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1.
Male rats received in 8 groups of 10 animals each for a period of 7 days 7 synthetic diets and one semisynthetic diet on maintenance requirement level. A L-amino acid mixture corresponding to the pattern of egg protein without glutamic acid was the protein source of the synthetic diets. Glutamic acid was supplemented successively from 0 to 58 mol-% of the total amino acid content. The crude protein source of diet 8 was whole egg powder. On the 8th day of experiment 5 animals per group were labelled by intragastric infusion (i.g.) with 14C-U-glutamic acid. During the following 24 hours the excretion of CO2 and 14CO2 was measured. Throughout the experimental feeding body weight was relative constant, however, when the synthetic diets were fed it was necessary to increase the daily amount of energy from 460 to 480 kJ/kg0,67. The relative 14CO2-excretion within 24 hours was 68-75% of the dose. However, the main part of the amount of radioactivity excreted during 24 hours was found after 4 to 6 hours already. Exponential functions calculated from the data of cumulative 14CO2-excretion suggest the existence of a fast process of 14CO2-formation directly from 14C-glutamic acid, reaching a plateau within 2 hours and a slow process of oxidation of intermediates of glutamic acid metabolism, causing a continued 14CO2-formation even after 24 hours. The oxidation of 14C-glutamic acid to CO2 decreased 2 to 14 hours after i.g. labelling if the glutamic acid content of the diet increased. The same was found for the specific radioactivity of 14CO2. A storage of intermediates of glutamic acid before degradation was assumed.  相似文献   

2.
Male rats (body weight 100 g) received during a 8 days experimental feeding period diets with different contents in glutamic acid. The daily feed intake was restricted to the energy maintenance level of 460 kJ/kg0.75. The diet contained a mixture of L-amino acids corresponding to the pattern of egg protein except glutamic acid. Glutamic acid was added successively at 10 levels (0 to 14,8% of dry matter) and the resulting diets were fed to groups of 4 animals each. At the end of the experimental feeding period 14C- and 15N-labelled glutamic acid were applied by intragastric infusion. CO2- and 14CO2-excretion was measured during the following 4 hours and the urinary N- and 15N-excretion during the following 24 hours. The CO2-excretion decreased from 53 to 44 mmol CO2/100 g body weight with increasing levels of dietary glutamic acid. This change seems to result from the increasing proportion of amino acids as an energetic fuel. While the amount of oxidized glutamic acid increased with increasing supplements of glutamic acid the relative 14CO2-excretion decreased from 57 to 48% of the applied radioactivity. The urinary 15N-excretion during 24 hours was 31% of the given amount of 15N if no glutamic acid was included in the diet. This proportion increased successively up to 52% in the case of the highest supply of glutamic acid. Because the total N-excretion increased at the same extent as the 15N-excretion a complete mixing of the NH2-groups resulting from glutamic acid due to desamination with the ammonia pool was assumed. No correlation between glutamic acid content of the diet and specific radioactivity of CO2 or atom-% 15N excess of urinary N was observed.  相似文献   

3.
40 rats with a body weight of 100 g received 7 semisynthetic diets with different contents of glutamic acid and one diet contained whole egg. A L-amino acid mixture corresponding to the pattern of egg protein was the protein source of the semisynthetic diets. Glutamic acid was supplemented successively from 0 to 58 mol-% of the total amino acid content. On the 8th day of experimental feeding the animals were labelled by subcutaneous injection of 14C-U-L-glutamic acid. Subsequently the CO2- and the 14CO2-excretion were measured for 24 hours. In this period 64 to 68% of the injected radioactivity were recovered as 14CO2. The curve pattern of 14CO2-excretion indicates two different processes of 14CO2-formation. One characterizing the direct degradation of glutamic acid to CO2 with a high rate constant and a second one with a lower rate constant characterizing the 14CO2-formation via metabolites of glutamic acid. 77% of the total 14CO2-excretion in 24 hours resulted from the direct oxidation of glutamic acid and 23% from the oxidation of intermediates. When 14CO2-formation was measured 10 to 24 hours after injection of 14C-glutamic acid a positive correlation to the content of glutamic acid in the diet was observed. The intestinal tissue contribute considerably to the catabolization of glutamic acid, however, there seems to exist an upper limit for this capacity.  相似文献   

