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1.
In a tripartite experiment with five rats each the suitability of 51Cr2O3 and TiO2 as markers was tested for estimating the transit time and passage rate as well as the total protein digestibility and the proportion of endogenous nitrogen in the small intestine with very small samples. Both markers are suited for these tests because of their simple analysis, their high recovery rate (94...105% for 51Cr2O3; 98...105% for TiO2) and their quantitative excretion in faeces within 3 days. Depending on the level of crude fibre (5.1 resp. 9.4% of DM) the transit time was found to be 7...8 h for a commercial breeding feed and 5...6 h for this commercial feed +15% straw meal. After the application of a single doses, the marker excretion of 50% appeared within 10 +/- 1 h resp. 8 +/- 1 h, and after the 12th hour there were no significant differences at all. The apparent N-digestibilities estimated by the conventional or the 51Cr2O3 resp. TiO2 indicator method did not show any differences. The proportion of endogenous nitrogen at the end of the small intestine calculated on the basis of the indicator dilution method was 83 +/- 11% for 51Cr2O3 and 83 +/- 12% for TiO2.  相似文献   

2.
In investigations with 30 young cows (twin cattle) the applicability of straw materials as sole roughage was tested during the first half of their second year of life (183 feeding days). In the course of the experiment sole feed pellets (I) and partly pelleted rations of dried feed (straw pellets plus loose wheat and loose wheat straw resp.; II) were used. Approximately 72% of the dry matter intake was provided from straw materials in both groups and on an average of the test period. Weight gain and feed expenditure were ascertained and at the end of the test period also the parameters of rumen fermentation and of the concentration of some metabolism parameters in the blood serum. With feed supply being restrictive (2.2 kg dry matter/100 kg live weight), a high dry matter intake from straw (1.6 kg/100 kg live weight or 4.8 kg/animal and day resp.) and average weight gains of between 574 (I) and 582 g (II) were achieved. The standard expenditure of energy (kEFUcattle) and protein stated in the GDR feed evaluation system for this period of development was undercut by 27 (II) and 29 (I)% and 12 (II) and 18 (I)% resp. On average the expenditure of kEFUcattle/kg weight gain was 4.75 (I) and 4.98 (II) and that of digestible crude protein/kg weight gain 679 (I) and 733 g (II). Compared to standard values the expenditure of energy and feed expenditure from concentrates was 80%. Rumen fermentation conditions corresponded to those of a high cellulolytic activity (C2: C3 ratio of greater than 4: 1). The only significant differences between the groups at the time of sampling were to be observed in the total concentration of volatile fatty acids and in the pH-value in the rumen. The absolute (1/animal) and relative (1/kg dry matter intake) volume of rumen fluid varied between 65 and 70 and between 10.5 and 12.5 1. The ascertained concentration of selected metabolism parameters were within the physiologic standard range.  相似文献   

3.
本研究测定分析了秸秆制粒饲喂肉牛对其采食、反刍、养分表观消化率、瘤胃发酵和增重的影响,以丰富秸秆饲料化利用方式。试验选取30头18月龄左右、活重接近的西杂肉牛,随机分成3组(每组10头),分别饲喂粉碎玉米秸秆(对照组)、玉米秸秆颗粒饲料(试验Ⅰ组)及玉米秸秆精粗饲料颗粒(试验Ⅱ组)。结果表明,1)秸秆制粒饲喂肉牛,其采食、反刍、咀嚼时间均有所缩短,且每食团咀嚼时间显著少于对照组(P=0.004),而试验Ⅱ组采食时长显著低于对照组(P=0.032)。2)除试验Ⅰ组中性洗涤纤维的表观消化率显著低于对照组外(P<0.05),3组肉牛其他养分的表观消化率均无显著差异。3)秸秆粉碎制料后饲喂肉牛影响瘤胃发酵,与对照组比较,试验Ⅰ组瘤胃pH值及丁酸含量显著下降(P<0.05),而乙酸含量和乙酸/丙酸显著升高(P<0.05);试验Ⅱ组瘤胃液丁酸含量显著下降(P<0.05),乙酸/丙酸及NH3-N含量显著升高(P<0.05)。4)秸秆粉碎制粒饲喂肉牛能显著增加日增重和饲料转化率(P<0.05),试验Ⅰ组及试验Ⅱ组日增重较对照组分别高出0.36和0.38 kg,饲料转化率(料重比)分别提高27.86%和29.09%。  相似文献   

