• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1460-1464
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• 2001

This study compared the lipid metabolism of white Leghorn layers between the growing and the laying periods. The study was conducted on thirty layers in the growing period (14 weeks old) and in the initial laying period (36 weeks old; 14 weeks from the onset of laying). Results indicated that all plasma lipid traits were significantly different (p<0.05) between the two periods. The estrogen concentration in the laying period was about 3 fold that in the growing period. Triacylglycerol (TG) concentration in the laying period was about 12 fold that in the growing period. The phospholipids, cholesterol, glycerol and non esterified fatty acid (NEFA) in the laying period were also higher than those in the growing period (p<0.05). Lipogenic enzyme activities in the laying period were higher than in the growing period (p<0.05). High-density lipoprotein (HDL) was the largest lipoprotein portion in growing layers. In laying hens, the major lipoprotein portion was very low-density lipoprotein (VLDL). It was also shown that protein is the primary component of HDL and TG is the largest portion of VLDL in both periods. In laying hens, VLDL contained more TG than that in growing layers (p<0.05). The VLDL particle size in laying hens was larger than that in growing layers (p<0.05). This study indicates that the lipid metabolism traits of a layer in the laying period were different from those in the growing period. The lipogenesis related traits in the laying period were markedly greater than in the growing period.

• Asian-Australasian Journal of Animal Sciences
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• 제26권7호
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• pp.921-929
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• 2013

Huoyan goose is a Chinese local breed famous for its higher laying performance, but the problems of variety degeneration have emerged recently, especially a decrease in the number of eggs laid. In order to better understand the molecular mechanism that underlies egg laying in Huoyan geese, gene profiles in the pituitary gland of Huoyan geese taken during the laying period and ceased period were investigated using the suppression subtractive hybridization (SSH) method. Total RNA was extracted from pituitary glands of ceased period and laying period geese. The cDNA in the pituitary glands of ceased geese was subtracted from the cDNA in the pituitary glands of laying geese (forward subtraction); the reverse subtraction was also performed. After sequencing and annotation, a total of 30 and 24 up and down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These genes mostly related to biosynthetic process, cellular nitrogen compound metabolic process, transport, cell differentiation, cellular protein modification process, signal transduction, small molecule metabolic process. Furthermore, eleven genes were selected for further analyses by quantitative real-time PCR (qRT-PCR). The qRT-PCR results for the most part were consistent with the SSH results. Among these genes, Synaptotagmin-1 (SYT1) and Stathmin-2 (STMN2) were substantially over-expressed in laying period compared to ceased period. These results could serve as an important reference for elucidating the molecular mechanism of higher laying performance in Huoyan geese.

• 한국가금학회지
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• 제47권4호
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• pp.237-245
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• 2020

본 연구는 종계의 품종, 산란 연령 및 종란의 보관 기간이 부화 성적에 미치는 영향을 살펴보고 자 한 것으로 한국토종닭인 재래황갈종, 토착레그혼종 및 토착로드종이 산란한 종란을 대상으로 산란 초기인 27~29주령 때 수집한 종란과 산란 후기인 50~52주령에 산란한 종란을 각각 3일, 7일 및 14일 보관 후 부화를 진행하였다. 조사 항목으로는 수정률, 부화율 및 배자발육중지율을 조사하고, 각 요인별 부화 성적을 분석하였다. 분석 결과, 종계의 품종, 산란 연령 및 종란의 보관 기간이 독립적으로 혹은 복합적으로 부화 성적에 영향을 미치는 것으로 나타났다. 종계의 품종에 따른 비교에서 토착로드종의 부화 성적이 가장 저조하였는데, 특히 이들이 산란 초기에 생산한 종란에서 초기 배자 사망률이 현저히 높게 나타났다. 산란 연령에 따른 부화 성적은 산란 초기에 생산한 종란의 부화율이 산란 후기에 생산한 종란에 비해 높게 나타났는데, 초기 배자 사망률은 산란 초기의 종란에서, 후기 배자 사망률 및 사롱란의 비율은 산란 후기의 종란에서 상대적으로 높게 나타났다. 종란의 보관 기간에 따른 부화 성적은 거의 대부분의 조사 항목에서 종란의 보관 기간이 길어질수록 부화 성적은 저하되는 것으로 나타났다. 이상의 결과를 종합할 때, 우수한 부화 성적을 얻기 위해서는 품종에 따른 각기 다른 부화 관리가 필요하며, 산란 후기에 생산된 종란의 이용은 피하고 종란의 보관 기간은 7일 이내로 짧게 하는 것이 바람직할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1258-1262
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• 1999

