Higher Meat Yield Research Articles

Genome-wide association analysis identifies candidate genes for carcass yields in Peking ducks.

Poultry meat, particularly Peking ducks, holds a significant global market share, prized for their high meat yield and fat content. However, understanding of the molecular genetic mechanisms influencing carcass yield in ducks is limited. This research aims to use genome-wide association analysis to uncover single-nucleotide polymorphisms influencing carcass yield in Peking ducks, followed by identifying candidate genes linked to carcass traits. In this study, we analyzed seven traits of 643 Peking ducks at age 42 days and identified novel loci associated with these traits. A total of 35 significant loci were detected, with eight SNPs reaching genome-wide significance. KIF20B, AGBL5, SGSM1, MRO, PLAG1, XKR4, and TGS1 were considered as important candidate genes influencing carcass yield in ducks. This study adds to the list of genes affecting Peking duck body traits, aiding marker-assisted breeding and enhancing economic yield.

Impact of steaming and peeling on the weight loss in blue swimming crabs in Pangkajene Islands, South Sulawesi

Abstract The blue swimming crab (Portunus pelagicus) is an important fishery resource in Indonesia because it has a high value and involves a lot of human resources. The pasteurized crab goes through several main stages, namely steaming, stripping, and canning. Steamed crabs will experience weight loss and produce a yield of meat in a certain amount and composition after peeling. This study aims to determine the weight loss during crab steaming and stripping processes on different sizes of crabs. The crabs were classified into three categories, namely small crab (carapace width <10 cm), big crab (carapace width >10 cm), and egg-berried female crabs. Technically, crabs were steamed for 20 minutes after the water boils with temperature of steaming of 80–90 °C. Steaming process wereallowed to stand for 60 minutes, followed by. peeling process where crab meat were separated from the skin. Weight measurements were taken on fresh, warm (shortly after steaming), and cooked crab (adjusted to room temperature) to calculate weight loss due to steaming while considering temperature adjustments and total loss. Results revealed the weight decrease about 16.75% during steaming, 19.61% during relaxation, and 27.47% during overall process. The highest meat yield was obtained from small crab by 30.64%, followed by large crab by 27.25%, and egg berried female by 24.39%.

Evaluation of growth performance, carcass yield, and proximate composition of fillets of male and female pirarucu (Arapaima gigas) during the fattening phase

The objective of this study was to evaluate the comparative growth performance, carcass yield, and the proximate composition of the muscle between male and female Arapaima gigas (pirarucu) during the fattening phase. Juvenile pirarucu (n = 114; 1126 ± 219 g; 55 ± 3 cm) were kept in 120 m2 brick tanks at a stocking density of 1.55 g m-2. Fish were raised under the same management conditions during 427 days and biometrics were performed monthly to evaluate the growth performance. Fish (n = 15 per collection day) were sampled at 91, 187, 273, 341 and 427 days to evaluate the carcass yield, proximate composition of the muscle and to determine its gender via histological analysis of the gonads. Data were analyzed using a multivariate statistical method. Growth performance, carcass yield and proximate composition of the muscle were similar between genders up to 427 days of rearing. The coefficients of variation in total weight and length that express the batch heterogeneity were higher for females throughout practically the whole experimental period. This was probably due to the dominance behavior between female fish, which also justifies why some females reached larger sizes at the end of the experiment. The yields for the fillet, abdominal muscle and loin were greater at 273 days compared to other sampling events, regardless of gender. Partial harvesting of pirarucu during the fattening phase can therefore be a management strategy for slaughtering fish with a higher meat yield.

Whole-Genome Scanning for Selection Signatures Reveals Candidate Genes Associated with Growth and Tail Length in Sheep.

