Guanidinoacetic acid supplementation in broiler chickens fed on corn-soybean diets affects performance in the finisher period and energy metabolites in breast muscle independent of diet nutrient density     

M. Majdeddin  H. Kermanshahi  S. De Smet  J. Michiels 《British poultry science》2018,59(4):443-451

(1) Guanidinoacetic acid (GAA) is the single immediate endogenous precursor of creatine (Cr). It was hypothesised that dietary GAA would have different effects on performance and energy metabolites in breast muscle depending on the nutrient density (ND) of corn-soybean-based diets.

(2) A total of 540 one-day-old male Ross 308 broilers were allocated to 9 dietary treatments with 6 replicates (10 birds each) in a 3 × 3 factorial arrangement with three levels of ND (low, 2800; medium, 2950 and high, 3100 kcal metabolizable energy (ME)/kg; and with the other nutrients being constant relative to ME) and supplemented with three levels of GAA (0, 0.6 and 1.2 g/kg) in a 42-d feeding trial.

(3) In the starter and grower periods, increasing levels of ND improved body weight (BW), average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR), with the exception of ADFI in the starter period. GAA supplementation did not affect performance characteristics. All performance indicators responded markedly to increasing ND in the finisher period, whereas the highest GAA level reduced ADFI compared to the unsupplemented control (156 vs. 162 g/d) and concomitantly FCR (1.81 vs. 1.93). No interactive effects were noted for any performance trait. The high ND diet resulted in more breast meat yield on d42, associated with higher fat content and darker colour compared to the other ND levels. The GAA supplementation did not affect carcass and breast traits. At the end of the experiment, Cr was elevated when feeding GAA at 1.2 g/kg (5455 vs. 4338 mg/kg fresh muscle).

(4) To conclude, ND had a substantial effect on performance and carcass traits, whereas any effect of GAA was limited to FCR in the finisher period and independent of diet ND level.  相似文献   

Stress steroid levels and the short-term impact of routine dehorning in female southern white rhinoceroses (Ceratotherium simum simum)     

Marcha Badenhorst  Michelle Otto  Annemieke C van der Goot 《African Zoology》2016,51(4):211-215

Rhinoceros populations in Africa are under severe threat as a result of surging poaching rates and risk-mitigation strategies are continuously adapted in an attempt to ensure the survival of the species. This study compared faecal glucocorticoid metabolite (fGCM) levels of two age classes of limited free-ranging female white rhinos with fGCM levels of adult free-ranging female white rhinos. Subsequently, fGCM alterations in the limited free-ranging animals were monitored following routine dehorning as a measure of the animals’ short-term physiological stress response. Baseline fGCM levels differed significantly between tested groups, with both free-ranging and limited free-ranging adult animals showing significantly higher fGCM levels compared with limited free-ranging juvenile females. In contrast, baseline fGCM levels did not differ significantly between limited free-ranging and free-ranging adult individuals. Routine dehorning procedures resulted in a short-term stress response expressed by a significant increase in fGCM levels 48 h post-dehorning, with stress steroid levels returning to pre-dehorning concentrations 72 h after the procedure.  相似文献   

Relative abundance and activity of melanized hyphae in different soil ecosystems     

Annemieke van der Wal  Jaap Bloem  Wietse de Boer 《Soil biology & biochemistry》2009,41(2):417-419

Here we report on the frequency of melanized fungal hyphae in 323 soils, covering different land use types. The proportion of total hyphae that was melanized averaged 61%. Arable fields with loamy sand, heathlands and city parks on sandy soils had the highest percentage of melanized hyphae. In addition to the frequency determinations, a microcosm study was performed on the role of melanized hyphae in two different ecosystems: an ex-arable field and a forest. Melanized hyphae appeared to be part of the active hyphae in the forest soil but not in the ex-arable soil. In conclusion, our results indicate that (1) melanized hyphae represent a large proportion of the total fungal biomass in soils and that (2) their function might differ between ecosystems.  相似文献   

The influence of supplemental alpha-galactosidase and phytase in a vegetable ration for dogs on the digestibility of organic components and phytate phosphorus     

