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1.
Two growth studies were conducted to determine the Met and Lys requirements of growing cattle. In each 84-d trial, steer calves were fed individually diets containing 44% sorghum silage, 44% corn cobs, and 12% supplement (DM basis) at an equal percentage of BW. In Trial 1, 95 crossbred steers (251 kg) were supplemented with urea or meat and bone meal (MBM). Incremental amounts of rumen-protected Met were added to MBM to provide 0, .45, .9, 1.35, 3, and 6 g/d metabolizable Met. In Trial 2, 60 steers (210 kg) were supplemented with urea or corn gluten meal (CGM). Incremental amounts of rumen-protected Lys were added to CGM to provide 0, 1, 2, 3, 4, 5, 6, 8, and 10 g/d metabolizable Lys. Supplementation with MBM and CGM increased the supply of metabolizable protein to the animal. Steers fed MBM plus 0 Met gained 49 g/d more than steers fed urea, whereas steers fed CGM plus 0 Lys gained 150 g/d more than steers fed urea. Supplementation of rumen-protected Met and Lys improved ADG in steers fed MBM and CGM, respectively (P < .10). Nonlinear analysis, comparing gain vs supplemental Met and Lys intake, predicted supplemental Met and Lys requirements of 2.9 and .9 g/d, respectively. This amount of additional Met promoted .13 kg/ d gain greater than MBM alone, and this amount of additional Lys promoted .10 kg/d gain greater than the CGM alone. Metabolizable Met and Lys requirements were predicted from Level 1 of NRC (1996) calculated metabolizable protein supply, amino acid analysis of abomasal contents, and the maximum response to supplemental AA. Steers gaining .39 kg/d required 11.6 g/ d Met or 3. 1% of the metabolizable protein requirement, whereas steers gaining .56 kg/d required 22.5 g/d Lys or 5.7% of the metabolizable protein requirement.  相似文献   

2.
The objectives of this research were to determine 1) the effects of hydrolysis time on feather meal (FTH) protein digestion and ruminal escape and 2) whether adding blood meal (BM) to FTH evoked a complementary response in animal performance. A lamb digestion trial was conducted to estimate true protein digestibility of soybean meal (SBM), BM, and FTH hydrolyzed for 10, 12, 15, or 18 min. Ruminal escape was estimated in situ. Two 94-d growth trials were conducted using 60 growing calves (226 kg) per trial to evaluate urea, FTH, BM, and 87.5:12.5, 75:25, and 50:50 combinations (CP percentage basis) of FTH:BM. There were small numerical differences in estimated escape of protein from the rumen and DM and protein digestibilities due to hydrolysis time. True protein digestibility of the 10- and 18-min samples was 5% higher (P less than .05) than for the 12- or 15-min FTH samples. In the growth trial, the slope-ratio technique showed that the most efficiently used protein supplement was 100% BM (protein efficiency = 2.45 +/- .19). No differences (P = .30) in protein efficiency were observed among supplements containing various combinations of FTH:BM. There was a quadratic (P less than .01) response to the level of BM, indicating a complementary effect. The largest complementary effect occurred at the 12.5% level of the BM addition. There were no nutritionally important effects of hydrolysis time between 10 and 18 min. Furthermore, supplements can be formulated more economically using small amounts of BM with FTH without compromising biological efficiency.  相似文献   

3.
Complementary responses between rendered protein meals were investigated in this study. In a preliminary trial using 12 mature wethers in two replications, there was no difference (P greater than .20) in N digestibility between meat and bone meal (MBM; 96.7%), feather meal (FTH; 89.8%), and soybean meal (SBM; 98.7%). In a 112-d growth trial, individually fed calves (n = 120; 230 kg) received graded levels of FTH, MBM, 50:50 MBM-FTH (CP basis), or SBM with or without tryptophan (Trp) supplementation. Additions of Trp increased plasma Trp levels (P less than .05) but failed to improve efficiency of protein utilization (P greater than .35). Pooled results showed that this efficiency was greater (P less than .05) for FTH (1.47) than for MBM (1.04), FTH:MBM (.80), or SBM (.66). A trial was conducted to determine whether Trp addition reduces growth response to FTH:MBM (50:50) combinations. Calves (n = 230; 285 kg) were blocked by sex and weight into six replications and received FTH:MBM supplying 35% of the supplemental CP fed alone or with a high or low level of Trp supplement. Negative (urea only) and positive controls were included. Calves receiving FTH:MBM combinations gained faster (P less than .10) and were more efficient (P less than .10) than urea-supplemented calves. Performance was not altered by Trp addition. Calves (n = 120; 230 kg) were individually fed in two replications (43 or 48% CP MBM in Replications 1 and 2, respectively) of a growth trial to determine whether there was a complementary response between blood meal (BM) and MBM.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