4.
In experiments with colostomized broiler hens apparent digestibility of the crude nutrients of the ration after straw meal supplements of 20, 30 and 40 g per animal was determined. In addition, the 15N digestibility of straw meal and wheat was ascertained on the basis of straw meal supplements. The digestibility of the crude nutrients of the rations decreased significantly (P less than 0.05) after the straw meal supplement. The adaptation of the test animals to the straw meal intake resulted, at a daily consumption of 20 g straw meal, in an increase of the apparent crude fat digestibility (P less than 0.05) in dependence on the time of straw meal feeding, in which the original values without straw meal supplement were not reached. The digestibility of the 15N excess (15N') of the wheat was, at 86 +/- 1%, largely independent of the straw meal intake. The apparent digestibility of the straw-15N excess in broiler hens of 42 +/- 8 to 55 +/- 2% is surprisingly high.  相似文献   

5.
After 15N-labelling over 7 days male albino rats (92-95 g live weight) received either a wheat or whole egg diet (10 animals each) for 4 days. On the following day of the experiment 5 animals each continued to receive their diets as their morning meal (group 1 whole egg, group 3 wheat) and 5 animals each after the previous feeding of a wheat diet received a 2.9 g whole egg diet (group 2) and after the previous feeding of a whole egg diet a 2.85 g wheat diet (group 4) resp. This morning meal was supplemented with chromium(III)oxide. The rats consumed their meals within 20 minutes. The animals were killed 3.5 hours after the beginning of feed intake. At that time the following relative amounts (in % of the intake) could be detected in the stomach in the sequence of groups 1 to 4: Cr2O3 = 22.5; 26.5; 57.5 and 64.2; dry matter = 25.4; 22.1; 43.2 and 38.5. The better agreement between the whole egg diet and Cr2O3 can be explained with the hydrophobic qualities of Cr2O3 and the small disposition of the Cr2O3 to decompose in combination with the whole egg diet. In the first third of the small intestines less than 1% of the intake of Cr2O3 and a maximum of 3.5% of the DM could be detected. Between 20 and 36% of the Cr2O3 and between 15 and 20% of the dry matter intake were ascertained in the small intestines as a whole; in the large intestines the values were 12-20% of the Cr2O3 and 16-23% of the DM. Endogenous 15N-secretion could be ascertained in all parts of the digestive tract. According to the method suggested by U. Bergner and H. Bergner (1982), protein digestibility in the last third of the small intestines was calculated as follows: (formula; see text) The following ileal digestibility values were calculated for crude protein: whole egg = 95.6%; whole egg (wheat previously) = 95.5%; wheat = 94.1%; wheat (whole egg previously) = 85.1%. It is a precondition for the application of this method that at the time of killing representative quotas of the diet sample to be tested can be detected both in the stomach and the large intestine so that the decrease of 15N-labelling in the ileum is actually caused by the test protein.  相似文献   

6.
This study was conducted to determine true ileal AA digestibility coefficients and the endogenous AA outputs associated with barley samples for growing-finishing pigs using the regression analysis technique with dual digestibility markers. Six barrows, with 30.5 and 58.6 kg average initial and final BW, were fitted with a simple T-cannula at the distal ileum and fed six barley-based diets at close to ad libitum feed intake according to a 6 x 6 Latin square design. The six diets contained 97% of six barley samples varying from low to high in CP and AA contents (8.5, 9.2, 9.8, 11.5, 12.6, and 15.6% CP, respectively, on DM basis). The dietary NDF content ranged from 16.8 to 23.8% on DM basis. Chromic oxide (Cr2O3) and acid-insoluble ash (AIA) were used as digestibility markers. Each experimental period lasted 7 d. Ileal digesta were collected, at 2-h intervals, for a total of 24 h during d 6 and 7. There were linear relationships (P < 0.01) between dietary contents of apparent ileally digestible and total CP and AA as determined by using either Cr2O3 or AIA as a digestibility marker. The use of Cr2O3 vs AIA affected (P < 0.01) the determination of true ileal AA digestibility coefficients and the endogenous CP and AA outputs. However, there were no differences (P > 0.01) in the true ileal AA digestibility coefficients in barley samples between this study and the average values reported in the literature. The endogenous CP and AA outputs determined in this study were higher (P < 0.01) than reported values (35.1+/-3.0 vs 14.7+/-1.1 g CP/kg DMI). It is concluded that dual digestibility markers should be used to measure true ileal AA digestibility coefficients and endogenous AA outputs when dietary fiber content is high and the ileal digesta is collected through a simple T-cannula in the pig. True rather than apparent ileal AA digestibility coefficients determined in barley samples should be used in diet formulation for swine. The gastrointestinal endogenous AA secretion, recycling, and output losses are important in whole-body AA utilization and homeostasis, especially when fiber-enriched diets are fed to growing-finishing pigs.  相似文献   