B. de Smet  M. Hesta  M. Seynaeve  G. Janssens  P. Vanrolleghem  R. O. de Wilde 《Journal of animal physiology and animal nutrition》1999,81(1):1-8

The use of dry feeds for dogs is increasing for different reasons: in comparison to wet canned feed it is easier to handle, the amount to be given is smaller and the daily cost is less. In producing a dry pellet more vegetable ingredients are used that can contain several antinutritional factors. Some of them can be eliminated by heating. Others like galactosides and phytates are heat-resistant but can be broken down by adding the appropriate enzymes. The specific enzymes are indeed not secreted by the animal itself. In farm animals, e.g. pigs, alpha-galactosidase has been introduced in order to enhance the energetic value of these alphagalactosides (Veldman et al. 1993). In companion animals this enzyme is more often indicated as an antiflatulence agent, because the main alpha-galactosides present in legume seeds (stachyose, raffinose) are known as flatulence components (Fleming 1981). These oligosaccharides do not necessarily imply an overall lower nutrient digestibility. Zuo et al. (1996) did not prove a significant difference in digestibility between conventional and low oligosaccharide soybean meal in dog rations. Others however, (Wiernusz et al. 1995) reported the highest digestibilities and the best stool quality of those rations that contained the least amount of soybean oligosaccharides. On the other hand, phytates (phospho-inositols) are known as complexing agents of several divalent cations (Fe, Mg, Zn, Ca) and are themselves considered as a phosphorus source, unavailable to monogastric animals. Phytase is the appropriate enzyme, which is not secreted by the animal itself, but, when added to the diet, can enhance the bio-availability of several minerals and trace elements (Rimbach et al. 1994) by hydrolysing the phospho-inositol molecule. The aim of the experiment, reported here, is to investigate the influence of the addition of alpha-galactosidase, phytase, or both to a nearly complete vegetable ration, consisting of a relatively high content of galactosides and phytates. The combination of both enzymes was carried out because Wenk et al. (1993) reported a possible interaction between a carbohydrase and a phytase enzyme in pigs.  相似文献   

Extent and duration of virulent virus excretion upon challenge of pigs vaccinated with different glycoprotein-deleted Aujeszky's disease vaccines   总被引：3，自引：0，他引：3  

M B Pensaert  K De Smet  K De Waele 《Veterinary microbiology》1990,22(2-3):107-117

Different deleted Aujeszky's disease vaccines were compared for their ability to induce an immunity which suppresses virus excretion optimally upon infection. Groups of pigs were vaccinated once with attenuated deleted Aujeszky's disease vaccine (gI, gX or gp63 negative), suspended in phosphate buffered saline. Two additional groups were vaccinated with a gI deleted vaccine virus suspended in an oil-in-water emulsion. Other groups were vaccinated twice with gI deleted inactivated vaccines. The three control groups included were: pigs immune after infection, unvaccinated pigs and pigs receiving vaccine without known deletion in the envelope. Experimental challenge took place 3 or 4 weeks after the only or the last vaccination. The number of excreting pigs, the duration of excretion and the virus titers excreted, were determined for all the groups. All the pigs vaccinated with glycoprotein deletion vaccines suspended in phosphate buffered saline, excreted virus for 2 to 6 days after challenge. A 100 to 1000 fold reduction in excreted virus titers was obtained in vaccinated pigs compared to unvaccinated ones. Some vaccines suppressed virus excretion better than others, but no correlation could be made between the type of deletion (gI, gX or gp63) and the degree of reduction in virus excretion. Similar results were obtained with two applications of inactivated vaccines. The lowest number of excreting pigs, the lowest duration of excretion and the lowest titers were obtained in groups vaccinated with the attenuated vaccine suspended in an oil-in-water emulsion. No vaccine suppressed virus excretion totally.  相似文献   

The effect of different concentrations of linseed oil or fish oil in the maternal diet on the fatty acid composition and oxidative status of sows and piglets          下载免费PDF全文