4.
Laboratory, digestion and growth studies were used to evaluate energy and protein supplements for ammoniated (4% of the forage DM) stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis) hay. Ammoniation increased (P less than .05) total N concentration (.7 to .9% vs 1.7 to 2.0%) and in vitro digestion of OM, NDF and ADF and reduced (P less than .05) NDF concentration of stargrass hay. Two digestion (3 x 3 Latin square, 250-kg steers) and two growth (400-kg Brahman crossbred cull cows, eight head per pasture, two pastures per treatment, November through February) trials evaluated citrus pulp or liquid cane molasses (Trial 1) and molasses or molasses plus cottonseed meal (Trial 2) supplementation of ammoniated hay. Supplementation with byproduct energy sources, citrus pulp or molasses (either alone or with cottonseed meal), improved (P less than .05) OM digestibility but reduced (P less than .05) NDF and ADF digestibilities. Apparent nutrient digestibilities were similar (P greater than .05) between diets supplemented with citrus pulp and molasses and between diets supplemented with molasses and molasses plus cottonseed meal. In Trial 1, ADG by cull cows was greater (P less than .05) for citrus pulp- (.71 kg) or molasses-(.68 kg) supplemented diets than for hay fed alone (.49 kg). In Trial ADG was greater (P less than .05) for cull cows fed ammoniated hay supplemented with molasses plus cottonseed meal (.85 kg) than for those supplemented with molasses only (.69 kg). Feeding cows over the winter increased their (P less than .05) carcass weight, marbling score, USDA quality grade and lipid percentage of the 9-10-11 rib section compared with cows slaughtered at the beginning of the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
Eight male Holstein calves (body weight 68 +/- 5 kg; age 75 +/- 6 d), each with a permanent re-entrant pancreatic cannula and T-type ileal and duodenal cannulas, were used in a crossover design with four animals per group to determine amino acid kinetics and digestibilities in the digestive tract of calves fed soybean meal (SBM) and canola meal (CM) protein. The SBM and CM diets were fed twice daily at a level of 900 g at each feeding time (air-dry basis). With the exception of methionine, crude protein and amino acid flows at the proximal duodenum, expressed as a percentage of intake, were not influenced by dietary protein source. Apparent ileal and total tract digestibilities of CP and amino acids were reduced (P less than .05) by feeding CM compared to SBM, but apparent ileal digestibility of methionine was not affected by dietary protein source. Except for methionine, net disappearance of all amino acids in the small intestine, relative to the amount fed, was higher for the SBM diet than for the CM diet. Net disappearance or synthesis of amino acids in the large intestine were not affected by dietary protein source. Similarly, dietary protein source did not affect (P greater than .05) the secretion of pancreatic juice or concentrations of protein, chymotrypsin and trypsin in pancreatic juice. Soybean meal protein has higher ileal and total gastrointestinal tract digestibility than CM protein for young, growing calves.  相似文献   