7.
In studies with weaned piglets of the land race the usability of partly hydrolysed straw meal (PSM) in concentrate - straw meal mixtures was tested over a period of 56 days (42nd-98th day of life; 1st-8th week of feeding. The hydrolysed straw product was there tested in a parallel experiment each without and after neutralization (by means of CaCO3) in quotas of 5, 10 and 15% as supplement to the concentrate feed (based on dry matter) in comparison to a sole concentrate feeding. Daily weight gain and feed and energy expenditure as well as nutrient digestibility and the buffer effect of the PSM rations were ascertained. Measured by weight gain, feed intake and concentrate- and energy expenditure related weight gain, a 10% quota of partly hydrolysed straw meal in a period near weaning (1st-4th week of feeding) had the highest effect and was far superior to traditional concentrate feeding. Lower quotas of PSM in this period did not show a sufficient dietetic effect (diarrhea symptoms), higher reduced the effect on the performance parameters. In the period more remote from weaning (5th-8th week of feeding) the effect of the straw meal integration was generally reduced, a quota of about 5% proved optimal. The registered higher daily weight gains in the total test period (1st-8th week of feeding in which concentrate - straw meal mixtures (relative 106-130%) were closely related to the daily intake of digestibility organic matter. The decrease in digestibility of organic matter in the total ration remained small with the use of the well fermentable crude fibre from the hydrolysed straw product and the balance was overcompensated by higher feed intake. A pH-value decrease of the feed mixtures and a physiologically suitable influence on the pH-value in the stomachs of the test animals could be ascertained due to the buffer capacity of the hydrolysed straw products used. With regard to this, the non-buffered hydrolysed straw product had a higher effect, which was, among other things, reflected in higher performances.  相似文献   

8.
In studies with 16 breeding sows of the country species the feed value of straw materials and their fitness for use were ascertained in a long-term experiment. On the feeding basis of a concentrate ration (IV) untreated (I), HCl treated (II = HCl treatment without steaming) and partly hydrolysed straw meal (III = HCl treatment with subsequent steaming) were tested. In the course of the experiment and at a nutrient level of 1 (maintenance requirement), the digestibility of the organic matter of the ration and that of some major and trace elements, N and mineral balances as well as feed passage rate and water excretion in faeces were ascertained at selected measuring times. The following mean results were achieved: The integration of all straw materials tested lead to a significant reduction of the digestibility of the organic matter of the total ration, the least negative effect was caused by partly hydrolysed straw meal (III). The fractions crude protein, crude fibre and N-free extracts were mainly affected. Straw meal integration had a gravidity-conditioned influence on the daily N balance. Increased N excretion in faeces could only be compensated by non-pregnant animals by a decreased N excretion in urine. The mineral balance (Ca, P, Na, Cu and Mn) remained largely uninfluenced by the straw supplement. The feed passage rate was reduced by the use of all straw meal variants to ca. 50% of the value measured after the sole feeding of concentrate (IV). Feed passage rate and water excretion in faeces were approximately reciprocal. The digestibility of the organic matter of the straw materials ascertained according to the difference method amounted to 7.4 (I), 18.1 (II) and 27.9% (III); that of the N-free extracts in the same sequence to 10.0, 22.0 and 34.9%. The calculated energetic feed value was for I = 70.7, for II = 154.9 and for III = 240.7 EFUpig/kg DM.  相似文献   

