• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.929-934
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• 2001

The physiological role of brain somatostatin in the central regulation of feed intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of somatostastin 1-28 (SRIF) at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCI solution were given ad libitum. Feed, water and salt intake were measured during ICV infusion of artificial cerebrospinal fluid (CSF) and SRIF. The feed intake during SRIF infusion on days 2 to 5 increased significantly compared to that during CSF infusion. Water intake, when compared to that during CSF infusion, only increased significantly on day 4. NaCI intake during SRIF infusion was not different from that during CSF infusion. Mean arterial blood pressure (MAP) and heart rate during SRIF infusion were not different from those during CSF infusion. The plasma concentrations of Na, K, Cl, osmolality and total protein during SRIF infusion were also not different from those values during CSF infusion.There are two possible mechanisms, that is, the suppression of brain SRIF on feed suppressing hormones and the direct actions on brain mechanisms controlling feed intake, explaining how SRIF works in the brain to bring about increases in feed intake in sheep fed on hay. The results indicate that brain SRIF increases feed intake in sheep fed on hay.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.366-370
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• 2002

The objective of this study was to examine whether feeding induced hypovolemia (decrease in plasma volume) acts on the regulation of feed intake in goats fed on dry forage. In order to prevent feeding induced hypovolemia, a 2 h intravenous infusion (16-18 ml/min) of isotonic mannitol solution was begun 1 h prior to feeding and continued until 1 h after the start of the 2 h feeding period. The intravenous infusion of isotonic mannitol solution (MI) decreased plasma osmolality by 1.0%, plasma total protein concentration by 4.2% and hematocrit by 5.9%, respectively. In comparison with no infusion (NI), MI significantly decreased thirst level by approximately 13%. At the completion of the 2 h feeding period, cumulative feed intake had been increased by 43% by MI. In conclusion, feeding induced hypovolemia in goats fed on dry forage increased thirst level more than the increase in plasma osmolality did. The results demonstrate that feeding induced hypovolemia is one of the factors controlling feed intake in goats fed on dry forage.

• 한국가금학회지
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• 제42권3호
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• pp.205-214
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• 2015

본 연구는 100주령 이상의 산란성계에서 사료 급이량 조절에 따른 생산성, 도체 수율 및 육질을 주령에 따라 평가하고자 실시하였다. 공시 동물은 100주령 Hy-Line Brown 200수를 선별하여 A형 2단 케이지에 대조구 포함 총 5처리구로 구성하여 처리당 4반복, 반복당 10수씩(2수 수용 케이지 10개) 난괴법으로 임의 배치하였다. 시험 기간 동안 물은 자유 섭취하게 하였으며, 일반적인 점등관리(자연일조 + 조명; 16hr)를 실시하였다. 시험구는 대조구(일일 사료 섭취량 100%), 90%, 60%, 50%, 20% 총 5처리였다. 산란율은 사양 시험 기간 동안 일일 사료 섭취량이 감소함에 따라 산란율 및 사료 요구량은 유의적으로(P<0.05) 감소하였다. 도체 수율 역시 사양시험 기간 동안 일일 사료 섭취량이 감소함에 따라 도체 수율 및 부분육(가슴, 다리, 날개) 비율이 유의적으로(P<0.05) 감소하였다. Leukocyte 함량은 일일 사료 섭취량이 50%, 20%일 때 WBC, HE, LY, MO 및 EO 함량의 비율이 유의적으로(P<0.05) 높았다. 가슴육 내 일반 성분항목, 보수력, 가열감량 및 지방산 함량에 있어서는 사양시험 기간과 일일 사료 섭취량에 따른 유의적인 차이는 나타나지 않았다. 본 실험 결과 일일 사료 섭취량이 감소할수록 생산성과 도체율이 감소하였으나, 일일사료 섭취량을 60% 수준까지 낮춰도 무방하다고 생각되며, 계육 품질에 미치는 영향은 나타나지 않았다.

