Isolated canine and murine intestinal cells exhibit a different pattern of fuel utilization for oxidative metabolism

The amount and type of dietary fiber influences the end-products of fermentation and thus fuel availability to intestinal tissue. Metabolic fuel usage was studied in intestinal cells isolated from dogs consuming a commercial diet or from rats consuming either a commercial rat diet or dog diet to examine preferential fuel usage, the effect of diet, and species differences. Production of 14CO2 was measured by incubating cells in media containing either D-[U-14C]glucose, [1-14C]n-butyrate, L-[U-14C]glutamine, or [1-14C]propionate with or without competing substrates. The presence of a mixture of 5 mM each of glucose, butyrate, propionate, and acetate and 1 mM glutamine in the media decreased CO2 production from glucose, glutamine, and propionate by canine enterocytes (P < 0.05) and from glutamine and propionate by canine colonocytes (P < 0.05). The presence of glutamine in the media decreased glucose oxidation by murine enterocytes, regardless of the diet. Similarly, glutamine decreased glucose oxidation by murine colonocytes (P < 0.05), but only when the rats had consumed the rat diet. Regardless of diet, murine colonocytes oxidized more butyrate (P < 0.01) than did enterocytes, and murine enterocytes tended (P < 0.07) to oxidize more glucose than did colonocytes. The proportion of propionate in colonic contents was higher in dogs than in rats (P < 0.02), and the proportion of butyrate tended to be higher in contents from rats than in those from dogs (P < 0.08). Colonic and cecal wet weights were decreased (P < 0.05) when rats were fed the commercial dog diet. Preferred utilization of substrates by isolated canine enterocytes and colonocytes differed from that of murine intestinal cells. These differences were only partially overcome by feeding the same diet to each species.     

Effect of supplementation of multi-microbe probiotic product on growth performance, apparent digestibility, cecal microbiota and small intestinal morphology of broilers

The present study investigated the effect of inclusion of multi-microbe probiotic product on growth performance, apparent digestibility of nutrients, cecal microbiota and small intestinal morphology in broilers. Four hundred days-old Ross chicks were randomly allotted to five treatments on the basis of body weight (BW). Each treatment had four replicates of 20 chicks in each. Experimental diets were fed in two phases, starter (day 0-21) and finisher (day 22-35). Dietary treatments were; basal diet without any antimicrobial (NC), basal diet added with 20 mg Avilamycin/kg of diet (PC), 10(7) cfu multi-microbe probiotic/kg of diet (P1), 10(8) cfu multi-microbe probiotic/kg of diet (P2), and 10(9) cfu multi-microbe probiotic/kg of diet (P3). Overall BW gain and feed conversion ratio were better (p < 0.05) for treatments PC, P2 and P3 compared with NC and P1, with P1 being better (p < 0.05) than NC. Overall feed intake in treatments PC, P1, P2 and P3 were greater (p < 0.05) than NC. Apparent digestibility of dry matter and crude protein were greater (p < 0.05) in treatments PC, P2 and P3 compared with NC, with P1 being intermediate and not different form NC, PC, P2 and P3. At d 21 and 35, treatments PC, P1, P2 and P3 showed lower (p < 0.05) cecal Clostridium and Coliforms count in relation to NC. Moreover, cecal Clostridium (d 21) and Coliforms (d 21 and 35) count were lower (p < 0.05) in treatment PC in relation to P1; with P2 and P3 being intermediate and not different from PC. However, there was no effect of dietary treatments on cecal total anaerobic bacteria and Bifidobacterium spp. count. The villus height of duodenum in treatment PC was greater (p < 0.05) than NC, with P1, P2 and P3 being intermediate. Villus height of ileum in treatment PC was greater (p < 0.05) than in treatments P1 and NC, whereas it remained comparable among treatments PC, P2 and P3. Villus height to crypt depth ratio of ileum was greater (p < 0.05) for treatment PC, P2 and P3 compared with that in P1 and NC. It is concluded that multi-microbe probiotic inclusion at 10(8) and 10(9) cfu/kg diet had beneficial effects on broilers growth performance, apparent digestibility of nutrients and intestinal morphology and can be used as replacement to antibiotics growth promoter in broiler nutrition.     