S. Tanghe  J. Missotten  K. Raes  S. De Smet 《Journal of animal physiology and animal nutrition》2015,99(5):938-949

N‐3 polyunsaturated fatty acids (PUFA) are essential for foetal development. Hence, including n‐3 PUFA in the sow diet can be beneficial for reproduction. Both the amount and form (precursor fatty acids vs. long chain PUFA) of supplementation are important in this respect. Furthermore, including n‐3 PUFA in the diet can have negative effects, such as decreased arachidonic acid (ARA) concentration and increased oxidative stress. This study aimed to compare the efficacy to increase eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in the piglet, when different concentrations of linseed oil (LO, source of precursor α‐linolenic acid) or fish oil (FO, source of EPA and DHA) were included in the maternal diet. Sows were fed a palm oil diet or a diet including 0.5% or 2% LO or FO from day 45 of gestation until weaning. Linoleic acid (LA) was kept constant in the diets to prevent a decrease in ARA, and all diets were supplemented with α‐tocopherol acetate (150 mg/kg) and organic selenium (0.4 mg/kg) to prevent oxidative stress. Feeding 0.5% LO or 0.5% FO to the sows resulted in comparable EPA concentrations in the 5‐day old piglet liver, but both diets resulted in lower EPA concentrations than when 2% LO was fed. The highest EPA concentration was obtained when 2% FO was fed. The DHA level in the piglet liver could only be increased when FO, but not LO, was fed to the sows. The 2% FO diet had no advantage over the 0.5% FO diet to increase DHA in the piglet. Despite the constant LA concentration in the sow diet, a decrease in ARA could not be avoided when LO or FO were included in the diet. Feeding 2% FO to the sows increased the malondialdehyde concentration (marker for lipid peroxidation) in sow plasma, but not in piglets.  相似文献   

Abatement of High Concentrated Ammonia Loaded Waste Gases in Compost Biofilters     

Smet  Erik  van Langenhove  Herman  Maes  Katrien 《Water, air, and soil pollution》2000,119(1-4):177-190

The performance of lab-scale compostbiofilters for the purification of waste gasescontaining high (>70 mg m^-3) ammoniaconcentrations was studied. When using fresh compostmaterial, no effect of inoculating the compostmaterial with a nitrifying culture was observed sincehigh elimination capacities (up to 350 gNH₃ m^-3 d^-1) were obtained in both theinoculated and the non-inoculated biofilter. Due tothe physico-chemical interaction of NH₃ with thecompost material at the start of the experiment, nomicrobiological start-up period was observed and highremoval efficiencies were obtained from the first dayon. Next to this, no NH₃-toxicity was observedeven at concentrations up to 550 mg NH₃ m^-3.About 50% of the NH₃-removal was found to benitrified, while the other 50% remained in thebiofilter as NH ⁺₄ . As a result of this, noacidification of the carrier material was observed andNH₄NO₃ accumulated in the biofilter. Due toosmotic effects, however, a complete inhibition innitrification and NH₃-removal was obtained at ameasured NH₄NO₃-concentration in the compostmaterial of 6–7 g N kg^-1, corresponding to acumulative NH₃-removal in the biofilter of ±6000 g m^-3. Finally, it was illustrated that theremoval of the odorant dimethyl sulfide (Me₂S) ina Hyphomicrobium MS3-inoculated compostbiofilter is completely inhibited due toNH₃-toxicity at a waste gas concentration of 100 mg NH₃ m^-3. Next to this, theNH ⁺₄ - and NO ^?₃ -concentrations inthe compost material that were shown to inhibit thenitrification, also strongly affected theMe₂S-degrading activity of Hyphomicrobium MS3.

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Constraints on development of fungal biomass and decomposition processes during restoration of arable sandy soils     

Annemieke van der Wal  Johannes A. van Veen  Richard C. Summerbell 《Soil biology & biochemistry》2006,38(9):2890-2902

