• Animal Bioscience
• /
• 제36권2호
• /
• pp.295-306
• /
• 2023

Objective: Inhibiting the p38 mitogen-activated protein kinase (MAPK) signaling pathway delays differentiation and increases proliferation of muscle stem cells in most species. Here, we aimed to investigate the effect of p38 inhibitor (p38i) treatment on the proliferation and differentiation of chicken muscle stem cells. Methods: Chicken muscle stem cells were collected from the muscle tissues of Hy-line Brown chicken embryos at embryonic day 18, then isolated by the preplating method. Cells were cultured for 4 days in growth medium supplemented with dimethyl sulfoxide or 1, 10, 20 μM of p38i, then subcultured for up to 4 passages. Differentiation was induced for 3 days with differentiation medium. Each treatment was replicated 3 times. Results: The proliferation and mRNA expression of paired box 7 gene and myogenic factor 5 gene, as well as the mRNA expression of myogenic differentiation marker gene myogenin were significantly higher in p38i-treated cultures than in control (p<0.05), but immunofluorescence staining and mRNA expression of myosin heavy chain (MHC) were not significantly different between the two groups. Oil red O staining of accumulated lipid droplets in differentiated cell cultures revealed a higher lipid density in p38i-treated cultures than in control; however, the expression of the adipogenic marker gene peroxisome proliferator activated receptor gamma was not significantly different between the two groups. Conclusion: p38 inhibition in chicken muscle stem cells improves cell proliferation, but the effects on myogenic differentiation and lipid accumulation require additional analysis. Further studies are needed on the chicken p38-MAPK pathway to understand the muscle and fat development mechanism.

• 농업과학연구
• /
• 제49권1호
• /
• pp.19-29
• /
• 2022

The present experiment was conducted to evaluate the effects of single-sex or mixed rearing on the growth and laying performance, blood parameters, egg quality, and feather scores of laying hens in an aviary system. A total of 2,928 (females, 2,856; males, 72), Hy-Line Brown chickens at 20 weeks were evenly assigned to two treatments: termed here the single-sex (only female) and mixed-sex (female to male 20 : 1) conditions. They were allowed an ad libitum diet for 20 weeks in an aviary system. There were eight replicates of each treatment, each consisting of 12.42 m²·birds^-1 (n=183), respectively. The body weight and uniformity in the mixed-sex condition were higher than those in the single-sex condition, but egg production did not show any significant differences between the two types of treatment for 20 weeks. The mixed-sex group showed an effect through stress parameters (corticosterone), whereas the feather score on the back was low at the end of the experiment. These results suggest that the presence of males affect corticosterone level for mating but can reduce the vigilance and aggressive behavior of laying hens.

• Plant Breeding and Biotechnology
• /
• 제7권3호
• /
• pp.272-286
• /
• 2019

Developing elite hybrid rice varieties is one important objective of rice breeding programs. Several genes related to male sterilities, restores, and pollinators have been identified through map-based gene cloning within natural variations of rice. These identified genes are good targets for introducing genetic traits in molecular breeding. This study was conducted to breed elite hybrid lines with major genes related to hybrid traits and disease/insect resistance in 240 genetic resources and F₁ hybrid combinations of rice. Molecular markers were reset for three major hybrid genes (S5, Rf3, Rf4) and thirteen disease/insect resistant genes (rice bacterial blight resistance genes Xa3, Xa4, xa5, Xa7, xa13, Xa21; blast resistance genes Pita, Pib, Pi5, Pii; brown planthopper resistant genes Bph18(t) and tungro virus resistance gene tsv1). Genotypes were then analyzed using molecular marker-assisted selection (MAS). Biological assay was then performed at the Red River Delta region in Vietnam using eleven F₁ hybrid combinations and two control vatieties. Results showed that nine F₁ hybrid combinations were highly resistant to rice bacterial blight and blast. Finally, eight F₁ hybrid rice varieties with resistance to disease/insect were selected from eleven F₁ hybrid combinations. Their characteristics such as agricultural traits and yields were then investigated. These F₁ hybrid rice varieties developed with major genes related to hybrid traits and disease/insect resistant genes could be useful for hybrid breeding programs to achieve high yield with biotic and abiotic resistance.

