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1.
The influence of straight feeds on the fermentation pattern in the bovine rumen was investigated by feeding with hay, grass pellets, dried beet pulp with molasses and rolled oats. The study comprised 3 rumenfistulated dairy heifers, and the parameters measured were ammonia, pH and volatile fatty acids (VFA) in the rumen fluid, and non-glucogenic/glucogenic ratio (NGGR) in the VFA mixture.Typical differences related to the structure and chemical composition of the diets were demonstrated by the parameters measured. Fermentation of the easily digestible feeds resulted in so extensive variations that representative means could be obtained only by analyzing samples collected frequently throughout the feeding cycle.Rumen pH was found highly correlated to total VFA concentration for all the feeds examined, and the regression coefficients showed that diets, based upon beets and oats, were fermented under low buffering capacity.  相似文献   

2.
Dried sugar beet pulp was fed to sheep in mixture with molasses (BPM), molasses plus urea (BPMU) or with hay (BPH) in comparison to whole diet of hay (H) in four metabolic trials. There were no significant differences among the four rations although BPMU reflected the highest digestibility of nutrients. The BPH had the highest feeding value (total digestible nutrients "TDN" and metabolizable energy) and caused the highest retention of nitrogen. Blood profile revealed that there were no significant effect of the rations on packed cell volume, haemoglobin, activity of glutamic pyruvic transaminase, Mg and Na. Whereas glucose, total N, Ca, P and K significantly affected. The BPMU and BPH were found to be the best mixtures of the four tested rations in respect to the digestibility, feeding value and blood picture. Thus, dried sugar beet pulp could be offered to animals in a mixture with molasses and urea or with hay according to the availability and price of the other ingredients than beet pulp, i.e. molasses and urea or hay.  相似文献   

3.
An in vitro trial was conducted to investigate the effect of different inoculum sources (buffalo vs. cattle) on rumen fermentation and degradability. Incubations were carried out using rumen fluid obtained from buffalo or cattle fed the same diet [60% grass hay and 40% concentrate; 18 kg dry matter (DM)/day]. The fermentation kinetics of eight feeds commonly used in ruminant nutrition (alfalfa hay, barley meal, beet pulp, corn meal and silage, ryegrass hay and silage and soya bean meal s.e.) were studied with the in vitro gas production technique and rumen fermentation parameters (substrate disappearance, pH and volatile fatty acids production) were determined after 120 h of incubation. The linear relationship indicates that the microbial metabolic pathways of the two inocula for all the substrates were qualitatively similar, albeit often quantitatively different. In this in vitro study, a significant influence of rumen inoculum (buffalo vs. cow) on fermentation and degradability of the examined substrates was found. The differences in buffalo and cattle rumen fermentation can be explained with a different microbial activity of the two ruminant species, because of different amount of microbial population or microbial population constituted by different species of bacteria and protozoa.  相似文献   

4.
Wethers were fed complete granular feed rations including 41.81% of grass hay, 25.28% of barley, 15.37% of sawdust, 14.98% of molasses, 1.32% of urea, and 1.24% of mineral supplement in dry matter for 24 weeks. Samples of the dorsal rumen sac of these wethers were subjected to patho-anatomical, histological, histo-chemical, and electron-microscopical examination. Volatile fatty acids were also determined in the rumen fluid of slaughtered animals. The control group was given the same diet in the classical form with long hay. The rumen contents of the slaughtered animals of the experimental group had an increased level of total volatile fatty acids (125.93 mM) and butyric acid (17.8 M%). The acetate:propionate ratio was 3.66. No substantial differences were observed in enzymatic activity. Electronograms recorded an increase in the number of T cells and keratinizing cells -- this suggests an increased intensity of the process of keratinization.  相似文献   

