Animal Biotechnology and the Quality of Meat Production, 1991
Insulin-like Growth Factor-I (IGF-I) is known to be a growth promoting factor in mammals. This ef... more Insulin-like Growth Factor-I (IGF-I) is known to be a growth promoting factor in mammals. This effect also includes a shift from lipid to protein synthesis and IGF-I therefore has been proposed to function as a lean growth factor. In broilers selection has resulted in fast growing strains which however often show an undesired fat accumulation. In the following study, the effect of IGF-I on body weight, fat deposition and distribution, and on circulating levels of IGF-I, growth hormone (GH), tyroxine (T4) and triiodotyronine (T3) was examined. Different doses of IGF-I (0, 0.03, 0.1 and 0.3 mg/kg BW.day) were administered by mini-osmotic pumps in 40 broiler chicks of a commercial strain between 4 and 6 weeks of age since fat deposition is maximal during this period. Blood samples were taken prior to and 1 and 2 weeks after implantation. Plasma IGF-I, GH, T3 and T4 levels were measured by RIA. At the end of the experimental period all birds were killed, abdominal fat measured, leg and breast muscles dissected and fat extracted. Body weight and relative growth were not affected by IGF-I treatment. However, while fat content in breast and thigh muscles remain unchanged, % abdominal fat was decreased significantly (P < 0.01) with 0.3 mg IGF-I treatment. Plasma IGF-I levels increased, as expected, in a dose-dependent way, while GH did not change with treatment but decreased with increasing age in all groups. A transient decrease in plasma T4 and increase in T3 was observed, at least with the higher IGF-doses. After 2 weeks the effect of IGF on circulating thyroid hormone levels disappeared. Although no effect of IGF-I on body weight or growth rate in commercial broiler chicks was observed, a decrease in abdominal fat indicate a repartition of nutrients available for net energy accretion. The observation that only the abdominal fat depot was affected confirms many other reports indicating a higher flexibility in fat content for depot fat compared to intra-and intermuscular fat. Since T3 is extremely effective in reducing abdominal fat in chickens, the increased T3 levels following IGF-I administration may also be, partly or totally, responsible for the abdominal fat reduction. Further research into causes of the T3-IGF-I interaction and its consequences on animal growth are needed to elucidate this.
Different animal models have been used to study the effects of prenatal protein undernutrition an... more Different animal models have been used to study the effects of prenatal protein undernutrition and the mechanisms by which these occur. In mammals, the maternal diet is manipulated, exerting both direct nutritional and indirect hormonal effects. Chicken embryos develop independent from the hen in the egg. Therefore, in the chicken, the direct effects of protein deficiency by albumen removal early during incubation can be examined. Prenatal protein undernutrition was established in layer-type eggs by the partial replacement of albumen by saline at embryonic day 1 (albumen-deprived group), compared to a mock-treated sham and a non-treated control group. At hatch, survival of the albumen-deprived group was lower compared to the control and sham group due to increased early mortality by the manipulation. No treatment differences in yolk-free body weight or yolk weight could be detected. The water content of the yolk was reduced, whereas the water content of the carcass was increased in the albumen-deprived group, compared to the control group, indicating less uptake of nutrients from the yolk. At embryonic day 16, 20 and at hatch, plasma triiodothyronine (T 3 ), corticosterone, lactate or glucose concentrations and hepatic glycogen content were not affected by treatment. At embryonic day 20, the plasma thyroxine (T 4 ) concentrations of the albumen-deprived embryos was reduced compared to the control group, indicating a decreased metabolic rate. Screening for differential protein expression in the liver at hatch using two-dimensional difference gel electrophoresis revealed not only changed abundance of proteins important for amino acid metabolism, but also of enzymes related to energy and glucose metabolism. Interestingly, GLUT1, a glucose transporter, and PCK2 and FBP1, two out of three regulatory enzymes of the gluconeogenesis were dysregulated. No parallel differences in gene expressions causing the differences in protein abundance could be detected pointing to posttranscriptional or post-translational regulation of the observed differences. Citation: Willems E, Hu T-T, Soler Vasco L, Buyse J, Decuypere E, et al. (2014) Embryonic Protein Undernutrition by Albumen Removal Programs the Hepatic Amino Acid and Glucose Metabolism during the Perinatal Period in an Avian Model. PLoS ONE 9(4): e94902.
Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana (Bertoni) Bertoni. T... more Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana (Bertoni) Bertoni. The literature about Stevia, the occurrence of its sweeteners, their biosynthetic pathway and toxicological aspects are discussed. Injection experiments or perfusion ...
Comparative Biochemistry and Physiology: Pharmacology, Toxicology and Endocrinology, 1994
The disappearance rates for glycosylated (GcGH) and non-glycosylated chicken growth hormone (NGcG... more The disappearance rates for glycosylated (GcGH) and non-glycosylated chicken growth hormone (NGcGH) were compared following their intravenous injection into anaesthetized adult laying hens. The metabolic clearance rate of GcGH was about 20% lower (P = 0.13) compared to NGcGH. Similarly, there was a tendency towards a longer half-life for GcGH. No major physiological significance could be attributed to the glycosylation state of the preparations as far as their effects on circulating insulin-like growth factor I and iodohormone levels were concerned.
The health benefits of omega-3 polyunsaturated fatty acids (n−3 PUFA) are generally recognized. U... more The health benefits of omega-3 polyunsaturated fatty acids (n−3 PUFA) are generally recognized. Unfortunately, in most western countries, the recommended daily intake of these compounds is rarely met. Therefore, enrichment of commonly occurring foods can boost intake of these fatty acids. In this regard, eggs are an interesting target, as they form an integral part of the diet. Their n−3 PUFA profile can be modified through feed supplementation. A traditional n−3 PUFA source to be added to hens' diet is flaxseed, a plant source rich in α-linolenic acid. Alternatively, hens are often fed fish oil, which is rich in long chain n−3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A more recent trend is feed supplementation with microalgae as a source of EPA and/or DHA. In this paper, recent scientific literature concerning n−3 PUFA enrichment in eggs is reviewed, giving an overview of advantages and disadvantages of the different approaches.
Sixteen Holstein cows were assigned to 2 groups to evaluate the caloric and metabolic effect of f... more Sixteen Holstein cows were assigned to 2 groups to evaluate the caloric and metabolic effect of feeding marine algae (ALG) from 3 wk prepartum until 12 wk postpartum. Milk production characteristics and the profiles of hormones and metabolites in the serum were monitored from −7 to 46 d in milk (DIM) and in follicular fluid (FF) from 14 to 46 DIM. All cows received a corn-and grass silage-based partially mixed ration supplemented with concentrate and protein supplement. In the diet of the ALG group, 2 kg of the concentrate was replaced by a concentrate containing ALG (44 g/d of docosahexaenoic acid). Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. The ALG diet increased milk yield (41.2 vs. 38.2 kg/d) and decreased milk fat yield (1.181 vs. 1.493 kg/d) and milk fat content (31.6 vs. 40.7 g/kg). Protein yield (1.336 vs. 1.301 kg/d) was not affected but a tendency toward decreased milk protein content (32.8 vs. 34.7 g/kg) was observed. Marine algae supplementation increased the β-hydroxybutyric acid (BHBA) concentration in FF of the ALG cows compared with that in the controls (0.992 vs. 0.718 mmol/L). The total protein concentration in FF was decreased in ALG (62.9 vs. 67.6 g/L). Plasma and serum metabolites did not significantly differ between treatments except for a tendency toward a lower concentration of urea in the serum of the control compared with ALG (4.69 vs. 5.13 mmol/L). Based on metabolizable energy calculations, a daily energy-sparing effect of 3.48 Mcal was obtained due to milk fat depression (MFD). The concomitant increase in milk yield suggests that at least part of this spared energy is used to stimulate milk production. Theoretically, 3.48 Mcal of ME could lead to an increase in milk yield of 7.43 kg/d, which is higher than the observed 3 kg/d. However, when evaluating nutrient requirements during MFD in early lactation, we calculated that increased milk production is caused by a propionate-saving effect of 2.71 mol in the udder when milk fat is depressed. Concurrent increased BHBA concentrations in FF in the ALG group cannot be attributed to a worsened energy status of the animals because all other indicators contradict any change in energy balance, indicating that BHBA might not be an appropriate metabolic parameter to estimate the energy balance in early lactating dairy cows during MFD.
