British Poultry Science最新文献

1. The aim of this research was to explore the influence of overfeeding on goose meat quality in foie gras production. Forty Tianfu Meat Geese were averagely separated into normal-feeding group (control group) and overfeeding group (force-feeding group), randomly. After overfeeding, the breast muscle and leg muscle were collected, and then the determinations of meat quality variables were performed. The cluster analysis, principal component analysis (PCA) and partial least square-discriminate analysis (PL-SDA) were performed to comprehensively estimate the influence of overfeeding on goose meat quality.2. Overfeeding increased the weights of breast muscle and leg muscle (p < 0.05), increased L*, a* and b* values of breast muscle and leg muscle (p < 0.05), increased the hardness values of breast muscle and leg muscle (p < 0.05), decreased the cooking loss of breast muscle (p < 0.05). In nutritional variables, overfeeding increased the contents of crude fat of breast muscle and leg muscle (p < 0.05). In breast muscle, overfeeding increased the contents of Ala, Tyr, Lys and Val, and decreased the contents of Arg and Phe (p < 0.05); in leg muscle, overfeeding decreased the contents of Asp, Glu, Ser, Ala, Tyr, Val, Phe, Ile and Leu, and increased the contents of Arg, His and Lys (p < 0.05). In fatty acids composition, the contents of C14:0, C16:1, C16:0, C18:2n6c, C18:1n9c, C18:0 and C20:0 of breast muscle significantly increased after overfeeding (p < 0.05). PCA and PLS-DA suggested that overfeeding had significant influence on the meat quality of the breast muscle and leg muscle.3. In conclusion, overfeeding improved the meat quality of overfed geese.

1. In recent years, the coating of meat and related products has shown potential in extending shelf life. However, there are no studies on coating with nanoemulsion solutions using vacuum impregnation (VI) technique in meat matrices. This study evaluated the impact of nanoemulsion coating solutions, comprising chia mucilage and different concentrations of sage essential oil (SEO) on antioxidant properties and quality characteristics of turkey breast during storage using VI.2. Five coating solutions were developed, including coating with water (CV), chia mucilage (CMV), chia mucilage + 0.5% SEO (CMS1V), chia mucilage + 1% SEO (CMS2V) and chia mucilage + 1.5% SEO (CMS3V).3. The results indicated that increasing the SEO in nanoemulsion solutions significantly boosted antioxidant activity. Incorporating sage essential oil at a concentration of 1.5%, led to a notable reduction in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS), which suggested reduced lipid oxidation. Additionally, the carbonyl and sulphhydryl content of turkey strips were significantly influenced by nanoemulsion coating solutions. Microbiological analysis revealed that nanoemulsions containing chia mucilage + SEO effectively reduced microbial load during storage, highlighting the antimicrobial properties of SEO. Furthermore, nanoemulsion coatings containing SEO inhibited the increase in total volatile basic nitrogen (TVB-N) values during storage, which extended the freshness of the meat.4. Overall, incorporating SEO into nanoemulsion coatings, alongside chia mucilage, maintained the quality attributes of turkey breast during storage, confirming the potential of nanoemulsion coatings in extending shelf life and preserving meat product quality.

1. This study evaluated the effect of oil-in-water (o/w) emulsion supplementation in feed compared to a conventional oil and emulsifier combination on fat and protein digestibility and growth performance in broiler chickens. The effects of this supplementation on macronutrient digestion kinetics were investigated through simulated in vitro digestion based on the broiler gastrointestinal tract.2. A total of 450 one-d-old Ross 308 chickens were assigned to one of the five dietary treatments consisting of nine replicates of 10 broilers each. The treatments included a control diet containing oil (3.25%) without emulsifiers, (NON-EM Low) or with a low emulsifier inclusion (0.10%), an EM Low diet supplemented with o/w emulsion using a low emulsifier concentration (3.25% oil; 0.10% emulsifier), a NON-EM High diet supplemented with oil (3.25%) and a emulsifier at high inclusion (0.65%) or a EM High diet supplemented with o/w emulsion using emulsifier at high inclusion (3.25% oil; 0.65% emulsifier). The feeding trial lasted 21 d using growing broilers.3. Body weight gain was higher in o/w emulsion diets EM Low and High compared to the other three diets. Fat digestibility at 21 d of age was not significantly different, although protein digestibility was lower in birds fed EM Low and EM High diets.4. In vitro digestion was substantially different in lipolysis, protein and starch hydrolysis kinetics. O/w emulsion supplementation reduced lag times in lipolysis and starch digestibility, and adding emulsifier altered the overall protein and lipid digestion kinetic behaviour.5. In conclusion, this study showed that o/w emulsion supplementation significantly improved broiler performance, most likely caused by differences in nutrient digestion kinetics in the starter phase. This research showed the potential of in vitro simulation to complement in vivo trials to understand digestion kinetics or to perform screening of potential diets before performing in vivo trials.

