Effects of feeding fat-coated butyrate on mucosal morphology and function in the small intestine of the pig

As shown earlier, pig rations with high starch and purine content initiate mucosal hypertrophy by stimulating mitotic activity and DNA formation in the small intestine, whereas in the colon butyrate inhibits apoptosis and thus increases crypt depth. It was the aim of this study to combine these effects by targeting fat-coated butyrate into the small intestine where it usually does not occur, and to investigate effects on mucosal development and function. Three groups of five pigs were fed 3.6 kg/day of either a low-energy ration [deficit group, 6.6 MJ metabolizable energy (ME)/kg] or a high-energy ration (13.7 MJ ME/kg) that was supplemented with brewing yeast as a source of purines. The third ration was of high energy and contained purines and was additionally supplemented with coated butyrate (13.5 MJ ME/kg; 29 g calcium butyrate/kg). Rations were fed for 5 days. After killing, tissue samples were obtained from the proximal, medial and distal parts of jejunum for histology. Chyme samples were obtained from the ileum of all animals and used for sucrase determination. Villus size was not changed by feeding, but butyrate had an effect on plica height and area mainly in the medial jejunum. Plica area in the butyrate group (4.2 mm(2)) was significantly higher (p 相似文献   

The effect of dietary protein content on calcium and phosphorus retention in the growing Iberian pig

The effects of dietary protein content (DPC) from excessive (192 g/kg DM) to marginally deficient (101 g/kg DM) upon whole-body retention of Ca and P was studied in 25 purebred Iberian pigs growing from 15 to 50 kg BW by means of a comparative slaughter experiment which included a digestibility trial. Ca and P retention related to intake remained unaffected at 0.228 ± 0.0072 and 0.184 ± 0.0052, reaching 3.64 ± 0.119 and 2.00 ± 0.057 g Ca and P per day respectively. Pigs fed on diets containing protein levels in excess of requirements had significantly higher concentrations of Ca and P (P < 0.05) in their bodies (14.41–14.99 and 7.88–8.08 g Ca and P/kg fat-free empty-body gain respectively) than those given adequate or marginally deficient amounts of dietary protein (11.80–12.72 and 6.61–7.01 g Ca and P/kg fat-free empty-body gain respectively). In a second experiment, made with 25 Iberian pigs of 21 kg initial weight, daily intakes of Ca and P to maintain zero retention were determined using five experimental diets in which the concentrations of Ca and P were varied by the addition of graded levels of Ca carbonate and inorganic phosphate to a basal diet balanced in protein-to-energy ratio (131 g CP; 13.8–14.4 MJ ME/kg DM). Growth rate and protein deposition were unaffected by the level of Ca and P in the diet and reached average values of 485 ± 15.4 and 103 ± 1.2 g/d. Increasing the dietary Ca and P levels increased the absolute amounts of Ca and P retained daily from 0.69 to 5.77 and 1.12 to 3.70 g respectively (P < 0.001). Highly significant (P < 0.001) curvilinear regressions were obtained when relating Ca and P absorption or retention (g/d) with Ca and P intake (g/d). From these equations, daily maintenance requirements of 105 and 72 mg/kg BW for Ca and P respectively were obtained. Average total net requirements of Ca and P for the Iberian pig at this stage of growth were estimated to be 5.25 and 3.10 g/d respectively, considerably lower than those reported for conventional and high-performance pig genotypes.     

Effect of trenbolone acetate on protein synthesis and degradation rates in fused bovine satellite cell cultures

Although androgenic and estrogenic steroids are widely used to enhance muscle growth and increase feed efficiency in feedlot cattle, their mechanism of action is not well understood. Although in vivo studies have indicated that androgens affect protein synthesis and protein degradation rate in muscle, results from in vitro studies have been inconsistent. We have examined the effects of trenbolone acetate (TBA), a synthetic androgen, on protein synthesis and degradation rates in fused bovine satellite cell (BSC) cultures. Additionally, we have examined the effects of compounds that interfere with binding of TBA or insulin-like growth factor-1 (IGF-1) to their respective receptors on TBA-induced alterations in protein synthesis and degradation rates in BSC cultures. Treatment of fused BSC cultures with TBA results in a concentration-dependent increase (P < 0.05) in protein synthesis rate and a decrease (P < 0.05) in degradation rate, establishing that TBA directly affects these parameters. Flutamide, a compound that prevents androgen binding to the androgen receptor, suppresses (P < 0.05) TBA-induced alterations in protein synthesis and degradation in fused BSC cultures, indicating the androgen receptor is involved. JB1, a competitive inhibitor of IGF-1 binding to the type 1 IGF receptor (IGF1R), suppresses (P < 0.05) TBA-induced alterations in protein synthesis and degradation, indicating that this receptor also is involved in the actions of TBA on both synthesis and degradation. In summary, our data show that TBA acts directly to alter both protein synthesis and degradation rates in fused BSC cultures via mechanisms involving both the androgen receptor and IGF1R.     

