• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.2031-2038
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• 2020

Objective: This study aimed to determine the effect of intermittent feeding and cold water on performance and carcass traits in broiler chickens between 4 to 6 wk of age exposed to daily high temperature. Methods: Broilers were assigned to four treatment groups according to a 2×2 factorial design between 22 to 42 d of age (80 broilers per treatment, 4 replications). Broilers were divided into two main groups as feeding type (ad-libitum [AL] and intermittent [IF] for 6 h daily) and sub-groups as water temperature (normal [NW], 24.9℃ and cold [CW], 16.4℃). Heat treatment was applied between 11.00 to 17.00 h daily between 22 to 42 d of age. Results: Live weight at 6th wk was not affected by feeding type and water temperature, but the live weight was significantly higher in IF chickens at the 5th wk (p<0.05). Average weekly gain of IF broiler chickens were higher compared to AL group at 4, 5, and 6 wk of age (p< 0.05). Although feeding type did not affect feed intake in 4 and 5th wk, feed intake was higher in IF chickens at 6th wk (p<0.01). In addition, feeding type and water temperature did not affect feed conversion ratio and interactions were not significant (p>0.05). Water temperature had no significant effect on heart, liver, gizzard, and abdominal fat percentages (p>0.05). Conclusion: It is concluded that IF increased the average weekly gain in chickens reared under daily heat stress for 6 h between 22 to 42 d of age. IF in hot environmental conditions slightly increased performance without adversely affecting health, welfare, and physiological traits, whereas CW implementation had no significant effect on performance. It can also be said that IF suppresses a sudden increase in body temperature depending on age and live weight.

• 한국가금학회지
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• 제43권3호
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• pp.169-176
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• 2016

An experiment was conducted to evaluate the growth performance and meat quality traits of broilers fed a diet supplemented with dry-ground curry leaves (Murraya koenigii). A total of 750 one-day-old broiler chicks (Cobbs 500) were arranged in the experiment with a completely randomized design and allotted to one of five treatments, with $T_1-Control$ and $T_2-T_5$ curry leaves powder levels (i.e., 0.3%, 0.6%, 0.9% and 1.2%, respectively). The initial body weights, final body weights and daily feed intake were measured over an experimental period of 32 days. At the conclusion of the experiment, the carcass weights and meat quality parameters were measured. The birds fed diets supplemented with curry leaves powder had a higher weight gain (P<0.05; ADG), improved feed conversion ratio (P<0.05; FCR) and lower mortality (P<0.05) rates compared to the birds in the control group. Nonetheless, there was no difference (P>0.05) in feed intake among the dietary treatments. Similarly, supplementation of curry leaves powder had no effect (P>0.05) on the proportions of the carcass, leg meat and drumstick. No differences were (P>0.05) observed in cooking loss or the pH of meat from broilers fed the curry leaves supplemented diet. However, curry leaf supplementation affected (P<0.05) the meat water holding capacity. A sensory evaluation showed higher levels of taste and tenderness in meat from broilers fed with curry leaves powder. In conclusion, our results suggested that curry leaves powder improved the growth performance of broilers, with a lower incidence of mortality and improvement of some meat qualities.

• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.103-112
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• 1994

This study was a sequential experiment consisting if feeding trial and in vitro culture studies. Feeding was conducted by $2{\times}2{\times}2$ factorial design with two cimaterol levels (0, 0.25 mg/kg), two energy levels (3,200, 2,900 ME kcal/kg) and two sexes. In starting period (0-21 days) broilers were fed diets containing two energy level without dietary supplementation of cimaterol. During finishing period (21-42 days) cimaterol groups were fed cimaterol supplemented diets. In vitro cultures were carried out to study the cellular metabolism of protein and fat in liver and adipose tissues prepared from chicks used in feeding trials. Body weight gain was significantly improved by the administration of cimaterol to experimental diets by 2.4% (p < 0.05). Feed intake was reduced by cimaterol administration at the high energy level, but this trend was reversed at low energy level. Feed efficiency was improved by cimaterol administration and at high energy level the difference (5.7%) was significant(p < 0.05). The administration of cimaterol had no effects on percentage of abdominal fat content, giblet and neck. There was little difference in carcass yield between control and cimaterol treated group. The administration of cimaterol had no effects on nutrient metabolizability or carcass composition. The results of in vitro studies with liver tissues showed that cimaterol increased the lipolytic activities (p < 0.05) and decreased lipogenic activities (p < 0.05). In in vitro studies with acinar cell of liver tissues. cimaterol increased the amount of retained protein and decreased secreted protein at high energy level. but the trend was opposite at low energy level.