The effect of different high‐fat diets on erythrocyte osmotic fragility,growth performance and serum lipid concentrations in male,Japanese quail (Coturnix coturnix japonica)

Poultry diets are formulated with additional animal fat or vegetable oils to improve growth rate and feed conversion efficiency. High‐fat diet feeding in rats and fish has been shown to result in alterations in the phospholipid composition and cholesterol content of the erythrocyte membrane, in turn affecting erythrocyte osmotic fragility. In contrast, the few studies performed using high‐fat diet feeding in avian species show no changes in erythrocyte osmotic fragility. This study made use of the Japanese quail as no data exists on investigation of this species with respect to high‐fat diet feeding and erythrocyte osmotic fragility. Fifty‐seven male quail were randomly divided into six groups and fed either a standard diet (commercial poultry feed) or one of five high‐fat diets (commercial poultry feed with 22% of either coconut oil, lard, palm oil, soya bean oil or sunflower oil on a weight/weight basis) for 12 weeks. All birds on the high‐fat diets were significantly heavier (p < 0.05) after the 12‐week feeding period, than when commencing the dietary intervention. Serum triglyceride concentrations of birds in all high‐fat diet groups were significantly lower (p < 0.05) than birds in the standard diet group, whereas only birds in the palm oil group had significantly lower (p < 0.05) serum cholesterol concentrations compared to the standard diet group. Fragiligrams of erythrocytes from birds in the various dietary groups were similar. High‐fat diet feeding with different types of additional fat did not affect the osmotic fragility of the quail erythrocytes. Feeding quail high‐energy diets of varying degrees of fatty acid saturation was well tolerated and did not seem to affect the overall health status of the birds. Resistance of avian erythrocytes to modification by excess dietary fat may be a general characteristic of avian erythrocytes.     

Effects of dietary pyridoxine on haemato-immunological responses of Labeo rohita fingerlings reared at higher water temperature

A sixty-day feeding trial was carried out to elucidate the effect of dietary pyridoxine (PN) on hemato-immunological parameters in Labeo rohita fingerlings exposed to an elevated temperature (ET) of 33 °C. Two hundred and seventy fingerlings (6.71 ± 0.32 g) were randomly distributed into six treatments in triplicates (15 fish/tank). Five iso-nitrogenous (356.3 ± 2.7 g/kg crude protein) purified diets were prepared with graded levels (0, 10, 50, 100 and 200 mg/kg diet) of PN. Six treatment groups were P10T26 (10 mg PN + ambient temperature (26 °C), P0T33 (0 mg PN + ET), P10T33 (10 mg PN + ET), P50T33 (50 mg PN + ET), P100T33 (100 mg PN + ET) and P200T33 (200 mg PN + ET). The responses of L. rohita fingerlings to dietary PN were assessed in terms of growth and by analysing some hemato-immunological parameters. When PN supplementation increased from 10 to 200 mg/kg diet, a significant improvement in weight gain percentage was observed. Erythrocyte (RBC) count, leucocyte (WBC) count, haemoglobin content and respiratory burst activity were significantly (p < 0.05) higher in 100 mg PN/kg diet-fed group than their non-PN-fed counterpart. Also, serum albumin, globulin and lysozyme activity were found significantly (p < 0.05) higher in PN-fed groups. The overall results indicated that dietary PN supplementation at 100 mg/kg diet may reverse the negative effects caused by ET and may protect the haemato-immunological status of L. rohita fingerlings reared at higher water temperature.     