Effect of highly fermentable dietary fiber on the development of swine dysentery and on pig performance in a "Pure--Culture Challenge Model"

This study tried to evaluate the effect of highly fermentable fiber on the incidence and severity of swine dysentery (SD) after experimental oral infection with pure cultures of Brachyspira (B.) hyodysenteriae. Forty eight growing pigs were allocated to two groups and treated until slaughter as follows: Group 1 (n = 24): infected with B. hyodysenteriae and fed with a food containing 9.6% highly fermentable neutral detergent fiber. Group 2 (n = 24): infected with B. hyodysenteriae and fed with a food containing 6.1% low fermentable neutral detergent fiber. Pigs of each group were intragastrically inoculated on each of three consecutive days with pure culture of 1.8 x 10(10) B. hyodysenteriae. All pigs were monitored daily until slaughter. Faecal shedding of B. hyodysenteriae by polymerase chain reaction, antibody response by IFA, clinical signs, growth performance and extents of gross and microscopical lesions specific for swine dysentery were determined. Faecal shedding of B. hyodysenteriae and antibodies specific for B. hyodysenteriae were detected at day 30 post infectionem. Significant (p < 0.05) milder clinical signs typical for swine dysentery were detected in group 1, fed with 9.6% high fermentable fiber compared to group two fed with a food containing 6.1% low fermentable neutral detergent fiber. Daily weight gain differed significantly (p < 0.05) between the groups (group one 780 g vs. group two 760 g). Food conversion efficiency showed in group one a significant (p < 0.05) better (3.28) result than in group two (3.38). Feed consumption presented significantly (p < 0.001) better results in group one compared to group two (2.38 kg vs. 2.25 kg). From our experimental findings we conclude that in production units suffering of swine dysentery high levels of highly fermentable fiber in diet may increase health and performance.     

Interactive effects of dietary crude protein and fermentable carbohydrate levels on odour from pig manure

The objective of this study was to determine the effects of dietary levels of crude protein (CP) and levels of fermentable carbohydrates (FC) and their interaction on odour emission, odour intensity, odour hedonic tone, and ammonia emission from pig manure, and manure characteristics. An experiment was conducted with finishing pigs (n = 36) in a 2 × 3 factorial randomized complete block arrangement with 6 treatment combinations in 6 blocks. There were 2 dietary CP levels (low 12%; high 18%) and 3 digestible FC levels: (low 95.5; medium 145.5; and high 195.5 g/kg feed, as-fed basis). Pigs with an initial body weight (BW) of 57.7 ± 2.5 kg were penned individually in partly slatted floor pens. Faeces and urine of each pig accumulated in separate manure pits under the slatted floor. In the 6th week of the collection period air samples were collected directly above the manure in each pit. Manure samples were taken for manure characteristics. Air samples were analyzed for odour concentration and for hedonic tone and odour intensity. Manure samples were analyzed for volatile fatty acids (VFA), indoles, phenoles, sulphurous compounds, ammonium, and total N concentrations. Dietary CP level and FC level did not affect odour emission, odour intensity and hedonic tone but their interaction affected odour emission at P = 0.06. At a high dietary CP level, increased FC level decreased odour emission, while at a low CP level, increased FC level increased odour emission from pig manure. Total N and ammonium concentrations, and ammonia emission from pig manure were reduced at low dietary CP level (P < 0.001). High FC level led to low ammonia emission from pig manure (P = 0.01). Manure pH increased at high dietary CP level (P < 0.001) and decreased when FC level increased (P < 0.05). Total VFA concentration increased at high dietary CP level (P < 0.001) and when FC level increased (P < 0.001). Enhanced dietary CP increased the manure concentrations of phenol (P < 0.001), cresols (P = 0.01), indole (P < 0.001), 4-ethylphenol (P < 0.001) and carbon disulfide (P < 0.001), but FC did not affect concentrations of these compounds (P > 0.05) in the manure. We conclude that the interaction between dietary CP and FC plays a role in odour production and emission. Ammonia emission from pig manure can be reduced substantially by decreasing dietary CP and by increasing FC.     