• Asian-Australasian Journal of Animal Sciences
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• 제28권12호
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• pp.1686-1695
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• 2015

Molecular marker selection has been an acceptable tool in the acceleration of the genetic response of desired traits to improve production performance in chickens. The crossbreds from commercial parent stock (PS) broilers with four Thai synthetic breeds; Kaen Thong (KT), Khai Mook Esarn (KM), Soi Nin (SN), and Soi Pet (SP) were used to study the association among chicken growth hormones (cGH) and the insulin-like growth factor (IGF-I) genes for growth and carcass traits; for the purpose of developing a suitable terminal breeding program for Thai broilers. A total of 408 chickens of four Thai broiler lines were genotyped, using polymerase chain reaction-restriction fragment length polymorphism methods. The cGH gene was significantly associated with body weight at hatching; at 4, 6, 8, 10 weeks of age and with average daily gain (ADG); during 2 to 4, 4 to 6, 0 to 6, 0 to 8, and 0 to 10 weeks of age in $PS{\times}KM$ chickens. For $PS{\times}KT$ populations, cGH gene showed significant association with body weight at hatching, and ADG; during 8 to 10 weeks of age. The single nucleotide polymorphism variant confirmed that allele G has positive effects for body weight and ADG. Within carcass traits, cGH revealed a tentative association within the dressing percentage. For the IGF-I gene polymorphism, there were significant associations with body weight at hatching; at 2, 4, and 6 weeks of age and ADG; during 0 to 2, 4 to 6, and 0 to 6 weeks of age; in all of four Thai broiler populations. There were tentative associations of the IGF-I gene within the percentages of breast muscles and wings. Thus, cGH gene may be used as a candidate gene, to improve growth traits of Thai broilers.

• 한국축산식품학회지
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• 제40권3호
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• pp.338-349
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• 2020

The effects of organic Zn-L-selenomethionine (Zn-L-SeMet) at 0.3 ppm on carcass composition, meat characteristics, fatty acid composition, glutathione peroxidase activity, and ribonucleotide content were compared against the commercial inorganic sodium selenite (Na-Se) and the combination of the two, in commercial broilers. A total of 540 one day-old chicks were assigned at random to 3 dietary treatments : i) commercial inorganic selenium as control or T1, ii) a 1:1 ratio of inorganic and organic selenium as T2, and iii) organic selenium as T3. Carcass composition, meat characteristics, cholesterol content, fatty acid composition, and ribonucleotide content were generally unaffected by treatments. However, discrepancy were significantly observed in glutathione peroxidase activity (GSH-Px) and water holding capacity, with organic selenium showing higher glutathione peroxidase activity (p<0.01) and lower shrinkage loss (p<0.05), respectively. These findings could be explained by the contribution of organic selenium in bioavailability of GSH-Px. However, having conducted in a commercial close house system with sufficient amount of nutritional supplementation, the present study demonstrated little or no effects of organic Zn-L-SeMet on meat characteristics, fatty acid composition, and ribonucleotide content (flavor characteristic) in broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.416-422
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• 2013