Compared to Chinese indigenous sheep, Western sheep have rapid growth rate, larger physique, and higher meat yield. These excellent Western sheep were introduced into China for crossbreeding to expedite the enhancement of production performance and mutton quality in local breeds. Here, we investigated population genetic structure and genome-wide selection signatures among the Chinese indigenous sheep and the introduced sheep based on whole-genome resequencing data. The PCA, N-J tree and ADMIXTURE results showed significant genetic difference between Chinese indigenous sheep and introduced sheep. The nucleotide diversity (π) and linkage disequilibrium (LD) decay results indicated that the genomic diversity of introduced breeds were lower. Then, Fst & π ratio, XP-EHH, and de-correlated composite of multiple signals (DCMS) methods were used to detect the selection signals. The results showed that we identified important candidate genes related to growth rate and body size in the introduced breeds. Selected genes with stronger selection signatures are associated with growth rate (CRADD), embryonic development (BVES, LIN28B, and WNT11), body size (HMGA2, MSRB3, and PTCH1), muscle development and fat metabolism (MSTN, PDE3A, LGALS12, GGPS1, and SAR1B), wool color (ASIP), and hair development (KRT71, KRT74, and IRF2BP2). Thus, these genes have the potential to serve as candidate genes for enhancing the growth traits of Chinese indigenous sheep. We also identified tail-length trait-related candidate genes (HOXB13, LIN28A, PAX3, and VEGFA) in Chinese long-tailed breeds. Among these genes, HOXB13 is the main candidate gene for sheep tail length phenotype. LIN28A, PAX3, and VEGFA are related to embryonic development and angiogenesis, so these genes may be candidate genes for sheep tail type traits. This study will serve as a foundation for further genetic improvement of Chinese indigenous sheep and as a reference for studies related to growth and development of sheep.

Integrated Metabolomics and Transcriptomics Analyses Reveal the Candidate Genes Regulating the Meat Quality Change by Castration in Yudong Black Goats (Capra hircus).

Yudong black goats (YDGs) are a local breed in southwest China that possess unique meat qualities and produce a high meat yield, making them ideal models for studying goat meat quality. Castration may decrease off-odors, significantly change metabolites and improve meat quality. Using multi-omics techniques, this study focused on Yudong black goat wethers (YDW, n = 4) and Yudong black bucks (YDB, n = 4). The findings revealed that 33 differentially expressed genes (DEGs) and 279 significantly changed metabolites (SCMs) influenced goat meat quality by affecting fat accumulation and lipolysis regulatory processes. Herein, several candidate genes (IGF1, TNNT2, PPP2R2C, MAPK10 and VNN1, etc.) were identified that play a role in regulating meat quality, non-castrated and castrated, alongside a series of metabolites that may serve as potential meat quality biomarkers. Lipids (triglycerides, oxidized lipids_5-iso PGF2VI, ceramide (t18:1/36:2(2OH)) and Carnitine C20:5, etc.) were significantly higher in the castrated goats. These results revealed that lipids and hydrophilic metabolites were affected by castration, which might be beneficial in terms of goat meat quality. This study aimed to investigate the differences in meat quality between uncastrated and castrated male goats and the possible molecular regulatory mechanisms.

A comparative study on the flavour of wild Chinese mitten crab (Eriocheir sinensis) along the eastern coast of China

Chinese mitten crab (Eriocheir sinensis) is widely distributed along the eastern coast of China and is considered one of the most economically important crabs in China. Evaluating its taste substances can help to develop new varieties of Eriocheir sinensis with distinctive flavours to meet the diversified needs of the market. In the current research work, we compared the meat yield and flavour of wild adult male Eriocheir sinensis muscle from five rivers. The results showed that crabs from the Min River had the highest meat yield (32.94 ± 2.93%). The electronic tongue showed that the taste profiles of Min River and Ou River crabs were similar. The Min River crabs had the highest total amino acid content of 1404.01 ± 2.83 mg/100 g, of which sweet amino acids accounted for 64.9%, the highest 5′-inosine phosphate of 14.49 ± 2.11 mg/100 g, and the highest equivalent umami concentration (3.82 gMSG/100 g). Taste activity value analysis showed that crabs in Min River, Ou River, and Yangtze River were more influenced by alanine, arginine, and 5′-guanosine phosphate. Overall, wild male Eriocheir sinensis from Min River enriched the flavour substance, making it a potentially valuable resource for the Eriocheir sinensis industry.