9.
Recent investigations suggest that the development of multinutrient feed blocks with inclusion of tree and shrub leaves could improve the nutritive value and digestibility of straw. In order to test these possibilities, three types of multinutrient blocks (MNB) namely: MNB0 (wheat bran?=?100 %; Tithonia diversifolia leaf?=?0 %), MNB50 (wheat bran?=?50 %; T. diversifolia leaf?=?50 %) and MNB100 (wheat bran?=?0 %; T. diversifolia leaf?=?100 %) were fed for 15 days in a 3?×?3 Latin square arrangement to West African dwarf goats consuming Brachiaria ruziziensis straw. The blocks presented a good cohesion and a good hardness. The inclusion of T. diversifolia improved levels of crude protein, mineral, feed unit for milk production (UFL) and feed unit for meat production (UFV), but decreased palatability. The effects on the digestibility of B. ruziziensis straw were evaluated in nine West African dwarf goats fed individually with MNB0 + straw, MNB50 + straw and MNB100 + straw. The dry matter, organic matter and crude fibre digestibility of B. ruziziensis straw increased slightly with increasing level of inclusion of T. diversifolia. The apparent digestibility of nitrogen was comparable for all diets independent of the level of inclusion of T. diversifolia. This study showed that the inclusion of T. diversifolia leaves in the MNBs can be recommended to improve the feeding of goats during periods of drought.  相似文献   

10.
The digestibility of the crude nutrients of 6 rations on the basis of oat, hay and wheat straw (in one case a straw-concentrate mixture as sole feed) was compared at a nutrition level of 1.0 and 1.3 resp. with adult geldings of the species "Noble Crossbreed", adult pony geldings and wethers The energy concentration of the rations varied between 424 and 585 EFUcattle/kg DM, the crude fibre content between 17 and 25% of the DM. In the studied field, a good agreement between horse and pony could be ascertained as to the digestibility of the organic matter and NFE. There are partly considerable differences between the apparent digestibility of crude protein and crude fibre. The differences in the digestibility of crude fibre between horse and sheep increase with a growing crude fibre content. The differences of the apparent digestibility between horse and pony on the one hand and sheep on the other were highly significant in all cases.  相似文献   

11.
The study evaluated the use of yttrium oxide (Y(2)O(3)) as an inert marker in studies of apparent total tract digestibility in dogs, blue foxes and mink. Comparison was made with total faecal collection, and use of chromic oxide (Cr(2)O(3)) as marker respectively. Four experimental diets were added 0.1 g/kg yttrium oxide and 10 g/kg chromic oxide and fed to four animals of each species. Faecal recovery of yttrium oxide was 94.4% (SEM +/- 1.0), and of chromic oxide 105.8% (SEM +/- 1.5). The digestibilities of dry matter, crude protein, crude fat, starch and total carbohydrates obtained by total collection and yttrium oxide as marker showed close similarity, and in most cases not significant differences, independent of species and diets. In dogs, overall digestibilities of main nutrients with chromic oxide as marker were not significantly different from overall means obtained with yttrium oxide (p > 0.05). Overall digestibility of dry matter, crude protein and total carbohydrates in blue foxes and mink was significantly higher with chromic oxide than with yttrium oxide (p < 0.05). In dogs and blue foxes, digestibilities of individual amino acids determined by use of yttrium oxide were not different from values obtained using total collection of faeces, both within diets and for overall mean (p > 0.05). Overall amino acid digestibilities in dogs determined with chromic oxide as marker were similar to corresponding figures for yttrium oxide, whereas use of chromic oxide resulted in significantly higher digestibilites for a number of amino acids compared with yttrium oxide in foxes and mink (p < 0.05). The digestibilities of most main nutrients and amino acids revealed no interaction between diet and method (p > 0.05). The study showed that yttrium oxide can be used in low concentration in the feed, and allows high accuracy of analyses and thereby precise digestibility determination. It is concluded that yttrium oxide is an alternative inert marker to chromic oxide in the studied species.  相似文献   