5.
Fifteen Boer goat bucks, (6–8 months old), were allocated into two groups and fed ad libitum for a period of 29 days. The WH group (winter hay; n = 8) received a chopped diet consisting of grass hay, predominantly Themeda trianda grass (cut during the winter) from a natural pasture (veld). The WH+S group (winter hay plus supplement; n = 7) received a chopped diet consisting of Themeda trianda veld hay, supplemented with maize meal, molasses meal and urea. Body weights and feed consumption were recorded. Animals were slaughtered and carcass characteristics (weight and percentages of selected carcass cuts) and the carcass chemical composition were determined. The WH+S animals showed a higher live weight and cumulated feed intake. Carcass cuts from WH animals represented a higher percentage of the total carcass, especially cuts where muscle depots are higher (legs, best end chops and prime cuts). There is an attempt by non-supplemented animals to preserve the body's nitrogen reserves under prolonged nutritional stress conditions, and there is consequently a necessity to supplement feeding of small ruminants fed winter veld hay, especially if the animals are to be used in subsequent breeding seasons.  相似文献   

6.
Three sheep were fed a pelleted high-roughage diet either once, 6, or 24 times per day in a 3 x 3 Latin square trial. During each 21-d period, 14 d were allowed for adaptation followed by a 7-d collection period, in which samples for microbial counts were taken on d 1 and 5 and several rumen parameters were measured on d 2 and 6. Bacterial concentrations were not different between feeding frequencies on the first sampling day but were higher (P < 0.05) on the second sampling day when the sheep were fed 24 times a day. Fungal concentrations were not different among feeding frequencies on either sampling day. No effects of feeding frequency were observed for the concentration of cellulolytic bacteria or fungi. On d 2, ruminal volume was larger (P < 0.05) with six feedings than with one feeding and fluid volume turnover was greater (P < 0.05) when sheep were fed 24 times per day. Rumen pH values were higher (P < 0.01) on both d 1 and 5 when the sheep were fed once a day and the percentage of rumen dry matter was highest (P < 0.02) with 24 feedings. These findings would suggest that if the same amount of a given diet is fed daily, the number of feedings does not markedly affect microbial concentrations, rumen volume, or liquid turnover time.  相似文献   

7.
The feeding value of Phyllanthus discoideus (also called Margaritaria discoidea) leaves was evaluated using eight two-year-old West African Dwarf sheep fed natural grass hay. Four of the animals were fistulated ruminally and used for ammonia and volatile fatty acid determination in the fluid. Dried leaves of Phyllanthus discoideus were offered at two levels (25% and 50% of DMI, diets D25% and D50%, respectively) as supplements to the basal hay diet. The CP content of the control, D25% and D50% diets were 11.5, 12.6 and 13.6%, respectively, and their digestible energy amounted to 58.2, 61.1 and 56.9%, respectively. Rumen liquor was sampled one hour before and one, three and five hours after the morning feeding. Sheep fed the control diet had a higher ruminal ammonia concentration than those fed diet D25%. Similarly, ruminal ammonia concentration was higher in sheep fed the control diet than those fed the diet D50%. Five hours after feeding the ruminal ammonia concentration was significantly lower than one hour after feeding. The VFA concentrations in rumen fluid of sheep fed the control diet was inferior to those fed diets D25% and D50%. Sheep fed diet D50% showed significantly higher VFA concentrations than those fed diet D25%. Digestibility of organic matter and digestible energy did not show any significant difference. However, a marginal increase in organic matter digestibility of 3.5% was observed in diet D25% compared with the control diet. There was no significant difference in the N-digestibility in sheep fed the control, D25% and D50% diets. Nevertheless, a marginal improvement in N-digestibility (1.5%) and N-retention (2.7%) was observed with the highest level of Phyllanthus discoideus (D50%). In conclusion, Phyllanthus discoideus appears as a particularly valuable feedstuff because it contains low levels of condensed tannins (12.8 g/kg), high CP content (156 g/kg) and a relatively high GE content (19.3 kJ/g DM). Although the improvement in N-digestibility and N-retention were only marginal the feeding of Phyllanthus discoideus could be justified under extreme shortage of feed resources during dry season. It should also be mentioned that a much more pronounced effect by supplementation with Phyllanthus discoideus could be expected when poor quality grass hay prevalent in West Africa during the dry season is fed. Phyllanthus discoideus could serve as a supplement to poor quality grass at 25% to 50% of supplementation.  相似文献   