With an attempt to elucidating the lipid metabolism of Tsaiya ducks, thirty ducks at growing (8 weeks of age) and laying periods (10 weeks after the onset of laying) were examined, respectively. The ducks were randomly allocated into ad libitum feeding and 3-day fasting groups, to investigate their in vitro hepatocytes lipogenesis capacity and adipocytes lipolysis rate. Results indicate that (1) the capacity of hepatocytes incorporation of glucose and acetate into total lipid and metabolite of $^{14}CO_2$ production during the laying period was greater than during the growing period. Approximately 50% of the glucose or acetate converted into triacylglycerol (TG) by the hepatocytes were recovered as fatty acid during the growing period, while it was 65-70% during the laying period. (2) Acetate used for lipogenesis ability was superior to glucose in both periods. (3) The adipocytes lipolysis rate was increased significantly (p<0.05) by fasting. In contrast, the capacity of incorporated glucose or acetate into total lipid, triacylglycerol, fatty acid and glycerol by hepatocytes was reduced significantly (p<0.05) by fasting.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1090-1095
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• 1999

In order to minimize the occurrence of fatty liver, this study investigated how adding a high level of dietary choline or methionine affected the lipid metabolism of Tsaiya ducks. Feeding trials were conducted with sixty Tsaiya ducks during their growing period, when they were 8-12 weeks old, and during their laying period, 10-14 weeks after the onset of laying when they were 26-30 weeks old. The ducks were randomly assigned to one of three groups: a control group (basal diet), a group in which methionine was added to the basal diet, and a group in which choline was added to the basal diet. The levels of methionine and choline added were twice as high as the levels recommended by the NRC for layer-type chickens. Experimental results indicated that adding choline to the basal diet of growing ducks significantly (p<0.05) increased their body weight, while adding methionine significantly (p<0.05)reduced their body weight. Adding either choline or methionine reduced the ducks' liver fat content in both the growing and the laying periods (p<0.05). Ducks receiving added methionine or choline in their diets displayed enhanced egg production (p<0.05). Adding choline increased serum triacylglycerol (TG) in the laying period (p<0.05). Adding either choline or methionine did not significantly (p>0.05) affect the t-globulin level. Adding methionine increased the activity of liver malic dehydrogenase in both the growing and the laying periods, and increased fatty acid synthetase in the laying period (p<0.05). While adding choline markedly (p>0.05) increased VLDL and apo B in both the growing and the laying periods, it decreased HDL and apo A in the laying period (p<0.05). This study found that adding a high level of choline to the basal diets of Tsaiya ducks in both the growing and the laying periods had beneficial effects. Furthermore, adding methionine affected the lipid metabolism of Tsaiya ducks to a lesser extent than adding choline.

• Animal Bioscience
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• 제34권3_spc호
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• pp.457-462
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• 2021

Objective: The aim of this study was to investigate the effects of Enteromorpha powder supplementation on reproduction-related hormones and genes in the late laying period of Zi geese. Methods: A total of 312 (1-year-old) Zi geese with similar laying rate were randomly divided into 2 groups with 6 replicates each, each with 21 female geese and 5 male geese. The control group was fed with a basal diet and the test group was fed with a diet containing 3% Enteromorpha powder. The trial period lasted for 7 weeks. Results: Our results showed that the laying rate was improved in the test group at each week of trial (p<0.01), and the levels of estradiol in serum and prolactin in ovary were increased compared with the control group (p<0.05). Conclusion: Based on above results, Enteromorpha powder supplementation at 3% could promote reproductive performance during the late laying period of Zi geese.

• 한국가금학회지
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• 제13권1호
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• pp.23-30
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• 1986

닭의 산란기를 I기(25-40 주령), II기(41-55주령), III기(56-69주령)의 3기로 구분하고 각 산란기에서의 에너지대사를 측정하여 얻은 결과는 다음과 같다. 1. 산란계의 절식시 열생산량(FHP)은 대사체중당 산란 I기 81.5Kcal, IIrl 76.1Kcal, IIIrl 97.5Kcal였다. 즉 FHP는 산란기에 의하여 변화하고 특히 III기의 FHP가 높게 나타났다. 이 현상은 III기에 공시계의 우모가 손상 또는 탈락하여 열손실을 크게 한 때문으로 생각된다. 2. 호흡시험에 있어서 사료 ME섭취량과 에너지 축적량(ER)과의 회귀식에서 구한 유지를 위한 ME 요구량(MEm)은 산란I, II, III기에 있어서 각각 대사체중당 123Kcal, 111Kcal, 131Kcal 였으며, 전기간 평균 119Kcal였다. 또 생산을 위한 ME의 정미이용효율(NAME)을 산란I기 76%, II기 79%, III기 74%, 전 기간 평균에선 79%였다. 즉 산란 III기는 I기 또는 II기에 비하하여 MEm가 높고 NAME가 낮은 성적을 보이고 있다.

