• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.113-132
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• 2005

With the demand for free-range products increasing and the pressure on the intensive poultry industry to improve poultry welfare especially in western countries, the number of free-range poultry farms has increased significantly. The USA, Australia and European countries have developed Codes of Practice for free-range poultry farming which detail the minimum standards of husbandry and welfare for birds. However, the performance and liveability of free-range birds needs to be improved and more knowledge is required on bird husbandry, feed supply, disease control and heat wave management. This review examines the husbandry, welfare, nutrition and disease issues associated with free-range poultry systems and discusses the potential of incorporating free-range poultry into a crop-pasture rotation system.

• Journal of Veterinary Science
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• v.23 no.1
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• pp.2.1-2.18
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• 2022

Background: Co-infections of the porcine reproductive and respiratory syndrome virus (PRRSV) and the Haemophilus parasuis (HPS) are severe in Chinese pigs, but the immune response genes against co-infected with 2 pathogens in the lungs have not been reported. Objectives: To understand the effect of PRRSV and/or HPS infection on the genes expression associated with lung immune function. Methods: The expression of the immune-related genes was analyzed using RNA-sequencing and bioinformatics. Differentially expressed genes (DEGs) were detected and identified by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and western blotting assays. Results: All experimental pigs showed clinical symptoms and lung lesions. RNA-seq analysis showed that 922 DEGs in co-challenged pigs were more than in the HPS group (709 DEGs) and the PRRSV group (676 DEGs). Eleven DEGs validated by qRT-PCR were consistent with the RNA sequencing results. Eleven common Kyoto Encyclopedia of Genes and Genomes pathways related to infection and immune were found in single-infected and co-challenged pigs, including autophagy, cytokine-cytokine receptor interaction, and antigen processing and presentation, involving different DEGs. A model of immune response to infection with PRRSV and HPS was predicted among the DEGs in the co-challenged pigs. Dual oxidase 1 (DUOX1) and interleukin-21 (IL21) were detected by IHC and western blot and showed significant differences between the co-challenged pigs and the controls. Conclusions: These findings elucidated the transcriptome changes in the lungs after PRRSV and/or HPS infections, providing ideas for further study to inhibit ROS production and promote pulmonary fibrosis caused by co-challenging with PRRSV and HPS.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.773-780
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• 2017

Objective: "Hatchability" is an important economic trait in domestic poultry. Studies on poultry hatchability focus mainly on the genetic background, egg quality, and incubation conditions, whereas the molecular mechanisms behind the phenomenon that some ducklings failed to break their eggshells are poorly understood. Methods: In this study, the transcriptional differences between the livers of normally hatched and assisted ducklings were systematically analyzed. Results: The results showed that the clean reads were de novo assembled into 161,804 and 159,083 unigenes (${\geq}200-bp$ long) by using Trinity, with an average length of 1,206 bp and 882 bp, respectively. The defined criteria of the absolute value of log2 fold-change ${\geq}1$ and false discovery rate${\leq}0.05$ were differentially expressed and were significant. As a result, 1,629 unigenes were identified, the assisted ducklings showed 510 significantly upregulated and 1,119 significantly down-regulated unigenes. In general, the metabolic rate in the livers of the assisted ducklings was lower than that in the normal ducklings; however, compared to normal ducklings, glucose-6-phosphatase and ATP synthase subunit alpha 1 associated with energy metabolism were significantly upregulated in the assisted group. The genes involved in immune defense such as major histocompatibility complex (MHC) class I antigen alpha chain and MHC class II beta chain 1 were downregulated in the assisted ducklings. Conclusion: These data provide abundant sequence resources for studying the functional genome of the livers in ducks and other poultry. In addition, our study provided insight into the molecular mechanism by which the phenomenon of weak embryos is regulated.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.657-664
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• 1997

432 Babcock ISA white leghorn pullets reared for 8 weeks on a standard managemental conditions were exposed to feed/nutrient and light restrictions from 9 to 20 weeks of age. Four feeding regimes i. e. 100, 85 or 70 percent of the recommended allowance and low energy (2,500 Kcal/kg) low protein (13% CP) ration were fed each in the three light regimes i. e. (A) Natural day light starting from 13.24 hr/day at 8 weeks of age and ending 10.41 hr/day at the end of 20 weeks; (B) Constant 11 hr/day light and (C) starting with 13 hr/day at 8 weeks and decreasing @ 20 min/week till 20 weeks of age. At the age of 20 weeks all the birds were shifted to separate cages under uniform lighting feeding and management. During the 21st week light was increased to 12 hr a day and thereafter with an increase of 30 min per week, increased to 16 hr a day at the age of 29 weeks. From 20 weeks onward till 72 week age, all the birds were offered commercial layer rations ad libitum, prepared according to climatic conditions. The results of the study revealed that birds reared under natural and constant light had higher weights than decreasing light, yet they could not out perform during production period. The effect of feed and nutrient restriction, on the other hand, was found significant during rearing as well as production period. The birds exposed to higher level of feed and those exposed to nutrient restriction were lighter in weight. The 100% fed birds laid their first egg at an early age. However, those reared on 85% of the recommendation excelled all other groups in terms of produced number of eggs, egg mass, hen housed and hen day production and net returns.

