Effects of dietary lipid sources on growth performance and carcass traits in Pekin ducks

Effects of different energy and protein levels on growth performance, carcass traits, and meat quality of Pekin ducks

This study was conducted to determine the effects of different energy and protein levels on growth performance, carcass traits, meat quality, and taste scores of Pekin ducks. A total of 1,800 numbers of 15-day-old ducks (10 replicate pens, 60 birds/pen, 819 ± 18 g/duck) were blocked based on body weight (BW) and randomly allotted to three treatments with different metabolizable energy (ME) and crude protein (CP) levels in this 28-day experiment. Dietary treatments were as follows: (1) low energy protein (LEP), 3,150 kcal/kg and 16% for the grower diet and 3,250 kcal/kg and 15% for the finisher diet; (2) medium energy protein (MEP), 3,250 kcal/kg and 16.5% for the grower diet and 3,350 kcal/kg and 15.5% for the finisher diet; (3) high energy protein (HEP), 3,350 kcal/kg and 17% for the grower diet and 3,450 kcal/kg and 16% for the finisher diet. During days 15-28, body weight gain (BWG) in the LEP group was higher (p < 0.05), whereas FI, F/G, and caloric conversion were lower (p < 0.05) in the MEP and HEP groups. During days 29-42, birds fed with LEP and HEP diets had lower (p < 0.05) BWG but higher F/G and caloric conversion compared with those fed with the MEP diet. Birds fed with the LEP diet had higher (p < 0.05) BWG than those fed with MEP and HEP diets throughout the experiment. The abdominal fat yield in the LEP group was lower (p < 0.05) than in the HEP group. Birds fed with the LEP diet had higher (p < 0.05) left breast meat yields than those fed with MEP and HEP diets. The roasting loss in the LEP and HEP groups was lower (p < 0.05) than in the MEP group. Birds fed with LEP and HEP diets had higher (p < 0.05) comprehensive scores, flavor scores, scent scores, and taste scores, but lower color scores compared with those fed with the MEP diet. In summary, the LEP diet with the lowest cost may be the most appropriate based on growth performance, roasting loss, and taste scores.

Identification of Candidate Genes for Sebum Deposition in Pekin Ducks Using Genome-Wide Association Studies

BACKGROUND

Sebum deposition is a vital trait influencing meat quality and production efficiency in Pekin ducks. Providing insights into the genetic basis of fat deposition could help improve breeding strategies aimed at producing high-quality meat ducks. This study aimed to identify the genetic mechanisms and lipid metabolism pathways regulating subcutaneous and intramuscular fat deposition in two Pekin duck strains: Nankou No. 1 and Jingdian.

METHODS

A total of 72 male ducks, Nankou No. 1 (n = 36) and Jingdian (n = 36), were raised under controlled conditions for 42 days. On days 28, 35, and 42, ducks from each group were selected and slaughtered, and their subcutaneous and liver tissues were collected to analyze lipid enzyme activities. On day 42, additional ducks from each strain were slaughtered and evaluated for carcass performance, as well as intramuscular and sebum yield. Genome-wide association analysis (GWAS) was conducted in the Nankou No. 1 strain.

CONCLUSION

Our results showed statistically significant differences in intramuscular and subcutaneous fat yield between the two strains, with Nankou No. 1 exhibiting a higher yield than Jingdian (p < 0.05). The GWAS results identified 96 significant single nucleotide polymorphisms (SNPs), associated with sebum deposition. Functional annotation identified ALDH7A1 as a key candidate gene involved in lipid metabolism and fat storage regulation in Pekin ducks, Nankou No. 1 strain. Enzyme activity assays in liver and subcutaneous tissues revealed breed-specific differences in lipid metabolism, aligning with genetic findings. The activities of the lipid enzymes changed over time, suggesting changes in the developmental stages. The results on fat yield and enzymatic activities further align with molecular findings from the GWAS, which identified variations in lipid metabolism pathways. These results highlight genetic markers and biochemical pathways related to fat deposition in Pekin ducks, offering new insights for selective breeding programs aimed at optimizing fat content in meat production. Further research is needed to clarify the specific role of ALDH7A1 in lipid metabolism and its potential to enhance fat deposition traits in poultry.

The Application of Duck Embryonic Fibroblasts CCL-141 as a Cell Model for Adipogenesis

The duck embryo fibroblast cell line CCL-141, which is currently the only commercialized duck cell line, has been underexplored in adipogenesis research. (1) Background: This study establishes an experimental protocol to induce adipogenesis in CCL-141 cells, addressing the importance of understanding gene functions in this process. (2) Methods: Chicken serum, fatty acids, insulin, and all-trans retinoic acid were used to treat CCL-141 cells, with adipogenesis confirmed by Oil Red O staining and gene expression quantification. CRISPR/Cas9 technology was applied to knockout PPARγ, and the resulting adipogenic phenotype was assessed. (3) Results: The treatments promoted adipogenesis, and the knockout of PPARγ validated the cell line's utility for gene function studies. (4) Conclusions: CCL-141 cells are a suitable model for investigating duck adipogenesis, contributing to the understanding of regulatory factors in this biological process.