12.
Two groups of four pigs each were fed ad libitum with rations containing 70.7% barley, 7.7% fish meal, 0.7% Sussopan, 0.9% mixed minerals and 20% straw meal. Group 1 received partly hydrolysed straw meal, group 2 untreated straw meal. When those rations were given, weight increase performances of 767 g per animal and day in group 1 and 537 g per animal and day in group 2 were achieved in a preliminary 30-day feeding period. On the basis ofthe weight of the feed remnants, a consumption of 19.7% dry matter of the straw meal (group 1) resp. 18,5% (group 2) of the total intake of dry matter could be ascertained. At an average live weight of 93 kg (group 1) resp. 87.5 kg (group 2) the digestibility of both rations was examined. A significant difference was only found for the crude protein fraction with an apparent digestibility of 74.6% in group 1 and of 79.1% in group 2. Those pigs which received partly hydrolysed straw meal consumed 71.4 g N per animal and day, of which 25,4% were excreted in feces and 32.4% in urine. Those animals which were fed with untreated straw meal consumed 62.9 g N per animals and day of which 20.8% were excreted in feces and 49.7% in urine. The higher N-excretion in feces could also be proved for most amino acids the feeding with partly hydrolysed straw meal. For arginine, serine, glutamic acid, proline, isoleucine and Leucine these differences were significant. Differences concerning N-retention could not be found between the groups. 25% of the organic matter of the partly hydrolysed straw meal, 9.4% of the crude fibre and 44.2% of the N-free extractives were digestible. Of the untreated straw, 12.9% of the organic matter, 5.5% ofthe crude fibres and 21.7% of the N-free extractives were digestible. 193 EFpig were calculated for partly hydrolysed and 105 EFpig for untreated straw meal per kg dry matter. The result of substracting the CaCl2 of the partly hydrolysed straw meal is 205 EFpig per kg dry matter of the straw.  相似文献   

13.
The apparent digestibility of a molassed, chaffed grass hay/straw mixture was determined using four mature horses (mean weight 606 kg). Animals were stalled individually and kept on rubber mats. A preliminary feeding period of 18 days was followed by a 10 day collection period. Chromium-mordanted hay was given before the first feed at 08.00 h and subsequent meals were at 12.00, 16.00 and 20.00 h. On Days 3 and 10 of the collection, all faeces were sampled over a 24 h period. In addition, throughout the 10 day collection, faecal material was sampled at 10.00 and 16.00 h. The mean (+/- se) chromium recovery was 96.5 per cent +/- 0.76 and the hay/straw mixture contained 7 MJDE/kg dry matter and 15.1 g DCP/kg dry matter. There was no significant difference between the methods used to estimate apparent digestibility although chromium measurements consistently underestimated whilst acid-insoluble ash consistently overestimated digestibility values. There was a large variation in faecal chromium concentration for each horse over a 24 h period compared to acid-insoluble ash concentrations and, consequently, indirect estimates of apparent digestibility of nutrients in the equine are prone to large errors if chromium is used as a marker. If total faecal collection is impractical, acid-insoluble ash is the preferred indirect marker for the estimation of apparent digestibility coefficients for nutrients in horses.  相似文献   

14.
Texturized vegetable protein (TVP) from soy is widely used in dog foods but contains indigestible carbohydrate, which may affect intestinal transit. This study was conducted to determine whether TVP affects oroileal transit of the marker chromic oxide (Cr2O3). Four canned diets with Cr2O3 added were fed to eight cannulated mixed-breed dogs in a Latin-square design. The four diets contained reciprocal proportions of protein from TVP (0 to 57%) and from beef (100 to 43%). Ileal effluent was collected during wk 3 of each diet period, prececal apparent digestibility was measured on d 1 to 3 (eight dogs), and rate of appearance of Cr2O3 and chyme was measured on d 4 (six dogs). There was a postprandial delay before any chyme or Cr2O3 was collected, but from 2 to 8 h postprandially the rate of excretion was almost constant (approximately 11%/h). As TVP increased, mean prececal digestibility of protein and carbohydrate decreased from 77 to 71% and from 80 to 62%, respectively. Chyme excretion from 2 to 8 h postprandially increased from 5.8 to 8.3 g DM/h (P < .0001) as TVP increased but times for transit of Cr2O3 and appearance of chyme (as percentage total collected/hour) did not change. Mean times to first appearance and 15, 50, and 95% excretion were 76, 160, 347, and 707 min for Cr2O3 and 60, 147, 338, and 712 min for chyme, respectively. Mean Cr2O3 recovery was 93%. In conclusion, small intestinal transit of Cr2O3 was unaffected by increasing dietary TVP despite marked changes in carbohydrate digestibility.  相似文献   

