• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1706-1710
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• 2006

Leptin receptor (OBR) is a member of the class I cytokine receptor family. It signals mainly via the JAK/STAT pathway and plays an important role in regulating body energy storage and metabolism. This study was designed to investigate the effects of the OBR gene on chicken growth and body composition. Broiler lines selected divergently for or against abdominal fat were used. Primers for the exon9-region in the OBR gene were designed using chicken genomic sequences from the public genome domain. A C/A single nucleotide polymorphism (SNP) was found and its three genotypes (AA, AB and BB) were identified in this population. The results showed that the OBR polymorphism was associated with fatness traits, such as abdominal fat weight and abdominal fat percentage. This research suggests that OBR or a linked gene has effect on fat deposition in the chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.1057-1068
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• 2014

The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1409-1414
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• 2006

The objective of this study was to screen single nucleotide polymorphisms (SNPs) of the chicken lipoprotein lipase gene (LPL), using 545 F1 hybrids developed from $4{\times}4$ diallel crossing of four chicken breeds, and to analyze the associations between polymorphisms of the LPL and chicken fat deposition traits. PCR-SSCP was used to detect SNPs in LPL. Fifteen sets of primers were designed to amplify DNA fragments covering the 5'flanking and coding regions of LPL. It showed that there existed 5 polymorphic loci in the 5'flanking region and coding region, respectively. Association analysis was carried out between 10 polymorphic loci and intermuscular fat width, abdominal fat weight, and thickness of subcutaneous fat using ANCOVA, respectively. The results indicated that, in the 5'flanking region, the loci d and e significantly affected thickness of subcutaneous fat (p<0.05), abdominal fat weight (p<0.01) and subcutaneous fat (p<0.05), while in the coding region, synonymous mutation in exon 8 was significantly associated with intermuscular fat width (p<0.05), however, the non-synonymous mutations in exon 7 and exon 9 did not show statistically significant effects on fat deposition traits in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1389-1394
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• 2008

Abdominal fat characters are complex and economically important in the poultry industry. Their selection may benefit from the implementation of marker-assisted selection (MAS). The objective of this study was to identify the markers linked to QTL responsible for fatness traits. The Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) were used in the study. A total of 596 individuals from the divergent tails from the 6th to the 10th generations were genotyped at 23 microsatellite markers on chromosome 1. The differences of allele frequencies of all marker alleles between the divergent tails across the five generations were recorded. The allele frequencies of five markers, including LEI0209, LEI0146, MCW0036, ADL328 and MCW0115, had significant differences between the two tails in all five generations. The resulting p-values using Fisher's exact test on eleven markers, containing MCW248, MCW0010, MCW0106, LEI0252, LEI0068, MCW0018, MCW0061, LEI0088, MCW200, MCW283 and ROS0025, had a decreasing tendency from the 6th to the 10th generation. Statistical analysis showed that polymorphisms of the eight markers, including LEI0209, LEI0146, ROS0025, MCW0115, MCW0010, MCW0036, MCW283, ADL328, were significantly (p<0.0011) or suggestively (p<0.05) associated with abdominal fat content (AFW and AFP) across generations. It is concluded that the eight markers could be associated with the QTL affecting the deposition of abdominal fat in broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1221-1225
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• 2005