Использование жиров различного происхождения в комбикормах для бройлеров

Purpose. Determination of the effectiveness of using fats of various origins in compound feed for broiler chickens. Materials and Мethods. A scientific and economic experiment was carried out on 4 groups of broiler chickens of the Cobb-500 cross at the Verkhnevolzhskaya Poultry Farm (Russia, Tver region). The poultry-rearing period was 37 days. Broilers in the control group received the main diet according to the growing phases; for chickens in the experimental groups, part of the sunflower oil in the diet was replaced with animal feed fat "Olisa": in group 2 – 0.5% in CCF Rost, 1.0% in Finish-1 and Finish- 2; in group 3 – 1.0% in CCF Rost, 1.5% in Finish-1 and Finish-2; in group 4 – 1.5% in CCF Rost, 2.0% in Finish-1 and Finish-2. The dynamics of live weight were recorded by weekly control weighing of broiler chickens. The safety of the poultry population was determined by counting dead birds. The absolute and average daily gain in live weight, the cost of feed per 1 kg of gain in live weight, the productivity index and other indicators were also determined during the growing process. Results. The introduction of 1.5% animal feed fat “Olisa” into the compound feed instead of part of the sunflower oil in CCF Rost and 2.0% in Finish-1 and Finish-2 contributed to an increase in both the average daily and absolute gain in live weight. The latter indicator was higher in broiler chickens of the fourth experimental group by 8.6% compared to the control group. Poultry from the same group had a higher meat yield per 1 m2 of floor area. Their productivity index was higher than in the control group by 6.6%. At the same time, the safety of poultry population in all groups participating in the experiment was high. Conclusion. Replacing part of the sunflower oil in feed with animal fat in the optimal dosage contributes to obtain high live weight, daily gain, safety of broiler chickens and productivity index.

LENGTH-WEIGHT RELATIONSHIPS OF THREE FRESHWATER MUSSEL SPECIES FROM THE AMAZON (UNIONIDA, HYRIIDAE)

Length-weight relationships of three freshwater mussel species (Hyriidae), Eastern Amazon: the length-weight relationships allow important biological estimates for the fisheries management of species. Through this relationship, it is possible to estimate the weight of the individuals by their lengths, from which the biomass of the studied population can be determined. In addition, it gathers important data to assess the ecological patterns of different populations. The aim of this study was to analyze the length-weight relationships and their respective meat yields of three species of freshwater mussels: Castalia ambigua, Triplodon corrugatus and Paxyodon syrmatophorus from Capim River Bay, Pará, Brazil. For this, the total length, visceral weight, and total weight of 1,057 individuals were determined. All three relationships were considered strong, with determination coefficients greater than 0.9. The species C. ambigua showed negative allometric growth, while the other species P. syrmatophorus and T. corrugatus showed isometric growth. The species with the highest meat yield was P. syrmatophorus with 14.8%. The study presents the first parameter record of weight-length relationships for these three freshwater mussel species.

De Novo Assembly, Characterization and Comparative Transcriptome Analysis of the Gonads of Jade Perch (Scortum barcoo).

Due to the high meat yield and rich nutritional content, jade perch (Scortum barcoo) has become an important commercial aquaculture species in China. Jade perch has a slow growth rate, taking 3-4 years to reach sexual maturity, and has almost no difference in body size between males and females. However, the study of its gonad development and reproduction regulation is still blank, which limited the yield increase. Herein, the gonad transcriptomes of juvenile males and females of S. barcoo were identified for the first time. A total of 107,060 unigenes were successfully annotated. By comparing male and female gonad transcriptomes, a total of 23,849 differentially expressed genes (DEGs) were identified, of which 9517 were downregulated, and 14,332 were upregulated in the testis. In addition, a large number of DEGs involved in sex differentiation, gonadal development and differentiation and gametogenesis were identified, and the differential expression patterns of some genes were further verified using real-time fluorescence quantitative PCR. The results of this study will provide a valuable resource for further studies on sex determination and gonadal development of S. barcoo.

