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1.
Hendriks WH Sritharan K Hodgkinson SM 《Journal of animal physiology and animal nutrition》2002,86(9-10):333-341
The aim of the study was to determine and compare the endogenous ileal excretions of nitrogen and amino acids under protein-free and peptide alimentation by the dog and rat. Two diets were prepared, one that was devoid of protein and the other containing 23% enzyme hydrolysed casein. Chromic oxide was included in the diets as an indigestible marker. A total of 10 mixed breed dogs were fed hourly either a protein-free or enzymatically hydrolysed casein diet for a total of 10 days. A faecal sample was obtained from each dog on day 9 while digesta was obtained from the terminal 20 cm of the ileum directly after euthanasia on day 10. A total of 12 8-week-old Sprague-Dawley rats received the same diets as the dogs. A faecal sample from each rat was obtained on day 7 while ileal digesta samples were obtained on day 8. The endogenous ileal excretions of most amino acids were greater in the dogs and rats that received the enzymatically hydrolysed casein diet compared with those receiving the protein free diet. Whereas the pattern of endogenous amino acid excretion was similar in the rats and dogs, the dogs excreted a significantly greater amount of nitrogen (1.91 vs. 2.27 and 1.63 vs. 4.12 g/kg dry matter intake for the protein-free and peptide alimentation method, respectively) and all amino acids except for glycine, isoleucine and leucine. Endogenous ileal amino acid excretions are higher in dogs compared to omnivorous animals such as rats and pigs but similar to the carnivorous cat. 相似文献
2.
1. Maize, wheat and barley meals, and a protein-free diet were each force-fed to 24 intact and 24 caecectomised adult cockerels. For each test, birds were starved of solid food for 48 h, fed, and then excreta collected for 48 h. 2. Quantities of nitrogen (N) and amino acids excreted after feeding the protein-free diet did not differ between intact and caecectomised birds. 3. True digestibility coefficients of N and amino acids did not differ between intact and caecectomised birds. 4. Differences between cereals in apparent digestibility of amino acids were inconsistent and more readily attributed to differences between amino acid intake than bioavailability. 5. Differences between cereals in true digestibility of amino acids were confined to higher values for N, aspartic acid, alanine and leucine in maize than in barley or wheat meals. 相似文献
3.
去盲肠鸡和未去盲肠鸡测定大豆粕、棉仁粕、菜籽粕氨基酸消化率的研究 总被引：3，自引：0，他引：3
分别用２４只去盲肠和未去盲肠健康公鸡，测定了豆粕、棉仁粕和菜籽粕的氨基酸消化率。试验结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ＜０．０５）；在大豆粕中，胱氨酸、苏氨酸等５种氨基酸的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）；在棉仁粕和菜籽粕中，除个别氨基酸外，大多数氨基酸及氨基酸总和的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５），可见，饲料种类、试鸡有无盲肠均影响饲料ＡＡＡＤ和ＴＡＡＤ。盲肠微生物对内源及饲料中未消化蛋白质、多肽及氨基酸具有分解作用，干扰饲料ＡＡＡＤ和ＴＡＡＤ测定。对于不易消化，氨基酸含量相对不平衡的低品质蛋白质饲料干扰尤其严重。因此用去盲肠公鸡测定的饲料ＡＡＤ值更接近氨基酸在消化道内消化吸收的真实情况。 相似文献
4.
Fumaric and sorbic acid as additives in broiler feed 总被引：2，自引：0，他引：2
Pirgozliev V Murphy TC Owens B George J McCann ME 《Research in veterinary science》2008,84(3):387-394
The aim of the experiment was to study the effect of dietary organic acids, fumaric and sorbic, on nitrogen corrected apparent metabolisable energy (AME(N)), metabolisability of nutrients, endogenous losses and performance on young broiler chickens. A total of 56 male Ross broilers were used in a growing experiment from 14 to 30d age. Seven experimental wheat-based (655g/kg) diets were formulated. The control diet did not contain organic acids. The other six diets were produced with the addition of fumaric or sorbic acids, replacing 0.5% , 1.0% or 1.5% of the wheat. The organic acid supplemented diets contained higher levels of AME(N) compared to the control diet. Overall, birds offered organic acids had lower feed intake. Dietary organic acids did not significantly affect weight gain or feed efficiency, however, birds offered supplemented diets had lower numbers of Lactic acid bacteria and Coliforms in the ileum and caeca. Birds offered organic acids had lower levels of endogenous losses compared to control fed birds. There was a negative relationship between AME(N) of the diets and excreted endogenous losses, measured as sialic acid. It can be concluded that the decrease in secretions from the gastrointestinal tract in the presence of fumaric and sorbic acids may be a mechanism involved in the mode of action of dietary organic acids. 相似文献
5.
