British Poultry Science最新文献

1. This study investigated the potential effects of exposure to glyphosate from feed on breeder hens on egg hatchability and chick health. Hens received diets with no added glyphosate (Gly as a control (Con), or with addition of 1.5 (Gly_1.5), 4.5 (Gly_4.5) and 13.5 (Gly_13.5) mg/kg glyphosate in the diet resulting in analysed contents of 0.01, 1,47, 3.59 and 11.6 mg per kg diet, respectively.2. There were no effects of glyphosate in diets fed to breeder hens on hatchability of fertilised eggs (0.95, 0.93, 0.91 and 0.90 for Con, Gly_1.5, Gly_4.5 and Gly_13.5, respectively). Even though no effects of glyphosate were observed on one-day-old progeny chick quality, a post hoc analysis indicated that the navel score was best for chicks from the Con group compared to chicks from the combined Gly groups (p = 0.025). Weight gain of the chicks at 8 d of age was not affected.3. For immune competence and leukocyte subset counts in whole blood from breeder hens and one-day-old chicks, the results showed higher numbers of B-cells (p = 0.005) and monocytes (p = 0.027) as well as phagocytic activity of lymphocytes (p = 0.015). These were associated with higher glyphosate levels in peripheral blood from hens, whereas only phagocytic activity of lymphocytes was seen in chicks (p = 0.004). Total antioxidant capacity in blood plasma of hens and one-day old chicks was not affected.4. In conclusion, only some immune changes were associated in both hens and chicks with up to 11.6 mg glyphosate/kg diet fed to breeder hens.

1. This study examined the role of the central adropin and its interaction with dopaminergic and serotoninergic system on feed intake in broiler chicken. This study included eight experiments with four treatment groups each with 11 replicates for each group.2. In experiment 1, group 1 received ICV injection of the saline and groups 2-4 received ICV injection of adropin (0.5, 1 and 2 µg, respectively). In experiment 2, birds in group 1 received ICV injection of the saline, group 2 were injected with SCH23390 (D₁ receptor antagonist, 5 nmol), group 3 received ICV injection of the adropin (2 µg) and group 4 were injected with co-injection of the SCH23390 and adropin. Experiments 3-8 were similar to experiment 2, except AMI-193 (D₂ receptor antagonist, 5 nmol), NGB2904 (D₃ receptor antagonist, 6.4 nmol), L-741,742 (D₄ receptor antagonist, 6.4 nmol), PCPA (serotonin synthesis inhibitor, 1.25 µg), 8-OH-DPAT (5-HT₁A receptor antagonist, 15.25 nmol) and SB-242,084 (5-HT₂C receptor antagonist, 1.5 µg) were injected instead of SCH23390. Feed intake was measured until 120 min post injection.3. From the results, ICV injection of adropin (1 and 2 µg) decreased feed intake compared to the control group (p < 0.05). Co-injection of adropin and SCH23390 and for adropin and AMI-193 and for adropin and 5-HT₂C receptor antagonist decreased hypophagia compared to the control group (p < 0.05).4. These results suggested that adropin has a hypophagic role and is linked to D₁ and D₂ and 5-HT₂C receptors in neonatal broiler chickens.

1. This experiment examined the antioxidant and antimicrobial activities of aniseed oil (AO) in meat emulsions. Spices are integral part of emulsion-based products imparting desirable flavours. In the search for chemical-free preservatives, these spices hold promising potential for extending the shelf-life of meat emulsions.2. Three different levels of aniseed essential oil viz. AO1 (0.25%), AO2 (0.5%), AO3 (0.75%) and control C (without aniseed essential oil) were incorporated in chicken meat emulsions. Samples were assessed for changes in physico-chemical, antioxidant activity, lipid oxidation, microbiological parameters and visual sensory scores during refrigerated storage under aerobic packaging. Samples were evaluated at a regular interval of 3 d until the appearance of incipient spoilage.3. Titratable acidity, emulsion stability and extract release volume decreased significantly, whereas pH value increased (p < 0.05) among all samples throughout storage. Total phenolic, 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic and 2,2-diphenyl-1-picrylhydrazyl acid per cent inhibition increased as the level of aniseed oil incorporation increased among groups. However, this value reduced considerably (p < 0.05) during storage.4. Peroxide value, thiobarbituric acid reactive substances, free fatty acid content and microbial quality parameters increased (p < 0.05) by the end of storage. Visual sensory attributes score of AO2 were rated higher than AO3, although sensory score declined (p < 0.05) in all groups during storage.5. The results showed that AO2 maintained better sensorial characteristics than AO3 and sustained physicochemical, antioxidant and antimicrobial activity compared to the control, AO1.