15.
The digestibility of the nutrients of Fermosin was tested on pigs and the following values were ascertained: organic matter=86%, crude protein=89% and N-free extractives=83%. The net energy ascertained on the basis of the content of nutrients and the digestibility of the nutrients of Fermosin amounts to 617 energetic feed units for pigs/kg dry matter. The true digestibility of the amino acids of Fermosin was determined on pigs and chicken. For lysin the true digestibility was ascertained as 95% (pigs) and 73% (Broilers). Due to the different digestion abilities of the two animal species, corresponding differences in the digestibility of the other amino acids were found as well.  相似文献   

16.
In order to use rice straw as forage in livestock feeding, the effects of steam-treated rice straw (at 15.5 kgf/cm2 for 120 s) feeding on growth performance, plasma volatile fatty acid profile, and nutrient digestibility of goats were determined. Twenty male goats (18.69?±?0.34 kg) were used in an 84-day trial. The goats were divided into four groups of five goats each to receive steam-treated (STRS) or untreated (UTRS) rice straw diet under closed house (CH) and open house (OH) systems. The results revealed that the goats fed with STRS had significantly higher dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility; similarly, the average daily weight gain and feed conversion ratio were higher for STRS groups under both CH and OH systems than those for UTRS. The plasma protein and insulin in STRS and cholesterol in UTRS groups was higher (P?P?>?0.05) at 30 days. The plasma amylase, lipase, T3, T4 and glucagon at 30 and 60 days were not different (P?>?0.05) among the groups. The plasma acetate, propionate, butyrate, and total volatile fatty acid were higher (P?P?>?0.05) on these parameters. It could be concluded that steam treatment of rice straw at 15.5 kgf/cm2 for 120 s increased apparent nutrient digestibility, hence increased the growth and feed efficiency of growing goats.  相似文献   

17.
Two lots of straw pellets (supplemented with 10% molasses), produced either with a 5 mm sieve in a hammer mill (lot A) or with a 12 mm sieve (lot B) from wheat straw, were tested with 4 sheep (wethers, average live weight 43 kg) and 4 bulls (average 170 kg). After carrying out a digestibility experiment, the mean retention time (mrt), the 80%-excretion of the markers and the transit time were ascertained with the help of 51Cr-EDTA and 103Ru-phenanthroline. The digestibility of carbohydrates (both crude fibre and N-free extracts) was significantly higher for the bulls than for the sheep. Mrt, transit time and 80%-marker excretion were ascertained as follows: (Table: see text) The better digestion performance of carbohydrates from pelleted wheat straw in bulls in contrast to the sheep is due to the longer retention time of the digesta in the digestive tract of bulls. In connection with the considerably higher ruminating capacity of cattle in comparison to sheep, a longer retention time of the straw particles (Welch, 1982) in the reticulo-rumen must be considered.  相似文献   

18.
为研究不同精粗饲料比例对压缩型TMR颗粒饲料成型品质的影响,试验设计3个不同水平的精粗饲料比5∶5、4∶6、3∶7,粗饲料选用玉米秸秆和苜蓿干草,两者比例分别为1∶2、1∶1、2∶1,采用双因子多水平试验设计,按照压缩TMR颗粒饲料生产工艺流程生产压缩型TMR颗粒饲料,比较不同水平下,精粗比对压缩型TMR颗粒饲料感官性质、含粉率、粉化率、硬度、容重、密度、长度和直径等物理指标的影响。试验结果表明:随着饲料中精饲料比例的降低,粗饲料比例的增加,压缩型TMR颗粒饲料的感官品质下降,颗粒含粉率和粉化率显著增加(P < 0.05),硬度显著降低(P < 0.05),容重和密度显著降低(P < 0.05),颗粒长度显著增加(P < 0.05),对颗粒直径没有显著影响(P > 0.05)|不同粗饲料组成玉米秸秆与苜蓿干草比对饲料成型品质影响不显著(P > 0.05)|不同精粗比与粗饲料组成的交互作用对颗粒含容重和密度有显著影响(P < 0.05)。 [关键词] 压缩型TMR颗粒饲料|感官性质|物理指标  相似文献   