J Bartelt Anke Jadamus Frigga Wiese Ewa Swiech Lucyna Buraczewska O Simon 《Archives of Animal Nutrition》2002,56(2):93-107
Sixteen male growing pigs of about 24 kg BW were fitted with both a duodenal re-entrant and a post-valve T-shaped cannula inserted in the caecum. The animals were divided into four groups. Each group received one of the following diets: corn starch-soybean protein isolate-based diet without (diet C) and with carboxymethylcellulose (diet CMC) or a rye-wheat-based diet without (diet RW) and with xylanase addition (diet RWX). The diets provided similar levels of apparent precaecal digestible crude protein (CP), lysine, methionine + cystine, threonine and tryptophan. Additionally, [15N]-yeast was given with the diets during the first 10 days of the experiment. For estimation of digesta viscosity, N-flow of dietary and endogenous origin, apparent precaecal digestibilities of dry matter (DM), CP, amino acids and non starch polysaccharides (NSP) (only in pigs fed diets RW and RWX), ileal and duodenal digesta were quantitatively collected on day 16 and 17, respectively. The endogenous N-proportion was measured by the ratio of 15N enrichment in the digesta and urine. The duodenal and ileal digesta supernatant viscosity increased as carboxymethylcellulose was included into the diet. Xylanase addition to the rye-wheat based diet reduced the viscosity in the ileal digesta. There were no differences in precaecal digestibilities of DM, CP and amino acids between diet C and CMC. The precaecal digestibilities of DM and soluble and insoluble NSP increased from 69.5% to 73.9%, from 1.3% to 47.9% and from 17.0% to 35.4%, respectively, as xylanase was added to the rye-wheat-based diet. The apparent precaecal digestibility of most essential amino acids increased by 2 to 5 percent units. The amounts of endogenous N at the duodenal level were estimated to be 158, 233, 313 and 276 mg per 12 h per kg0.75 BW of pigs fed diets C, CMC, RW and RWX, respectively. The corresponding values at the ileal level were 95, 107, 164 and 150 mg per 12 h per kg0.75 BW. For endogenous N amounts, significant differences were observed between diets C and CMC (duodenum) and also between semi-purified and cereal-based diets (duodenum and ileum). Methodological aspects for the estimation of endogenous N using the isotope dilution technique are discussed. Obviously, the digesta viscosity per se does not affect the nutrient absorption and endogenous N flow within the small intestine of pigs. Other properties of complex dietary fibre, digesta passage rate or bacterial activity probably contribute to the observed changes. 相似文献
6.
24 experimental birds were fed the same basal ration containing 74% high-protein wheat, 4% extracted soya bean meal, 7% extracted groundnut meal, 2% feed yeast, 1.75% dried green meal, 1.25% mixed vitamins and 10% of a mineral mixture. The birds were placed in 4 groups each comprising 6 hens. The first two groups received an optimum of lysine (0.68%) added to the ration. The rations for the two other groups contained 0.55% lysine. 6 birds of each group receiving either the lysinesupplemented or the unsupplemented rations were colostomated to investigate in which way the hydrolysed urine would affect the true amino acid digestibility. 8.3% of urinary N from the total amount of faecal N were precipitated as uranyl acetate in the faeces of hens fed the lysine-supplemented ration as compared with 7.3% urinary N in birds receiving the unsupplemented ration. The corresponding figures for non-precipitable faecal N were 8.9% and 8.2%. A comparison was made between the levels of amino acids excreted by colostomated and non-colostomated hens showing that 12.4% +/- 3% and 11.7% +/- 3% more amino acids (figures for the supplemented and unsupplemented rations) were excreted in the presence of urine. On the basis of these results the authors recommend that only colostomated hens should be used in digestibility and total metabolism trials. 相似文献
7.