日粮共轭亚油酸对不同性别肉仔鸡生长性能及脂肪代谢相关酶的影响

试验采用2×2因子设计(日粮类型0%或1%CLA,肉鸡性别)研究日粮CLA对不同性别肉仔鸡生长性能、屠体性状和脂肪代谢相关酶的影响。结果表明:日粮中添加1%CLA可以显著增加各性别肉仔鸡各阶段的体增重,并改善了4～6、0～6周的饲料转化效率(P<0.05),可以显著提高各性别肉仔鸡的胸肌率、同时显著降低各性别肉仔鸡的腹脂率(P<0.05),显著降低了各性别肉仔鸡腹脂脂蛋白脂酶(LPL)活性及其mRNA相对表达量(P<0.05),显著降低了各性别肉仔鸡腹脂及肝脏硬脂酰辅酶A去饱和酶(SCD)mRNA相对表达量(P<0.05)。另外除体增重部分指标外,性别和日粮CLA对肉仔鸡屠体性状和脂肪代谢相关酶的影响不存在互作关系。     

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance,hydrocyanide intake and haematological parameters of broiler chicks

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2?×?2?+?1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P?P?P?P?P?P?P?P?P?P?P?P?P?P?相似文献   

Effects of phytogenic feed additives,probiotic and mannan-oligosaccharides on performance,blood metabolites,meat quality,intestinal morphology,and microbial population of Japanese quail

ABSTRACT

1. The aim of this experiment was to investigate the effects of ajwain (Trachyspermum ammi) and dill (Anethum graveolens) essential oils (AEO and DEO, respectively), probiotic (PRO) and mannan-oligosaccharides (MOS) on the growth performance, serum metabolites, meat quality, intestinal morphology and microbial populations of Japanese quail.

2. A total of 375 one-day-old Japanese quail were randomly allocated into five treatment groups with five replicates of 15 birds each for a 42 d feeding experiment. The dietary treatments were a basal diet (control) or the same diet supplemented with PRO (0.15 g/kg feed), MOS (2 g/kg feed), AEO (0.25 g/kg feed) or DEO (0.25 g/kg feed).

3. AEO, MOS, and PRO supplementation increased weight gain, while diets supplemented with AEO decreased feed intake (FI), and improved feed conversion ratio from d 1 to 21 (P < 0.05). The relative weight of the gizzard was higher in birds supplemented with AEO compared to control group, while the birds fed MOS diet had the longest intestine (P < 0.05). Ceca length was greater in control, MOS and PRO groups (P < 0.05). Both essential oils decreased malondialdehyde (MDA) concentration of breast meat and percentage of cooking loss in quail (P < 0.05). The villus length (VL) was greater in birds fed diet supplemented with MOS, AEO, and DEO (P < 0.05).The population of E.coli decreased in Japanese quail fed MOS, while Lactobacilli spp. count was increased in the MOS group (P < 0.05).

4. In conclusion, AEO, MOS, and PRO supplementation exhibited a positive effect on growth performance, while lipid peroxidation of the meat decreased in birds fed AEO and DEO diets. The intestinal morphometric indices increased in quail fed the AEO, MOS, and DEO diets. Supplementation with MOS modulated intestinal microbial populations of the Japanese quail.     

军曹鱼幼鱼日粮锌最适添加量的研究

试验选用234尾军曹鱼随机分为6个处理,每处理设3个重复,每重复13尾鱼,采用单因素浓度梯度法研究军曹鱼幼鱼商品饲料中锌的最适添加量。在基础日粮(锌含量为75.47mg/kg)中分别添加锌0、30、70、110、150和190mg/kg,制成6种试验日粮,分别投喂军曹鱼幼鱼6周。试验结果表明,基础日粮组鱼成活率、饲料系数、特定生长率、血清碱性磷酸酶(AKP)活性、肌肉和血清锌含量与添加锌组无显著差异(P>0.05)。添加锌组骨骼和肝脏锌含量与基础日粮组差异显著(P<0.05),表现为随锌添加的增加而上升的趋势。以成活率和特定生长率为评价指标,军曹鱼商品日粮中的锌含量可以满足其正常生长需求,不需要额外添加锌。     