• Animal Bioscience
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• v.35 no.4
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• pp.517-526
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• 2022

Objective: The growth differentiation factor 8 (GDF8) gene plays a key role in bone formation, resorption, and skeletal muscle development in mammals. Here, we studied the genetic variants of GDF8 and their contribution to body conformation traits in Chinese Dabieshan cattle. Methods: Single nucleotide polymorphisms (SNPs) were identified in the bovine GDF8 gene by DNA sequencing. Phylogenetic analysis, motif analysis, and genetic diversity analysis were conducted using bioinformatics software. Association analysis between five SNPs, haplotype combinations, and body conformation traits was conducted in 380 individuals. Results: The GDF8 was highly conserved in seven species, and the GDF8 sequence of cattle was most similar to the sequences of sheep and goat based on the phylogenetic analysis. The motif analysis showed that there were 12 significant motifs in GDF8. Genetic diversity analysis indicated that the polymorphism information content of the five studied SNPs was within 0.25 to 0.5. Haplotype analysis revealed a total of 12 different haplotypes and those with a frequency of <0.05 were excluded. Linkage disequilibrium analysis showed a strong linkage (r²>0.330) between the following SNPs: g.5070C>A, g.5076T>C, and g.5148A>C. Association analysis indicated these five SNPs were associated with some of the body conformation traits (p<0.05), and the animals with haplotype combination H1H1 (-GGGG CCTTAA-) had greater wither height, hip height, heart girth, abdominal girth, and pin bone width than the other (p<0.05) Dabieshan cattle. Conclusion: Overall, our results indicate that the genetic variants of GDF8 affected the body conformation traits of Chinese Dabieshan cattle, and the GDF8 gene could make a strong candidate gene in Dabieshan cattle breeding programs.

• Animal Bioscience
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• v.37 no.1
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• pp.28-38
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• 2024

Objective: Tibetan chickens, which have unique adaptations to extreme high-altitude environments, exhibit phenotypic and physiological characteristics that are distinct from those of lowland chickens. However, the mechanisms underlying hypoxic adaptation in the liver of chickens remain unknown. Methods: RNA-sequencing (RNA-Seq) technology was used to assess the differentially expressed genes (DEGs) involved in hypoxia adaptation in highland chickens (native Tibetan chicken [HT]) and lowland chickens (Langshan chicken [LS], Beijing You chicken [BJ], Qingyuan Partridge chicken [QY], and Chahua chicken [CH]). Results: A total of 352 co-DEGs were specifically screened between HT and four native lowland chicken breeds. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses indicated that these co-DEGs were widely involved in lipid metabolism processes, such as the peroxisome proliferator-activated receptors (PPAR) signaling pathway, fatty acid degradation, fatty acid metabolism and fatty acid biosynthesis. To further determine the relationship from the 352 co-DEGs, protein-protein interaction network was carried out and identified eight genes (ACSL1, CPT1A, ACOX1, PPARC1A, SCD, ACSBG2, ACACA, and FASN) as the potential regulating genes that are responsible for the altitude difference between the HT and other four lowland chicken breeds. Conclusion: This study provides novel insights into the molecular mechanisms regulating hypoxia adaptation via lipid metabolism in Tibetan chickens and other highland animals.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.468-475
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• 2018

The present trial was carried out to study the effect of sea buckthorn seed supplementation on egg quality of laying birds. A total of 160 Rhode Island Red${\times}$Fayoumi layers was divided into four groups of 40 birds each, which was further replicated four times with 10 hens per replicate. Group one was kept as a control, while other three groups were supplemented with sea buckthorn seed powder at a dose rate of 1 (T1), 2 (T2) and 3 (T3) g/kg of feed. The results showed that egg production was significantly (p<0.05) higher in T3 at the end of the study. Egg weight was significantly (p<0.05) high in T2 and T3 during week 39 and 40. Egg yolk weight was significantly (p<0.05) in T3 compared to the control. Significantly (p<0.01) lower egg cholesterol was recorded in T2 and T3. From the results of the present study, we concluded that laying hens supplemented with sea buckthorn at the rate of 2 and 3 g/kg improved the egg quality parameters and egg cholesterol.

• Monthly Duck's Village
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• s.70
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• pp.50-51
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• 2009

The duck meat market has grown significantly in recent years and is likely to continue with genetic and husbandry advances, making duck increasingly competitive to other poultry and meat products. Duck meat currently represents less than 10% of total poultry meat production and is largely concentrated in China and southern Asia.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.253-257
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• 2003

The suitability of processed cardboard(PC) as litter of broiler house was evaluated by comparing the growth performances of broiler chicks reared on the PC with those of birds reared on conventional rice hull litter(RH) as the control group. A total of 180 male broiler chick (5d old, Ross) were randomly divided into 2 groups and placed into 2 types of litter, PC and RH, with 3 replicates of 30 birds per replicate. Commercial broiler feeds and water were provided ad libitum for 5 weeks. The body weight gains of the birds reared on PC were heavier than those on RH(P<0.05). The average feed conversion rate of chicks reared on PC was appeared to be improved as compared to that of the control. The Enterobacter aerogens counts in PC were significantly rduced than those in the control litter(P<0.05), but a total number of Salmonella and E. coli were not affected by the litter materials. No difference was observed between the average moisture contents of the litters. The average mortality of the chicks reared on PC was significantly lower than that of RH(P<0.05). The results indicate that processed cardboard can substitute other conventional litter materials when the others are in short supply or expensive.

• Korean Journal of Poultry Science
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• v.20 no.1
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• pp.17-31
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• 1993

Several aspects about the epidemiological status of chicken coccidiosis, its control measures and recent research activities in Korea are discussed in this paper. Medication with different available anticoccidial drugs has been reasonably effective in treating and preventing serious outbreaks of coccidiosis in chicken, but the disease remains one of the most expensive and common diseases of popultry production in this country, and more recently its incidence is increasing, possibly due to the more intensive methods of husbandry and the immergence of resistant strains of coccidia. Therefore, this necessitates a continuous search for new methods such as medication program (shuttl and rotation program) and immunization using attenuated strains or parasite antigens.