1. Further-processed poultry products, such as chicken nuggets, are susceptible to rapid lipid oxidation and microbial spoilage. Natural ingredients from various plants or fruits may contribute to improving the quality and extending the shelf life of meat products. In the present study, the use of encapsulated raspberry powder (ERP; control, 0.5%, 1.0%) in chicken nugget production with and without phosphate (0.0%, 0.3%) and its effects on chemical composition, lipid oxidation, microbial quality and shelf life were examined.2. Phosphate and ERP had effects on chemical composition and a_w; (p < 0.01). During storage, the ratio of O₂ and N₂ increased and the amount of CO₂ decreased (p < 0.05), but the increase in samples with 1.0% ERP addition was lower than in the control and 0.5% groups.3. Both the use of ERP (p < 0.01) and phosphate (p < 0.01) for nugget production prevented lipid oxidation. The lowest was determined in samples containing phosphate + 1.0% ERP (p < 0.05) during storage. However, the TBARS values were within acceptable limits (<1 mg MDA/kg) for all the samples with 0.5% and 1.0% ERP added with phosphate.4. The counts of total aerobic mesophilic bacteria decreased depending on the level of ERP added to the nugget composition (p < 0.01). Counts only exceeded 6 log CFU/g in the control samples on the 120^th day of storage. Salmonella spp. and Listeria monocytogenes were negative in all nugget samples during storage. The counts of Enterobacteriaceae were below the detectable limit (<2.0 log CFU/g) during storage.

1. The effects of feeding regimen, NSPase, extent of grinding and their interaction on the performance, digestive tract characteristics and ileal microbiota were studied. Eleven-day-old Ross 308 male broilers were given ad libitum (ADL) or intermittent (INT) access to finely (FG) or coarsely (CG) ground barley-based pelleted diets, with or without NSPase in a replicated pen trial. All birds had 4 h darkness separated with 1 h light periods with feed access. In addition, INT birds had access to feed through three 1 h feeding periods and one 2 h feeding period, with 3 h feed restriction periods in between.2. The INT feeding decreased weight gain (p < 0.001) but did not affect FCR. Supplementation with NSPase increased (p = 0.018) weight gain, but there was a tendency (p = 0.063) for it to be improved in INT-fed birds only. Including NSPase improved FCR, but only with FG diets (p = 0.037) and in INT group (p = 0.033).3. The CG diet significantly reduced (p = 0.044) pH of the gizzard contents and increased (p = 0.035) gizzard relative weight compared to FG. Addition of NSPase (p < 0.001) or FG (p = 0.049) reduced jejunal digesta viscosity. The FG diet improved (p = 0.019) starch digestibility compared to CG. In NSPase-supplemented diets, CG increased ileal protein digestibility compared to FG in birds fed ADL only, resulting in a three-way interaction(p = 0.012).4. The FG diet increased ileal concentration of total eubacteria and Lactobacillus spp. (p = 0.049), whilst INT feeding increased ileal concentration of Streptococcus spp. (p = 0.001). In NSPase-containing diets, FG increased ileal density of Enterococcus spp. in INT-fed birds (p = 0.027).5. In conclusion, finely-ground barley in pelleted diets responded better to NSPase enzymes than coarsely ground, particularly under INT feeding.