载铜硅酸盐纳米微粒对生长猪舍内氨气和粪便菌群的影响

本研究以杜×长×大三元杂交生长猪为对象,探讨载铜硅酸盐纳米微粒(CSN)对生长猪的生长性能、粪便菌群、舍内氨气浓度的影响。选择体重32kg左右杜×长×大三元杂交生长猪360头,随机平均饲养于2个畜舍,对照组饲喂基础日粮,试验组饲喂基础日粮+0.3%CSN。结果表明:试验组与对照组相比,平均日增重提高12.07%(P<0.05),饲料增重比降低10.97%(P<0.05);试验组早、中、晚氨气浓度比对照组分别降低了20.08%、23.10%、21.19%(P<0.01);试验组粪便中沙门氏菌和大肠杆菌的数量显著降低,分别比对照组降低了5.96%、7.99%(P<0.05)。     

Influence of a combination of formic and propionic acids added to wheat- and barley-based diets on the performance and gut histomorphology of broiler chickens

Day-old male chicks were used to test the effects of a combination of formic and propionic acids (CFP) added to wheat- and barley-based diets on the performance and gut histomorphology of broilers. The CFP, containing formic and propionic acids based on an inorganic phyllo-silicate carrier, was added to starter and grower broiler diets of standard (NRC, 1994) or lower nutrient density (LND) using different levels of wheat and barley. Body weight gain (BWG) and feed conversion ratio (FCR) of broiler chicks were significantly (P < 0.001) improved by CFP supplementation at 21 days of age regardless of nutrient density (ND). However, at 35 days of age CFP addition significantly (P < 0.001) increased BWG and FCR. Proventriculus weight was also significantly affected by the dietary treatments. Ileal viscosity was significantly (P < 0.05) affected by ND which was associated with wheat and barley contents, whereas feed viscosity was significantly (P < 0.05) affected by CFP supplementation. Villus height was significantly (P < 0.05) increased by the CFP supplementation. In the case of villus width, an interaction effect was observed: there was a significant (P < 0.05) decrease in the group fed the standard ND diet, but only a numerical decrease in the group fed the LND diet compared to control group. No significant effect of dietary treatment on the thickness of the lamina muscularis mucosae could be detected.     

Effect of dietary inclusion of fermented pigeon pea (Cajanus cajan) meal on growth, apparent nutrient digestibility and blood parameters of cockerel chicks

The effect of dietary inclusion of fermented pigeon pea meal (FPPM) on growth response, apparent nutrient digestibility, haematological indices and serum biochemistry of cockerel chicks was studied using 240-day-old cockerel chicks allotted to four dietary treatments consisting of 60 birds each. Four experimental diets were formulated to include FPPM at 0, 50, 100 and 150?g/kg inclusion levels, respectively. Each of the diets was fed to 60 birds replicated six times with ten birds per replicate. The feeding trial lasted for 56?days. Results indicated that final live weight (linear (L). quadratic (Q): P??0.05) by the inclusion of FPPM. Haemoglobin and serum uric acid concentrations were also reduced (P?相似文献   

Effect of mannan oligosaccharides and fructan on growth performance, nutrient digestibility, blood profile, and diarrhea score in weanling pigs