去盲肠和未去盲肠公鸡测定饲料氨基酸消化率的比较研究 总被引：11，自引：0，他引：11
应用Sibbald“TME”方法,比较了去盲肠和未去盲肠公鸡对饲料氨基酸的消化率。试验测定了10种饲料的去盲肠和未去盲肠公鸡的氨基酸消化率。结果表明,未去盲肠鸡对10种饲料的氨基酸表观和真消化率均高于去盲肠鸡。轻度受热鱼粉、重度受热鱼粉、脱毒棉籽饼、未脱毒棉籽饼和豆饼的表观氨基酸消化率在去盲肠鸡和未去盲肠鸡之间存在显著差异(P<0.05),未受热鱼粉和芝麻饼的表观氨基酸消化率在去盲肠鸡和未去盲肠鸡之间不存在显著差异(P>0.05)。轻度受热鱼粉、重度受热鱼粉、豆饼的真氨基酸消化率在去盲肠鸡和未去盲肠鸡之间存在显著差异(P<0.05);未受热鱼粉、脱毒棉籽饼、未脱毒棉籽饼和芝麻粕的真氨基酸消化率在去盲肠鸡和未去盲肠鸡之间不存在显著差异(P>0.05)。去盲肠鸡内源氨基酸排出量显著高于未去盲肠鸡(P>0.05)。微生物对未消化食糜中的肽类、氨基酸具有降解作用。 相似文献
8.
Three trials were performed with chicks from 5–8 to 22–29 d of age in order to compare the relative content of available sulphur amino acids (SAA) in maize and in milo grains, and to determine whether or not milo was a poorer source than maize in any additional amino acid. The cereal grains were substituted for each other on an isonitrogenous basis in grain‐soyabean meal diets, their crude protein content ranging from 16–6 to 17–8 per cent, and these diets were control‐fed in uniform quantities. The maize and milo diets of each trial were supplemented with three common levels of DL‐methionine, and with a fourth level which was calculated to be in excess of the SAA requirement. The relative available SAA content of the grains was estimated by using the regression equations for the best fitting lines to calculate the amounts of added methionine required with the two diets to obtain a certain common weight gain. The difference between these two quantities was then related to the dietary cereal protein.
In all trials linear graded responses were obtained to increments of DL‐methionine, with both maize and milo diets, and the differences in chick performance between these two dietary cereals were eliminated once methionine supplementation was high enough. Thus, under the conditions of this study, SAA were the first and only limiting amino acids for both types of diet.
The calculated differences in SAA between maize and milo protein were 1.53, 1.31 and 0.96 percentage points for trials 1.3, respectively. Since milo protein thus contained, on an average, 1.27 percentage points less available SAA than maize protein, which can be assumed to contain 3–89 per cent SAA, the estimated available SAA content of milo protein was 2.62 per cent. 相似文献
9.
试验旨在测定大米粉氨基酸消化率的同时,探讨去盲肠与正常黄羽肉鸡对大米粉氨基酸消化率的影响。结果表明:大米粉中氨基酸表观消化率去盲肠鸡普遍高于正常鸡,丙氨酸、亮氨酸和赖氨酸差异显著(P<0.05);大米粉中氨基酸的真消化率亦普遍表现为去盲肠鸡高于正常鸡,丙氨酸差异显著(P<0.05),酪氨酸差异极显著(P<0.01)。大米粉的总氨基酸表观消化率和真消化率在两种试鸡间差异不显著(P>0.05)。去盲肠鸡的内源氨基酸排泄量大多数测值高于正常鸡,但差异不显著(P>0.05)。本试验建议用正常鸡的测定值表示黄羽肉鸡对大米粉的氨基酸消化率。 相似文献
10.