Effect of feeding garlic leaf on microbial nitrogen supply,kinetics of plasma phenylalanine,tyrosine and protein synthesis in sheep

The objective of the present study was to assess the feeding effects of garlic leaf on microbial N supply (MNS), turnover rates of plasma phenylalanine (PheTR) and tyrosine (TyrTR) and whole body protein synthesis (WBPS) in sheep. The sheep were fed either mixed hay (Hay‐diet, as control) or hay plus garlic leaf diet (GL‐diet, at a ratio of 9:1) in a crossover design each for a 21 day period. The isotope dilution method using [²H₅]Phe and [²H₂]Tyr was performed on the 21st day of each dietary treatment. Nitrogen intake remained similar between the diets and N absorption and N digestibility were higher (P < 0.05) in the GL‐diet than Hay‐diet. Total purine derivatives excretion and MNS were greater (P < 0.05) in the GL‐diet than the Hay‐diet. Plasma PheTR tended to be higher (P = 0.06) during GL feeding and TyrTR did not differ between the diets. Further, WBPS tended to be greater (P = 0.05) for the GL‐diet compared with the Hay‐diet. Hence, the present results suggest that garlic leaf may have positive effects on N metabolism by influencing MNS in sheep and could be used as a potential ruminant feed in the future.     

Effects of dietary protein and fermentable fiber on nitrogen excretion patterns and plasma urea in grower pigs

Effects of dietary protein concentration (high, 18.5; low, 15.7%) and fermentable fiber (control; soyhulls, SH; and sugar beet pulp, SBP) on N excretion patterns and plasma urea were tested in a 2 x 3 factorial arrangement. The objectives were: 1) to determine if reduced dietary protein together with fermentable fiber would reduce urinary N excretion further than a single diet manipulation, 2) to determine if effects of diet manipulations were similar between pigs with restricted and free access of feed, and 3) to further develop predictions of urinary N excretion using plasma urea. Diets were formulated to 3.30 Mcal digestible energy (DE)/kg and 2.4 g of digestible lysine per Mcal DE, and supplemented with lysine, methionine, tryptophan, threonine, isoleucine, leucine, or valine to ensure meeting an ideal AA profile. Pigs (30.5 +/- 3 kg; n = 36) were housed in metabolism crates with restricted access to feed (3 x 110 kcal DE/kg BW(0.75)) from d 1 to 18, and free access from d 19 to 26. Feces and urine were collected from d 15 to 18 and d 23 to 26, and blood was sampled on d 17 and 25. With restricted access to feed, urinary N was reduced 28% and N retention was reduced 12% for the low- compared to high-protein diet (P < 0.01; as g/d). Fecal N was increased 4% units for SH and 6.5% units for SBP (P < 0.01; as % of N intake) and urinary N was reduced 5% units for SH (P < 0.10) and 9% units for SBP (P < 0.05) compared to the control. With free access to feed, urinary N was reduced 27% (P < 0.05; as g/d) and N retention was reduced 7% (P < 0.10) for the low- compared to high-protein diet. Fecal N was increased 5% units for SH and 9% units for SBP (P < 0.001; as % of N intake), and urinary N was reduced 9% units for SH and 10% units for SBP (P < 0.01) compared to the control. For either restricted or free access to feed, fermentable fiber did not affect N retention (P > 0.10). A protein x fiber interaction was not observed for urinary N excretion (P > 0.10), indicating that reducing dietary protein and including fermentable fiber reduced urinary N excretion in an additive manner. Daily urinary N excretion was related positively and linearly with plasma urea in pigs with free access to feed (R2 = 0.71; at 0800). In summary, reduction of dietary protein reduced urine N excretion, and fermentable fiber shifted N excretion from urine to feces. Effects of dietary protein and fermentable fiber on reducing urinary N excretion are additive.     

