a metabolic illness causing irreversible distension of the crop muscles due to weakened supporting ligaments. The present study assessed the physical, haematological and biochemical features of broiler chickens afflicted by pendulous crop (PC). 2. Fifty-six broiler chickens, male and female Cobb 500, were used. Forty-two-day old animals were chosen from the batch by verifying the volume of the organ and 28 healthy and 28 animals with PC were selected. The birds were weighed, assessed and 4 ml of blood was collected for cell count and serum biochemistry analysis. 3. Birds with PC had lack of co-ordination, difficulty in locomotion and regurgitation of the contents of the crop. Body weight was similar in PC and healthy birds (p > 0.05), however the absolute and relative crop weight in affected birds was higher than in healthy birds (p < 0.05). 4. When analysing the blood count, the mean corpuscular haemoglobin concentration (MCHC) in afflicted birds was lower than in healthy birds (p < 0.05). Serum biochemistry analysis showed that creatine kinase (CK) was higher in afflicted birds, and uric acid (UA) and triglycerides (TC) were lower in birds with PC (p < 0.05). 5. This disease compromises the physical state, behaviour and crop weight of birds, but did not cause significant haematological changes. However, it modified creatine kinase, which suggested changes in muscle metabolism and impairment of the digestion and nutrient’s absorption process.