4.
Male Wistar rats (weighing some 80 g at the start of the experiment) were fed diets containing maize gluten as protein carrier and which was supplemented with amino acids (except lysine) in such way that their concentrations came up to the requirement norms. Lysine was gradually supplemented this resulting in 10 diets of different lysine content (1.6-10.6 g lysine/16 g N). On the 7th experimental day, 4 animals of each group were labelled with 14C-lysine and subjected to 2-hour measuring of 14CO2-excretion. On the following day, the animals were injected i.p. 15N-lysine, the urine being collected over 24 hours to determine 15N-frequency in urine. Both 14CO2-excretion and 15N-frequency in urine were found to remain constant at a lysine content of the diet up to 4.5 g/16 g N and rose steeply from 5.8 g lysine/16 N on. Under the experimental conditions chosen the lysine requirement is deduced to be 5 g/16 g N. This method of lysine requirement determination is highly sensitive and exact because it covers the catabolization of the amino acids under study and not so parameters that are known to be influenced by other factors such as growth, N-balance, total N-conversion or CO2-formation. The method can also be applied to metabolic situations not connected with productive performances.  相似文献   

5.
Male Wistar rats (of 60 g live weight) allotted in 10 groups were fed diets with gradually increasing lysine levels ranging from 1.4 to 7.4 g lysine/16 g N. Feed intake was restricted so much that the experimental animals did not change their live weights during the last 3 days of the 8-day experiment period. On the 7th experimental day, 4 animals of each group were injected i.p. 14-C-L-lysine, the 14CO2-excretion being subsequently measured over a period of 2 hours. On the next day, 6 animals of each group were applied an i.p. injected of 15N-L-lysine, the urine being collected over the following 24-hour period to measure the 15N-frequency. Applying both labelling methods, an increased catabolisation of the amino acid was observed after the metabolically necessary lysine requirement had been covered. The methods are very sensitive and revealed, under the experimental conditions chosed, a lysine requirement coverage of about 3 g lysine/16 g N. The possibility of using also 15N-labelled compounds in the metabolism-oriented amino acid requirement determination is likely to facilitate the transfer of the methodology to farm animals and would thus allow to study the amino acid requirement of man. The metabolism-oriented amino acid requirement determination will likewise allow to estimate exact amino acid requirement data under conditions that cannot be rated on the basis of productive yields.  相似文献   

6.
This experiment was designed to narrow the estimated range for lysine requirement of broiler chickens determined by isotopic techniques. In addition the influence of a long-term feed withdrawal previous 14C-lysine-injection on the lysine catabolism was investigated. 120 male broiler chickens 7 to 21 days posthatching received a diet based on wheat and wheat gluten. Lysine content was varied from 8.3 to 16.0 g/kg DM (3.2 to 6.3 g/16 g N) at 8 levels by supplementing the basal diet with L-lysine-HCl. After the feeding period animals of each group were labelled with 14C-L-lysine by intravenous injection 5.5 and 15.5 hours after feed withdrawal, respectively. During the following 4 hours the excretion of 14CO2 and CO2 was measured. Highest body weight gain was observed in the group with 13.8 g lysine/kg DM. In case of 14CO2 excretion measurements starting 5.5 hours after feed withdrawal an increase of 14CO2 excretion was observed if the lysine content of the diet exceeded 11.6 g/kg DM. This estimated range for lysine requirement (11.6 to 12.7 g/kg DM with 26% CP in the DM) was lower compared with the lysine requirement estimated by the growth curve (12.7 to 13.8 g/kg DM). This discrepancy could be explained by the fact that the results of the metabolism oriented determination of lysine requirement represent the requirement at the actual age, while the feeding experiment reflects a mean lysine requirement of the previous period of 14 days. If the animals were labelled with 14C-lysine 15.5 hours after feed withdrawal no clear response in 14CO2 excretion and specific radioactivity of CO2 on the dietary lysine content was observed.  相似文献   