6.
Peanut skins were fed at 15% of steer diets in metabolism and feedlot trials. Elevation of dietary protein using soybean meal or soybean meal plus urea and ammoniation of skins were evaluated as methods of overcoming detrimental performance and digestibility effects of tannins in peanut skins. Digestibility of dry matter, crude protein and energy were not different (P greater than .05) for steers fed a control diet with 11.4% crude protein with no skins compared with high-protein 15% peanut skin diets with soybean meal (15.5% crude protein) or soybean meal plus urea (16% crude protein). Dry matter, crude protein and energy digestibilities of control and of high-protein peanut skin diets were higher (P less than .05) compared with an 11.4% crude protein peanut skin diet and a 12.2% crude protein diet with ammoniated peanut skins. Ether extract digestibility was higher (P less than .05) for all peanut skin diets compared with the control. Nitrogen retention (g/d) was not different (P greater than .05) for control and high-protein peanut skin diets, and nitrogen retention on these diets was higher (P less than .05) compared with the lower protein and ammoniated peanut skin diets. Diets fed in the metabolism trial, except for the ammoniated peanut skin diet, were fed to 96 steers (345 kg initial wt) in a 109-d feedlot trial. Performance was lower (P less than .05) for steers fed the lower-protein peanut skin diet compared with other treatments through d 56; this diet was discontinued as a treatment on d 62.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
The objective of two experiments was to correlate plasma levels of urea N (PUN) and the percentage of urine N in the form of urea (UUN) to weight gain in response to different dietary protein regimens for growing Angus steers. In Exp. 1, 60 steers (302 kg BW) were assigned to various levels of dietary N (control plus supplemental N to provide from 100 to 400 g more crude protein daily) within two sources of supplemental N (soybean meal [SBM] or a mixture of two parts corn gluten meal:one part blood meal [CGM:BM]). In Exp. 2, 27 steers (229 kg BW) were fed two levels of SBM, and half of the steers received growth-promoting implants. Steers were housed in groups of 12 and fed individually for 84 d in both experiments. Corn silage was fed at a restricted rate to minimize orts. Jugular blood and urine samples were collected during the experiments. In Exp. 1, maximal ADG of steers fed SBM (1.0 kg) was reached with 671 g/d total crude protein, or 531 g/d metabolizable protein. Maximal ADG of steers fed CGM:BM (0.91 kg) was reached with 589 g/d total crude protein, or 539 g/d metabolizable protein. The DMI was higher (P < 0.07) for steers fed SBM (6.37 kg/d) than for steers fed CGM:BM (6.14 kg/d). Increasing ruminal escape protein from 36% (SBM) to 65% (CGM:BM) of CP decreased (P < 0.05) endogenous production of urea, as evidenced by lower concentrations of urea in blood and lower UUN. In Exp. 2, increasing supplemental protein from 100 to 200 g/d increased (P < 0.05) ADG and PUN. Implants lowered (P < 0.05) UUN, particularly at the higher level of supplemental protein. Protein supplementation of growing steers can be managed to maintain acceptable ADG yet decrease excretion of urea in the urine.  相似文献   

8.
Two trials were conducted to evaluate the effects of protein source (48% CP soybean meal or casein) and carbohydrate source (25% dextrose or 25% lactose) on digestibility and digesta flow rate in early-weaned pigs. Diets contained 10% crude soybean oil and were formulated to contain 3.5 g lysine, 2.3 g Ca and 2.0 g P per 1,000 kcal DE of diet. In Trial 1, nutrient digestibility was greater for older than for younger pigs. Apparent digestibilities for energy, DM, CP and fat were lower (P less than .08) for younger and older pigs fed soybean meal rather than casein. Digestibility of soluble carbohydrates was less (P less than .02) for younger pigs fed soybean meal rather than casein as a protein source. Fat digestibility was lower (P less than .05) in younger pigs fed dextrose than in pigs fed lactose. A protein X carbohydrate source interaction (P less than .01) existed for fat digestibility by older pigs. In Trial 2, pigs were euthanatized, and digestibilities anterior to the ileum and the colon (pre-ileal and pre-cecal) were determined. At the ileum, fat digestibility was lower (P less than .05) for pigs fed soybean meal, whereas CP digestibility was lower (P less than .05) for pigs fed either soybean meal or dextrose. A protein X carbohydrate interaction was observed for ileal digestibilities of DM (P less than .06) and total carbohydrates (P less than .03) with lowest values obtained for the soybean meal plus dextrose diet. For casein diets, digestibility values were similar between the two carbohydrate sources.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
Meat-and-bone meal (MBM), which had been heated (150 degrees C) for 0, 1.5, 3 or 5 h, was used along with an indigestible marker in four diets which were fed to young growing chickens and adult cockerels fitted with ileal cannulae. The ileal digesta from each group of birds were sampled and the apparent amino acid digestibilities of the four diets containing MBM were determined. The apparent digestibility values from growing chickens were higher (P less than 0.05) than those from cannulated cockerels. Differences in apparent digestibility of amino acids between diets as a result of heat treatment were consistent for all amino acids when comparing both techniques, with the exception of glutamic acid and arginine.  相似文献   