This experiment was conducted to evaluate the effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and fatty acid composition of breast and drumstick meat in broiler chickens. A total of 480 broilers were randomly allotted into three dietary treatments, including T (basal diet, 5% tallow), O1 (2% olive oil+3% tallow), and O2 (5% olive oil). During d 0 to 21, broilers fed the diet supplemented with 5% olive oil showed lower (p<0.05) body weight gain (BWG) and feed intake (FI) compared with those fed the T diet. Serum triglyceride concentration was reduced (p<0.05), while high density lipoprotein (HDL)-cholesterol concentration was increased (p<0.05) in the O2 treatment group compared with the T and O1 treatment groups. The addition of olive oil to the diets induced a reduction (p<0.05) in the total saturated fatty acid (SFA) contents in breast and drumstick meat, and increased (p<0.05) the total unsaturated fatty acid (USFA) contents and USFA/SFA ratios. In conclusion, a diet with 5% olive oil could decrease BWG and FI of broilers during the starter period (wk 0 to 3), and cause an increase in the serum HDL-cholesterol level, while decreasing the serum triglyceride concentration. Furthermore, USFA level and USFA/SFA ratios in breast and drumstick meat were increased by dietary supplementation of 2 or 5% olive oil.

• Animal Bioscience
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• 제34권7호
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• pp.1243-1252
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• 2021

Objective: An experiment was conducted to investigate the continuous and intermittent lighting program effects on terms of the productive performance, carcass traits, blood biochemical parameters, innate immune and oxidative status in broiler chicks. Methods: A total of 600 Cobb-500 one day old chicks were randomly allocated into six equal groups (100 chicks per treated group with five replicates of 20 chicks each) based on lighting program; 22 continuous lighting (22 C), 11 h lighting+1 darkness twice daily (11 L/1 D), 20 h continuous lighting (20 C), 5 h lighting+1 darkness four times daily (5 L/1 D), 18 h continuous lighting (18 C) and the final group subjected for 3 h lighting+1 h darkness six times daily (3 L/1 D). The experimental period lasted 42 days. Results: Compared with those under the intermittent light program, broiler chicks exposed to continuous lighting for 22 h had significant improvement in live body weight and carcass (dressing and breast percentage) measured traits. Though reducing lighting hours significantly reduced feed intake and feed conversion ratio values. Different lighting programs revealed no significant effect on all blood biochemical parameters. Oxidative stress and innate immunity parameters significantly enhance by reducing lighting hours (3L/1D). Conclusion: The findings suggest that reducing lighting hours up to 3L/1D would be more useful in enhancing feed efficiency, innate immunity, and oxidative status compared with continuous lighting programs on broilers.

• 한국축산식품학회지
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• 제31권2호
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• pp.207-214
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• 2011

The influence of supplementing diets with various levels of organic zinc (OZ) on the performance, meat quality attributes, and sensory properties of broiler chickens was investigated. A total of 3,200 1-d-old female broiler chicks were randomly allotted to 16 floor pens (replicates) with 200 birds per pen. A corn-wheat-soybean meal basal diet (control) was formulated and 20 ppm OZ (20 OZ), 40 ppm OZ (40 OZ), or 80 ppm OZ (80 OZ) was added to the basal diet to form four dietary treatments with four replicates per treatment. Live performance of broiler chickens, meat quality, and sensory properties were evaluated. The results showed no significant difference among the treatments for live performance of broiler chickens. Significant increases (p<0.05) in thigh skin epidermis and dermis thickness were shown in the OZ supplementation groups; however, no effect of OZ on the thickness of back skin epidermis or dermis was found. Dietary OZ levels did not affect the pH of breast and thigh meat or the water holding capacity (WHC) of thigh meat, but the WHC of breast meat increased significantly (p<0.05) when birds were fed 40 OZ and 80 OZ. Results of a sensory analysis showed no differences among the dietary treatments. In conclusion, dietary OZ did not affect live performance or sensory properties of broiler chickens but did increase the WHC of breast meat and thickness of skin layers; thus, improving carcass quality in broiler chickens.