7.
The objective of this study was to examine the effects of diet energy density (high versus low) and increased milk yield, induced by increased milking frequency (two versus three times daily), on the hepatic status of triacylglycerol (TAG) and glycogen content and hepatic long chain fatty acid (LCFA) oxidation capacity in early lactation in a 2 x 2 factorial design. Forty multiparous Danish-Holstein dairy cows were used from 8 weeks before to 8 weeks after calving. Liver biopsies and blood samples were taken in weeks -2, 2, and 7 from calving. The cows fed the high energy density diet, compared with the cows fed the low energy density diet, had an 18 and 28% higher milk production and net energy intake, respectively. Milk yield was increased by 10% when the cows were milked three times compared with twice daily. Complete (CO2 production) and incomplete (ketone body production) LCFA oxidation capacity in the liver were 35 and 32% higher, respectively, and liver TAG content was 48% lower for the cows fed the high energy density diet compared with the low energy density diet. Overall there was no effect of milking frequency on liver parameters. However, a significant interaction between diet and milking frequency showed that the cows milked three times daily and fed the low energy density diet had the lowest liver LCFA oxidation (CO2 and ketone body) capacity. Furthermore, these cows had the numerically highest liver TAG content. The results for liver LCFA metabolism are discussed in relation to the plasma concentration of metabolites and insulin. In conclusion, cows in early lactation given a high energy density diet will, in general, have a lower risk of high TAG infiltration in the liver.  相似文献   

8.
Purified diets, designed to supply a balanced sufficiency but not excess of essential amino acids, were supplemented with glycine, glutamic acid, proline or diammonium citrate (DAC) and fed to broiler chicks from the 7 d stage. Slow growth was obtained unless the diet was supplemented with 1 % L‐proline, confirming other work which suggests that proline should be reclassified as an essential amino acid for the chick. Increasing the level of glycine in the diet from 1 ‐o to 1 ‐6% did not result in a marked growth response.

Adding 11–07% DAC to the diet gave a significant growth response and a significant increase in the plasma level of amino acids. The utilisation of DAC was equivalent to that of an isonitrogenous supplement of glutamic acid in one experiment, but was significantly poorer than that of glutamic acid in another.

A significant linear regression of live‐weight gain on nitrogen intake was derived (r = 0–8582): growth was better on a practical than on any of the purified diets used but was in close accordance with this relationship. Partition of the nitrogen intake into intakes of the various nitrogenous components gave more precise correlations. Use of intakes of essential amino acids, DAC, glutamic acid, proline and added glycine explained over 90% of the variance; use of essential amino acids, glutamic acid and proline explained over 83% of the variance.  相似文献   


9.
Lambs (29 +/- 2.5 kg) were fed three diets at various intakes to determine whether diet composition or level of intake was reflected in changes in diet digestibility or ruminal fluid characteristics. In Exp. 1, a 90% concentrated, pelleted diet or a whole shelled corn diet with a pelleted protein supplement was fed at three levels of intake: ad libitum and 92.5 and 85% of ad libitum (n = 15). Exp. 2 compared the 90% concentrate diet with diets in which the energy density was diluted to 55 or 72.5% concentrate by including alfalfa hay as a possible method of restricting energy intake (n = 6). Lambs were adapted to diets for 13 d; feces were collected for 6 d and ruminal fluid was collected 0, 3, and 6 h after feeding on the day following fecal collection. Restricting intake in Exp. 1 did not affect DM digestibility or digestibility of CP or starch. Digestibility of ADF was increased (P less than .10) by restricting intake. Ruminal fluid pH, ammonia concentration and VFA concentrations were affected little by either restricted intake level. Digestibility of DM was 4% higher (P less than .001) and starch 5% higher (P less than .001) for the whole shelled corn diet than for the pelleted, high-concentrate diet. Ruminal pH of lambs fed the whole shelled corn diet was higher and fluctuated less than the ruminal pH of lambs fed the high-concentrate, pelleted diet. In Exp. 2, diet digestibility was reduced (P less than .01) and ruminal pH was increased (P less than .002) by addition of hay. Restricted feeding of lambs did not seem to increase diet digestibility or alter ruminal conditions.  相似文献   