A total of 150 weanling pigs [(Yorkshire × Landrace) × Duroc] with an average BW of 7.22 ± 0.80 kg (21 d of age) were used in a 28-d trial to determine the effects of dietary fructan and mannan oligosaccharides on growth performance, nutrient digestibility, blood profile, and diarrhea score in weanling pigs. Pigs were allotted randomly to 1 of 5 dietary treatments: 1) negative control (NC), basal diet; 2) positive control (PC), NC + 0.01% apramycin (165 mg/kg); 3) NC + 0.1% fructan (FC); 4) NC + 0.1% mannan oligosaccharide source (MO); and 5) NC + 0.05% fructan + 0.05% mannan oligosaccharide source (FM). There were 3 replications per treatment with 10 pigs per pen (5 barrows and 5 gilts). From d 0 to 14, ADG and ADFI of pigs fed the PC, MO, and FM diets were greater (P < 0.05) than pigs fed the NC diet. From d 15 to 28, there were no differences (P > 0.05) in ADG, ADFI, and G:F. During the overall period (d 0 to 28), pigs fed the MO diet had a greater ADG than pigs fed the NC diet (P < 0.05). Pigs fed the PC and MO diets increased ADFI (P < 0.05) compared with pigs fed the NC diet. However, no differences were detected among dietary treatments in G:F during the overall experimental period. On d 14, the apparent total tract digestibility (ATTD) of DM and N in pigs fed the PC, MO, and FM diets was greater (P < 0.05) than pigs fed the NC diet. The ATTD of DM increased (P < 0.05) in pigs fed the MO and FM diets compared with pigs fed the FC diet. However, at the end of the experiment, pigs fed the FM diet had a greater (P < 0.05) ATTD of DM compared with pigs fed the NC diet. Additionally, there were no differences in IgG, red blood cells, white blood cells, and lymphocyte counts among dietary treatments on d 0, 14, or 28. The diarrhea score in pigs fed the MO diet was reduced (P < 0.05) compared with pigs fed the NC diet. In conclusion, mannan oligosaccharides have a beneficial effect on growth performance and nutrient digestibility in weanling pigs. Furthermore, mannan oligosaccharides can decrease diarrhea score in weanling pigs.     

Wet corn gluten feed and alfalfa hay combinations in steam-flaked corn finishing cattle diets

One finishing trial and one digestibility trial were used to evaluate wet corn gluten feed (WCGF) and alfalfa hay (AH) combinations in steam-flaked corn (SFC) finishing diets. In Exp. 1, 631 crossbred heifers (initial BW = 284 +/- 7.9 kg) were fed SFC-based diets containing combinations of WCGF (25, 35, or 45% of diet DM) and AH (2 or 6% of dietary DM) in a 2 x 3 factorial arrangement of treatments. No interactions existed between WCGF and AH for heifer performance. Increasing dietary WCGF linearly decreased gain efficiency (P < 0.01), dietary NEg concentration (P < 0.05), and 12th-rib fat thickness (P = 0.10). Cattle fed 35% WCGF had the lowest occurrence of abscessed livers, resulting in a quadratic response (P < 0.05) as dietary WCGF increased. In Exp. 2, 12 ruminally cannulated Jersey steers (585 kg) were fed SFC-based diets containing combinations of WCGF (25 or 45% of diet DM) and AH (0, 2, or 6% of diet DM) in an incomplete Latin square design with a 2 x 3 factorial arrangement of treatments. Starch intake was lower (P < 0.05), but NDF intake was greater (P < 0.05) as AH and WCGF increased in the diet. Ruminal pH was increased by AH (linear, P < 0.05) and tended (P < 0.07) to increase with WCGF. Feeding 2% AH led to the greatest ruminal NH3 but the lowest total VFA and propionate (quadratic, P < 0.05). Addition of AH to diets containing 25% WCGF increased acetate to a greater extent than addition to diets containing 45% WCGF (AH x WCGF interaction, P < 0.05). Feeding 45% WCGF tended to increase passage rate (P = 0.17) and decrease (P < 0.05) total tract OM digestibility but increase (P < 0.05) in situ degradation of DM from AH and WCGF. Interactions between AH and WCGF existed (P < 0.05) for ruminal fluid volume (quadratic effect of AH x WCGF level), in situ SFC degradation (linear effect of AH x WCGF level), and in situ rate of WCGF DM disappearance (quadratic effect of AH x WCGF level). We conclude that AH levels may be decreased when WCGF is added to SFC diets as 25% or more of the dietary DM.     