• Journal of Animal Science and Technology
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• 제44권2호
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• pp.221-232
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• 2002

시험은 사료내 필수아미노산 결핍이 rat의 사료섭취량과 혈액 및 뇌내 전이상엽피질(PPC)의 유리아미노산 농도 변화에 미치는 영향을 조사하여 뇌내 섭식조절 메카니즘을 구명하고자 하였다. 시험에 이용된 모든 사료의 질소원은 순수 아미노산 혼합물을 이용하였으며, 질소수준은 15%로 하였다. 사료는 하루 6시간 동안 섭취하도록 훈련을 시켰으며(17:00-21:00, meal feeding method), 사료섭취량과 증체량은 사료급여 7일째부터 매시간 측정하였다. 실험 1에서 사료섭취량과 증체량을 사료급여 후 매시간 측정하였으며, 혈액 및 PPC의 아미노산 농도는 사료급여 11일째의 0, 1, 2, 3, 6시간 후에 관찰하였다. 실험 2에서는 complete diet에서 11일째에 lysine 결핍사료로 교체하여 사료섭취량, 증체량 및 혈액 및 PPC의 아미노산 농도는 실험 1과 동일하게 측정하였다. 실험 1에서 complete diet 급여에 따른 사료섭취량은 7일째부터 일일섭취량(15g/day)을 충족하였다. 또한 11일째의 혈액 및 뇌의 유리 아미노산 농도는 사료급여 한시간 후에 증가하였으나, 그 후에는 일정한 수준을 유지하였다. 반면, 실험 2에서는 complete diet에서 lysine 결핍사료로 교체함에 따른 사료섭취량은 급격하게 감소하였고(P$<$0.05), 혈액 및 PPC의 유리 lysine 농도는 lysine 결핍사료 급여 2시간 후에 유의적(p$<$0.05)으로 감소하였으며, 누적 사료섭취량은 사료급여 4시간째 유의적으로 감소하였다(p$<$0.05). 따라서 이상의 결과로 보아 아미노산 결핍사료 섭취에 따른 혈액과 PPC의 해당 아미노산의 농도 감소는 사료섭취량의 감소에 비하여 빠르게 반응하였고, 이러한 결과로 미루어 사료중 아미노산 결핍에 반응하는 부위의 일부분으로 뇌내 PPC가 직접적인 관여를 한다고 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.35-40
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• 2001

The physiological role of brain neuropeptide Y (NPY) in the central regulation of grass intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of NPY at a dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCl solution were given ad libitum. Feed intake during ICV NPY infusion increased significantly compared to that during ICV artificial cerebrospinal fluid (CSF) infusion. Water and NaCl intake during ICV NPY infusion remained unchanged. Mean arterial blood pressure (MAP) and plasma osmolality during ICV NPY infusion were not significantly different from those during ICV CSF infusion. On the other hand, plasma glucose concentration during ICV NPY infusion increased significantly compared to that during ICV CSF infusion. The results suggest that brain NPY acts as a hunger factor in brain mechanisms controlling feeding to increase grass intake in sheep.

• Asian-Australasian Journal of Animal Sciences
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• 제17권3호
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• pp.330-336
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• 2004

Six 16 months old Holstein steers were offered ad libitum feed for 7 months, to determine the (1) relationships of backfat thickness (BFT) to plasma leptin, and insulin; and (2) associations of TDN intake/kg body weight (BW) to plasma leptin, BFT and insulin. Feed intake, body weight and BFT were measured on selected monthly ages from day 1 to 8, day 1 and 8, and day 8, respectively. Blood was sampled on day 8 and the plasma was analyzed for leptin, insulin, glucose, NEFA, total cholesterol and triglyceride. Body weight and BFT increased, while TDN intake per kg BW decreased from 16 to 23 months old. Plasma leptin increased and mimicked the level of insulin, resulting to significant correlation (r=0.54; p<0.002). TDN intake was negatively related to plasma leptin (r=0.49; p<0.004), insulin (r=0.41; p<0.02) and BFT at 12 to 13th rib (r=0.48; p<0.005). Backfat thickness at 12 to 13th rib was positively related to plasma leptin (r=0.45; p<0.01). Negative associations of TDN intake with plasma leptin and BFT during finishing period suggest long-term involvement of adipose tissues in the feed intake regulation of steers fed high concentrate diet.