10.
Hydrolyzed feather meal as a protein source for growing calves   总被引：1，自引：0，他引：1  
Growth, digestion and in situ studies were conducted to determine the protein value of hydrolyzed feather meal (Fth) for growing ruminants. Dacron bags containing blood meal (BM), Fth, corn gluten meal (CGM) and soybean meal (SBM) were suspended in the rumen of two steers for 12 h to estimate escape protein. The escape protein value for Fth, 69.1%, was less than that for BM (82.8%) and CGM (80.4%; P less than .05) but greater than that for SBM (26.6%; P less than .05). Apparent protein digestion by lambs was similar (P greater than .10) for isonitrogenous diets containing urea (U), BM, Fth, CGM and SBM. Amino acid contents of the protein sources before vs after a 12-h ruminal in situ digestion were similar (P greater than .10). In a growth study, a basal diet of 80% ensiled corncobs and 20% alfalfa was fed to 60 individually fed crossbred steers (215 kg BW). Steers were supplemented with U, BM, Fth, 1/2 BM:1/2 Fth, 1/2 BM:1/2 CGM and 1/3 BM:1/3 Fth:1/3 CGM (protein basis). Protein sources were fed at 30, 45 and 60% of the supplemental N with urea supplying the remainder. Protein efficiency was calculated using the slope ratio technique. Protein efficiency was similar (P greater than .10) for BM- and Fth-supplemented calves. Protein efficiencies were similar (P greater than .10) for BM:CGM, BM:Fth and BM:Fth:CGM combinations. These data indicate the Fth is a digestible high escape protein source that is useful in diets for growing ruminants.  相似文献   