8.
Six rumen-fistulated Merino sheep were used in a crossover design experiment to evaluate the effects of an exogenous fibrolytic enzyme preparation (12 g/d; ENZ), delivered directly into the rumen, on diet digestibility, ruminal fermentation, and microbial protein synthesis. The enzyme contained endoglucanase and xylanase activities. Sheep were fed a mixed grass hay:concentrate (70:30; DM basis) diet at a daily rate of 46.1 g/kg of BW(0.75). Samples of grass hay were incubated in situ in the rumen of each sheep to measure DM and NDF degradation. The supplementation with ENZ did not affect diet digestibility (P = 0.30 to 0.66), urinary excretion of purine derivatives (P = 0.34), ruminal pH (P = 0.46), or concentrations of NH(3)-N (P = 0.69) and total VFA (P = 0.97). In contrast, molar proportion of propionate were greater (P = 0.001) and acetate:propionate ratio was lower (P < 0.001) in ENZ-supplemented sheep. In addition, ENZ supplementation tended to increase (P = 0.06) numbers of cellulolytic bacteria at 4 h after feeding. Both the ruminally insoluble potentially degradable fraction of grass hay DM and its fractional rate of degradation were increased (P = 0.002 and 0.05, respectively) by ENZ treatment. Supplementation with ENZ also increased (P = 0.01 to 0.02) effective and potential degradability of grass hay DM and NDF. Ruminal fluid endoglucanase and xylanase activities were greater (P < 0.001 and 0.03, respectively) in ENZ-supplemented sheep than in control animals. It was found that ENZ supplementation did not affect either exoglucanase (P = 0.12) or amylase (P = 0.83) activity. The results indicate that supplementing ENZ directly into the rumen increased the fibrolytic activity and stimulated the growth of cellulolytic bacteria without a prefeeding feed-enzyme interaction.  相似文献   

9.
The objectives of this experiment were to determine a NE value for pressed beet pulp and the value of concentrated separator by-product (de-sugared molasses) as a ruminal N source in growing and finishing diets for beef cattle. One hundred forty-four cross-bred beef steers (282 +/- 23 kg of initial BW) were used in 2 experiments (growing and finishing). A randomized complete block design was used, with a 3 x 2 factorial arrangement of treatments (level of pressed beet pulp and inclusion of concentrated separator by-product) for both studies. Steers were blocked by BW and allotted randomly to 1 of 6 treatments. In the growing study, the control diet contained 49.5% corn, 31.5% corn silage, 10.0% alfalfa hay, and 9.0% supplement (DM basis). Pressed beet pulp replaced corn at 0, 20, or 40% of dietary DM, and concentrated separator by-product replaced corn and urea at 10% of dietary DM. The growing study lasted for 84 d. Initial BW was an average of 2-d BW after a 3-d, restricted (1.75% of BW) feeding of 50% alfalfa hay and 50% corn silage (DM basis), and final BW was an average of 2-d BW after a 3-d, restricted (1.75% of BW) feeding of 31.5% corn silage, 10.0% alfalfa hay, 25.0% dry-rolled corn, 20.0% pressed beet pulp, 5.0% concentrated separator by-product, and 8.5% supplement (DM basis). After the growing study, the steers were weighed (415 +/- 32 kg), rerandomized, and allotted to 1 of 6 finishing diets. The control diet for the finishing study included 45% dry-rolled corn, 40% high-moisture corn, 5% brome hay, 5% pressed beet pulp, and 5% supplement. Pressed beet pulp replaced high-moisture corn at 5.0, 12.5, and 20.0% of the dietary DM, and concentrated separator by-product replaced high-moisture corn and supplement at 10.0% of diet DM. Steers were slaughtered on d 83 or 98 of the study. In the growing study, the addition of pressed beet pulp to growing diets linearly decreased (P = 0.001) DMI and ADG and inclusion of 10% concentrated separator by-product decreased (P = 0.001) G:F. Increased levels of pressed beet pulp in the finishing diets caused a linear decrease (P = 0.001) in ADG and tended (P = 0.06 and 0.07 for kg/d and % of BW, respectively) to quadratically decrease DMI, whereas addition of concentrated separator by-product increased (P = 0.02 and 0.001 for kg/d and % of BW, respectively) DMI. Apparent NEg of pressed beet pulp was 94.2% of that of corn in the growing study and 81.5% of that of corn in the finishing study.  相似文献   