In a two-factorial experiment on 96 young male rats, the effects of substituting 10% raw potato starch (PS), pectins (PEC), or cellulose (CEL) for corn starch (CS) were studied using an unsupplemented protein-free (PF) diet or a PF diet supplemented either with DL-methionine or urea. The pH and the short chain fatty acids (SCFA) content in caecal digesta, as well as caecal digesta and tissue weights were determined and used as the criteria of caecal fermentation intensity. Blood urea level, amount of N excreted via faeces and urine, DAPA content, and amino acid composition of faecal protein were analyzed as indices of protein metabolism. A 10-day adaptation period to the carbohydrates fed with the casein diet preceded the experimental period of feeding the respective carbohydrates with protein-free diets. Dietary carbohydrates significantly influenced total and individual SCFA content in caecal digesta, as well as other parameters related to the intensity of fermentation. Potato starch and pectins were more intensively fermented than cellulose. Supplementation of the PF diet with methionine and urea affected only caecal isobutyric and valeric acid content in a way dependent on the carbohydrates present in the diet. Carbohydrates significantly altered the routes of N excretion. Faecal excretion was increased by all carbohydrates studied compared to corn starch, pectins had the most marked effect. Urinary excretion was significantly increased by cellulose (as compared with the PEC and PS groups) and decreased by pectins as compared with all other groups. There was an interaction between the effects of carbohydrates and type of protein-free diet on faecal and urinary excretion. The sum of amino acids in faecal protein was the lowest on the PEC diet, but the amino acid composition expressed as a per cent of total amino acid content was similar in all groups. It can be concluded that dietary carbohydrates alter the excretion patterns of endogenous nitrogen in rats in different ways and that this effect is related to the intensity of their fermentation in the hind gut. 相似文献
11.
Digestibility trials were performed with laying hens receiving 3 types of rations containing equal proportions of the same dietary components. The percentage of high-protein wheat in these rations was 74%. Ration I was supplemented with 0.12% lysine while 0.06% lysine was added to ration II; ration III remained unsupplemented. The crude protein content of rations 1 to 3 was 16.1%, 16.5% and 16.6%, respectively. The corresponding lysine percentages were 0.66, 0.62 and 0.56. Studies were made to investigate the influence of different lysine levels on the rate of N excretion and various amino acid data. These studies were carried out during two successive laying periods. Only random differences between the data for urinary N excretion and N balances per kg liveweight were obtained in the two laying periods and for the different lysine levels. The true lysine digestibility was significantly lower in the poor-lysine ration as compared with the ration with 0.66% lysine. Moreover, the absorptive capacity for thio-amino acids is influenced by the lysine level of the ration. The proportion of lysine contained in faecal crude protein increased with the decreasing lysine content of the ration. Similarly, the total number of amino acids present in faecal crude protein increased with the declining supply of lysine. These findings suggest that relatively more NPN compounds are excreted in the faeces if adequate amounts of amino acids are supplied rather than when one amino acid is deficient. 相似文献
12.
C. Pedersen S. Boisen J. A. Fernández 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(3):141-149
Two experiments were carried out to investigate endogenous crude protein (N 2 6.25) (CP) losses in growing pigs. In experiment I, 42 cross-bred gilts [live weight (LW) 35-40 kg] were fitted with a simple T-cannula at the terminal ileum. Seven experimental diets (four feedstuffs: barley, wheat, soyabean meal and rapeseed meal, and three mixtures with varying compositions of the same feedstuff batches) were investigated. Each diet was fed at six different CP levels, obtained after dilution with a 1:1 mixture of sucrose and dextrose. In total, 42 different diets were used and on each pig three different diets were tested. In experiment II, 12 (LW , 18 kg) plus eight (LW , 88 kg) cross-bred castrates were fitted with a simple T-cannula at the terminal ileum. Four experimental diets based on casein as the sole protein source and with CP dietary levels from 6 to 25% were used. By extrapolation to zero CP intake the basal endogenous protein loss in experiment I was 15.7 g kg -1 dry matter (DM) intake, when including all diets, and 14.3 g kg -1 DM intake after excluding the barley diets. In experiment II the basal endogenous CP loss was 11.3 g kg -1 DM intake. In experiment I a relative increase in almost all amino acids in the endogenous CP loss was found when the dietary CP level in the diets increased from zero to 17%. Exceptions were glycine, which was constant, and proline, which decreased significantly from 176 to 58 g 160 g -1 CP. However, the sum of proline and glutamic acid in the endogenous protein loss was almost constant. Similar results were obtained after correction for undigested dietary CP and amino acids, based on in vitro analyses of CP digestibility. In a supplementary study, ileal samples, selected for unusually high levels of proline were analysed for free amino acids. For proline, 36-64% was free, whereas insignificant proportions of the other amino acids were free. It is concluded that the composition of endogenous CP is generally relatively constant. However, experimental conditions with low or inappropriate dietary CP supply may influence the composition and occasionally induce unexpected high levels of proline from secretion of free proline into the lumen of the digestive tract. 相似文献
13.