华南虎原野式环境中的饲养管理与部分行为的观察

1998年 9月从苏州引进 2雄 1雌共 3头亚成体华南虎在梅花山原野式环境中进行饲养、管理、野化训练和生殖等移地保护研究。结果表明 ,原野式环境中的华南虎 ,其饲养、管理、体质和许多行为表现与笼舍环境里的华南虎有显著差异。1　材料与方法1 1　种虎及其生活环境从苏州引进 1 997年 1月和 6月出生的国际编号 2 78号雌虎和 2 84、 2 85号雄虎共 3头亚成华南虎作为本研究的华南虎材料 ,于 1 998年 9月 2 6日进入梅花山原野式环境中。在海拔 70 0ｍ福建省梅花山的山顶上建靠原野式环境 ,四周设 4 5ｍ高铁丝网围栏 ,内植草皮、茅草、常绿树、…     

冬季饲养育肥猪温度差异影响增重效果的试验

冬季气温低，给养猪管理带来诸多不便。没有取暖保温设施和通风换气设备的猪舍，如果不注意猪舍环境控制，就会影响猪的正常生长水平的发挥，甚至引发一些疾病，出现死亡等，从而影响养猪的经济效益。本试验通过改善猪舍的管理条件来提高猪的消化率和抗病能力，为快速育肥提供科学依据，现将试验结果报告如下。     

华芬复合酶对猪生长性能的影响

复合酶制剂作为绿色饲料添加剂已经在饲料企业和养殖企业中得到了广泛的应用。试验在以玉米、豆粕为主的高品质口粮中添加0．1％复合酶制剂，小猪和中猪日增重分别比对照组提高6．31％和3．32％；料重比分别比对照组下降6．03％和3．42％；腹泻发病率分别比对照组降低40．91％和4．55％。为在以后养猪生产中推广使用，提供了依据。     

饲喂方式对生长肥育猪生产性能的影响

利用自动食槽对生长肥育猪(20～60kg)进行饲喂，采用自由采食比定时饲喂日增重高20.27%(P＜0.01)；每千克增重消耗饲料，试验组比对照组平均少耗0.175kg，(P＜0.01)。     

Dietary protein and fermentable carbohydrates contents influence growth performance and intestinal characteristics in newly weaned pigs

Increasing the dietary amount of fermentable carbohydrates (FC) may counteract the negative effects of protein fermentation in newly weaned piglets. To study this hypothesis, 272 newly weaned piglets were allotted to 4 dietary treatments in a 2 × 2 factorial arrangement with low and high FC (7.5 and 13.5%) and crude protein (CP, 15 and 22%) content as respective factors. Intestinal histology, enzyme activity, microbiota and fermentation products were determined in 8 pigs per treatment 7 days post-weaning.

In the 4 wk experimental period, interactions between dietary CP and FC content were found for feed intake (P = 0.022), daily gain (P = 0.001), and gain:feed (P = 0.033). The high-FC content reduced daily gain by 50 g/d in the low-CP diet, whereas the FC content did not affect growth performance in the high-CP diet. Over the 4 wk experimental period, daily gain (350 g/d) and feed intake (519 g/d) were highest for piglets on the low-CP low-FC diet. The high-FC content resulted in an increase in number of lactobacilli (P = 0.047) and a decrease of total coliforms (P = 0.06) in the small intestine. It increased the lactic acid content (P = 0.08) and reduced the ammonia content (P = 0.04) in the small intestine and increased the VFA content in the colon (P = 0.009). The reduction in CP content reduced ammonia concentration in the small intestine (P = 0.003). We concluded that dietary FC influenced microbial population and fermentation products in the gut. However, this was not reflected in an increased growth performance.     

大豆浓缩蛋白对超早期断奶仔猪生产性能、小肠粘膜结构和细胞免疫机能的影响

为探讨大豆浓缩蛋白在超早期断奶仔猪饲粮中的应用,试验选用72头14日龄杜×(大×长)三元杂交断奶仔猪随机分为4组:处理一,不添加血浆蛋白粉和大豆浓缩蛋白;处理二,添加5%血浆蛋白粉,不添加大豆浓缩蛋白;处理三,添加2.5%血浆蛋白粉和5%大豆浓缩蛋白;处理四,不添加血浆蛋白粉,添加10%大豆浓缩蛋白。每处理3个重复(栏),每重复6头猪,试验为期4周。试验结果表明:超早期断奶仔猪饲粮添加5%血浆蛋白粉提高了仔猪采食量(P<0.05)与日增重(P<0.01),降低仔猪料重比(P<0.01);大豆浓缩蛋白未能提高仔猪采食量(P>0.05),可在一定程度上提高仔猪日增重与饲料效率(P>0.05);大豆浓缩蛋白对仔猪小肠粘膜结构和细胞免疫机能没有影响(P>0.05),但有降低仔猪免疫激活状态的趋势(P>0.05)。     