10.
The gastrointestinal microflora of veal calves reared on different diets was studied because the nature of this microflora affects the quality of veal as a result of contamination of carcass surfaces with intestinal contents during slaughter. Diet A consisted of a milk substitute, diet B of milk substitute + straw pellets and diet C of milk substitute + straw pellets + concentrates. In the rumen fluid of calves reared on diet A significantly higher counts of Gram-negative bacteria but lower counts of thermotrophic enterobacteriaceae were found than in calves reared on diets B or C. As for the faecal flora, diets B and C seem to result in significantly lower counts of Gram-negative bacteria and thermotrophic enterobacteriaceae. In 46% of the faecal specimens and 62% of the specimens of rumen fluid from calves fed on milk substitute only, Pseudomonas aeruginosa was isolated in mean counts of 4.1 log cfu/g and 5.2 log cfu/g respectively. P. aeruginosa could not be isolated from any specimen from calves receiving straw pellets. These results indicate that the inclusion of straw pellets in the diet of veal calves may increase the bacteriological safety and keeping quality of veal.  相似文献   

11.
In an experiment with wethers the effect of the feeding with pelleted feed rations and the partial replacement of coarse fodder by non-treated beech sawdust on the motorial activity of the rumen was observed. The rumen motility was measured through a rumen fistula by means of the balloon method with the help of a capacitator primary unit, an electric manometer and a recording instrument. Over a period of 24 weeks the animals consumed 1.3 kg dry matter per day. It consisted of 41.8% meadow hay, 25.3% barley, 15.4% sawdust, 15.0% molasses, 1.3% urea, 0.76% mixed minerals and 0.48% hexametaphosphate in the form of pellets (test group) or the traditional classical form (control group). The feeding of pellets diminished the frequency (P less than 0.001) and the intensity of rumen contractions before and 1, 3 and 5 hours after feeding. Maximal frequency values were registered one hour after the food intake. During this time the number of secondary contractions of the rumen increased; differences of the frequency were, however, not registered, which means that the different physical form of the diet had no influence on the motorial activity of the rumen and that the food intake as such is the decisive factor. The diminished rumen motility in further hours after feeding was effected by treating the feed (grinding and pelleting).  相似文献   

12.
The consumption of solid feed is essential for successful transition from a pre-ruminant to a functional digestive tract. Lambs fed starter rations containing highly fermentable carbohydrates often experience dramatic changes in concentrations of rumen and blood metabolites. The optimal amount of roughage required in the diet of pre-ruminant animals is still unclear. The objective of this study was to determine the effect of feeding alfalfa hay on performance and rumen development in young Balouchi lambs. In a completely randomized design, 30 lambs were fed one of three experimental diets consisting of a control, without alfalfa hay (C), a diet containing 7.5% alfalfa hay (A1), and a diet containing 15% alfalfa hay (A2). Lambs fed A1 and A2 diets had lower dry matter intake during the pre-weaning period (P?P?=?0.02), but feed conversion ratio and average daily gain were not affected by feeding alfalfa hay. Concentration of beta-hydroxybutyric acid was higher in C compared with the A1 and A2 groups (P?P?=?0.04) and increased thickness of muscular layer (P?=?0.05). We concluded that including 15% alfalfa hay in the starter diet could reduce thickness of the keratinization layer and increase muscularity of rumen wall without adverse effects on growth and performance of newborn lambs.  相似文献   