10.
1. The influence of dietary conjugated linoleic acid isomer (CLA, 0 and 10 g/kg) on the metabolic and physiological responses to immune stimulation induced by a single injection of Salmonella enteritidis lipopolysaccharide (LPS) or repeated injections of LPS and Sephadex G-50 was determined in male broiler chicks. 2. In experiment 1, 10-d-old chicks were fed on experimental diets for 14 d and half of the birds fed on each diet were injected intraperitoneally with LPS (1.5 mg/kg body weight). In experiment 2,7-d-old chicks were fed on experimental diets for 18 d. Immune stimulation was started at 19 d old and continued for 5 d. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of LPS at 19, 21 and 23 d of age, and with 250 mg/kg body weight of Sephadex at 20 and 22 d of age to stimulate the immune system. 3. In experiment 1, giving CLA prevented an increase in blood heterophil to lymphocyte ratio 7 h after a single injection of LPS, and increases in plasma ceruloplasmin and alpha 1 acid glycoprotein (AGP) 24 h after the injection, but not 7 h after the injection. CLA also prevented a decrease in food intake for 24 h after LPS injection. 4. In experiment 2, the CLA diet partially prevented reductions in body weight gain and weight gain to feed intake ratio caused by repeated injections of LPS and Sephadex. Feeding CLA prevented increases in plasma ceruloplasmin and AGP at 24 d of age caused by repeated injections of LPS and Sephadex, but not at 20 d of age. 5. These results suggest that feeding CLA alleviates some undesirable metabolic and physiological changes induced by immunological stimulation in male broiler chicks.  相似文献   

11.
Male Albino rats (90-100 g) were fed ad libitum (with limited periods of feeding) for 14 days. The diets were adjusted to a crude protein content of 10%. Powdered whole egg, fish meal, yeast and gelatine were used as protein sources. Additionally, one group of rats was fed a protein-free diet. On the 15th day of experiment the rats were fed a test diet at a level of 2 g per 100 g of body weight. 2 hrs after that the rats received 25 muCi of 3H glycine and 5 muCi of 14C-L-Leucine per 100 g of body weight administered by way of intragastric infusion. It was found that a large proportion of the radioactive amino acids were absorbed as early as after 0.5 hr. The highest rate of absorption was observed in animals fed dietary proteins of poor quality or a protein free diet, so that in animals receiving a gelatine diet or a protein-free diet only 68.4% or 56.4% of the administered amount of 14C activity were detected inside the gastro intestinal tract after 0.5 hr. Analogous data for the 3H activity were 52.4% and 25.3%. Maximum absorption occurred after 3-7 hrs. Following this the level of radioactivity in the intestinal contents again increased reaching a peak value after 14-24 hrs; in the case of 14C activity this peak value amounted to 25.4% of the administered dose in animals fed the gelatine diet and 32.8% in the group receiving the protein-free diet. It was established that the major proportion of the resecreted amount of 14C activity was present in leucine. Until 72 hrs after the intake of 14C activity the level of radioactivity was again found to decline, a processes which was induced by processes occurring in the large intestines. Moreover, evidence was obtained in confirmation of previous findings, indicating that the composition of faecal amino acids was constant and unaffected by dietary proteins.  相似文献   

12.
将年龄、胎次相同，年产奶量大于5000kg的围产期健康奶牛30头随机分为3组，每组10头。Ⅰ组饲喂中国奶牛饲养标准（2000）减少20％日粮（能量摄入80％组）。Ⅱ组饲喂中国奶牛饲养标准（2000）日粮（能量摄入100％组），Ⅲ组饲喂中国奶牛饲养标准（2000）增加20％日粮（能量摄入120％组）。试验从产前28d开始至产后56d结束，产后各组奶牛均饲喂标准泌乳日粮。采用内对照RT—PCR方法，检测了干乳期摄入不同能量的围产期奶牛肝脏活体组织载脂蛋白B100（apoB100）mRNA丰度。结果表明。apoB100mRNA相对表达量，产前至产后Ⅰ、Ⅲ组均呈先升高后降低的趋势，Ⅲ组产后apoB100mRNA丰度降低了61．45％，Ⅰ组呈逐渐降低的趋势，各组均在产后28d达最低值（Ⅰ组，P〈0．05；Ⅱ、Ⅲ组，P〈0．01）。产前14d至产后1d，apoB100mRNA相对表达量Ⅲ组高于Ⅰ组，Ⅰ组高于Ⅱ组，组间差异极显著（P〈0．01）；产后28d。Ⅰ组高于Ⅱ、Ⅲ组（P〈0．05）。由此可见，围产期奶牛能量摄入水平对肝脏载脂蛋白B100mRNA丰度有显著影响。  相似文献   

