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《The Journal of Applied Poultry Research》2016,25(4):571-580
Two experiments were conducted to ascertain digestible Thr to Lys ratio of male broilers from 21 to 35 d of age (experiment 1) and 35 to 49 d of age (experiment 2) based on growth performance and processing yields. In both experiments, 2 diets (dilution and summit; 3,108 kcal ME/kg and 18.2% CP in experiment 1; 3,163 kcal ME/kg and 17.2% CP in experiment 2) consisting of corn, soybean meal, poultry by-product meal, and peanut meal formulated to be surfeit in limiting amino acids with exception of digestible Lys and Thr were mixed at various proportions to create 8 titration dose-response diets. Digestible Lys was formulated to contain 95% of the requirements from 21 to 35 and 35 to 49 d of age. In each experiment, gradient treatment structure was arranged in a randomized complete block design. Calculated digestible Thr to Lys ratios ranged from 0.512 to 0.806 in approximately increments of 0.040 (1,600 Hubbard × Cobb 500 broilers; experiment 1) and 0.552 to 0.793 in approximately increments of 0.035 (3,000 Ross × Ross 708 broilers; experiment 2). In experiment 1, digestible Thr to Lys ratio for male Hubbard × Cobb 500 broilers was estimated at 0.68 and 0.67 for BW gain and feed conversion from 21 to 35 d of age. In experiment 2, digestible Thr to Lys ratio of Ross × Ross 708 was determined at 0.68 and 0.63 for feed conversion ratio with quadratic and linear broken-line models, respectively. Meat weights and yields were not affected by the dietary treatments in either experiment. These data indicate that a digestible Thr to Lys ratio of 0.68 can optimize growth performance of broilers from 21 to 35 and 35 to 49 d of age. 相似文献
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Matthew S Crouse Kyle J McLean Josephine Dwamena Tammi L Neville Ana Clara B Menezes Alison K Ward Lawrence P Reynolds Carl R Dahlen Bryan W Neville Pawel P Borowicz Joel S Caton 《Journal of animal science》2021,99(1)
We hypothesized that maternal nutrition during the first 50 d of gestation would influence the abundance of hexose transporters, SLC2A1, SLC2A3, and SLC2A5, and cationic amino acid transporters, SLC7A1 and SLC7A2, in heifer uteroplacental tissues. Angus-cross heifers (n = 43) were estrus synchronized, bred via artificial insemination, and assigned at breeding to 1 of 2 dietary intake groups (CON = 100% of requirements to achieve 0.45 kg/d of BW gain or RES = 60% of CON intake) and ovariohysterectomized on day 16, 34, or 50 of gestation (n = 6 to 9/d) in a completely randomized design with a 2 × 3 factorial arrangement of treatments. Uterine cross-sections were collected from the horn ipsilateral to the corpus luteum, fixed in 10% neutral buffered formalin, sectioned at 5 µm, and stained via immunofluorescence for transporters. For each image, areas of fetal membrane (FM; chorioallantois), luminal epithelium (ENDO), superficial glands (SG), deep glands (DG), and myometrium (MYO) were analyzed separately for relative intensity of fluorescence as an indicator of transporter abundance. Analysis of FM was only conducted for days 34 and 50. No transporters in target areas were influenced by a day × treatment interaction (P ≥ 0.06). In ENDO, all transporters were differentially abundant from days 16 to 50 of gestation (P ≤ 0.04), and SLC7A2 was greater (P = 0.05) for RES vs. CON. In SG, SLC7A1 and SLC7A2 were greater (P ≤ 0.04) at day 34 vs. day 16. In DG, SLC2A3 and SLC7A1 were greater (P ≤ 0.05) for CON vs. RES heifers; furthermore, SLC7A1 was greater (P < 0.01) at day 50 vs. days 16 and 34 of gestation. In MYO, SLC7A1 was greater (P < 0.01) for CON vs. RES and was greater (P = 0.02) at days 34 and 50 vs. day 16. There were no differences in FM (P ≥ 0.06). Analysis of all uterine tissues at day 16 determined that SLC2A1, SLC2A3, and SLC7A2 were all differentially abundant across uterine tissue type (P < 0.01), and SLC7A1 was greater (P = 0.02) for CON vs. RES. Analysis of all uteroplacental tissues at days 34 and 50 demonstrated that all transporters differed (P < 0.01) across uteroplacental tissues, and SLC7A1 was greater (P < 0.01) for CON vs. RES. These data are interpreted to imply that transporters are differentially affected by day of gestation, and that hexose and cationic amino acid transporters are differentially abundant across utero-placental tissue types, and that SLC7A1 is responsive to maternal nutritional treatment. 相似文献
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《The Journal of Applied Poultry Research》2009,18(2):338-347
Physiological stress is one of many concerns facing the modern broiler producer. Research has yet to reveal mechanisms that would allow the producer to efficiently minimize the detrimental impacts of physiological stress on broiler performance. One possible approach for improvement in this area is to elucidate the effects of different nutrient regimens on stressed broilers. Sufficient prior knowledge of the effects of stress on metabolism and nutrient digestibility, as well as effective stress induction models, is essential to any researcher interested in delineating the effects of nutrients on stressed broilers. This review examines the physiological mechanisms that activate and control stress, as well as the effects of stress on immunity, metabolism, and broiler performance. Validation procedures for stress induction models are also examined. Additionally, this review examines available research focused on amino acid digest-libility in the presence of stress, digestibility assays necessary for this research, and nutrients that have been shown to have the potential for stress reduction or amelioration. 相似文献
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《The Journal of Applied Poultry Research》2009,18(2):244-251