13.
The effect was studied of bentonite and spent sugar beet pulp on the ammonia level in the rumen juice sheep fed hay, ground barley and a urea supplementation. In comparison with a control trial, the nitrogen supply to the rumen juice proved more continuous, this fact improving the conditions for the microbial protein synthesis at the time fo the strongest fermentation. The interaction of bentonite, beet pectin and ammonium ions is attributed to the ion exchange.  相似文献   

14.
Soybean hulls have been used as a feed ingredient for horses for many years and are generally used as a fiber source. The NRC (11) gives them an energy value of 1.88 Mcal DE/kg DM, which is comparable with a medium quality grass hay. Recent evidence suggests that soybean hulls may have a higher energy value. Two feeding trials were conducted to evaluate the energy value of soybean hulls by using them to replace oats in a concentrate for weanling horses. In Exp. 1, 16 Thoroughbred and Quarter Horse weanlings, 145.2 4.1 d of age, were paired within breed and gender subgroups and assigned at random to either the oats or soybean hull-based concentrate. Soybean hulls replaced oats at 25% of the concentrate. Concentrates were fed individually to appetite for two, 1.5-h feeding periods daily with the concentrate restricted to the lesser amount consumed by the pair based on percentage of BW. Coastal bermudagrass (Cynodon dactylon) hay (12.8% CP) was group fed at 1.0 kg/100 kg BW daily. The BW and measurements of the weanlings were made at 14-d intervals for 112 d, and the weanlings were radiographed for bone mineral deposition determinations at the start and conclusion of the study. Experiment 2 used 13 weanlings starting at 143.8 ± 4.2 d of age and was identical to Exp. 1 except the source of the Coastal bermudagrass hay was different and the concentrate intake was fed ad libitum during the two, 1.5-h feeding periods. In Exp. 1, no differences in feed or nutrient intake, BW, or body measurement gains were detected (P > 0.05) except for body length gain, which was greater for the weanlings on the oat-based concentrate (P < 0.05). The weanlings gained 0.73 and 0.70 kg/d on the oat and soybean hull-based concentrates, respectively. In Exp. 2, the protein content of the hay (7.0% CP) was less than the previous year, resulting in a protein intake below NRC (11) recommendations. No differences in BW, withers height, or body length gain were detected (P < 0.05), but heart girth (P < 0.05) and hip height gain (P < 0.05) were both greater for the weanlings fed the oat-based concentrate. The weanlings gained 0.74 and 0.61 kg/d on the oat and soybean hull-based concentrates, respectively. Bone mineral deposition was not different between diet groups for either experiment. Results suggest that soybean hulls have an energy value for weanling horses that is similar to oats when fed with medium quality grass hay. When fed with low quality grass hay, soybean hulls do not seem to be as valuable as oats, perhaps because of either the slow energy release or the availability of protein in the foregut.  相似文献   