• Animal Bioscience
• /
• 제35권9호
• /
• pp.1408-1417
• /
• 2022

Objective: The objective of this study was to determine whether dietary black soldier fly (Hermetia illucens, HI) larvae oil (HILO) could serve as an alternative fat source to soybean oil (SBO) in laying hen diets. Methods: We randomly assigned 25-week-old Hy-line Brown laying hens (n = 144) to receive (n = 6 hens/group; eight replicates) a control or an experimental diet in which SBO was replaced with 50% (50HILO) or 100% HILO (100HILO). Results: Dietary HILO did not negatively affect body weight or productive performance during the study. The eggs also had similar quality parameters, proximate composition, and cholesterol levels. However, the yolk color index was significantly higher (p<0.01) in the 100HILO than in the other groups. Dietary HILO significantly altered the composition of fatty acids (FAs) in abdominal fat and eggs. Total saturated fatty acids (SFAs) and total polyunsaturated FAs (PUFAs) were significantly increased and decreased in the 50HILO and 100HILO groups, respectively, compared with those in the control group (p<0.001 and p<0.0001, respectively). Specifically, the medium-chain FAs lauric and myristic acids were remarkably increased in the abdominal fat of laying hens fed HILO (p<0.0001), whereas only myristic acid increased in eggs (p<0.0001). Undesirable heavy metal (aluminum, fluorine, arsenic, lead, mercury, and cadmium) concentrations were below permissible limits in eggs. Conclusion: We considered that HILO could be an alternative dietary fat to SBO for laying hens with maintained productive performance and good egg quality.

• Animal Bioscience
• /
• 제35권9호
• /
• pp.1426-1433
• /
• 2022

Objective: The present research was conducted to evaluate the interactive effect of dietary concentration of calcium (Ca) and 25-hydroxy vitamin D3 (25OHD3) on the performance, blood composition and digestibility of laying hens. Methods: A total of 540 Hy-line brown laying hens aged 61 to 70 weeks were randomly allotted in a 3×3 factorial arrangement, consisting of three levels of 25OHD3 (0, 25, and 50 ㎍/kg) and three levels of Ca (3.5%, 4.0%, and 4.5%). All diets had basal concentration of 3,000 IU/kg of vitamin D3 including the 2,800 kcal/kg of metabolic energy and 16% of crude protein. Results: The results showed that interactive effect (p<0.05) between Ca and 25OHD3 was such that dietary 25OHD3 linearly increased interleukin-6 at all levels of Ca inclusion. Interaction (p<0.05) occurred with the highest parathyroid hormone in laying hens that received dietary concentration of Ca (3.5%) with 25OHD3 (50 ㎍/kg), and Ca (4.0%) with 25OHD3 (50 ㎍/kg). Egg production and egg weight significantly (p<0.05) increased in the 4.5% Ca group compared to the 3.5% to 4.0% Ca groups. Egg shell thickness and tibia bone length also increased (p<0.05) in groups fed a high-Ca diet (4.0% to 4.5%). Phosphorus digestibility significantly (p<0.05) increased along with dietary Ca level. Among the tested 25OHD3 groups, higher (p<0.05) egg production and tibia thickness were present in hens fed 50 ㎍/kg of 25OHD3. Furthermore, Ca digestibility serum Ca and 25OHD3 were significantly increased in group offered 50 ㎍/kg of 25OHD3. Conclusion: The results gathered in this study indicate that dietary concentrations of 4.0% to 4.5% Ca and 50 ㎍/kg 25OHD3 improve the performance of hens from 61 to 70 weeks of age.

• Animal Bioscience
• /
• 제36권11호
• /
• pp.1727-1737
• /
• 2023

Objective: The poultry industry is a primary source of animal protein worldwide. The gut microbiota of poultry birds, such as chickens and ducks, is critical in maintaining their health, growth, and productivity. This study aimed to identify longitudinal changes in the gut microbiota of laying hens from birth to the pre-laying stage. Methods: From a total of 80 Hy-Line Brown laying hens, birds were selected based on weight at equal intervals to collect feces (n = 20 per growth) and ileal contents (n = 10 per growth) for each growth stage (days 10, 21, 58, and 101). The V4 regions of the 16S rRNA gene were amplified after extracting DNA from feces and ileal contents. Amplicon sequencing was performed using Illumina, followed by analysis. Results: Microbial diversity increased with growth stages, regardless of sampling sites. Microbial community analysis indicated that Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phyla in the feces and ileal. The abundance of Lactobacillus was highest on day 10, and that of Escherichia-shigella was higher on day 21 than those at the other stages at the genus level (for the feces and ileal contents; p<0.05). Furthermore, Turicibacter was the most abundant genus after changing feed (for the feces and ileal contents; p<0.05). The fecal Ruminococcus torques and ileal Lysinibacillus were negatively correlated with the body weights of chickens (p<0.05). Conclusion: The gut microbiota of laying hens changes during the four growth stages, and interactions between microbiota and feed may be present. Our findings provide valuable data for understanding the gut microbiota of laying hens at various growth stages and future applied studies.