11.
Protein value of feather meal for ruminants as affected by blood additions   总被引：3，自引：0，他引：3  
In situ digestion and growth studies were conducted to determine the effects of adding blood to feather meal. In the in situ and digestion studies, soybean meal (SBM), blood meal (BM), feather meal (Fth) and two combinations of 55% raw blood and 45% feathers (RB + F) were used. Feathers and blood were combined either before or after steam hydrolysis of feathers. Ruminal escape protein of Fth was greater than that of SBM but less than that of BM (P less than .10) determined in situ after 12 h of incubation. Ruminal in situ protein digestion was lower (P less than .10) than for the other treatments (P less than .10) when blood was hydrolyzed with feathers. Total tract digestibility was similar (P greater than .10) for SBM, BM and the mixture of RB + F when the blood was not hydrolyzed. In the growth study, calves were supplemented with urea, SBM, BM, Fth or a combination of BM and Fth (BM + Fth; each supplied an equal portion of supplemental protein). The slope ratio technique was used to evaluate the protein sources. The most efficiently used protein sources were BM and BM + Fth compared to SBM and Fth (P less than .05). There was a numerical but not significant (P greater than .1) complementary effect of adding BM to Fth. Soybean meal and Fth had similar protein efficiencies (P greater than .20). Estimated amino acid flow to the small intestine based on in situ amino acid degradation suggested that the complementary effect observed for BM + Fth was due to BM supplying lysine and Fth providing sulfur amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
An experiment was conducted with ileally cannulated pigs to determine the apparent digestibility of amino acids and N in raw or heated conventional or low-trypsin-inhibitor soybeans. Six littermate barrows initially averaging 24 kg were fed cornstarch-based diets (10.5% CP, .68% lysine, 3,558 kcal of ME/kg) supplemented with raw (unheated), conventional soybeans; raw, low-trypsin-inhibitor soybeans; heated, conventional soybeans; heated, low-trypsin-inhibitor soybeans; or solvent-extracted soybean meal. Heating was achieved by autoclaving soybeans (after grinding) for 20 min at 110 degrees C. The urease activities of the two raw soybean sources were similar, but the trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was about one-half that of the raw, conventional soybeans. The lower trypsin inhibitor activity of the raw, low-trypsin-inhibitor soybeans was associated with an improvement in the apparent digestibility of amino acids and N compared with the raw, conventional soybeans (P less than .05). Heating reduced the urease and trypsin inhibitor activities and improved (P less than .05) the apparent digestibility of amino acids and N in both types of soybeans. However, the heated, conventional soybeans contained more trypsin inhibitor activity than the heated, low-trypsin-inhibitor soybeans and the digestibilities of the amino acids were lower (P less than .05). Although the urease and trypsin inhibitor activities of the two heated soybean sources were similar to or less than those of soybean meal, the digestibilities of amino acids were not as great (P less than .05) in the heated soybeans as in soybean meal.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
1. The apparent ileal and excreta digestibilities of amino acids in 15 samples representing 12 food ingredients were determined using 5-week-old male broiler chickens. The ingredients included 3 samples of cereals (wheat, maize and sorghum), 6 samples of plant protein meals (soyabean meal, cottonseed meal, canola meal and sunflower meal) and 6 samples of animal protein meals (meat meal, meat-and-bone meal, feather meal and fish meal). 2. The test ingredients were incorporated as the sole source of dietary protein in assay diets. Each diet was offered ad libitum to 3 pens (4 birds/pen) from d 35 to d 42 post-hatching. Total collection of excreta was carried out during the last 4 d. All birds were killed on d 42 and the contents of the lower half of the ileum were collected. Apparent ileal and excreta amino acid digestibilities were calculated using acid-insoluble ash as the indigestible marker. 3. The influence of site of measurement was found to vary among food ingredients, among samples within an ingredient and among different amino acids within an ingredient. Ileal amino acid digestibility values were similar in some ingredients, but significantly lower or higher in others than the corresponding excreta values. 4. Average ileal and excreta amino acid digestibilities in sorghum and maize were similar, but significant differences were observed for individual amino acids. In contrast, ileal amino acid digestibility values were higher than the corresponding excreta digestibility values in wheat. 5. The average ileal and excreta digestibilites of amino acids in the 3 soyabean meal samples were similar although small, but significant differences were noted for individual amino acids. Site of measurement had no effect on the digestibility of amino acids in canola meal. Digestibilities of valine, isoleucine, phenylalanine, histidine, glutamic acid, alanine and tyrosine in sunflower meal and those of valine, methionine, isoleucine, leucine, lysine, glutamic acid and alanine in cottonseed meal were lower by excreta analysis. 6. Digestibilities in animal protein meals, with the exception of blood meal and fish meal, were consistently higher by excreta analysis. Ileal-excreta differences in individual amino acid digestibilities were more evident in feather meal, meat meal and meat-and-bone meal. 7. Threonine and valine were the indispensable amino acids that were more frequently influenced by the site of measurement. Of the dispensable amino acids, aspartic acid, serine, glutamic acid and alanine were the most affected. 8. Differences determined between ileal and excreta digestibilities in the present study clearly demonstrate that amino acid metabolism by hindgut microflora in chickens may be substantial and that digestibilities measured in the terminal ileum are more accurate measures of amino acid availability than those measured in the excreta.  相似文献   