The detrimental effects of physiological stress on broilers are well documented. However, little research exists to delineate the effects of different nutritional regimens on the stress response in broilers. Hence, an experiment was conducted to examine the effects of sucrose and supplemental water electrolytes on Ross 308 male broilers during corticosterone-induced stress, as well as the particle grind size during poststress recovery. Feeding broilers supplemental water electrolytes during corticosterone-induced stress resulted in improved live performance. Feeding water sucrose to stressed broilers did not result in live performance improvements during the stress period. However, broilers fed water-sucrose or water-electrolyte treatments during the stress period had improved feed conversion during stress recovery. Feeding broilers a diet with increased particle size during stress recovery had no effect on live performance. Carcass measurements were not affected by any treatment. Water-electrolyte or water-sucrose supplements appear to have some potential as stress amelioration agents and thus should be researched more thoroughly. 相似文献
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Xiaolong Hu Lei Wan Shuibing Liu Biao Chen Wen Li Chonghua Wu Ting Xiong Suwang Xi Huirong Mao Sanfeng Liu 《Animal Science Journal》2021,92(1):e13638
The aim of this study was to compare the meat quality and evaluate the chemical composition of Chinese Ningdu yellow chicken of different weights once they have reached market age. Thirty hens at the day of age 118 were selected and divided into three groups according to their weight: light weight (1288.00 ± 69.78 g, n = 10), medium weight (1407.17 ± 39.40 g, n = 10), heavy weight (1581.6 ± 46.59 g, n = 10), and the differences in weight among these three groups are significant. Biochemical, histological, and metabonomic approaches were used to obtain index values of meat quality and chemical composition. Compared with meat from lighter chickens, muscle fiber density was significantly lower in heavier chickens, and meat pH was positively correlated with chicken weight. Though the amount of all measured amino acids were not different among three weight groups of chicken, the levels of several kinds of fatty acids exhibited significant differences or correlations, including linolenic acid, arachidonic acid, myristic acid, oleic acid, and docosahexaenoic acid (DHA). These results contribute to help customers choose the optimal chicken weight depending upon the food to be cooked. 相似文献
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小麦戊聚糖对肉仔鸡内源氮及氨基酸分泌的影响 总被引：5，自引：0，他引：5
本试验采用酶解酪蛋白和超滤的方法研究小麦麸皮水提取戊聚糖(WEP)和碱提取戊聚糖A(EP)对肉仔鸡内源氮及氨基酸分泌的影响。60只35日龄肉仔鸡随机分成3组,对应3种日粮处理,分别是纯合日粮对照组,纯合日粮添加4%WEP或4%AEP试验组。结果表明,与对照组纯合日粮相比,添加W EP和AEP肉仔鸡内源氮的分泌量分别增加8%和13%P(>0.05),同时,显著增加了肉仔鸡内源氨基酸的分泌(P<0.05),其中AEP对促进内源氮和氨基酸分泌的作用更大。添加AEP比添加WEP肉仔鸡内源氨基酸分泌量提高26%(P>0.05),是对照组纯合日粮分泌量的3.42倍(P<0.05),添加W EP的氨基酸分泌量是对照组的2.71倍(P<0.05)。说明小麦戊聚糖能够作用于肉仔鸡肠壁从而增加其内源氮和氨基酸分泌。 相似文献
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《The Journal of Applied Poultry Research》2015,24(3):304-315
A study was conducted to evaluate field performance and economic impacts of feeding diets varying in AME and amino acid (AA) densities to Cobb 500 female broiler grillers (eviscerated carcass averaging 1.0 kg). Corn–soy diets were fed to birds in a factorial arrangement of 3 AME (low, moderate, and high) by 3 AA densities (low, moderate, and high). Differences in AA and AME average values were of 10 and 1.5%, respectively. Treatments had 8 replications of 40 birds allocated in floor pens. Live performance was significantly improved in parallel with increases in AME and AA; however, carcass yield increased and abdominal fat was reduced only when AA was increased (P < 0.05). Gross margins (GM) for each treatment were calculated using scenarios of high and low market costs for corn, soybean meal, as well as for carcass prices. Costs were classified as variable [costs of feeding (CF), fixed farm costs (FFC), and fixed processing costs (FPC)] and their behavior in response to nutritional density was studied. All cost components, (CF, FFC, and FPC) decreased as AME increased, which resulted in the lowest total costs (TC) for the highest AME diets in all scenarios tested, as well as the greatest GM for those dietary programs. In contrast to AME, cost components moved in opposite directions in response to AA density whereby, in 4 out of 7 scenarios, optimizing CF did not result in greater GM. The present study was conducted with low-weight carcasses and, therefore, conclusions made from the presented data are restricted to this type of product. It is concluded that when broiler grillers are objects of study, the use of CF as the sole criteria to choose an optimal feeding program, without considering significant fixed costs present along the production and meat processing chains, tends to underestimate the economic potential of increasing nutrient density. 相似文献
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The consumption of poultry meats exceeds 50% of total meat consumption. With the outbreak of bovine spongiform encephalopathy and foot and mouth disease, the consumption of poultry meat is set to increase. The use of meat bone meal derived from cattle and pigs is prohibited. Therefore, plant protein has to be used more frequently and the importance of the study of amino acid nutrition is increasing. In order to improve dietary efficiency, it is necessary to elucidate the exact amino acid requirements of poultry. The amino acid requirements are not constant and are affected by various factors. By using the plasma amino acid concentration as a parameter, it is possible to predict the amino acid requirements within a short period using a small number of animals repeatedly. By satisfying the amino acid requirements through supplementing crystalline amino acids, it is possible to reduce dietary protein and excretory nitrogen simultaneously. However, when the dietary protein is reduced, the abdominal fat tends to increase. This is solved by deciding the optimum dietary protein level, but it is difficult to control the taste of poultry meat by dietary amino acids. 相似文献