• BMB Reports
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• 제49권3호
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• pp.137-138
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• 2016

Satiety cues a feeding animal to cease further ingestion of food, thus protecting it from excessive energy gain. Impaired control of satiety is often associated with feeding-related disorders such as obesity. In our recent study, we reported the identification of a neural pathway that expresses the myoinhibitory peptide (MIP), critical for satiety responses in Drosophila. Targeted silencing of MIP neuron activity strikingly increased the body weight (BW) through elevated food intake. Similarly, genetic disruption of the gene encoding MIP also elevated feeding and BW. Suppressing the MIP pathway behaviorally transformed the satiated flies to feed similar to the starved ones, with augmented sensitivity to food. Conversely, temporal activation of MIP neuron markedly reduced the food intake and BW, and blunted the sensitivity of the starved flies to food as if they have been satiated. Shortly after termination of MIP neuron activation, the reduced BW reverted to the normal level along with a strong feeding rebound. Together our results reveal the switch-like role of the MIP pathway in feeding regulation by controlling satiety.

• Animal Bioscience
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• 제34권3_spc호
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• pp.443-448
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• 2021

Objective: Astaxanthin is a natural super antioxidant. The present study was carried out to investigate the effect of astaxanthin rich Phaffia rhodozyma (PR) supplementation in diets on laying production performance, egg quality, antioxidant defenses and immune defenses in laying hens. Methods: A total of five hundred and twelve 60-week-old Lohmann Brown laying hens (2,243±12 g) were randomly assigned to four groups, each including 4 replicates with 32 birds per replicate. Astaxanthin rich PR was added to corn-soybean meal diets to produce experimental diets containing 0 (Control), 800 mg/kg, 1,200 mg/kg, and 1,600 mg/kg PR, respectively. The astaxanthin content in the diet was 0.96 mg/kg, 1.44 mg/kg and 1.92 mg/kg respectively. Results: Results showed that dietary PR supplementation tended to increase daily feed intake (p = 0.0512). There was no effect of astaxanthin rich PR on Haugh units, albumen height, egg shape index, eggshell strength, and eggshell thickness at weeks 6 (p>0.05). However, egg yolk color was significantly improved (p<0.05). In addition, astaxanthin rich PR supplementation significantly increased serum glutathione peroxidase and superoxide dismutase activity (p<0.05), increased serum immunoglobulin G content (p<0.05), and reduced malondialdehyde content (p<0.05) in laying hens. Conclusion: In conclusion, astaxanthin rich PR can improve the color of egg yolk, enhance the antioxidant defenses, and regulate the immune function.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.593-600
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• 2006