14.
Ninety-six Hereford x Angus steers (mean initial BW = 295 kg) were used in two growth experiments conducted at moderate and high ambient temperatures (AT), 48 steers per AT. Within each AT, calves were assigned to six dietary treatments consisting of a basal diet (approximately 60% corn and 20% grass hay) supplemented with either 0, 2.5, or 5% fat and with either soybean meal (SBM) or Menhaden fish meal (FM) included at levels such that a ratio of 16.3 kcal of NEm per kilogram of CP was maintained. Blood and ruminal fluid were collected 40 d before slaughter. During the final 28 d of the moderate AT experiment, apparent digestibility of dietary components was measured in four individually fed steers from each dietary treatment. Steer ADG was not affected by fat, and DMI and efficiency of gain were not affected (P > .10) by treatment. Average daily gain was lower for steers fed FM than for those fed SBM at moderate AT but higher at high AT (CP source x AT interaction; P < .05). Ruminal ratio of acetate to propionate declined linearly with increasing fat at moderate AT but was not affected by fat at high AT (fat x AT interaction trend; P = .08). Plasma urea N concentration increased linearly (P < .05) with increasing fat and was higher (P < .05) in steers kept at high than in those kept at moderate AT. Although apparent digestibility was not altered in steers fed FM, DM and NDF (P < .05) and ADF (P = .07) digestibility decreased with increasing fat in steers fed SBM (CP source x fat interaction).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Five Yorkshire x Lacombe barrows (45 kg initial wt) fitted with duodenal cannulas approximately 10 cm from the pyloric sphincter were used to determine the influence of the pH of the predigestion solution (pH 1.0, 1.5, 2.0 or 2.5), pepsin activity (189 vs 377 IU/liter) and duration of predigestion (0, 1.5, 2.5 or 4.0 h) on the apparent digestibility of the protein in soybean meal (SBM), meal and bone meal (MBM) or canola meal (CM) determined with the Mobile Nylon Bag Technique (MNBT). An additional six barrows were used to determine protein digestibility by conventional methods. Protein digestibilities determined using conventional digestibility techniques were 93.1 +/- .7, 79.1 +/- 1.8 and 79.3 +/- 1.4% for the SBM, MBM and CM diets, respectively. Protein digestibilities determined with the MNBT were highest at pH 2.0 for all three protein sources. Increasing pepsin activity from 189 to 377 IU/liter resulted in a slight increase in the digestibility of SBM and CM, but not of MBM. The absence of predigestion (0 h) resulted in a dramatic reduction in protein digestibility; predigestion times of 1.5 or 2.5 h usually resulted in lower protein digestibilities than did a predigestion time of 4.0 h. The closest agreement between results obtained by the MNBT and conventional digestibility studies occurred with a pH of 2.0, a predigestion time of 4.0 h and a pepsin activity of 377 IU/liter.  相似文献   

16.
This study evaluated the effect of two rendering processes applied to meat and bone meal (MBM) production, associated or not with extrusion, by measuring diet apparent total tract digestibility of dogs and cats, and true digestibility of amino acids (AA) by cecectomized roosters. Four diets were evaluated, with the main protein source as follows: conventional and extruded MBM; high temperature and pressure (HPT; 135 °C, 3 bar, 20 min) and extruded MBM; conventional non‐extruded MBM; HPT non‐extruded MBM. Nutrient digestibility and food metabolizable energy content were evaluated with dogs and cats by the method of total collection of faeces. True AA digestibility was evaluated by a precision‐fed assay with cecectomized roosters. The evaluated MBM had high‐ash content. The HPT process of MBM increased the digestibility of crude protein of the diets by cats, and the true digestibility of several AA by cecectomized roosters. The extrusion process did not modify the apparent total tract nutrient digestibility of MBM by dogs and their amino acid digestibility by roosters, but increased the digestibility of the dietary protein by cats. Dogs fed HPT MBM presented a higher urea post‐prandial response, suggesting reductions in bioavailability and protein synthesis from absorbed AA.  相似文献   

17.
An experiment was conducted to compare apparent total tract protein digestibilities and apparent ileal digestibilities of protein and amino acids in growing pigs and adult pregnant and lactating sows. Twelve growing pigs and 12 sows were used and surgically fitted with simple T-cannulas at the distal ileum. Six experimental diets based on corn, barley, wheat, soybean meal, canola meal, or meat and bone meal were formulated, and each diet was fed to growing pigs, gestating sows, and lactating sows for 7 d. Chromium oxide was included in all diets as an indigestible marker (.25%) for calculating nutrient digestibilities. Fecal material was collected on d 5 of each feeding period by grab sampling, and ileal samples were collected for 12 h/d during the last 2 d of each feeding period. Apparent fecal protein digestibilities for all feed ingredients were higher (P < .05) in gestating and lactating sows compared to growing pigs, but no differences between the two groups of sows were observed (P > .05). At the distal ileum, no differences (P > .05) in protein digestibilities were detected between sows and growing pigs regardless of feed ingredient. For all feed ingredients tested, lactating sows had apparent ileal digestibilities of most amino acids that were two to six percentage units higher than those obtained in growing pigs, but not all of the differences were significant. Gestating sows had digestibilities of most amino acids that were intermediate between those of growing pigs and lactating sows. The combined results from the six feed ingredients showed that lactating sows had higher (P < .05) digestibilities of all indispensable amino acids except arginine, and gestating sows had higher (P < .05) digestibilities of five of the indispensable amino acids than did growing pigs. The results of this experiment indicate that apparent fecal protein and apparent ileal amino acid digestibilities obtained in growing pigs are not always representative of digestibilities in either gestating or lactating sows.  相似文献   