13.
Thirty-six Angus x Hereford heifers (365 +/- 60 kg) were used to determine the effects of supplemental dietary lipid sources on fatty acid composition of i.m., perianal (p.a.), and s.c. lipid depots. Lipid was supplied to diets as either corn oil or a rumen-protected conjugated linoleic acid (CLA) salt for two specific treatment periods of either the final 32 or 60 d on feed. Following an initial 56-d feeding period, heifers were fed one of three dietary treatments (DM basis): 1) basal diet containing 88% concentrate and 12% grass hay (CON), 2) basal diet plus 4% corn oil (OIL), or 3) basal diet plus 2% rumen-protected CLA salt (RPCLA) containing 31% CLA. The trans-10, cis-12 CLA concentration was greatest (P < 0.05) for heifers fed RPCLA and OIL diets and least (P < 0.05) for CON, regardless of time on dietary treatment. Heifers fed supplemental RPCLA had greater (P < 0.05) total CLA content than either CON- or OIL-fed heifers. Adipose tissue concentration of trans-11 vaccenic acid (TVA) was less (P < 0.05) for CON than OIL or RPCLA, which did not differ (P > 0.05). Percentages of C18:1 trans-10 were least (P < 0.05) in i.m. lipid compared with p.a. and s.c., which did not differ (P > 0.05). Following 60 d of lipid supplementation, heifers fed OIL and RPCLA had lower (P < 0.05) concentrations of oleic acid and total monounsaturated fatty acids (MUFA) compared with CON. The ratio of cis-9, trans-11 CLA:TVA was higher (P < 0.05) for heifers fed 60 vs. 32 d, but did not differ (P > 0.05) between adipose depots. Feeding OIL increased (P < 0.05) adipose concentration of C18:2 fatty acid, whereas feeding RPCLA increased (P < 0.05) total CLA isomers by 22%. Intramuscular lipid contained the lowest (P < 0.05) percentage of cis-9, trans-11 CLA, total CLA, C18:1 cis-9, C18:1 trans-10, and TVA. Total CLA and cis-9, trans-11 CLA isomers were increased (P < 0.05) in p.a. and s.c. adipose depots, whereas i.m. adipose tissue contained increased (P < 0.05) amounts of total PUFA. Results from this study indicate that short-term lipid supplementation to feedlot cattle can increase adipose tissue CLA concentrations, but only marginally (8.3 to 17.5%). Moreover, observed decreases in oleic acid and total MUFA concentrations of adipose tissues from heifers fed rumen-protected CLA or corn oil suggest that lipid supplementation may decrease delta9 desaturase activity in adipose tissues, which in turn would lower the conversion of TVA to cis-9, trans-11 CLA isomer.  相似文献   

14.
A trial using 64 weanling pigs (TR4×PIC C22) was conducted to determine the effects of menhaden fish oil supplementation and diet complexity on performance and immune response of nursery pigs. Pigs (17 days and 6.27±1.16 kg) were weaned into a segregated early wean facility and given free access to a complex diet for 7 days post-weaning. At day 0 (day 7 post-weaning), pigs were blocked by weight and allotted to 64 pens. Treatments (Trt) were arranged as a 2×2×2 factorial arrangement. Main effects included diet (complex versus simple), oil (menhaden fish (MFO) versus corn (CO)), and immunogen (saline versus lipopolysaccharide (LPS)). Experimental diets contained 6% oil (6% CO or 5% MFO+1% CO) and were fed for 14 days. On day 12, i.v. injections of either LPS (150 μg/kg) or saline were given, followed by blood collection at 30 min intervals for 6 h. After the immune challenge (day 14), pigs were placed onto a common corn-soybean meal fortified diet and growth performance was evaluated until termination of the study (day 28). Pigs were weighed and feed intakes recorded at 7, 14, and 28 days. Prior to immune challenge (day 12), there were differences in BW for pigs fed complex versus simple diets (P<0.01; 13.1 and 12.1 kg, respectively) and pigs fed CO versus MFO diets (P<0.05; 12.9 and 12.3 kg, respectively). During the challenge period, for pigs treated with LPS there was a Time×Immunogen×Oil effect (P<0.001) for serum cortisol with MFO fed pigs having lower serum cortisol as compared to CO fed pigs. Also, during the challenge period, for pigs treated with LPS there was a Time×Diet×Immunogen×Oil effect (P<0.001) for serum tumor necrosis factor- (TNF-) with pigs fed complex diets supplemented with CO having higher serum TNF- as compared with pigs fed complex diets supplemented with MFO. At days 14 and 28, LPS-treated pigs had lower BW than saline injected controls (P<0.001 and 0.01, respectively). In addition, pigs fed simplified diets continued to have lower BW after challenge compared to pigs fed a complex diet. Interestingly, there were no differences (P>0.10) in BW after challenge in pigs fed MFO. This study suggests that MFO supplementation alters the immune response during LPS challenge and that simplified diets may compromise nursery performance.  相似文献   