Investigation of the Role of Some Selected Virus Species in Abnormality of Calves

Early embryonic death, fetal resorption, fetal mummification/maceration, abortion, and abnormalities are some of the causes of losses in farm animals. In this study, it was aimed to make recommendations to clinician veterinarians by investigating the presence of bovine viral diarrhea virus (BVDV), Schmallenberg virus (SBV), Akabane virus (AKAV), and bovine herpesvirus-1 (BHV-1) viruses in calves with congenital anomalies. A total of 34 calves of different breeds and sexes, between 1 day and 2 months of age which were brought to Fırat University Animal Hospital for diagnosis and treatment and found to have congenital anomalies after a general clinical examination during visits to the neighboring villages, were included in the study. The abnormalities detected in the calves were as follows: Hydrocephalus, cerebellar hypoplasia, brahignati inferior, mandibular laterognathism, arthrogryposis, cheilognathopalatoschisis, coccygeal agenesis, atresia ani, bouleture/arqure, ocular and orbital deformities, dermoid cysts, miniature, renal and urinary system anomalies. PCR results showed pestivirus was detected in 6 of 34 (17.6%) calves with abnormalities. After sequencing, the expected PCR product (288 nucleotides) for pestivirus showed high identity (97% and above) to the BVDV-1 strain/isolates in the GenBank. In conclusion, although the primary purpose of cattle breeding is high meat and milk yield, it is also very important to continue the production process with healthy newborn calves. For this reason, even if congenital anomalies are seen at a low rate in calves, they should not be underestimated as they will cause economic losses, and we believe that clinician veterinarians should not ignore these diseases.

Differences in gut bacterial community composition between modern and slower-growing broiler breeder lines: Implications of growth selection on microbiome composition.

In the last century broiler chicken lines have undergone an extensive breeding regime aimed primarily at growth and high meat yield. It is not known if breeding has also resulted in a change to the broiler breeder's associated gut microbiota. Here we compared the gut microbiota of 37-week-old commercial Cobb breeding dams with dams from a broiler Legacy line which has not undergone selection since 1986. The dams from both lines were kept together in the same shed under the same management protocol from day of hatch to avoid additional confounders. We chose this age to allow significant bacterial exchange, thus avoiding exposure dependent artifacts and so that we could compare dams at the same developmental state of adulthood and peak laying performance. Significant differences in the composition of the cecum bacterial communities were found. Bacteria of the genus Akkermansia, implicated in mucin degradation and associated with host metabolic health, accounted for 4.98% ± 5.04% of the Cobb cecum community, but were mostly absent from the ceca of the Legacy line dams. Inversely, Legacy dams had higher levels of Clostridiales, Lactobacillales and Aeromonadales. These results show that breeding has resulted in a change in the gut microbiota composition, likely by changing the physiological conditions in the mucosa. It remains unclear if changes in gut microbiota composition are a part of the mechanism affecting growth or are a secondary result of other physiological changes accelerating growth. Therefore, the identification of these changes opens the door to further targeted research.

Genetic diversity and signatures of selection in BoHuai goat revealed by whole-genome sequencing