18.
The intestinal supply of amino acids (AA) in sheep fed alkaline hydrogen peroxide-treated wheat straw (AHPWS)-based diets supplemented with soybean meal (SBM) or corn grain plus combinations of corn gluten meal (CGM) and blood meal (BM) was measured in a 5 X 5 latin square. Sheep (avg wt 45 kg) with ruminal, duodenal and ileal cannulas were fed diets containing 65% AHPWS supplemented with the following protein sources: soybean meal (SBM), corn gluten meal (CGM), blood meal (BM), 2/3 CGM:1/3 BM and 1/3 CGM:2/3 BM. Total nitrogen (N) flow at the duodenum was not affected (P greater than .05) by protein source. Flows of bacterial N and AA increased (P less than .05) and flows of nonbacterial N and AA decreased (P less than .05) when wethers were fed SBM vs corn plus other protein sources. When diets contained SBM, quantities of total AA at the duodenum were lower (P less than .05) and the profile of AA supplied to the intestine was altered substantially. Total flows of AA at the duodenum and total quantities of AA disappearing from the small intestine were similar (P greater than .05) for all diets containing BM and CGM, but flows and disappearance of valine, histidine, lysine and arginine increased linearly (P less than .05), whereas flows and disappearance of leucine, isoleucine and methionine decreased linearly (P less than .05) as BM replaced CGM in the diets. Results suggest that quantities of individual AA flowing to the duodenum and disappearing from the intestine of wethers fed AHPWS-based diets can be altered by source of dietary protein. Furthermore, feeding protein sources resistant to ruminal degradation in combination may improve the profile of AA supplied to the intestine.  相似文献   

19.
Eight digestion trials were conducted with pigs fitted with ileal T-cannulas to determine the apparent digestibilities of N and amino acids in common protein feedstuffs. Trial-to-trial variation was minimal as determined by the variation in digestibilities for soybean meal, which was evaluated in each trial. Apparent digestibilities varied widely; ileal N digestibility ranged from 88 to 63%, and ileal lysine digestibility ranged from 93 to 40%. In general, ring-dried blood meal, corn gluten meal, Menhaden fish meal, poultry-by-product meal and extruded whole soybeans were the most digestible, followed by canola meal, sunflower meal, peanut meal and meat and bone meal. Cottonseed meal and feather meal were the least digestible. Mean values for each feedstuff agree well with published data. Variation in digestibilities among samples of the same feedstuff was greater for the meat and bone meals. Regression of ileal essential amino acid digestibilities on ileal and fecal N digestibility indicated that amino acid digestibilities can be predicted more precisely from ileal N digestibility than from fecal N digestibility. However, neither ileal nor fecal N digestibility could be used with a high degree of certainty to predict ileal amino acid digestibilities.  相似文献   

20.
Three pig experiments were conducted using a chemically defined, amino acid diet under conditions in which all nutrients were 100% bioavailable to assess the maximal portion of the sulfur amino acid (SAA) requirement that could be furnished by cystine (Cys). In Exp. 1, a methionine (Met)-deficient diet containing .12% L-Met and .40% L-Cys was supplemented with graded levels of L-Met. Pigs weighing 10 kg initially responded quadratically (P less than .05) to Met supplementation. A two-slope, broken-line regression model (weight gain regressed on percentage of dietary Met) estimated an infection point at .23% dietary Met. A constant level of .46% dietary SAA with differing Met:Cys weight (wt:wt) ratios was used in Exp. 2. Pigs fed Met:Cys ratios of 60:40 and 50:50 had similar (P greater than .05) weight gains, but pigs fed a 40:60 Met:Cys ratio gained less (P less than .05) than those fed the other diets. Maintaining dietary sulfur at .111% in Exp. 3, pigs fed Met:Cys ratios (wt:wt) of 100:0, 55:45, 50:50, and 45:55 gained weight at similar (P greater than .05) rates, but pigs fed the 45:55 Met:Cys ratio had a tendency to produce lower weight gains. Regardless of whether a constant dietary SAA or sulfur level was maintained, no more than 50% of the young pig's total SAA requirement (wt:wt) could be furnished by Cys.  相似文献   

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