• 농업과학연구
• /
• 제50권2호
• /
• pp.249-256
• /
• 2023

The purpose of this experiment was to determine the influence of providing laying hens with extra feed on egg production and egg quality parameters. A total of 480 laying hens (38-weeks old), were divided into five treatment groups (eight replicate cages/treatment and 12 layer/replicate) according to their starting body weight (1.98 ± 0.05 kg) in this four-week feeding trial. Five different feed allowances of the same diet (105, 110, 115, 120, and 125 g·day^-1·bird^-1) were assigned to layers. Daily inspections of remaining feed (around 0.1g) and layer mortality (0%) showed no harmful impact of supplying extra feed to layers. Providing 120 and 125 g of feed per day to layers resulted in the highest final body weight, large-egg ratio, and improved yolk color among all treatment groups. Layers receiving 125 g of feed daily had the highest egg weight, but the highest egg production ratio was observed in layers receiving 110 g of feed/day. The additional supply of feed did not have a negative impact on the productive performance or egg quality of the layers. The provision of 125 g feed per day led to an improvement of large-egg ratio, egg weight, and yolk color, but likely led to obesity of the layers, which manifested as an increase in body weight and a decline in the egg production ratio. We concluded that 110 grams of feed was the proper quantity after taking into consideration the significance of the health of the laying hen to the overall production performance.

• 생명과학회지
• /
• 제22권8호
• /
• pp.1099-1106
• /
• 2012

체지방감소 효과가 있는 시판 conjugated linoleic acid (CLA)의 색깔을 제거하고 이 색깔의 세포독성에 관한 연구를 하였다. 황갈색의 시판 CLA 제품을 구입하여 crude CLA (c-CLA) 시료로 하였다. c-CLA 시료를 감압증류(10 mmHg-$220^{\circ}C$, 10 mmHg-$235^{\circ}C$, 10 mmHg-$240^{\circ}C$, 20 mmHg-$260^{\circ}C$; 30분)하여 증류된 CLA (distilled CLA; d-CLA) 시료와 증류되지 않고 남아있는 황갈색 CLA (residual CLA; r-CLA) 시료로 분리하였다. 10 mmHg-$220^{\circ}C$에서 증류하여 얻은 d-CLA 시료의 색깔은 L (brightness), a (red/blue), b (yellow/green)로 분석한 결과 무색에 가까웠고 r-CLA 시료는 황갈색이었고, 이들 두 CLA 시료의 CLA 이성체 조성은 변하지 않았다. 따라서 10 mmHg-$220^{\circ}C$에서 얻은 r-CLA 시료의 인체암세포(유방암 MCF-7. 폐암 A-549, 직장암 HT-29, 전립선암 PC-3)와 인체 정상세포(신경모세포 SK-N-SH)에 대한 세포독성을 d-CLA 시료와 비교하였다. 이들 암세포와 정상세포에 r-CLA 시료와 d-CLA 시료 처리 2일 후의 세포독성에는 차이가 없었다. 따라서 본 연구에서 c-CLA 시료에 함유된 색소는 10 mmHg-$220^{\circ}C$로 감압증류 하여 제거할 수 있었고, r-CLA 시료의 세포독성은 d-CLA 시료의 세포독성과 차이가 없었다. 이와 같은 결과는 c-CLA 시료에 함유된 색소는 세포생육에 아무런 영향을 미치지 않고 인체에 아무런 영향을 미치지 않음을 의미한다.