1. An experiment was designed to determine if decreasing excess amino acids in the diets of chicks would improve metabolic efficiency, as indicated by growth rate and food efficiency. 2. Semi-purified diets were fed with crude protein contents of 180 or 230 g/kg. The sources of protein were maize gluten meal, groundnut meal, sesame meal or soya-bean meal. Crystalline amino acids were supplemented to meet all amino acid requirements. 3. The dietary crude protein content had no statistically significant effect on weight gain or food consumption. The probability that the higher protein improved gain per food was 0.06. Protein source had a significant effect on all the responses measured. 4. Decreased concentrations of excess amino acids in chick diets had no favourable effects on weight gain or gain per food. Lower protein diets were more expensive per unit of gain. 相似文献
14.
The assessment of the protein quality of silaged maize ear products was carried out on the basis of crude protein and amino acid analyses and of N balance measurings with growing pigs including comparative studies with maize corns and cereals. The differences found in the amino acid concentrations between the individual maize ear products could be verified on the basis of the analysed values of husks, cobs and corns. There were no significant differences in the parameters of total protein utilization (PNu, b-value) between the studied silages. The differing crude fibre content resulted, however, in reverse shifts in N excretion in faeces and urine, i.e. diminished protein digestibility was compensated by improved intermediary utilization. 相似文献
15.
去盲肠鸡和未去盲肠鸡测定花生粕、胡麻粕、芝麻粕氨基酸消化率的研究 总被引：2，自引：0，他引：2
分别用２４只去盲肠和未去盲肠健康公鸡，测定了花生粕、胡麻粕和芝麻粕的氨基酸消化率。结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ＜０．０５）；在花生粕中，胱氨酸、赖氨酸、天冬氨酸和谷氨酸的ＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）；在胡麻粕和芝麻粕中，除酪氨酸和脯氨酸外，其它各种氨基酸及１６种氨基酸总和的ＡＡＡＤ和ＴＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）。鸡盲肠微生物对内源及饲料中未消化蛋白质、多肽及氨基酸具有分解作用，干扰饲料ＡＡＡＤ和ＴＡＡＤ测定。对于不易消化、氨基酸含量相对不平衡的低品质蛋白质饲料干扰尤其严重。在测定的３种饼粕中，花生粕氨基酸消化率最高，胡麻粕次之。过度热处理的芝麻粕氨基酸平均消化率为４７．３％，赖氨酸消化率为２１．７％。 相似文献
16.
Performance and nutrient balance in growing swine fed low-protein diets supplemented with amino acids and potassium 总被引：2，自引：0，他引：2
Five experiments, using 216 barrows and gilts (initial weight 19.9 to 23.7 kg), were conducted to evaluate the effects of improving amino acid balance by supplementing low-protein corn-soybean meal diets with essential amino acids. Three experiments were growth studies lasting approximately 3 wk, and the other two were 4-d metabolism trials. The control diets in each of the experiments were formulated to contain .80% lysine and contained approximately 17% CP. The other diets were formulated from a basal diet containing a 10.9% CP, fortified corn-soybean meal mixture, which included crystalline L-lysine.HCI, L-tryptophan, L-threonine, L-isoleucine, DL-methionine and L-valine to correct amino acid deficiencies. Nonessential N (glutamic acid or urea) also was added to some of the diets to increase the CP equivalent to 12 or 13%. Supplemental K (as a salt of bicarbonate or glutamate) was included in selected diets to increase the K concentration to the same level as that of the control diet. Growth rate of pigs fed the basal diet was similar (P greater than .05) to that of the control diets in only one growth study. Added glutamic acid and urea did not improve either growth rate or N retention. Added K improved K digestibility but did not increase K retention, N retention or growth rate. Improving amino acid balance by adding essential amino acids to low-protein diets did not benefit performance beyond that of a typical corn-soybean meal diet. Under our conditions, K, N, and nonessential N were not limiting. 相似文献
17.