In an earlier study we reported the apparent stabilization of a low fungal biomass in ex-arable lands during the first decades after abandonment. It was hypothesized that the lack of increase in fungal biomass was due to constraints on development of fungi with persistent hyphae such as lignocellulolytic basidiomycetes and ericoid mycorrhizal fungi. With respect to the former group, the slow increase of the pool of lignocellulose-rich organic matter was expected to be the major constraint for their development. To study this, we enriched soil samples of one arable land, of two recently abandoned arable lands, of one older abandoned arable land and of heathland with carbon substrates that differed in composition (glucose, cellulose and sawdust). In addition, we combined the effect of carbon addition on fungal biomass development in arable and recently abandoned lands with inoculation of 1% of soil from the older abandoned site and the heathland. All treatments induced a fast increase and a subsequent rapid decline in fungal biomass in the arable and ex-arable fields. Denaturing Gradient Gel Electrophoresis (DGGE) band patterns and enzyme activities did show differences between the carbon treatments but not between the recent and older abandoned field sites, indicating a similarly responding fungal community even after three decades of land abandonment and irrespective of soil inoculation. Identification of fungi by sequencing and culturing confirmed that decomposition processes were mostly dominated by opportunistic fungi in arable and ex-arable fields. In the heathland, only a very slow increase of microbial activity was observed after addition of carbon and sequencing of DGGE bands showed that ericoid mycorrhiza (ERM) fungi were responsible for carbon decomposition. We conclude that an increase of enduringly present fungal hyphae in ex-arable land may only be possible when a separate litter layer develops and/or when suitable host plants for ERM fungi become established.  相似文献   

Field experiments to evaluate the feasibility of eradication of Aujeszky's disease virus by different vaccination schedules.     

K De Smet  K De Waele  M Pensaert  D Goovaerts  E De Ridder 《The Veterinary quarterly》1992,14(1):22-28

In the present report, the extent of the reduction in Aujeszky's disease virus (ADV) dissemination achieved when pigs were intensively vaccinated with gI-deleted vaccines under field circumstances, was examined. On widely dispersed breeding-fattening farms, a gI-negative status was most rapidly obtained and the rate of new waves of infections was lowest when the attenuated Bartha strain was administered to both the sows and the fatteners. It was more difficult not only to reach but also to keep a gI-negative status on farms on which the sows were vaccinated with an inactivated vaccine and the fatteners with the attenuated Bartha strain or when the fattening pigs were not vaccinated at all. In a densely populated area, 9 of the 17 farms had gI-positive fatteners at the start of the intensive vaccination programme in which the attenuated Bartha strain was given to both the sows and the fatteners. Antibodies were not detected in the sera of the fatteners of each farm at some time during the experiments, but the fatteners on 7 of the 18 farms still showed antibodies against gI after 20 months of vaccination. At the end of the experiment, the percentage of fatteners with antibodies on these farms was markedly reduced compared with the percentage at the start of the experiment. Therefore, elimination of field virus may be feasible if intensive vaccination is carried out over a sufficiently long period of time. However, the high rate of reinfections experienced either due to reintroduction of the virus or to recrudescence should be a warning against too much optimism, particularly in regions with a dense swine population.  相似文献   

Immunocompetence in organically fed finishing pigs: effect of corn cob mix     

Millet S  Cox E  Van Paemel M  Raes K  Lobeau M  De Saeger S  De Smet S  Goddeeris BM  Janssens GP 《Veterinary journal (London, England : 1997)》2006,171(2):301-307

Two consecutive experiments were performed to evaluate the effects on the immune response of corn cob mix (CCM) in an organic pig diet. The immunoglobulin (Ig) M, IgA and IgG responses against an intramuscularly injected model antigen, bovine thyroglobulin, were used as indicator. The experiments were performed in an organic barn with nine pens of four crossbred pigs (two barrows and two sows) from 45 kg to slaughter. In the first experiment, the organic concentrate was mixed with organic CCM-silage to obtain three concentrate: CCM ratios of 100:0, 80:20 and 60:40 (w:w). In the second experiment, three concentrates were produced to obtain diets with equal nutrient levels on a dry matter basis after 0%, 20% and 40% CCM inclusion. Higher inclusion rates of CCM in the ration were accompanied by lower thyroglobulin-specific IgG responses. These effects could not be attributed to one specific component of the CCM, such as fatty acid composition, although there was a degree of correlation with lower vitamin A concentrations. Mycotoxin concentrations were absent or minimal. The study indicated that dietary ingredient composition may affect immunocompetence.  相似文献