Supplementation of Selenium Nanoparticles-Loaded Chitosan Improves Production Performance,Intestinal Morphology,and Gut Microflora in Broiler Chickens

The current study aimed to evaluate the efficacy of selenium nanoparticles (SeNPs), combined or loaded with chitosan (COS), in broiler chickens reared under standard management protocols. The parameters under investigation were production performance, organ development, components of the intestinal barrier, and ileal microbial count. Two hundred and forty day-old chicks were raised in five groups, with each group containing eight replicates (n=6/replicate). The control group received a basal diet whereas the other four groups received basal diets supplemented with SeNPs (0.5 mg/kg), COS (200 mg/kg), SeNPs+COS (0.5 mg/kg SeNPs + 200 mg/kg COS), and SeNPs-loaded COS (SeNPs-L-COS) (200 mg/kg) respectively. On day 35, two birds/replicate were sampled to collect the viscera under investigation. The results revealed that dietary inclusion of SeNPs-L-COS increased (p<0.05) the body weight gain and improved (p<0.05) feed conversion ratio. Similarly, SeNPs-L-COS supplementation increased (p<0.05) the small intestinal villus surface area as well as the count of acidic goblet cells and intraepithelial lymphocytes when compared with the control group. Whereas the total goblet cell count was higher (p<0.05) in the small intestines of both the SeNPs+COS and SeNPs-L-COS groups. Microbial analysis of ileal contents also revealed an increase (p<0.05) in Lactobacilli species count with a concurrent decrease (p<0.05) in Escherichia coli count in the SeNPs-L-COS group when compared with the COS and control groups. Based on the results of the current trial, we can conclude that supplementation with SeNPs-L-COS is a superior combination for promoting the gut health and performance of broilers.     

日粮NDF水平对断奶獭兔血液免疫细胞与肠道特性的影响

研究日粮中性洗涤纤维(NDF)水平对断奶獭兔血液免疫细胞、小肠分泌型免疫球蛋白A(sIgA)、盲肠微生物及盲肠pH的影响,为揭示日粮NDF和肠道健康关系和断奶獭兔日粮的配制提供理论依据。选择35日龄体重差异不显著的断奶獭兔56只,随机分成4组,每组14只(每只为一个重复)。分别饲喂NDF水平为29%,33%,37%,41%的日粮。预试7 d,正式试验28 d。试验结束后各组随机选取6只屠宰采样,测量血液及肠道各项指标。结果表明,随着日粮NDF水平提高,断奶獭兔白细胞数无显著差异 (P>0.05);血液淋巴细胞数上升(P<0.05);十二指肠和空肠sIgA+细胞数显著增加(P<0.05);盲肠总细菌数无显著差异(P>0.05);拟杆菌数先增加后减少,33%组显著高于其他各组(P<0.05);乳酸菌和大肠杆菌数降低,且乳酸菌29%组显著高于37%组和41%组(P<0.05),大肠杆菌41%组显著低于29%和33%组(P<0.05);盲肠pH值升高;腹泻率和死亡率降低。日粮NDF 水平提高对断奶獭兔的肠道健康有利,NDF 41%组断奶獭兔肠道最健康。     

Effects of supplemental rumen-protected conjugated linoleic acid or corn oil on fatty acid composition of adipose tissues in beef cattle

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.     

NutriDense and waxy corn hybrids: effects on site and extent of disappearance of nutrients in sheep