K Gruhn 《Archives of Animal Nutrition》1976,26(5):335-343
In the present paper regression techniques were used for determing the true digestibility of amino acids from lysine-supplemented rations fed to laying hens as compared with unsupplemented rations of the same composition. 5 groups of 4 hens each were investigated receiving graded amounts of food and nutrients. The daily amounts of pellets fed per bird in group 1 to 5 were 120 gms, 100 gms, 80 gms, 60 gms and 40 gms. The quantity of lysine contained in 100 gms of the pellets was 664 mg in ration 1 and 554 mg in ration 2, the corresponding N values being 2.57 gm and 2.62 mg. The total amount of endogenic amino acids excreted per day was 128 mg per kg of body weight in birds receiving the lysine-supplemented ration and 132 mg per kg of body weight for the lysine-deficient ration. Data for the true digestibility of lysine and isoleucine were significantly higher in the case of the lysine-supplemented ration than with the lysine-deficient mixture. Lysine values were 86% and 75%, the corresponding lysine data in crude faecal proteins 4.8% and 7.1%. Generally speaking, the crude faecal protein of hens fed the lysine-deficient diet contained higher proportions of most of the essential and non-essential amino acids. 相似文献
18.
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
19.
1. In order to investigate the effects of xylanase, amylase, protease and phytase in the diets of broiler chickens containing graded concentrations of metabolisable energy (ME), two 42-d experiments were conducted using a total of 2208 broiler chicks (8 treatments with 12 replicate pens in each experiment). 2. Four diets including one positive and three negative control diets were used. Three maize/soybean meal-based negative control (NC) diets were formulated to be identical in available phosphorus (P), calcium (Ca) and amino acids but NC1 contained approximately 0.17 MJ/kg less ME than NC2 and approximately 0.34 MJ/kg less ME than NC3. A positive control (PC) was fed for comparison and was formulated to be adequate in all nutrients, providing approximately 0.63 MJ/kg ME, 0.13% available P, 0.12% Ca and 1 to 2% amino acids more than NC1. 3. The reduction in nutrient density between NC1 and PC was determined using ingredient quality models Avichecktrade mark Corn and Phychecktrade mark that can predict the response to exogenous enzymes in maize/soybean meal-based broiler diets. Supplementation of each diet with or without a cocktail of xylanase, amylase, protease and phytase gave a total of 8 dietary treatments in a 4 x 2 factorial arrangement. The same treatments and diet designs were used in both experiments but conducted in different locations using different batches of maize, soybean meal and minor ingredients. 4. In both experiments, digestibility was improved by the addition of exogenous enzymes, particularly those for P, Ca and certain amino acids. In addition, the supplementation of the PC with enzymes elicited a positive response indicating that over-the-top addition of xylanase, amylase, protease and phytase may offer a nutritionally and economically viable alternative to feed cost reduction. 5. It can be concluded that the digestibility of nutrients by broilers fed on maize/soybean meal-based diets can be improved by the use of a combination of xylanase, amylase, protease and phytase. 相似文献
20.
Ideal amino acid profile and dietary lysine specification for broiler chickens of 20 to 40 days of age. 总被引：4，自引：0，他引：4
S Mack D Bercovici G De Groote B Leclercq M Lippens M Pack J B Schutte S Van Cauwenberghe 《British poultry science》1999,40(2):257-265
1. The aim of the study was to determine the ideal ratio of the essential amino acids lysine (Lys), methionine (Met), threonine (Thr), tryptophan (Trp), arginine (Arg), valine (Val) and isoleucine (Ile) and to assess the required dietary lysine concentration for optimum performance in broiler chickens of 2 commercial strains from 20 to 40 d of age. 2. An identical basal diet was used throughout all experiments. It consisted mainly of maize and soyabean meal and contained 172 g crude protein and 13.2 MJ AME(N) per kg. For each experiment, the basal diet was adequately supplemented with all essential amino acids except the one to be tested, which was supplemented in 6 graded concentrations in exchange for maize starch. One (Met, Trp, Arg, Val, Ile) or 2 (Lys, Thr) growth trials were conducted per amino acid tested and the response in weight gain, food: gain ratio, breast meat yield and abdominal fat were examined. 3. The ideal amino acid ratio relative to Lys (expressed as a percentage) was calculated to be 75% Met+Cys, 63% Thr, 19% Trp, 112% Arg, 71% Ile and 81% Val on a true faecal digestible basis when the data were subjected to broken-line regression analysis. From both lysine studies the concentration for optimum food: gain ratio was calculated, by exponential regression analysis, to be 11.5 g true faecal digestible lys per kg diet. 相似文献