1. Melan-A (MLANA) plays a key role in the development of the melanosome, making it a strong candidate for the pigmentation phenotype observed in animals. The main purpose of this study was to analyse the relationship between MLANA gene polymorphisms and tyrosinase (TYR) enzyme activity in skin tissues and melanin content in dorsal down feathers of Chinese yellow quail.2. The coding sequence region of MLANA mRNA was cloned and sequenced to detect polymorphisms. The melanin content in down feathers of 266 Chinese yellow quails was analysed by spectrophotometry, and TYR enzyme activity was measured in dorsal skin tissues. The expression of MLANA mRNA in skin tissues of individuals with different genotypes was analysed using RT-qPCR.3. One non-synonymous single nucleotide polymorphisms (NSSNP; c.218T/A) was identified, which resulted in a Leu36Val mutation in the transmembrane helix region of the MLANA protein. This NSSNP significantly reduced the expression level of MLANA mRNA and TYR enzyme activity in dorsal skin tissues, leading to a significant reduction in melanin content in down feathers.4. The c.218T/A locus of the MLANA gene is closely related to the pigmentation TYR of the down feathers in Chinese yellow quail and can be used as a molecular marker locus for breeding pure feather colour in quail.

1. Clustered regularly interspaced short palindromic repeats (CRISPR)-associated proteins (Cas) systems have been highlighted for their potential applications in controlling the spread of mobile genetic elements, including antimicrobial resistance (AMR) genes. This study investigated the characteristics of CRISPR-Cas systems in E. faecalis from commercial broiler farms and assessed the impact of these systems on AMR.2. All E. faecalis isolates contained CRISPR2, and CRISPR1-Cas and CRISPR3-Cas were identified in 84 (56.4%) and 144 (96.6%) isolates. A combination of CRISPR2 and CRISPR3-Cas and a combination of CRISPR1-Cas, CRISPR2 and CRISPR3-Cas were each identified in 27 (96.4%) farms.3. There were significant differences between CRISPR-Cas systems for phenotypic AMR: CRISPR1-Cas and CRISPR3-Cas. The E. faecalis isolates without CRISPR1-Cas showed higher resistance to most antimicrobials and had a higher prevalence of multidrug resistance (MDR) than those with CRISPR1-Cas. However, the resistance rate against most antimicrobials and the prevalence of MDR did not differ significantly depending on the presence or absence of CRISPR3-Cas.4. The E. faecalis isolates without CRISPR1-Cas harboured higher levels of all AMR genes, except for tetL, than those with CRISPR1-Cas. However, the E. faecalis isolates with CRISPR3-Cas showed a significant lower prevalence of tetL gene and a significantly higher prevalence of fexA and poxtA genes.5. In the distribution of rep families, the rep₉ family was predominant, followed by rep₁, rep₇, rep₂ and rep₈ families. Only prevalence of the rep₇ family was significantly higher in the E. faecalis isolates without CRISPR1-Cas (15.4%) than in those with CRISPR1-Cas (0%).6. This study is the first report on the characteristics of CRISPR-Cas systems in E. faecalis isolated from commercial broiler farm environments, and the results supported the hypothesis that the development of antimicrobial strategies requires an understanding of the distinctive capabilities between CRISPR1-Cas and CRISPR3-Cas and their underlying resistance mechanisms.