Six Suffolk wether lambs (40.9+/-1.05 kg) surgically fitted with ruminal and double-L-shaped duodenal and ileal cannulas were used in a 3 x 6 Latin rectangle design to investigate the effects of three corn hybrids on site and extent of disappearance of nutrients and rumen characteristics. Treatments were 1) a conventional yellow dent corn (CC) diet, 2) a NutriDense corn (NC) diet, and 3) a waxy corn (WC) diet. Diets consisted of 43.9% cracked corn grain, 39.1% cottonseed hulls, 15.3% soybean meal, 1.49% vitamin and mineral supplement, and 0.21% chromic oxide (DM basis). Lambs were fed twice daily at 1.8 x NEm requirement. Ruminal pH, fluid dilution rate, volume, NH3 N, and total VFA concentrations, as well as molar proportions of isobutyrate, butyrate, and valerate, were similar (P > 0.10) among dietary treatments. Apparent and true OM disappearances (g/d and percentage of OM intake) from the stomach were similar (P > 0.10) among dietary treatments. Apparent OM disappearance (percentage of duodenal OM flow) from the small intestine was higher (P < 0.05) for the WC than for the NC treatment. Apparent total tract OM disappearance (percentage of OM intake) was also similar (P > 0.10) among dietary treatments. Total apparent and true starch disappearances (g/d) from the stomach were higher (P < 0.05) for the WC diet than for the CC and NC diets. However, apparent and true starch disappearances from stomach as percentage of starch intake were higher (P < 0.05) for the WC diet than for the CC diet. Starch disappearance (g/d) from the small intestine was higher (P < 0.05) for the CC diet than for the WC diet; however, apparent starch disappearance (percentages of duodenal starch flow) from the small intestine was higher (P < 0.05) for the WC diet than for the CC diet. Duodenal flows of total N, bacterial N, NH3 N, and non-NH3 nonbacterial N (g/d) and efficiencies of bacterial protein production (g of bacterial N/kg of true or apparent OM disappearing in the stomach) were similar (P > 0.10) among dietary treatments. Apparent and true N disappearance from stomach (g/d) and apparent total tract N disappearance (percentage of N intake) were also similar (P > 0.10) among dietary treatments. Total N disappearance from the hindgut was -0.81, -1.06, and -1.46 g/d for CC, NC, and WC, respectively, and was different (P < 0.05) between CC and WC diets. Results indicated that higher ruminal starch disappearance in WC did not increase microbial N production or efficiency when compared to CC.     

Supplementation of carbohydrases or phytase individually or in combination to diets for weanling and growing-finishing pigs

The overall objective of the studies reported here was to evaluate the growth and nutrient utilization responses of pigs to dietary supplementation of phytate- or nonstarch polysaccharide-degrading enzymes. In Exp. 1, growth performance and nutrient digestibility responses of forty-eight 10-kg pigs to dietary supplementation of phytase or a cocktail of xylanase, amylase, and protease (XAP) alone or in combination were evaluated. The growth response of one hundred fifty 23-kg pigs to dietary supplementation of phytase or xylanase individually or in combination was studied in Exp. 2 in a 6-wk growth trial, whereas Exp. 3 investigated the nutrient digestibility and nutrient retention responses of thirty 24-kg pigs to dietary supplementation of the same enzymes used in Exp. 2. In Exp. 1, the pigs were used in a 28-d feeding trial. They were blocked by BW and sex and allocated to 6 dietary treatments. The treatments were a positive control (PC) diet; a negative control (NC) diet marginally deficient in P and DE; NC with phytase added at 500 or 1,000 phytase units (FTU)/kg; NC with xylanase at 2,500 units (U)/kg, amylase at 400 U/kg, and protease at 4,000 U/kg; and NC with a combination of phytase added at 500 FTU/kg and XAP as above. In Exp. 2 and 3, the 5 dietary treatments were positive control (PC), negative control (NC), NC plus 500 FTU of phytase/kg, NC plus 4,000 U of xylanase/kg, and NC plus phytase and xylanase. In Exp. 1, low levels of nonphytate P and DE in the NC diet depressed (P < 0.05) ADG of the pigs by 16%, but phytase linearly increased (P < 0.05) ADG by up to 24% compared with NC. The cocktail of XAP alone had no effect on ADG of pigs, but the combination of XAP and phytase increased (P < 0.05) ADG by 17% compared with the NC treatment. There was a linear increase (P < 0.01) in Ca and P digestibility in response to phytase. In Exp. 2, ADG was 7% greater in PC than NC (P < 0.05); there were no effects of enzyme addition on any response. In Exp. 3, addition of phytase alone or in combination with xylanase improved (P < 0.05) P digestibility. Phosphorus excretion was greatest (P < 0.01) in the PC and lowest (P < 0.05) in the diet with the combination of phytase and xylanase. The combination of phytase and xylanase improved P retention (P < 0.01) above the NC diet to a level similar to the PC diet. In conclusion, a combination of phytase and carbohydrases improved ADG in 10-kg but not 23-kg pigs, but was efficient in improving P digestibility in pigs of all ages.     