15.
A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.  相似文献   

16.
Crossbred wether lambs were used to assess the effect of altered forage:concentrate ratio and metabolizable energy intake on metabolism of substrates by ruminal epithelium using an isolated cell system. Lambs (n = 28; 20.1 +/- 3 kg BW) were assigned randomly to a factorial arrangement of dietary treatments consisting of either 75% forage or 75% concentrate fed once daily at either .099 or .181 Mcal ME x(kg BW(.75))(-1) x d(-1) for 52 d. After a 52-d feeding period, isolated rumen epithelial cells (IREC) were incubated in the presence of an oxidizable substrate with a single 14C label (acetate, propionate, butyrate, glucose, glutamate, and glutamine) at concentrations ranging from .1 to 50 mM, and substrate oxidation to 14CO2 or metabolism to beta-hydroxybutyrate (beta-HBA), acetoacetate, pyruvate, and lactate was determined. For all substrates, oxidation to CO2 was concentration-dependent and saturable within the physiological range. Differences in substrate oxidation to CO2 by IREC at specific substrate concentrations did not affect Vmax (maximal rate of substrate oxidation, nmol oxidized to CO2 x 1 x 10(6) cells(-1) x 90 min(-1)) and K(ox) (concentration of substrate at which half Vmax oxidation rate is achieved, mmoles/L) estimates for the dietary treatments. Production of beta-HBA from butyrate by IREC from the lambs fed 75% forage was not affected by ME intake; however, production was elevated by high ME intake of the 75% concentrate diet (diet x intake interaction; P < .02). Acetoacetate production from butyrate by IREC from lambs fed at high ME intake was greater (P = .001) than from those fed at low ME intake. Lactate and pyruvate production from glucose, glutamate, and propionate were generally unaffected by dietary treatment; however, rate of glutamine metabolism to lactate and pyruvate by IREC was increased with increased ME intake. The observed changes in metabolite production rates across groups did not affect the predicted Vmax and K(ox) parameter estimates. The estimated K(ox) values corroborate that VFA are the primary oxidizable fuels used by ruminal epithelial cells while illustrating that other substrates such as glucose, glutamate, and glutamine would not be expected to be oxidized extensively in vivo due to the high K(ox) relative to substrate concentrations in vivo. In conclusion, the capacity of isolated ruminal epithelial cells to oxidize substrates was largely unaffected by ME intake or dietary forage:concentrate ratio of the diet.  相似文献   