Insulin resistance in horses is an emerging field of interest as it is thought to be a contributi... more Insulin resistance in horses is an emerging field of interest as it is thought to be a contributing factor in the pathogenesis of many equine conditions. The objectives of the present study were to determine the effects of long-term oral administration of L-carnitine on insulin sensitivity, glucose disposal, plasma leptin concentrations and acylcarnitine spectrum both in plasma and urine. Six 3-year-old healthy warmblood geldings were used. In a double blind 2 × 2 Latin square design at a dosage of 100 mg/kg body weight (BW)/day for 28 days the effects of oral supplementation of L-carnitine (as fumarate) were assessed. Glucose disposal and insulin sensitivity were measured by means of the euglycemic-hyperinsulinemic clamp technique. Radioimmunoassays were used to determine plasma leptin and insulin concentrations. Electrospray tandem mass spectrometry was used to assess acylcarnitines both in plasma and urine. Statistical analysis was performed using a linear mixed-effects model and...
Aims: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus... more Aims: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus communities at specific locations in the adult gastrointestinal tract of different hosts. Methods and Results: Samples of the human, murine and avian gastrointestinal tract of subjects that received or not received a Lactobacillus probiotic were analysed by fluorescence in situ hybridization (FISH) with rRNA-targeted probes. High levels of endogenous lactobacilli were observed on the nonsecretory, stratified squamous epithelia present in the forestomach of mice and crop of chickens, respectively. These epithelial associations showed characteristics of bacterial biofilms, i.e. bacteria attached to a surface and embedded in a matrix of extracellular polymeric substances. In other regions of the analysed intestines, lactobacilli seemed to occur mainly as dispersed bacterial cells or as microcolonies. Exogenous administration of a Lactobacillus probiotic did increase the levels of loosely adherent Lactobacillus cells detected. However, the probiotic strains were unable to establish themselves inside the gastrointestinal biofilms. Conclusions: Gastrointestinal biofilms of lactobacilli occur only in specific niches in certain hosts, such as the murine forestomach and avian crop. Significance and Impact of the Study: Biofilm formation by lactobacilli in specific parts of animal gastrointestinal tracts was documented for the first time by FISH.
ABSTRACT Based on its described beneficial effects on small and large intestinal epithelium, buty... more ABSTRACT Based on its described beneficial effects on small and large intestinal epithelium, butyrate can be a very good alternative to antimicrobial growth promoters. Effective dietary application requires coating because the majority of uncoated butyrate is purportedly absorbed before reaching the proximal small intestine. Several studies using different protocols reported varying stomach passage times in chickens. In the present study, we compared feeding uncoated vs. fat coated [1-13C] labeled Ca butyrate, and compared the effect of butyrate coating with [1-13C] labeled octanoic acid which is an established indicator of stomach passage. By monitoring 13CO2 expiration continuously, we show that the majority (about 80%) of uncoated Ca butyrate is oxidized proximally of the small intestine, and that base line levels were reached after 6 h. Fat coating of Ca butyrate resulted in reduced proximal oxidation (from about 80% to about 45%), and in an extended release pattern of 13CO2 from butyrate similar to that of octanoic acid, and that the return to base line levels was extended to 12 h. This indicated that fat coating of butyrate results in absorption along the entire intestinal tract in broilers, offering an explanation for the described beneficial effects as a growth promoter.
Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology, 1997
Ten broiler-type chickens at 2 weeks of age were injected daily with 0.5 ml of normal sheep serum... more Ten broiler-type chickens at 2 weeks of age were injected daily with 0.5 ml of normal sheep serum while 10 others were similarly injected with 0.5 ml of a sheep anti-IGF-2 serum. Immunization with anti-IGF-2 serum had no significant effect upon body weight gain, on carcass composition, on appetite or food conversion. Liver weight was significantly increased (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05)
Journal of animal physiology and animal nutrition, 2015
Breeder age and nutrition are amongst the most important factors affecting progeny growth and dev... more Breeder age and nutrition are amongst the most important factors affecting progeny growth and development. The present experiment was carried out to evaluate the effects of n-3 fatty acid (FA), with special emphasis on the ratio of eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic (DHA, 22:6 n-3) acid, provided to the diet of ageing broiler breeder hens at different ratios, on the incubation parameters and the performance of the offspring. Four hundred and eighty Ross-308 broiler breeder hens were fed one of four different diets (120/treatment), with an equal fat content. The control diet was a basal diet, rich in n-6 FAs (CON). Blends of fish oil were used to enrich the three other diets in n-3 FA and to obtain different EPA/DHA ratios of 1/1 (EPA=DHA), 1/2 (DHA) or 2/1 (EPA). Every 5 weeks, incubation parameters were assessed. Every 15 weeks, offspring was reared until slaughter age on a standard diet. Breeder age affected almost all incubation and post-hatch parameters, wherea...
Journal of animal physiology and animal nutrition, Jan 3, 2015
In this study, we tested the hypothesis that in ovo feeding (IOF) of L-arginine (L-Arg) enhances ... more In this study, we tested the hypothesis that in ovo feeding (IOF) of L-arginine (L-Arg) enhances nitric oxide (NO) production, stimulates the process of myogenesis, and regulates post-hatching muscle growth. Different doses of L-Arg were injected into the amnion of chicken embryos at embryonic day (ED) 16. After hatching, the body weight of individual male chickens was recorded weekly for 3 weeks. During in vitro experiments, myoblasts of the pectoralis major (PM) were extracted at ED16 and were incubated in medium containing 0.01 mm L-Arg, 0.05 mm L-Arg, and (or) 0.05 mm L-nitro-arginine-methyl-ester (L-NAME), an inhibitor of nitric oxide synthase (NOS). When 25 mg/kg L-Arg/initial egg weight was injected, no difference was observed in body weight at hatch, but a significant decrease was found during the following 3 weeks compared to that of the non-injected and saline-injected control, and this also affected the growth of muscle mass. L-NAME inhibited gene expression of myogenic d...
Journal of animal physiology and animal nutrition, Jan 3, 2014
Small-scale urban dairy farms (n = 16) in and around Jimma, Ethiopia with cross-bred (Bos indicus... more Small-scale urban dairy farms (n = 16) in and around Jimma, Ethiopia with cross-bred (Bos indicus × Bos taurus) cows were enrolled in a double-blinded intervention study to investigate the effect of a trace element supplementation programme on trace element status and milk concentrations as well as performance [body condition score (BCS), milk yield, leptin], milk composition, antioxidant status (ferric-reducing ability of plasma (FRAP), thiobarbituric acid-reactive substances (TBARS)], blood biochemistry, serum proteins and immune response (antibody titre upon rabies vaccination). The farms were allocated to a (1) placebo or (2) Cu, Zn, Se, Co and I supplementation treatment for 150 d. On days 0 and 120, four lactating cows per farm were sampled for milk and plasma, and on day 150 for serum, following primo-vaccination. Cu deficiency was present in 17% and marginal Se deficiency in 30% of initially sampled cows, while no Zn shortage was detected. Over 120 days, trace element supple...