The effects of low levels of dietary trace minerals on the plasma levels, faecal excretion, health and performance of pigs in a hot African climate

The present study was performed in order to evaluate the effects of lower than usual industry levels of dietary trace minerals on plasma levels, faecal excretion, performance, mortality and morbidity in growing-finishing pigs in a hot African climate. Group 1 (n = 100 pigs) received a diet with common industry levels of trace minerals. Group 2 (n = 100 pigs) received reduced dietary trace mineral levels but were fed the same basic diet as Group 1. Mortality, morbidity, pig performance and carcass measurements were evaluated. Two pigs in Group 1 and three pigs in Group 2 died. Thirteen pigs in Group 1 and 27 pigs in Group 2 were medically treated (P < 0.05). Carcass masses, back fat depth, loin depth, and lean percent were not significantly different between the groups. However, the carcasses when evaluated revealed a non-significant higher back fat thickness, lower loin eye area and percentage of fat-free lean in barrows compared to gilts within each group. Despite lower initial masses, pigs fed diets containing industry levels of trace minerals were heavier (P < 0.05) and had a higher (P< 0.05) than average daily gains compared to those that received a diet containing lower levels of trace minerals. Faecal zinc excretion was significantly lower (P < 0.05) in pigs fed with lower dietary zinc levels. Copper, manganese and iron excretion were not affected (P > 0.05) by the dietary levels of these trace minerals. Plasma trace mineral concentrations were not affected by the dietary treatment.     

色氨酸对5～10周龄扬州鹅生长性能和屠宰性能的影响

选用270只21日龄的扬州公鹅,随机分成6组,每组3个重复,每个重复15只鹅。采用2×3二因子试验设计,采用两种饲喂方式(自由采食和90%限制饲喂,限制饲喂组鹅饲料供给量为前一天自由采食组饲料消耗量的90%)和低、中、高3个色氨酸(Trp)水平(含量分别为0.14%,0.22%和0.30%),分别对3个不同生长阶段的生长性能和屠宰性能指标进行测定。结果表明,在28～42日龄,与低、高Trp组相比,中Trp组扬州鹅平均日采食量和平均日增重显著提高(P<0.05),饲喂方式和Trp水平对扬州鹅平均日采食量、平均日增重和饲料转化率有交互作用(P<0.05);在42～56日龄,自由采食组扬州鹅平均日采食量和饲料转化率极显著高于限制饲喂组(P<0.01),平均日增重显著高于限制饲喂组(P<0.05)。与低、高Trp组相比,中Trp组扬州鹅平均日采食量显著提高(P<0.05),Trp水平对平均日增重和饲料转化率无显著影响(P>0.05),饲喂方式和Trp水平对扬州鹅平均日采食量有交互作用(P<0.05);在56～70日龄,Trp水平对扬州鹅平均日采食量、平均日增重和饲料转化率均无显著影响(P>0.05)。饲喂方式和Trp水平对扬州鹅平均日增重和饲料转化率有交互作用(P<0.05);在28～70日龄,自由采食组扬州鹅平均日采食量和平均日增重极显著高于限制饲喂组(P<0.01)。与低、高Trp组相比,中Trp组扬州鹅平均日采食量和平均日增重显著提高(P<0.05),而Trp水平对饲料转化率无显著影响(P>0.05),饲喂方式和Trp水平对扬州鹅平均日采食量和平均日增重有交互作用(P<0.05)。自由采食组扬州鹅全净膛率、胸肌率和腹脂率显著高于限制饲喂组(P<0.01),随着Trp水平的增加,扬州鹅胸肌率显著增加(P<0.01),而Trp水平对其他屠宰性能指标无显著影响(P>0.05),饲喂方式和Trp水平对扬州鹅腹脂率有交互作用(P<0.01)。由此可知,饲粮中Trp水平过低或过高均会对扬州鹅生长性能产生不利影响,并且这种不利的影响具有阶段性,因此日粮添加适当水平的Trp能够一定程度改善扬州鹅生长性能。