BackgroundCross breeding is an important way to improve livestock performance. As an important livestock and poultry resource in Henan Province of China, Bohuai goat was formed by crossing Boer goat and Huai goat. After more than 20 years of breeding, BoHuai goats showed many advantages, such as fast growth, good reproductive performance, and high meat yield. In order to better develop and protect Bohuai goats, we sequenced the whole genomes of 30 BoHuai goats and 5 Huai goats to analyze the genetic diversity, population structure and genomic regions under selection of BoHuai goat. Furthermore, we used 126 published genomes of world-wide goat to characterize the genomic variation of BoHuai goat.ResultsThe results showed that the nucleotide diversity of BoHuai goats was lower and the degree of linkage imbalance was higher than that of other breeds. The analysis of population structure showed that BoHuai goats have obvious differences from other goat breeds. In addition, the BoHuai goat is more closely related to the Boer goat than the Huai goat and is highly similar to the Boer goat. Group by selection signal in the BoHuai goat study, we found that one region on chromosome 7 shows a very strong selection signal, which suggests that it could well be the segment region under the intense artificial selection results. Through selective sweeps, we detected some genes related to important traits such as lipid metabolism (LDLR, STAR, ANGPTL8), fertility (STAR), and disease resistance (CD274, DHPS, PDCD1LG2).ConclusionIn this paper, we elucidated the genomic variation, ancestry composition, and selective signals related to important economic traits in BoHuai goats. Our studies on the genome of BoHuai goats will not only help to understand the characteristics of the crossbred but also provide a basis for the improvement of cross-breeding programs.

Large-scale genomic and transcriptomic analyses elucidate the genetic basis of high meat yield in chickens

IntroductionInvestigating the genetic markers and genomic signatures related to chicken meat production by combing multi-omics methods could provide new insights into modern chicken breeding technology systems. ObjectChicken is one of the most efficient and environmentally friendly livestock, especially the fast-growing white-feathered chicken (broiler), which is well known for high meat yield, but the underlying genetic basis is poorly understood. MethodWe generated whole-genome resequencing of three purebred broilers (n = 748) and six local breeds/lines (n = 114), and sequencing data of twelve chicken breeds (n = 199) were obtained from the NCBI database. Additionally, transcriptome sequencing of six tissues from two chicken breeds (n = 129) at two developmental stages was performed. A genome-wide association study combined with cis-eQTL mapping and the Mendelian randomization was applied. ResultWe identified > 17 million high-quality SNPs, of which 21.74% were newly identified, based on 21 chicken breeds/lines. A total of 163 protein-coding genes underwent positive selection in purebred broilers, and 83 genes were differentially expressed between purebred broilers and local chickens. Notably, muscle development was proven to be the major difference between purebred broilers and local chickens, or ancestors, based on genomic and transcriptomic evidence from multiple tissues and stages. The MYH1 gene family showed the top selection signatures and muscle-specific expression in purebred broilers. Furthermore, we found that the causal gene SOX6 influenced breast muscle yield and also related to myopathy occurrences. A refined haplotype was provided, which had a significant effect on SOX6 expression and phenotypic changes. ConclusionOur study provides a comprehensive atlas comprising the typical genomic variants and transcriptional characteristics for muscle development and suggests a new regulatory target (SOX6–MYH1s axis) for breast muscle yield and myopathy, which could aid in the development of genome-scale selective breeding aimed at high meat yield in broiler chickens.

Yetiştiriciği Yapılan Üç Tür Alabalığın; Kaynak Alabalığı (Salvelinus fontinalis, Mitchill 1814), Gökkuşağı Alabalığı (Oncorhynchus mykiss Walbaum, 1972) ve Karadeniz Alasının (Salmo trutta labrax Pallas 1811) Biyokimyasal Özelliklerinin Farklılıkları

The objective of this present study is to signify biochemical features of three reared trouts (brook trout, rainbow trout, Black Sea trout) that are economically consequential and reared fish species in the Eastern Black Sea region. The rainbow trout has been reared successfully for a long period of time. However, brook trout and the Black Sea trout have been two new species to be reared in the region with a high potential contribution to the economy. Therefore, there is a strong need to determine and report the differences between the fish (especially the two new species), levels of carbohydrates, energy, carotenes (Vitamin A), fatty acid, and proximate composition (protein, lipid, moisture, and ash). In addition, the lipid indices [Atherogenic Index (AI), Thrombogenic Index (TI), and polyene index (PI)] were also measured and reported for the trouts. Moreover, the color of the fillets of the fish was also measured. The results of this present study show that the average levels of moisture and protein varied while the average levels of lipid and ash were close to each other. The highest levels of carbohydrates, energy, and carotenes were determined in the muscle of brook trout in this study. The highest meat yield was also obtained from brook trout followed by Black Sea trout and rainbow trout. A total of 19 fatty acids were determined for Black Sea trout and brook trout and 17 fatty acids for rainbow trout in the present study. The omega-3 levels of the all trout used for the present study were roughly twice as much as that of the omega-6, except for rainbow trout.