1. This study tested the ability of broiler chickens to regulate dietary calcium (Ca) and retainable phosphorus (rP) intake when offered choices of complete diets varying in Ca and rP concentration from 0 to 21 d of age.2. Males and females were reared separately under standard conditions and offered either a single diet in some treatments, or in other treatments, a choice of two diets varying in Ca and rP concentration, resulting in 10 dietary treatments. Body weight and feed intake were measured at 7, 14 and 21 d. For each choice treatment, the intake of each diet as a proportion of the total intake was determined. Tibial ash concentration, Ca concentration, phosphorus (P) concentration and breaking strength were determined at 21 d.3. For the choice treatments, in which one diet was low in rP and the other high in rP, feed intake significantly favoured high rP concentration. Body weight gain responded positively to increasing rP intake, apparently regardless of Ca intake, although bone density and structural integrity were maximised when rP and Ca intake were both high.4. The principle that broiler chickens can select between feedstuffs to achieve intake that maximises growth, and, arguably, fitness, was seen in the diet choice of broiler chickens in the current experiment, at least for dietary Ca and rP.

1. This study was conducted to investigate the effects of dietary supplementation with benzoic acid (BA) and oregano essential oil (OEO) on the growth, performance, immune function and intestinal development of Langshan chickens.2. A total of 240 Langshan chickens were randomly allocated into five treatment groups in a 42 d trial (aged 30-72 d): Basal diet (CON); basal +50 mg/kg chlortetracycline (CTC); basal +2,000 mg/kg BA (BA); basal +300 mg/kg OEO (OEO); basal +2,000 mg/kg BA and 300 mg/kg OEO (BA+OEO).3. Compared with CON the BA, OEO and BA+OEO groups elevated jejunal goblet cell numbers (p < 0.05) and lowered serum interleukins IL-1β, IL-6, IL-8 and TNF-α at both 51 and 72 d of age (p < 0.001). The BA+OEO group altered caecal microbiota beta-diversity (p < 0.001) and increased Alistipes and Faecalibacterium spp. abundance compared to CON and CTC (p < 0.05).4. These results suggested that supplementing BA with OEO gave better responses than chlortetracycline in enhancing immune responses and intestinal health.

1. The objective of Experiment 1 was to determine the effect of fat source on basal endogenous losses of amino acids (BEL), histomorphology of the small intestine and caecal short-chain fatty acid (SCFA). Experiment 2 was conducted to determine the interactive effect of feedstuffs and fat types on coefficients of standardised ileal amino acid digestibility (cSIAAD) of maize and soybean meal (SBM), histomorphology of jejunum and ileum and the relative gene expression of amino acid transporters in the jejunal mucosa.2. In Experiment 1, a total of 80 broiler chickens were allocated to 16 metabolic cages (two diets, eight replicates each). Two nitrogen-free diets were formulated with soybean oil (25 g/kg, NFDS) or tallow (35 g/kg, NFDT) as fat sources. A total of 160 broiler chickens were allocated to 32 metabolic cages (four diets, eight replicates each) in Experiment 2. Four semi-purified diets consisted of maize or SBM as the sole protein source, each supplemented with either soybean oil or tallow as the fat type.3. In Experiment 1, there was no significant effect for any of the responses. In Experiment 2, there were no feedstuff × fat type interactions for any of the responses. The cSIAAD for Leu, Ala, Cys and Glu were greater (p < 0.05) for maize. The jejunal and ileal villi were longer, ileal crypts deeper and the relative expressions of peptide and amino acid transporter genes were greater (p < 0.05) for birds that received the SBM diets.4. In conclusion, under the conditions of this experiment, cSIAAD values determined with assay diets using the two fat types were similar.

1. This study investigated the metabolic effects of lipopolysaccharide (LPS, a pathogen-associated molecular pattern derived from gram-negative bacteria) and zymosan (a pathogen-associated molecular pattern derived from fungi) in young chickens (Gallus gallus domesticus).2. Liver RNA-seq analysis was performed on samples from chicks that received intraperitoneal injections of either LPS or zymosan. Pathogen-associated molecular patterns (PAMP) altered the expression of several genes associated with lipid, amino acid and carbohydrate metabolism in the liver. Moreover, both PAMP affected a common set of genes, with changes in their expression exhibiting a strong positive correlation (R ≥ 0.90). Subsequent analyses revealed that both PAMP altered plasma concentrations of several amino acids, including histidine.3. Finally, both PAMP significantly increased the mRNA expression of histidine decarboxylase and carnosine-N-methyltransferase, which are enzymes involved in the synthesis of histamine and anserine, respectively, in the liver and pectoralis major.4. These findings suggested that LPS and zymosan affect several metabolic pathways, particularly those related to amino acid metabolism and that they likely act through overlapping metabolic mechanisms.