15.
The objective of the present work was to assess the influence of partial replacement of oats with dried unmolassed sugar beet pulp (SBP) and/or maize oil on nutrient utilisation in horses fed a traditional hay and concentrate diet. The total tract digestibility of nutrients, urinary excretion and plasma parameters were studied in a 4 x 4 Latin-square design experiment with purebred Arabian geldings. Horses fed the SBP diets responded with a reduced (P<0.05) apparent digestibility of crude protein and feeding of maize oil resulted in an increased (P<0.05) apparent digestibility of crude fat. The apparent energy digestibility was unaffected by the replacement of oats with SBP, but increased (P<0.05) when maize oil replaced part of the oats. The urinary excretion of nitrogen increased (P<0.05) when maize oil replaced oats and the excretion of energy was higher (P<0.05) on the diets where oats were replaced by maize oil and SBP. There was a significant (P<0.05) effect across treatments of postprandial blood sampling time on plasma glucose and insulin concentrations. Also, plasma concentrations of glucose and insulin tended to be higher on the oats than on the SBP diets. In conclusion, the limited effects on the digestibility of nutrients and energy suggest that it should be possible to partially replace oats with maize oil and/or SBP in diets for horses without any impairing effects on the overall nutrient utilisation. However, the dietary-induced changes in the urinary excretion of energy and on plasma glucose and insulin levels, indicate a possible influence of dietary carbohydrate composition on nutrient utilisation at the organ level, which requires further study.  相似文献   

16.
Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatly depressed when only the less palatable grains were fed. In Trial 3, pony mares selected a diet containing 20 per cent dried distillers' grain and 80 per cent of a basal mixed diet of maize, oats, wheat bran, soybean meal, limestone and molasses over 100 per cent basal mixed diet, but selected the basal diet over diets containing 20 per cent blood meal, beet pulp or meat and bone meal and 80 per cent basal diet. They did not differentiate against diets containing 20 per cent alfalfa meal or 10 or 5 per cent meat and bone meal when the diets were compared to the basal mixed diet.  相似文献   

17.
The influence of the feeding ratio of a non‐forage fiber source and hay on ruminal mat characteristics and chewing activity was evaluated in dairy dry cows. Cows were fed four different diets: the ratios of alfalfa hay (AH) to beet pulp (BP) were 8:2 (dry matter basis, A8B2) and 2:8 (A2B8), and those of grass hay (GH) to BP were 8:2 (G8B2) and 2:8 (G2B8). Total eating time was decreased with increasing BP content (P < 0.01). Total rumination time for AH was shorter than that for GH (P < 0.01), and it decreased with increasing BP content (P < 0.01). The ruminal mat was detected by using a penetration resistance test of the rumen digesta. Penetration resistance value (PRV) of ruminal mat was highest with the G8B2 diet and PRV decreased with increasing BP content (P < 0.05) and feeding AH (P < 0.05). Thickness of the ruminal mat was greater for increasing BP content (P < 0.05). Simple linear regression of ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P < 0.001; n = 16). The results demonstrated that increasing the PRV of the ruminal mat stimulated rumination activity and a ruminal mat could be formed, although it was soft even when cows were offered a large quantity of BP.  相似文献   

18.
The feeding recommendations for the pet or house rabbit include grass hay fed ad libitum, dark leafy green vegetables fed at one cup per 5 pounds of body weight, and a maximum of 1 cup of high fiber pellets per 5 pounds of body weight. These recommendations are based on the feeding behavior, anatomy, and gastrointestinal physiology of the rabbit. Feeding this diet reduces the occurrence of common gastrointestinal tract disease in the house rabbit. This article reviews the feeding behavior, anatomy, and gastrointestinal physiology of the rabbit.  相似文献   