• 한국가금학회지
• /
• 제45권3호
• /
• pp.183-191
• /
• 2018

본 시험은 Salmonella gallinarum에 대한 Lactobacillus, medicinal plants extract, essential oil 급여 시 산란계의 생산성, 맹장 내 미생물 균총, 조직중량 및 혈구 조성에 미치는 영향을 조사하기 위하여 수행하였다. 공시동물로 65주령 산란계(Hy-line brown) 총 100수를 공시하였고, 시험처리는 항생제 무첨가구(NC)와 항생제 첨가구(PC)를 대조구로 하였으며, 유산균 0.1% 첨가구(LB), 약용식물 추출물 100 ppm 첨가구(MPE) 및 식물 추출물 100 ppm 첨가구(EO)를 처리구로 두었다. 배치 후 1주일동안 시험 사료를 급여하고, 이후 Salmonella gallinarum을 경구투여하였다. 조사항목으로는 생산성, 맹장 내 미생물 균총, 조직중량 및 혈구 조성을 조사하였다. Salmonella gallinarum를 경구투여한 처리구와 투여하지 않은 처리구의 경우, Salmonella gallinarum를 경구투여한 처리구가 산란율, 1일 산란량 및 사료섭취량이 다소 감소하는 경향을 보였고, 유산균(LB), 약용식물 추출물(MPE) 및 식물추출물(EO)을 급여하였을 때 약용식물 추출물(MPE)을 급여한 처리구가 대조구에 비해 다소 개선되었지만 처리구간의 통계적인 유의차는 없었다. 맹장 내 미생물의 경우, Salmonella gallinarum을 경구투여하였을 때, Salmonella 수가 유의하게 증가하였으나(P<0.05), coliform bacteria 및 유산균 수에는 영향을 미치지 않았으며, Salmonella gallinarum과 유산균(LB), 약용식물 추출물(MPE), 및 식물추출물(EO) 사이의 상호작용도 나타나지 않았다. 조직중량에서도 Salmonella gallinarum 경구투여와 유산균(LB), 약용식물(MPE) 및 식물추출물(MPE) 첨가에 대한 통계적인 유의차는 없었고, 혈구 조성에서도 Salmonella gallinarum 경구투여와 유산균(LB), 약용식물 추출물(MPE) 및 식물추출물(EO) 첨가에 대한 유의차는 없었지만 각각 총 백혈구 수가 증가하는 경향을 보이기도 하였다.

• 한국가금학회지
• /
• 제36권1호
• /
• pp.47-55
• /
• 2009

본 실험은 산란 후기 사료 내 거미 유래 단백질 분해효소 제 AZ의 첨가 급여가 산란계의 생산성, 계란의 품질, 혈액 특성, 장 내용물의 점도, 맹장 미생물 변화 및 맹장 내 암모니아 농도에 미치는 영향을 조사하기 위한 목적으로 수행하였다. 59주령의 Hy-Line Brown 실용계 200수를 공시하여 총 4개 처리에 각 처리구별 반복당 10수씩 5반복으로 완전 임의 배치하였고, 각각의 실험 사료에 AZ을 각각 0.05%, 0.075% 및 0.1% 혼합하여 총 5주간 급여하였다. 총 실험 기간 중 AZ 첨가에 따라 난중에서 유의한 차가 나타났으며, AZ 0.05%를 첨가한 처리구에서 가장 높은 증가가 나타났다(P<0.05). AZ 첨가는 난각 두께, 난각 강도, 난각색, 난황색 및 Haugh Unit는 처리구간 통계적 유의성은 없는 것으로 나타났다. 혈액 내 총 콜레스테롤 함량과 GOT 및 GPT 활성에 있어서는 처리구간 통계적 차이가 없는 것으로 나타났다. 맹장 내 미생물 균총을 조사해 본 결과 총 균수, 유산균수 및 대장균군수는 처리구간 차이를 보이지 않았다. 장 내용물의 점도 및 장내 암모니아 농도는 대조구에 비해 AZ을 첨가한 처리구에서 유의하게 감소하는 것으로 나타났다(P<0.05). 본 실험 결과, 식물성 및 동물성 단백질을 포함한 산란 후기 사료에 AZ의 첨가 급여는 난중 및 장 내 점도를 개선하고 암모니아 농도를 저감하는데 효과적이라는 것을 시사한다. 따라서 산란 후기 사료에 거미 유래 단백질 분해효소제 AZ의 첨가 급여는 산란 후기의 생산성, 장내 점도를 개선하여 사료 효소제로서 가치가 있는 것으로 판단된다. 또한 본 실험 결과 산란 후기 사료에서의 AZ의 첨가 수준은 0.05%와 0.075%에서 개선되는 결과가 나타났으나, 첨가 비용을 고려 할 때, 0.05% 첨가 수준이 가장 높은 효과가 있는 것으로 판단된다.