• 생명과학회지
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• 제21권11호
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• pp.1541-1548
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• 2011

본 연구는 파리번데기 동충하초(Cordyceps with fly pupa, CFP)의 급여가 브로일러의 성장능력에 미치는 영향을 조사하기 위하여 수행하였다. 부화 1일령 육계(Ross 308) 400수를 이용하여 4개의 처리구로 완전임의배치 한 후 35일 동안 사육하였다. 처리구는 T1 (CFP를 첨가하지 않은 무첨가 대조구), T2 (CFP 2.0% 첨가구), T3 (CFP 3.5% 첨가구) 및 T4 (CFP 5.0% 첨가구)로 구분하였다. 시험 전 기간 동안 브로일러의 증체량 및 사료효율은 T3가 유의하게 가장 높았으나(p<0.05) T1과 T2, T4 사이의 통계적인 유의차는 나타나지 않았다. 혈액 중성지방, 총 콜레스테롤 및 LDL.C 함량은 CFP 첨가구가 대조구에 비해서 유의하게 낮았다(p<0.05). 혈액 지질의 감소율 범위는 대조구와 비교할 때 CFP 첨가구에서 중성지방 5.32-10.63%, 총콜레스테롤 9.23-12.62%, LDL.C 44.67-53.81%로 나타났다. 복강지방 무게비율은 CFP 첨가구가 대조구와 비교할 때 유의하게 감소하였으며(p<0.05) 복강지방의 감소율 범위는 17.67-21.68%로 나타났다. 브로일러의 도체중, 도체율 및 도체중에 대한 가슴살과 피부를 포함한 다리살의 무게는 T3가 유의하게 가장 높았으며 T1과 T2, T4 사이의 통계적인 유의차가 인정되었다(p<0.05). 장 내 유해균인 E. coli, Salmonella는 CFP 첨가구가 대조구에 비해서 낮았으나 유익한 균인 Bifidobacteria는 CFP 첨가구가 대조구에 비해서 유의하게 높았다(p<0.05). 본 결과는 파리번데기 동충하초가 브로일러의 증체량 및 도체특성을 개선시킬 수 있음을 시사해준다.

• 한국가금학회지
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• 제40권1호
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• pp.41-47
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• 2013

본 시험은 세 가지 다른 사육 밀도가 대형 육계 암컷의 생산성과 도체 수율에 미치는 영향을 조사하기 위해 수행하였다. 처리구는 사육 밀도에 따라 T1(10.9 수/$m^2$), T2(12.4 수/$m^2$) 및 T3(13.9 수/$m^2$)로 하였다. 공시계는 1일령 Arbor Acre종 육계 암컷 492수를 선별하여 처리구당 4반복씩, 반복당 각각 36, 41 및 46수씩 나누어 완전임의 배치하였으며, 육계 초기(0~1주), 전기(1~3주) 및 후기(3~6주)로 나누어 총 6주 동안 사양시험을 실시하였다. 조사 항목으로 생존율, 체중, 증체량, 사료 섭취량, 사료 요구율, 생산지수, 도체 수율 그리고 부분육 비율(날개, 다리, 가슴, 등, 목)을 조사하였다. 6주 동안의 육성률은 세 처리구 모두 90% 이상으로 높게 나타났으며, 처리구 간 차이가 없었다. 육계의 체중은 3주령, 증체량, 사료 섭취량 및 사료 요구율은 2~3주령에 T3 처리구에서 가장 낮았으며(P<0.05), T1과 T2 처리구 사이에 서는 유의차가 없었다(P>0.05). T1, T2 및 T3 처리구의 생산지수는 각각 331.0, 340.8, 336.0으로 처리구 사이에 유의적인 차이는 발견되지 않았다. 4주령 육계의 도체 수율과 대부분의 부분육(날개, 가슴, 등, 목) 비율은 처리구 간 차이가 없었으나, 다리 부위의 비율은 T2에서 가장 높았다(P<0.05). 5주령 육계의 도체 수율은 T1처리구에서 76.2%로 가장 높았으나(P<0.05), 부분육 비율은 처리구 간 유의차가 없었다. 6주령 육계의 도체 수율과 부분육 비율은 처리구 간 차이가 없었다. 본 시험은 대형 육계 암컷을 위한 다양한 사육 밀도를 기초자료로 제공하였으며, 추가적인 연구가 필요하다고 사료된다.