The peroxisome proliferator-activated receptors (PPARs) are members of a superfamily of nuclear hormone receptors. Lots of studies in rodents and humans have shown that PPARs were involved in lipid metabolism and adipocyte differentiation. The main objective of this work was to detect the single nucleotide polymorphisms (SNPs) in whole coding regions of peroxisome proliferator-activated receptor alpha (PPAR-$\alpha$) and gamma (PPAR-$\gamma$) genes with approach of single strand conformation polymorphism (SSCP) in the chicken population of Arber Acres broiler, Hyline layer and three Chinese native breeds (Shiqiza, Beijing You, Bai'r). Two SNPs of C1029T and C297T were found in chicken PPAR-$\alpha$ and PPAR-$\gamma$ genes respectively and each SNP found three genotypes in the experimental populations. The results showed that the distribution frequency of 3 genotypes in Arber Acres broiler, Hyline layer and Chinese native breeds had significant differences on the PPAR-$\alpha$ and PPAR-$\gamma$ gene respectively (p<0.01). Furthermore, in the PPAR-$\alpha$ gene, the results of least square estimation for genotypes and body composition traits showed the BB genotype birds had higher abdominal fat weight (AFW) and percentage of abdominal fat (AFP) than AA genotype birds (p<0.05). From these we conjecture the PPAR-$\alpha$ and PPAR-$\gamma$ genes were suffered intensive selection during the long term commercial breeding and the PPAR-$\alpha$ gene may be a major gene or linked to the major genes that impact chicken fat metabolism and the SNPs could be used in molecular assistant selection (MAS) as a genetic marker for the chicken fatness traits.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1504-1510
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• 2013

Native chickens hold a significant share of the market in China. In response to the huge demand from the market, the productivity of Chinese native chickens needs to be improved. Cross breeding is an effective method to increase productivity, although it might affect meat quality. In this study, two pure lines (SD02 and SD03) of Erlang mountainous chickens were hybridized with a yellow feather and faster growing line (SD01). The effect of hybridization on carcass and meat quality (physiochemical and textural traits) was measured in the $F_1$ population at d 91 of age. The hybrids exhibited higher body weight and dressed weight, and amount of semi-eviscerated, eviscerated, breast muscle and abdominal fat (p<0.05). Abdominal fat yield also increased (p<0.05) compared to the offspring of the two pure-lines. Meanwhile, there was no significant difference in meat quality traits except for the myofiber diameter and density and the shear force of the breast muscle. Overall, the offspring of cross-lines were similar to pure lines in meat color, pH value, inosinic acid, crude protein, crude fat, dry matter, moisture content and amino acid composition in the breast muscle. These results suggest that productivity can be improved via cross-breeding while maintaining meat quality of the Erlang mountainous chicken.

• Animal Bioscience
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• v.34 no.7
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• pp.1193-1201
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• 2021

Objective: According to market demand, meat duck breeding mainly includes 2 breeding directions: lean Pekin duck (LPD) and fat Pekin duck (FPD). The aim of the present study was to compare carcass and meat quality traits between 2 strains, and to provide basic data for guidelines of processing and meat quality improvement. Methods: A total of 62 female Pekin ducks (32 LPDs and 30 FPDs) were slaughtered at the age of 42 days. The live body weight and carcass traits were measured and calculated. Physical properties of breast muscle were determined by texture analyzer and muscle fibers were measured by paraffin sections. The content of inosine monophosphate (IMP), intramuscular fat (IMF) and fatty acids composition were measured by high-performance liquid chromatography, Soxhlet extraction method and automated gas chromatography respectively. Results: The results showed that the bodyweight of LPDs was higher than that of FPDs. FPDs were significantly higher than LPDs in subcutaneous fat thickness, subcutaneous fat weight, subcutaneous fat percentage, abdominal fat percentage and abdominal fat shear force (p<0.01). LPDs were significantly higher than FPDs in breast muscle thickness, breast muscle weight, breast muscle rate and breast muscle shear force (p<0.01). The muscle fiber average area and fiber diameter of LPDs were significantly higher than those of FPDs (p<0.01). The muscle fiber density of LPDs was significantly lower than that of FPDs (p<0.01). The IMF of LPDs in the breast muscle was significantly higher than that in the FPDs (p<0.01). There was no significant difference between the 2 strains in IMP content (p>0.05). The polyunsaturated fatty acid content of LPDs was significantly higher than that of FPDs (p<0.01), and FPDs had higher saturated fatty acid and monounsaturated fatty acid levels (p<0.05). Conclusion: Long-term breeding work resulted in vast differences between the two strains Pekin ducks. This study provides a reference for differences between LPD and FPD that manifest as a result of long-term selection.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.705-710
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• 2013