1. This study evaluated the effect of acidified drinking water on the gastrointestinal function and intestinal health of broilers.2. A total of 630 one-day-old male broilers (Arbor Acre) were randomly assigned to one of three treatment groups: drinking water treatment (CON), drinking water + 0.5 ml Selko pH®/L (Selko pH), or + 0.85 ml Forticoat®/L (Forticoat) treated groups. Performance data, gut and digesta samples were collected from the broilers at the age of 21 and 42 d.3. The results showed that acidifying drinking water had no significant effect on body weight or average daily gain (ADG). However, addition of Forticoat significantly increased (p < 0.05) feed conversion ratio (FCR) throughout the experimental period and significantly increased (p < 0.05) pepsin activity on d 21. The Selko pH supplemented drinking water significantly increased (p < 0.05) the relative length of the duodenum and jejunum on d 21. The relative length of the jejunum and caecum on d 42 compared to birds receiving CON. The addition of the Forticoat to drinking water significantly increased (p < 0.05) the relative length of the jejunum and caecum on d 42 than for samples from birds in the CON group. In the caecal chyme, abundance of Blautia, Bifidobasterium, Faecalibacterium, Limosilactobacillus and Akkermania spp. on d 21 were significantly higher (p < 0.05) in the caecum of birds receiving Selko pH than those in CON group and the number of Escherichia Shigella in Selko pH and Forticoat group were significantly lower (p < 0.05).4. Overall, adding Seiko pH and Forticoat to drinking water improved pepsin activity, reduced the number of caecal pathogens, increased the number of beneficial bacteria and improved intestinal health in broilers.

1. This study evaluated the effects of cyclic eggshell temperature between 10 and 14 d of embryogenesis on traits viz. the expression of MYOZ2, PPARγ and GPx7 in breast muscle, meat quality and incidence of white striping at slaughter age.2. Eggs were obtained from Cobb and Ross broiler breeders to investigate the response of breeds to eggshell temperature, which regulated air temperature. A total of 784 eggs were incubated at either the control eggshell temperature (37.8°C) from 0 to 18 d or exposed to cyclic high eggshell temperature (CHT) at 38.8°C for 6 h/d between 10 and 14 d of incubation. The temperature was 36.8°C between 18 and 21 d. Hatched chicks were reared under optimum rearing conditions. The birds were sampled at 19 d of incubation, at hatch and at 42 d post-hatch.3. There was no effect of eggshell temperature on yolk-free body weight and residual yolk sac weight. The CHT chicks had wider breasts on the day of hatching.4. At hatch and 42d post-hatch, PPARγ expression in Cobb-CHT was upregulated 4.78-fold and downregulated 3.28-fold, respectively, compared to the Cobb-control. At slaughter age, chickens from Ross-CHT had 1.98- and 2.33-fold upregulated PPARγ and GPX7 expressions, respectively, compared to Ross-control. The CHT increased GPx7 expression in the Cobb-CHT day-old chicks compared to the Cobb-control. On ED19, MYOZ2 expression was upregulated in Cobb and downregulated in Ross by CHT.5. The effects of breed and eggshell temperature on pH₁₅, L*, a*, expressible juice and cooking loss were not significant. The CHT increased the incidence of severe white striping lesions in Ross chickens.6. It was concluded eggshell temperature modulated embryo development, incidence of white striping and expression of related genes differently in the two commercial breeds.

1. The amount of calcium and phosphorus in the empty, feather-free bodies of Cobb 700 breed males and females was measured from hatch to 15 weeks of age.2. A four-phase ad libitum feeding programme was used to feed 400 chicks of each sex. Feeds contained commercial levels of calcium and phosphorus which met or exceeded the requirements for energy, protein and amino acids. All birds were weighed weekly. Ten birds per sex were sampled at 0, 7, 14, 28, 42, 56, 70, 84 and 105 d of age. Defeathered birds were minced, freeze-dried and then analysed for protein, ash, calcium and phosphorus content.3. Amounts of Ca in males and females at 105 d averaged 54 and 37 g, respectively, and 105 d P content in males and females averaged 35 and 27 g, respectively. The allometry of ash, Ca and P with empty, feather-free body protein was assessed. Ash was isometric with body protein, while an allometric exponent greater than 1 was established for Ca and P with body protein.4. The allometric models and means for Ca and P relative to body protein were compared with models and means found in the literature. Comparison of the Ca/protein ratios with previous data suggested that modern broilers may not reach their potential bone mineral deposition with current dietary guidelines, even when growth rates were maximised.5. Theoretical allometric relationships between Ca and P in bone and bone-free body and body protein have now been proposed. The allometric relationship between Ca and P and empty, feather-free body protein offers a suitable way to model the growth of these minerals in the broiler body.