The effects of breed and sex on individual growth performance and feeding behaviour were studied between 45 and 90 kg BW in two replicates of forty group-housed pigs. The first and the second replicates were carried out during the warm season (i.e. between February and April 2003) and during the hot season (i.e. between August and October 2003), respectively. During the warm season, ambient temperature and relative humidity averaged $25.3^{\circ}C$ and 86.0%. The corresponding values for the hot season were $27.9^{\circ}C$ and 83.6%. The pigs were grouped in pens of 10 animals on the basis of breed (Creole or Large White) and sex (gilt or castrated male) and given ad libitum access to a grower diet (9.0 MJ/kg net energy and 158 g/kg crude protein) via feed intake recording equipment (Acema 48). An ear-tag transponder was inserted into each pig and this allowed the time, duration, and size of individual visits to be recorded. The growth performance and feeding pattern were significantly affected by breed, sex, and season. The Creole pigs (CR) had a lower average daily gain (ADG) (642 vs. 861 g/d, p<0.01) and carcass lean content ($LC_{90kg}$) (35.4 vs. 54.5%; p<0.01) and a higher backfat thickness at 90 kg BW ($BT_{90kg}$) (23.4 vs. 10.4 mm; p<0.01) than Large White pigs (LW) whereas the average daily feed intake (ADFI) was not affected by breed (2.34 vs. 2.22 kg/d, respectively for CR and LW pigs; p>0.10). Consequently, the food:gain ratio was higher in CR than in LW (3.65 vs. 2.58; p<0.01). CR had less frequent meals but ate more feed per meal than LW (5.9 vs. 8.8 meals/d and 431 vs. 279 g/meal; p<0.01). The rate of feed intake was lower (27.6 vs. 33.9 g/min; p<0.01) and the ingestion time per day and per meal were higher in CR than in LW (87.1 vs. 69.7 min/d and 15.8 vs. 8.4 min/meal; p<0.01). The ADFI and BT90 kg were higher (2.38 vs. 2.17 kg/d and 18.1 vs. 15.9 mm; p<0.05) and LC90 kg was lower (43.5 vs. 46.4%; p<0.01) in castrated males (CM) than in gilts (G) whereas ADG was not affected by sex (p = 0.12). The difference in lean content between CM and G was greater in CR than in LW. The ADFI and ADG were reduced during the hot season (2.18 vs.2.38 kg/d and 726 vs. 777 g/d, respectively; p<0.05) whereas feed conversion and carcass lean content were not affected by season (p>0.05). Average feeding time per meal and meal size decreased during the hot season (10.9 vs. 13.2 min/meal and 316 vs. 396 g/meal; p<0.01) whereas the rate of feed intake was not affected by season (p = 0.83). On average, 0.69 of total feed intake was consumed during the diurnal period. However, this partition of feed intake was significantly affected by breed, sex, and season. In conclusion, the breed, sex and season significantly affect performance and feeding pattern in growing pigs raised in a tropical climate. Moreover, the results obtained in the present study suggest that differences observed in BW composition between CR and LW are associated with difference in feeding behaviour, in particular, the short-term regulation of feed intake.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.727-738
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• 2002

본 시험은 각각의 필수아미노산 결핍사료 섭취에 의한 단기간의 섭식반응과 methionine 결핍(-Met) 사료 섭취시 뇌내 각 부위에 나타나는 Fos 면역반응을 조사하여 아미노산 결핍이 뇌내 섭식반응과 관련있는 부위를 명확히 알고자 수행하였다. 실험사료의 단백질원은 정제아미노산을 이용하였다. 시험에 이용된 모든 사료의 질소원은 순수 아미노산 혼합물을 이용하였으며, 사료내 단백질 함량은 15%로 하였다. 사료는 하루 6시간 동안 섭취하도록 적응을 시켰으며(17:00${\sim}$21:00, meal feeding method), 사료섭취량과 증체량은 사료급여 7일째부터 매시간 측정하였다. 실험 1에서는 각 필수아미노산 결핍사료가 사료섭취량, 체중 변화 및 섭식패턴에 미치는 영향을 관찰하였고, 실험 2에서는 Fos 면역조직 화학적 방법을 사용하여 methio- nine 결핍사료에 대하여 회피 반응을 나타내는 동안에 활성을 보이는 뇌의 영역을 확인하였다. 각 필수아미노산 결핍사료 섭취에 따른 초기 섭식 억제 정도는 methionine이 가장 강하게 나타난 반면 threonine이 가장 약하였다. 결핍사료 급여 3일째의 사료섭취량은 대조구 사료에 비하여 histidine(71%), leucine(68%), isoleucine (66%), threonine(63%), tryptophan(61%), valine (55%), phenylalanine(52%), methionine(51%), lysine(44%), arginine(24%) 순으로 억제되었다. 뇌 신경 영역에 Fos 면역활성은 PPC, amygdala 및 endopyriform cortex(EPC) 부분이 대조구에 비하여 강한 활성을 나타냈으나, LH, VMH 및 PVM에서는 대조구와 처리구가 비슷하게 나타냈다. 따라서 본 연구의 결과로 미루어 뇌내 PPC는 필수아미노산 결핍에 반응하는 초기 인식부위라는 것을 확인할 수 있었다.