Reduction of ammonia emission from growing pig rooms by feeding a lower protein diet supplemented with apple pomace

An experiment was conducted to determine the effect of supplementing a reduced crude protein (CP) diet with apple pomace on the ammonia emissions from growing pig rooms. Four pigs (45 kg BW) each were assigned to one of two diets. Each group was housed in a separate room and fed a standard diet (CP 16.6%) or a low CP, amino acid‐supplemented diet (CP 9.1%) containing 23.1% of dried apple pomace for two 7‐day experimental periods. After the completion of the first period, the pigs were switched to the other diet. The daily ammonia emissions, measured for 3 days after a 4‐day adaptation period, were much lower for pigs fed the apple pomace‐supplemented diet than for pigs fed the standard diet (0.47 g/pig vs 7.30 g/pig, respectively). The daily nitrogen intake for the standard diet and the apple pomace‐supplemented diet was 58.1 and 35.5 g/pig, respectively. The pigs fed the apple pomace‐supplemented diet excreted more fecal nitrogen than pigs fed the standard diet (17.5 g/day vs 11.0 g/day, respectively), but urinary nitrogen excretion with the apple pomace‐supplemented diet was estimated to be 2.9 g/day, which was much lower than that for the standard diet (27.0 g/day). The addition of apple pomace to a reduced CP, amino acid‐supplemented diet reduces urinary nitrogen excretion and thereby ammonia emission.     

稻草加酶青贮饲喂育成牛的效果研究

本研究以新鲜晚稻草为原料，探讨了添加Ｓｔｒａｗｚｙｍｅ酶制剂对青贮晚稻草发酵品质和育成牛生产性能的影响。试验设３个处理，试验１组每吨稻草（ＤＭ）加酶８００克和麸皮５０千克；试验２组每吨稻草加酶８００克；对照组只加水调制。各处理和２组的采食量分别对照组高５８．６％，３２．２％；日增重分别比对照组高３４．３％和１１．８％。青贮晚稻草中添加Ｓｔｒａｗｚｙｍｅ可以改善青贮晚稻草的发酵品质，提高营养价值。     

Effect of dietary electrolyte balance on nutrient digestibility determined at the end of the small intestine and over the total digestive tract in growing pigs

A replicated 4 x 4 Latin square digestion trial was conducted to determine the effect of electrolyte balance (EB = Na + K - Cl meq/kg of the diet) on apparent nutrient digestibilities in pigs fitted with ileal T-cannulas. Experimental diets were composed of corn and soybean meal with dietary EB altered by the substitution of CaCl2 for CaCO3, or NaHCO3 for corn and soybean meal. Electrolyte balance levels examined were -50, 100, 250 or 400 meq/kg of the diet. Increasing dietary EB concentration linearly increased (P less than .05 to P less than .02) apparent ileal digestibility of N, energy, DM and all amino acids, except alanine and methionine. However, nutrient and amino acid digestibilities measured over the total digestive tract were similar (P greater than .16) among EB levels. Increasing dietary EB resulted in a linear and quadratic (P less than .03) effect on daily urinary N excretion, resulting in a linear (P less than .05) improvement in N retention expressed both as a percentage of N intake and of absorbed N. Blood pH, total CO2, HCO3 and base excess concentrations increased linearly (P less than .02 to P less than .001) with increasing dietary EB. Dietary EB concentrations influenced nutrient and amino acid absorption measured near the end of the small intestine. Additionally, the N balance data per unit of N intake or N absorbed are indicative of an improved N utilization in pigs fed increasing dietary EB concentrations from -50 to 400 meq/kg.     