Effects of Dietary Supplementation with Cocrystals of Thymol and Carvacrol on Quality, Nutrient Composition, and Oxidative Stability of Broiler Meat

Consumer demand for high-quality meat has increased. This study aimed to investigate the potential application of cocrystals of thymol and carvacrol in broilers for high-quality meat production. Eight hundred 1-day-old chicks were assigned to four groups fed diets supplemented with 0, 40, 60, and 80 mg/kg of Crystal EO® (CEO), containing 25% cocrystals of thymol and carvacrol in a 42-d feeding trial. The results showed that dietary CEO supplementation decreased the muscle fiber diameter and increased the muscle fiber density, glycogen content, L*45 min value, and proportion of α-linolenic acid in the breast muscle; dietary 40 and 60 mg/kg of CEO decreased the lactate content, MDA concentration, cooking loss, shear force, and thrombogenicity index and increased the proportion of lauric acid in the breast muscle; dietary 60 and 80 mg/kg of CEO increased the glucose content, total superoxide dismutase, and total antioxidant capacity levels of breast muscle. Citrate synthase activity, free radical scavenging capacity, pH24 h and a*45 min values, and the cystine content in the breast muscle were especially higher in the 60 mg/kg CEO group compared to the control group. Collectively, dietary CEO supplementation improved meat quality and nutritional values and enhanced the antioxidant capacity of broiler meat, with 60 mg/kg of CEO having the greatest effect.

Characteristics of carcass and physicochemical traits of meat from male and female ducks fed a diet based on extruded soybean

Duck' meat is characterized by good nutritional properties and gaining popularity in the consumer market. Extruded soybean is potentially more digestible than commonly use soybean meal (SBM), and is expected to influence carcass traits and the quality of breast and leg muscles. The study' aim was to compare meat quality from both sexes' ducks fed a diet with extruded soybean (ESB) as a substitute for SBM. Cherry Valley ducks were divided into two groups. The control group (1) was fed an SBM-based diet, and the treatment group (2) with ESB. Each group was divided into sex subgroups with 50 birds in each (5 replicates, 10 ducks each). Dissection and analysis of meats' pH, colour, water-holding capacity (WHC), drip loss and chemical composition of breast and leg muscles were done. Interaction of Diet and Sex was calculated. In group 2 higher carcass weight, dressing percentage, weight of wings, leg muscles, total muscles, and better WHC were found. Dressing percentage, the proportion of neck with skin, breasts' and stomach' weight, and the weight and proportion of fat, and pH45min were higher in females (P < 0.05). The interaction was found for the pre-slaughter body weight, the weight of carcass remains, WHC in breasts (P < 0.05). The ESB feed had no negative effect on the analyzed traits and can be used in the ducks' diet. Improved the WHC indicates the high suitability of meat for processing. A positive effect of diet on the muscles' proportion and dressing percentage was noticed, which is important for consumers' market. The sex-related differences and interactions between variables suggest separate rearing due to sex.

Effects of legume-diet and sex of ducks on the growth performance, physicochemical traits of meat and fatty acid composition in fat

Duck meat enjoys growing popularity among consumers. Alternative protein sources to soybean are being investigated to eliminate genetically modified components from the poultry' diet. The aim of this study was to compare growth performance, quality of meat, and fatty acid composition in subcutaneous and abdominal fat from ducks fed a diet based on yellow lupin and rapeseed meal, sources of protein alternative to soybean meal (SBM). Ducks were allocated to different dietary treatment groups and reared for 8 weeks (N = 102 per group). Group A received a diet based on SBM, while group B was fed a diet based on yellow lupin with the addition of rapeseed meal. Both groups were divided into two subgroups, of male and female birds. Growth performance parameters and zoometric traits of ducks were monitored during the growth period. After 8 weeks selected birds were slaughtered and dissected (N = 10 per group). Carcass composition was calculated and selected traits of meat quality important for further processing were analysed. Subcutaneous and abdominal fat were collected to analyse fatty acid composition. The alternative diet had no negative effect on ducks' growth performance parameters and dressing percentage. The replacement of SBM with yellow lupin and rapeseed meal increased n-3 fatty acid content, which is important for consumers. In conclusion, SBM can be replaced with feed containing 60.10% of yellow lupin and 14.00% of rapeseed meal in concentrate. These sources of protein are mainly recommended for small poultry farms, which do not always have access to SBM and prepare poultry feed from their own crops.