• 한국가금학회지
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• 제48권1호
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• pp.1-12
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• 2021

본 연구는 종계의 품종, 산란 연령 및 종란의 보관 기간이 발생 병아리의 강건성에 미치는 영향을 살펴보고자 한 것이다. 시험은 황갈색 재래종, 토착 로드아일랜드종 및 토착 레그혼종을 이용하여 산란 초기(27~29주)와 산란 후기(50~52주) 때 생산한 종란을 각각 3일, 7일 및 14일 보관 후 부화하여 발생한 병아리를 대상으로 하였다. 분석 항목으로는 부화 시간, 발생 후 병아리의 생산능력 및 장기 무게를 조사하였고, 병아리의 생리적 활성도 파악을 위하여 IL-6 유전자 발현율 및 텔로미어의 상대적 길이를 분석하였으며, 스트레스 반응 정도를 알기 위하여 HSP 유전자 발현율 및 H/L ratio를 분석하였다. 분석 결과, 종계의 품종과 산란 시 연령이 발생 병아리의 강건성에 영향을 미치는 것으로 나타났고, 종란의 보관 기간은 병아리의 강건성에 크게 영향을 미치지 않는 것으로 나타났다. 공시된 토종닭 품종 중 토착 레그혼종 병아리가 가장 강건성이 약한 것으로 나타났는데, 이는 생존율이 저조하고 상대적으로 작은 심장을 가지며, 모든 생리활성지표가 낮고 스트레스 반응 지표들이 높았기 때문이다. 비록 산란 초기에 생산한 병아리들이 산란 후기에 생산한 병아리에 비해 생존율은 낮았지만, 생존 개체들의 생리활성지표가 높고, 스트레스 반응 지표들이 낮아 산란 후기 때 생산한 병아리에 비해 강건성이 높은 것으로 판단된다. 이상의 결과로부터 강건성이 높은 병아리를 얻기 위해서는 강건성이 강한 품종을 선정하여야 하고, 산란 후기에 생산한 병아리의 이용은 가급적 피하는 것이 바람직할 것으로 사료된다.

• 한국가금학회지
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• 제22권2호
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• pp.77-84
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• 1995

In order to investigate the effect of feeding live yeast culture on the performance of laying hens, a feeding trial was conducted with 96 20-wk-old Hy4ine brown layers during their laying period of 60 wk. The live yeast culture used was a product from Saccharomyces cerevisiae that was cultured on the corn-based substrate followed by careful drying of whole material not to lose the viability of yeast. Three levels of yeast culture as 0.5, 1.0, and 2.0% for three treatments and 0% for the control were included in the experimental diets. The feeding trial was carried out for 60 wk from August 26, 1992 to October 26, 1993. To evaluate the performance of layers during cold or hot periods as affected by the yeast culture feeding, data from the 12-wk winter period and 12-wk summer period were separated and analyzed accordingly. During 60 wk of laying period hen-day egg production was slightly but significantly(P<.05) improved by feeding the yeast culture. The average egg weight and daily egg weight(g /day) were also increased by the yeast culture. Feeding the yeast culture did not increase feed intake but feed efficiency was improved significantly (P<.05). No significant difference was detected in egg or eggshell qualities between control and yeast culture-treated groups. Feed intake and egg weight were not affected by the yeast culture feeding under both cold and hot period, but egg production and feed efficiency during hot summer improved significantly by its feeding. This result indicates that the effectiveness of the yeast culture feeding is greater during summer than winter for laying hens.

• 한국유기농업학회지
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• 제12권2호
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• pp.171-181
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• 2004

A study was conducted to investigate the effect of supplementing earthworm meal (EWM) on the performance of spent laying hens after induced molting, and fatty acid composition in egg yolks. A total of 90 laying hens at 73 weeks of age were fed the experimental diets containing 0.0% (Control) and 0.2% of EWM for 4 weeks. Eggs were collected and weighted every day and Egg production and feed conversion were recorded every week during the experimental period. However fatty acid composition of egg yolk were measured at last week of experimental period. An amount of feed intake increased by supplemental with EMW except for Erst week experimental period (P<0.05). When 76 and 77 week of age, egg production and daily egg mass were improved by the supplemented with EWM (P<0.01), but average egg weight was not different when fed a EWM, therefore feed/egg mass was significantly decreased when fed a EWM. The ratio of egg yolk n-6/n-3 fatty acids contents was significantly improved fed a EMW (P<0.05). It is concluded that supplementing 0.2% of earthworm meal in the spent laying hens after induced molting was fast in recover of physical strength, therefore improves laying performance.