17.
One hundred sixty pigs were used in a 2 x 2 factorial design to compare the performance response to daily injection of porcine somatotropin (PST); (0 or 2 mg/d) in animals fed a 14% CP corn-soy diet (control, C) to those fed a diet with 10% added fat (F) and calorie:protein and lysine:protein ratios similar to that of the C diet. Treatments, assigned randomly to 20 pens (n = 5/treatment) of eight pigs each, were initiated at 90 kg body weight and continued for 28 d. Responses to PST and dietary fat were typical. These include improved gain and feed efficiency and decreased feed intake. The effects of dietary fat on intake and efficiency were accounted for largely by the difference in energy density of these diets. Across diets, PST treatment resulted in a 13% improvement in ADG (P less than .001), a 13% decrease in feed intake (P less than .0001) and a 22% improvement in efficiency (P less than .0001). Of particular interest were the additive (PST x diet interaction, P less than .2) effects of PST and dietary fat on gain in these animals. Pigs treated with PST that were fed the F diet had greater rates of gain than did PST-treated pigs fed the C diet (P less than .05). Treatment with PST increased ADG by 9% in pigs consuming the C diet vs 16% in pigs fed the F diet. Similarly, dietary fat resulted in 4 and 11% increases in ADG in pigs treated with 0 or 2 mg of PST/d.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Thirty mink dams nursing litters of six kits were assigned to one of three dietary treatments [high protein (HP), medium protein (MP) and low protein (LP)], fed ad libitum for 4 week from parturition, to investigate the effects of protein supply on milk yield and milk composition in order to estimate the amino acid requirement of the lactating mink. Twelve dams were held in an intensive care unit and subjected to balance experiments and the kits were injected with deuterium oxide to determine water kinetics and milk yield. Eighteen dams were kept under normal farm conditions but with feed intake of dams and live weight gain of kits being determined and milk samples collected. The ME intake was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet, whereas the amino acid intake (g/day) was lowest (p < 0.05) in dams fed the LP diet. In the third and fourth weeks of lactation milk yield was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. Chemical composition of milk was not affected (p > 0.05) by dietary treatment. However, protein content tended (p = 0.06) to be lower in dams fed the LP diet. Amino acid content (g/16 g N) of milk was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. This resulted in the highest (p < 0.05) amino acid intake and highest (p < 0.001) live weights of kits nursed by dams fed the LP and MP diets, which may be explained by a combined effect of higher ME intake and reduced energetic costs for glucose production through less amino acids being used in gluconeogenesis. In conclusion, the improved performance of dams fed the LP diet suggested that their requirement of essential amino acids and non-specific N were covered, and the requirement of digestible amino acids of lactating mink (kg(0.75)) was, thereby, estimated by use of a factorial approach including the amino acid excretion in milk of LP dams.  相似文献   

19.
The main objective of this study was to find out whether the content of alpha-linolenic acid (ALA) in plasma cholesteryl-esters (CE) or triglycerides (TG) in parrots might serve as an index of ALA intake. The intake of ALA might be a risk factor for atherosclerosis, but on the basis of the fatty acid composition of seed mixtures the intake is difficult to assess due to selective eating of seeds. Parrots were fed two seed mixtures that differed in ALA content according to a cross over design. The macronutrient composition of the diets supplied differed from that of the diets consumed. The diets consumed had higher levels of dry matter, crude protein, crude fat and energy, and lower levels of crude fibre and crude ash. The ALA content, expressed as g/kg diet, was similar for the diet supplied and that consumed, irrespective of the type of diet. The diets had no systematic effect on plasma lipid concentrations. There were marked differences in plasma cholesterol concentrations between parrot species. When the diet with the low ALA content was fed (0.8% ALA of total fatty acids consumed, 1.1 g ALA/kg of diet consumed), the plasma CE and TG did not contain detectable ALA amounts. When the diet with the high ALA content was fed (4.2% ALA of total fatty acids consumed, 6.1 g ALA/kg of diet consumed), the plasma CE and TG contained about 1% ALA of total fatty acids. It is suggested that the content of ALA in plasma CE and TG might be used as an indicator of ALA intake.  相似文献   

20.
The objective of this study was to determine the effect of offering animals a multiforage choice (MF) of fresh herbages on dry matter intake (DMI), live weight gain, and animal welfare, in comparison with a monotonous diet of ryegrass (Lolium perenne L.). Twenty ram lambs (30.5 ± 0.9 kg initial live weight; mean ± SEM), were randomly allocated to either a diet consisting of diverse MF choice or a single forage ryegrass (SF) diet (n = 10 per treatment) for 35 d. Both diets were fed ad libitum; however, the MF diet was composed of set dry matter ratios of 24% chicory (Cichorium intybus L.), 30% lucerne (Medicago sativa L.), 25% plantain (Plantago lanceolata L.), and 21% ryegrass. The DMI of the MF lambs was 48% greater (P < 0.01) and the within animal day-to-day coefficient of variation (CV) of intake was 26% lower (P < 0.01) than the SF lambs. The average daily gain (ADG) of lambs offered the MF diet was 92% greater (P < 0.01) than the lambs offered the SF diet. The within-animal day-to-day CV of intake was negatively related to ADG (r = −0.59; P < 0.01). The MF lamb’s urinary N concentration was 30% lower (P < 0.01) than that of the SF lambs. The SF lambs spent more time (P < 0.05) exhibiting stereotypic behaviors in the afternoon and spent more time observing other animals than the MF. Overall, allocating an MF choice of fresh herbages as opposed to a single forage diet of ryegrass increases DMI and thereby animal performance, while potentially reducing urinary N excretion.  相似文献   

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