Transcriptome Sequencing Reveals Pathways Related to Proliferation and Differentiation of Shitou Goose Myoblasts.

Chinese Shitou goose is a type of large goose with high meat yield. Understanding the genetic regulation of muscle development in Shitou goose would be beneficial to improve the meat production traits of geese. Muscle development is regulated by genes related to myoblast proliferation and differentiation. In this study, the RNA-seq method was used to construct the mRNA and lncRNA expression profiles of Shitou goose myoblasts and myotubes. A total of 1664 differentially expressed (DE) mRNAs and 244 DE-lncRNAs were identified. The alternative mRNA splicing in proliferation and differentiation stages was also analyzed. Notably, pathways enriched in DE-mRNAs, DE-splicing transcripts, and DE-lncRNAs all point to the Wnt signaling pathway, indicating that the Wnt signaling is a key regulatory pathway of muscle development in Shitou goose. We also constructed the interactive network of DE-lncRNAs and DE-mRNAs and revealed some key genes of lncRNAs regulating the proliferation and differentiation of myoblasts. These results provide new insights for the study of the muscle development of the Shitou goose.

Quality Changes of Green Mussel (Perna viridis) at Different Steaming Conditions

This study investigates the effects of different steaming temperatures (80, 90, and 100 °C) and time (2, 4, and 6 min) combinations on the quality and safety of green mussels. Analyses were conducted on steamed green mussel meat to determine the optimum steaming conditions based on its morphometric, microbiological, and physico-chemical properties. Results showed that steaming at 80 °C for 2 min provides high meat yield, reduced the total APC by 90% and decreased Escherichia coli counts by 75%. However, it is important to increase the steaming temperature to 90 °C (for 6 min) or 100 °C (for 2, 4, and 6 min) in order to eliminate Salmonella spp. and Vibrio spp. in steamed mussels. Meanwhile, increasing the steaming temperature at 100 °C (for 2, 4, and 6 min) could lower the acidity of steamed mussel meat (at pH 6.8), which may increase expressible drip loss and leaching of nutrients such as lipids and proteins. The steaming method as a thermal shocking procedure to deliver minimally-processed green mussels is a practical yet crucial in achieving safe microbiological levels without compromising its yield and physico-chemical properties.

Effects of palm oil supplementation and fibrolytic enzymes in high forage diets on growth, carcass characteristics and fatty acid profiles of lambs

This study investigated the effects of palm oil and fibrolytic enzyme supplementation in high forage diets on growth, carcass characteristics and fatty acid composition of lambs. Forty South African Mutton Merino ram lambs were randomly assigned to four treatment groups (n = 10 lambs/ treatment) and fed a basal total mixed ration (TMR). The treatments were: TMR diet with Megalac as bypass oil (control); TMR diet supplemented with 3% palm oil; TMR diet with cellulase and xylanase enzymes and TMR diet supplemented with 3% palm oil and cellulase and xylanase enzymes. The lambs were slaughtered at a target weight of about 42 kg. Palm oil supplementation resulted in a longer feeding period (P < 0.05) and lower dressing percentage (P < 0.01), but the carcasses had higher meat yield (P < 0.01) and lower fat content (P < 0.05) compared to the other treatment groups. Additionally, palm oil supplementation increased the proportion of C18:0 (P < 0.05) while decreasing (P < 0.05) the proportion of C14:0 (P < 0.05) and C16:0 (P < 0.05) in fat depots, which may be beneficial for human health. The fibrolytic enzyme treatment had minimal effects on growth, carcass characteristics, meat quality and fatty acid composition of lambs. The interaction effect of palm oil and fibrolytic enzymes had positive effects on the UFA: SFA ratio due to an increase (P < 0.05) in C20:3n6 and C20:4n6 and a reduction (P < 0.05) in saturated fatty acids. The results suggest that methane mitigation strategies through palm oil and enzyme supplementation can be used in lamb diets without adverse effects on product quality.