Chemical composition of alfalfa silage with waste date and its feeding effect on ruminal fermentation characteristics and microbial protein synthesis in sheep

This study was conducted to evaluate the effect of feeding ensiled alfalfa with waste date on ruminal fermentation characteristics, microbial protein synthesis, protozoa population and blood parameters in sheep. Eight rams were used in a 2 × 2 change over design. Each experimental period consisted of 21 days including 16 days for adaptation and 5 days for sampling. For ensiling, fresh alfalfa (Medicago sativa L.) with different levels of waste date (Phoenix dactylifera L.) were mixed together and ensiled in 100‐l containers for 45 days. Chemical composition of silages such as dry matter (DM), crude protein, NH₃‐N, organic matter, NDF, ADF and pH were determined. Then, it was used as 30% (DM basis) in diets. The experimental diets were as follows: (i) control (diet containing alfalfa silage without waste date), (ii) diet containing alfalfa silage with 5 g waste date/95 g DM, (iii) diet containing alfalfa silage with 10 g waste date/90 g DM, and (iv) diet containing alfalfa silage with 15 g waste date/85 g DM. The results of this experiment showed that adding waste date to alfalfa during ensiling, improved silage quality, DM and energy level. Total protozoa population and all of holotrich, cellulolytic and entodinia in rumen fluid were increased linearly by increasing the level of waste date. Nitrogen (N) intake, urinary N excretion and nitrogen retention were affected by dietary treatments. Also, allantoin, uric acid, total purine derivatives, microbial protein synthesis, cholesterol level and blood urea nitrogen were significantly different. In conclusion, direct ensilage of alfalfa can be attained by mixing 15 g waste date/85 g DM and positive associative effects such as increased metabolizable energy (ME) and silage quality occurred.     

Influence of a flooding dose of valine on key indicators of metabolic status in the growing pig

A key concern with the flooding dose technique for measuring protein synthesis is that a large dose of amino acid (AA) can potentially change the animals’ hormonal and nutritional status, which in turn can influence protein synthesis. Among stable isotope tracers, 1‐[¹³C]‐valine is the preferred AA for measuring protein synthesis in gut tissue and mucins. A study was conducted to determine the impact of a flooding dose of valine on the metabolic status of pigs. Six barrows [16.5 kg body weight (BW)] were randomly assigned to intravenous infusions of either 150 mm valine (1.5 mmol/kg BW) or physiological saline, following a crossover design. Blood samples were taken 10 min prior to infusion, at the end of infusion, at 10‐min intervals for 60 min post‐infusion, and at 90 and 120 min post‐infusion. Plasma concentrations of insulin, glucose, AA, urea nitrogen and packed cell volume (PCV) were measured. Infusion of valine increased plasma valine concentrations (4129 vs. 582 μm ; P < 0.05) but had no influence on PCV (26.4% vs. 27.2%) and plasma concentrations of glucose (6.0 vs. 5.8 mm ) and insulin (8.2 vs. 8.5 μU/ml; P > 0.10). Plasma urea nitrogen concentration was reduced with valine infusion (8.5 vs. 7.8 mg/dl; P < 0.05). A flooding dose of valine had no impact on plasma concentrations of AA, and specifically branched‐chain AA such as leucine (240 vs. 231 μm ) and isoleucine (310 vs. 331 μm ; P > 0.10). There was, however, a slight increase in the plasma concentrations of threonine (224 vs. 263 μm ; P < 0.05) and a tendency towards reduced glycine (1387 vs. 1313 μm ; P < 0.10). The results indicate that a flooding dose of valine does not cause a substantial change in the metabolic status of growing pigs and is therefore suitable for measuring protein synthesis rates.     

纤维源对不同品种生长猪养分消化率和氮平衡的影响

试验旨在研究纤维源对不同品种生长猪养分消化率和氮平衡的影响试验选取体重相近、健康去势的烟台黑、鲁农2号生长猪各6头,饲喂玉米-豆粕型日粮,采用有重复的3×3拉丁方设计,三个处理分别为基础日粮组、10%大豆皮替代基础日粮组、10%地瓜蔓替代基础日粮组。于每期试验的第6、7 d连续收集48 h的粪样和尿样测定日粮养分消化率和氮平衡代谢。结果表明:日粮添加10%地瓜蔓,两品种生长猪养分消化率和氮平衡显著或极显著降低(P0.05或P0.01),添加10%大豆皮对其氮总利用率影响显著(P0.05),对其他则影响不显著(P0.05);除对干物质消化率(P0.01)、氮表观消化率(P0.05)外,猪的品种对养分消化率和氮平衡均有显著影响(P0.05);纤维源对养分消化率和氮平衡均影响极显著(P0.01);但二者的互作关系不明显(P0.05)。与烟台黑生长猪相比,纤维源对鲁农2号生长猪养分消化率及氮平衡代谢的影响更大。