1. The objective of the study was to investigate the effects of feeding varying levels of gamma-irradiated black soldier fly larvae (BSFL) and crushed grasshopper (GH) on performance, meat quality and organoleptic characteristics of broiler chickens2. A feeding trial with 546, one d old male broiler chicks was conducted for 42 d. The birds were weighed and randomly divided into seven dietary treatments in a completely randomised design experiment. Each treatment was replicated six times with 13 chicks in each. The experimental diets were isonitrogenic and isocaloric and consisted of: 1) basal diet (maize/soybean-based diet, control group) and diets 2-7 containing either 8%, 16% or 24% of BSFL or GH replacement instead of soybean meal in the basal diet, respectively.3. Results indicated that chicks fed 24% BSFL replacement exhibited a significant increase in average daily gain and a decrease in feed conversion ratio, along with marked improvements in carcass and breast meat yields (p < 0.05), while meat colour remained unaffected. In contrast, the sensory attributes of breast muscle were significantly enhanced in chicks receiving an 8% GH replacement (p < 0.05).4. The data showed that dietary inclusion of 24% BSFL enhanced growth performance, carcass traits and oxidative stability and 8% GH meal optimised meat sensory properties and lipid metabolism. These dietary interventions did not adversely affect meat colour, carcass traits or internal organ weights, which confirmed their safety and nutritional suitability. Gamma irradiation further promoted microbial safety, nutrient bioavailability, thereby demonstrating the advantages of irradiated insect-based feeds in poultry production.

1. Lincomycin, a lincosamide antibiotic, is commonly used for treating necrotic enteritis and chronic respiratory disease caused by avian mycoplasmas. Given its similar use in other birds, it has the potential to be applied off-label in geese. 2. This study examined the pharmacokinetics and tissue residues of Lincomycin in 16 healthy adult male geese. The study consisted of four phases, each separated by a one-month 'washout' period. Geese received Lincomycin via intravenous (IV, 1 mg/kg), single intramuscular (IM, 15 mg/kg), single oral (PO, 50 mg/kg) and multiple oral (SID, 5 mg/kg for 7 d consecutively) routes. Blood and tissue samples were collected at specific intervals for analysis using a validated UHPLC-MS/MS method. 3. Following IV administration, the mean values t1/2, V_d, and Cl were at 4.19 h, 2727.16 ml/kg, and 451.26 ml/h/kg, respectively. For both extravascular routes, Lincomycin displayed a high bioavailability (109% IM; 95% single PO) and rapid absorption (MAT 0.42 h IM; 2 h single PO) in geese. Multiple oral doses showed no plasma accumulation, but tissue data revealed quantifiable concentrations at 72 h. The calculated preliminary WT were determined as 1 d for the muscles, and 4 d for the kidneys and liver. 4. Despite the promising PK profile, the administered doses were inadequate to sustain drug concentrations above the MIC₉₀ for certain target pathogens, indicating the need for further optimisation of treatment regimens, including combinations with spectinomycin, as practiced in other animal species.

1. Artemisia capillaris Thunb. (ACT) is a semi-scrubby herb from the Artemisia genus of the Asteraceae family that has hepatobiliary effects. This study evaluated the effect of ACT on hepatic lipid buildup in laying hens and, hence, as a feed additive to treat fatty liver in laying hens.2. Hens were randomly allocated into one of five treatment groups: positive control group (to 35 weeks of age; PC), fatty liver control group (to 75 weeks of age; 75W), ACT low-dose intervention (1 g/h/d) group (to 75 weeks of age; 75W+L), ACT medium-dose intervention (2 g/h/d) group (to 75 weeks of age; 75W+M) and ACT high-dose intervention (4 g/h/d) group (to 75 weeks of age; 75W+H).3. Feeding ACT decreased the liver index and tissue sections revealed that it minimised hepatocellular steatosis and vacuolar degeneration, considerably lowered liver indicator enzyme (aspartate transaminase, AST and alanine transaminase, ALT) concentrations and improved liver function. Regarding hepatic fat formation, ACT reduced the amount of lipid droplets in the liver; the ACT group dramatically lowered serum triglycerides (TG), serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) while increasing high-density lipoprotein cholesterol (HDL-C). In terms of reproductive hormone markers, follicle-stimulating hormone (FSH) and luteinising hormone (LH) and vitellogenin (VTG) levels were dramatically elevated, while oestradiol (E2) levels were decreased in hens fed the ACT diets.4. Cyberpharmacology and molecular docking revealed that ACT primary target was AKT, which was able to reduce AKT protein phosphorylation as well as the protein expression of fatty acid synthesis-related genes ACC, FAS and SREBP-1c in the liver.5. In conclusion, ACT was able to dramatically reduce the protein expression of fatty acid production genes, enhance hepatic lipid metabolism in laying hens, reverse hepatic and dyslipidemic abnormalities in laying hens and ameliorate fatty liver conditions.