19.
The efficacy of replacing broiler litter with rice mill feed was evaluated in four experiments. In Exp. 1, 40 predominantly Angus steers (initial BW = 277+/-18.2 kg) were fed four dietary treatments for 112 d (five steers per pen; two pens per diet). Dietary treatments (DM basis) were as follows: 1) 47% broiler litter:53% corn; 2) 60% rice mill feed:40% corn; 3) 50% rice mill feed:50% corn; and 4) 40% rice mill feed:60% corn. All diets, along with bermudagrass hay, were fed free choice. Daily gains were faster (P < 0.10) for the 50:50 and 40:60 diets (1.26 and 1.30 kg/d, respectively) than for the broiler litter diet (0.89 kg/d). Daily DMI was less (P < 0.10) by steers consuming rice mill feed-based diets than by those consuming broiler litter-based diets. In Exp. 2, 16 Angus x Charolais steers (initial BW = 277+/-22.7 kg) were fed the same four diets used in Exp. 1 while housed in individual metabolism stalls for determination of nutrient digestibility. Daily DMI was not different (P > 0.10) among diets. Nutrient digestibilities did not differ among diets (P > 0.10). In Exp. 3, 40 Continental cross steers (initial BW = 257+/-21.3 kg) were fed one of four dietary treatments for 112 d (five steers per pen; two pens per diet). On a DM basis, diets were as follows: 1) 47% broiler litter:53% soyhulls; 2) 70% rice mill feed:30% soyhulls; 3) 60% rice mill feed:40% soyhulls; and 4) 50% rice mill feed:50% soyhulls. All diets, along with bermudagrass hay, were fed free choice. Daily gains were less (P < 0.05) for the broiler litter diet than for the 60:40 and 50:50 diets (1.05, 1.16, and 1.28 kg/d, respectively), and steers fed the broiler litter diet consumed less DM than did steers fed the varying rice mill feed-based diets (P < 0.10). In Exp. 4, 16 Angus x Charolais steers (initial BW = 292+/-21.1 kg) were fed the same four diets as in Exp. 3 while housed in individual metabolism stalls for determination of nutrient digestibility. Daily DMI was less (P < 0.01) for the broiler litter diet (5.0 kg/d) than for the 70:30, 60:40, and 50:50 diets (7.8, 7.9, and 7.9 kg/ d, respectively). Digestibilities for DM, OM, and ADF did not differ (P > 0.10) among treatments; however, CP digestibility was greatest (P < 0.10) for the 60:40 diet, and NDF digestibility was least (P < 0.10) for the 70:30 diet. Rice mill feed can be used to replace broiler litter to formulate low-cost diets for stocker calves. Soyhulls and corn can be blended with rice mill feed to produce acceptable backgrounding diets for growing beef calves.  相似文献   

20.
In connection with the measuring of parameters of the protein metabolism in parallel experiments, the energy metabolism of 6 chickens (origin Tetra B) in the live weight range between approximately 100 and 1,800 g was determined under conditions of restricted energy supply. 3 animals each received a feed mixture containing 20% (animal group 1) and 38% (animal group 2) crude protein. The amount of feed was daily increased by 1.5 g DM. The digestibility of energy and nitrogen was independent of the age. 66.3 +/- 3.3% and 64.0 +/- 5.0% resp. of the metabolisable energy were utilised for protein and fat retention. The energy maintenance requirement, determined at a live weight of 2,000 g, was independent of protein supply and averaged in the two animal groups 434 +/- 40 kJ metabolisable energy/kg live weight 0.75 . d. The result of multiple regression was, for the growth period investigated, an energy maintenance requirement of 403 +/- 32 kJ metabolisable energy/kg live weight 0.75 . d. 1.77 and 1.38 J metabolisable energy resp. were required for 1 J protein or fat retention. The energy requirement for protein retention was independent of the degree of protein supply. The results from the measuring of energy metabolism are discussed in connection with the kinetic parameters of protein metabolism ascertained in parallel experiments.  相似文献   

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