The Snakeskin Gourami (Trichopodus pectoralis) Tends to Exhibit XX/XY Sex Determination

The snakeskin gourami (Trichopodus pectoralis) has a high meat yield and is one of the top five aquaculture freshwater fishes in Thailand. The species is not externally sexually dimorphic, and its sex determination system is unknown. Understanding the sex determination system of this species will contribute to its full-scale commercialization. In this study, a cytogenetic analysis did not reveal any between-sex differences in chromosomal patterns. However, we used genotyping-by-sequencing to identify 4 male-linked loci and 1 female-linked locus, indicating that the snakeskin gourami tends to exhibit an XX/XY sex determination system. However, we did not find any male-specific loci after filtering the loci for a ratio of 100:0 ratio of males:females. This suggests that the putative Y chromosome is young and that the sex determination region is cryptic. This approach provides solid information that can help identify the sex determination mechanism and potential sex determination regions in the snakeskin gourami, allowing further investigation of genetic improvements in the species.

QUALITY OF CARP MEAT (Cyprinus carpio) PRODUCED IN A POND WITH THE ADDITION OF PURIFIED WASTEWATER ORIGINATING FROM THE SLAUGHTERHOUSE

The aim of the study was to investigate production parameters and nutritive quality of carp meat produced in a fish pond fed with fresh well water mixed with purified slaughterhouse wastewater. The quality of carp fillet was analyzed in view of both chemical parameters and seasonal variations, i.e., time of sampling. Our research idea was that purified slaughterhouse wastewater would provide essential nutrients for carp and positively affect the quality of fish meat, which was confirmed in this experiment. The total carp production at the end of study period was 3270 kg/ha. The research revealed a feed conversion ratio (FCR) of 1.5 kg of feed per one kg weight gain and a survival rate of 87%. Statistically significant difference (p &lt; 0.05) between meat protein content during spring and autumn season was established. Protein content in meat was higher during spring season, whereas higher fat content was established during autumn sampling season. The application of purified slaughterhouse wastewater provided high level of nutrients resulting in high meat yield per area unit and good chemical composition of meat. Such production model is meaningful in both economic and ecological aspect.

Mapping QTLs for Breast Muscle Weight in an F2 Intercross between Native Japanese Nagoya and White Plymouth Rock Chicken Breeds.

Nagoya (NAG), a native Japanese chicken breed, has high quality meat but low meat yield, whereas White Plymouth Rock (WPR), a parental breed of commercial broilers, has rapid growth but high body fat. We previously reported three quantitative trait loci (QTLs) for early postnatal growth in 239 F2 chickens between NAG and WPR breeds. In this study, using the same F2 chickens at 4 weeks of age, we performed genome-wide QTL analysis for breast muscle weight, fat weight and serum and liver levels of biochemical parameters. Two significant QTLs for pectoralis minor and/or major weights were revealed on chromosome 2 between 108 Mb and 127 Mb and chromosome 4 between 10 Mb and 68 Mb. However, no QTL for the other traits was detected. The two QTLs explained 7.0–11.1% of the phenotypic variances, and their alleles derived from WPR increased muscle weights. The chromosome 2 QTL may be a novel locus, whereas the chromosome 4 QTL coincided with a known QTL for meat quality. The findings provide information that is beneficial for genetic improvement of meat yield for the lean NAG breed and, furthermore, provide a better understanding of the genetic basis of chicken muscle development.