19.
This study investigated the effect of cereal grain species (sorghum, wheat, oats and barley), extent of processing (cracked barley, finely ground barley, and wet whole barley) and time of feeding (barley grain mixed with ryegrass hay or fed 2 h before hay was fed), on whole tract dry matter digestibility (WTDMD), and microbial protein synthesis (MPS), as a supplement to ryegrass hay when fed to rumen-cannulated sheep.Expected dry matter digestibility (EDMD) in mixtures of cereal grain and ryegrass hay was calculated by interpolation between in vitro dry matter digestibility (DMD) of each grain and the ryegrass hay. These were compared with measured actual WTDMD to detect positive or negative associative effects. Among grain species, the percentage difference in digestibility between actual WTDMD and EDMD was negative at − 6.6% units for wheat but positive at + 2.3%, + 4.3% and + 5.7% units for sorghum, oats, cracked or finely ground barley, respectively.As expected, the supplementation of sheep fed ryegrass hay with different sources of carbohydrates increased urinary allantoin output (as an indicator of MPS) when compared to sheep fed ryegrass hay alone. The concentration of urinary allantoin was significantly higher in sheep supplemented with sorghum (1916 mg/sheep/day) than wheat, oats or cracked barley ([mean ± S.E.M.] 1451 ± 24 mg/sheep/day) grain. There was a significantly higher urinary allantoin concentration in sheep fed cracked barley compared to finely ground barley or wet whole barley (1479 vs. 1095 vs. 1031 mg/sheep/day, respectively). There was no significant (P > 0.05) difference in urinary allantoin output, expressed as output/kg DM intake, when cracked barley was mixed and fed with the hay or fed 2 h before hay. However, in terms of total output of allantoin this was significantly higher (P < 0.05) (1479 vs. 1209 mg/sheep/day).In sacco degradability characteristics of organic matter and nitrogen for sorghum, oats, wheat, barley at different levels of processing and for ryegrass hay were also measured in the rumen of cannulated sheep.Among grain species, wheat had the highest effective organic matter degradability in the rumen (78.1%) while sorghum had the lowest. The effective degradability of protein of finely ground barley in the rumen was found to be higher than cracked barley or wet whole barley.Wheat grain, being highly degradable in the rumen, had a negative effect on WTDMD. In contrast, sorghum grain, being more slowly degradable in the rumen, would be expected to provide a substantially increased supply of energy to microbes over time in the rumen for MPS.Both cracked barley and finely ground barley also had a positive associative effect on WTDMD when fed with ryegrass increasing it by 5.7% units. The MPS was significantly higher (P < 0.05) in sheep fed cracked barley compared to finely ground barley or wet whole barley. This supports the hypothesis that slowly degrading carbohydrate sources synchronise more closely with available N from degradation of forage in the rumen.  相似文献   

20.
不同组合饲粮对绵羊瘤胃代谢参数的影响   总被引：1，自引：1，他引：0  
为研究不同饲粮组合,即对照饲粮(Ⅰ)、8%甜菜渣(Ⅱ)和8%苹果渣饲粮(Ⅲ)对瘤胃代谢参数的影响,选用3只安装永久性瘤胃瘘管的甘肃高山细毛羯羊(平均体质量22.5 kg),采用3×3拉丁方设计方案进行了试验。试验的3个饲粮循环均为预试期10 d,正试期9 d。结果表明, 1)各处理试羊的瘤胃液pH均值较相近(P＞0.05)。2)采食饲粮Ⅱ羊瘤胃液丙酸摩尔比较低(P=0.109),其乙酸/丙酸高于Ⅰ(P＜0.05)与Ⅲ(P＞0.05);但采食3种饲粮的羊均属乙酸型发酵。仅饲粮Ⅱ的总挥发性脂肪酸时段变化近似典型的抛物线;Ⅰ、Ⅲ 的总挥发性脂肪酸峰值分别出现在食后3与5 h。3)处理间瘤胃液总氮、蛋白氮、氨氮、尿素氮的均值及细菌氮浓度的差异均不显著(P＞0.05)。Ⅱ的总氮浓度始终较高,食后3,7 h呈现两峰;而其氨氮较低,食后1 h即出现峰值。Ⅰ、Ⅲ均在食后7 h达总氮最高值;Ⅰ未现峰值,Ⅲ于食后1,7 h出现峰值。可以认为:本试验饲粮间在瘤胃发酵类型与氮利用效率方面无显著差异,但仍显示出含8%甜菜渣饲粮,在稳定瘤胃环境、保持纤维素分解活性和氮利用方面有一定优势。  相似文献   

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