This study was conducted to determine the effects of three different fat sources and their combination on growth performance, carcass traits and intestinal measurements of broiler chickens reared to 42 d of age. Two hundred day-old male broiler chicks (Ross 308) were randomly assigned to one of five treatments with four replicates of 10 chicks based on a completely randomized design. The dietary treatments consisted of 4% added fat from three different sources and their combination as follows: T, diet containing 4% tallow; CO, diet containing 4% canola oil; SFO, diet containing 4% sunflower oil; TCO, diet containing 2% tallow+2% canola oil; TSFO, diet containing 2% tallow+2% sunflower oil. Dietary fat type affected significantly BW and gain as well as feed efficiency in birds fed the TCO diets compared with those fed the other diets. Dietary fat type also modified meat yield, resulting in a higher breast and drumstick yields in the birds fed TCO and TSFO diets, respectively. Most of internal organ relative weights and small intestine measurements were not influenced by dietary treatments, except for the abdominal fat pad weight that was lower in birds fed SFO and for small intestinal length that was influenced by fat source. Results from the current study suggested that the supplementation with a combination of vegetable and animal fat sources in broiler diet supported positively growth performance and carcass parameters.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1812-1819
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• 2007

Heart fatty acid-binding protein gene (H-FABP) is an important candidate gene for meat quality. One of the objectives of this study was to screen single nucleotide polymorphisms (SNP) of chicken H-FABP gene among 252 individuals that included 4 Chinese domestic chicken breeds (Fengkai Xinghua (T04), Huiyang Huxu (H), Qingyuan Ma (Q), Guangxi Xiayan (S1)), 2 breeds developed by the Institute of Animal Science, Guangdong Academy of Agricultural Sciences (Lingnan Huang (DC), dwarf chicken (E4)) and one introduced broiler (Abor Acre (AA)). Another objective of this study was to analyze the associations between polymorphisms of the H-FABP gene and fat deposition traits in chickens. PCR-SSCP was used to analyze SNPs in H-FABP and 4 SNPs (T260C, G675A, C783T and G2778A) were detected. Associations between polymorphic loci and intramuscular fat (IMF), abdominal fat weight (AFW) and abdominal fat percentage (AFP) were analyzed by ANCOVA method. The results showed that the T260C genotypes were significantly associated with IMF (p = 0.0233) and AFP (p = 0.0001); the G675A genotypes were significantly associated with AFW, AFP (p<0.01) and IMF (p<0.05); at the C783T locus, AFW and AFP differed highly between genotypes. However, the G2778A loci did not show any significant effect on fat deposition traits in this study. In addition, we found that there were some differences between AFP and definite haplotypes through a nonparametric statistical method, so the haplotypes based on the SNPs except G2778A loci were also significantly associated with IMF, AFW (g) (p<0.05) and AFP (%) (p<0.001). Significantly and suggestively dominant effects of H4H4 haplotype were observed for IMF and the H2H3 was dominant for AFW (g) and AFP (%). The results also revealed that H5H7 haplotype had a negative effect on IMF, while the H5H6 had a positive effect on AFW (g) and AFP (%).

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.524-530
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• 2012

Laying hens were fed commercial diets added with supplemented fat (SFAT) at 0.6, 1.2, and 1.8% in order to study the long term dietary effects - on - their productive performance from 22 to 75 wk of age. Five hundred and seventy six Single Comb White Leghorn hens were assigned to one of the four dietary treatments. The experimental phase consisted of three periods of 18 wk each. The final body weight and gain of hens fed on diets with SFAT at 1.2% and 1.8% were lower (p<0.05) than those hens given no SFAT. The SFAT at the 1.2% and 1.8% levels improved egg production rate, egg weight and mass, as well as FCR. Mortality and feed consumption were not affected by dietary SFAT. Administration of a diet with SFAT significantly decreased the cracked-broken egg ratio (p<0.01). The beneficial effects of SFAT on egg production performance were particularly more pronounced at intermediate and later ages. Hence, SFAT by period interactions were significant for all traits studied except feed intake. Hens fed SFAT deposited significantly higher abdominal fat than those on the no-SFAT diet. As a result, SFAT at 1.2% and 1.8% inclusion levels provided benefits in terms of efficient table egg production.