Animal Biotechnology and the Quality of Meat Production, 1991
Insulin-like Growth Factor-I (IGF-I) is known to be a growth promoting factor in mammals. This ef... more Insulin-like Growth Factor-I (IGF-I) is known to be a growth promoting factor in mammals. This effect also includes a shift from lipid to protein synthesis and IGF-I therefore has been proposed to function as a lean growth factor. In broilers selection has resulted in fast growing strains which however often show an undesired fat accumulation. In the following study, the effect of IGF-I on body weight, fat deposition and distribution, and on circulating levels of IGF-I, growth hormone (GH), tyroxine (T4) and triiodotyronine (T3) was examined. Different doses of IGF-I (0, 0.03, 0.1 and 0.3 mg/kg BW.day) were administered by mini-osmotic pumps in 40 broiler chicks of a commercial strain between 4 and 6 weeks of age since fat deposition is maximal during this period. Blood samples were taken prior to and 1 and 2 weeks after implantation. Plasma IGF-I, GH, T3 and T4 levels were measured by RIA. At the end of the experimental period all birds were killed, abdominal fat measured, leg and breast muscles dissected and fat extracted. Body weight and relative growth were not affected by IGF-I treatment. However, while fat content in breast and thigh muscles remain unchanged, % abdominal fat was decreased significantly (P < 0.01) with 0.3 mg IGF-I treatment. Plasma IGF-I levels increased, as expected, in a dose-dependent way, while GH did not change with treatment but decreased with increasing age in all groups. A transient decrease in plasma T4 and increase in T3 was observed, at least with the higher IGF-doses. After 2 weeks the effect of IGF on circulating thyroid hormone levels disappeared. Although no effect of IGF-I on body weight or growth rate in commercial broiler chicks was observed, a decrease in abdominal fat indicate a repartition of nutrients available for net energy accretion. The observation that only the abdominal fat depot was affected confirms many other reports indicating a higher flexibility in fat content for depot fat compared to intra-and intermuscular fat. Since T3 is extremely effective in reducing abdominal fat in chickens, the increased T3 levels following IGF-I administration may also be, partly or totally, responsible for the abdominal fat reduction. Further research into causes of the T3-IGF-I interaction and its consequences on animal growth are needed to elucidate this.
Different animal models have been used to study the effects of prenatal protein undernutrition an... more Different animal models have been used to study the effects of prenatal protein undernutrition and the mechanisms by which these occur. In mammals, the maternal diet is manipulated, exerting both direct nutritional and indirect hormonal effects. Chicken embryos develop independent from the hen in the egg. Therefore, in the chicken, the direct effects of protein deficiency by albumen removal early during incubation can be examined. Prenatal protein undernutrition was established in layer-type eggs by the partial replacement of albumen by saline at embryonic day 1 (albumen-deprived group), compared to a mock-treated sham and a non-treated control group. At hatch, survival of the albumen-deprived group was lower compared to the control and sham group due to increased early mortality by the manipulation. No treatment differences in yolk-free body weight or yolk weight could be detected. The water content of the yolk was reduced, whereas the water content of the carcass was increased in the albumen-deprived group, compared to the control group, indicating less uptake of nutrients from the yolk. At embryonic day 16, 20 and at hatch, plasma triiodothyronine (T 3 ), corticosterone, lactate or glucose concentrations and hepatic glycogen content were not affected by treatment. At embryonic day 20, the plasma thyroxine (T 4 ) concentrations of the albumen-deprived embryos was reduced compared to the control group, indicating a decreased metabolic rate. Screening for differential protein expression in the liver at hatch using two-dimensional difference gel electrophoresis revealed not only changed abundance of proteins important for amino acid metabolism, but also of enzymes related to energy and glucose metabolism. Interestingly, GLUT1, a glucose transporter, and PCK2 and FBP1, two out of three regulatory enzymes of the gluconeogenesis were dysregulated. No parallel differences in gene expressions causing the differences in protein abundance could be detected pointing to posttranscriptional or post-translational regulation of the observed differences. Citation: Willems E, Hu T-T, Soler Vasco L, Buyse J, Decuypere E, et al. (2014) Embryonic Protein Undernutrition by Albumen Removal Programs the Hepatic Amino Acid and Glucose Metabolism during the Perinatal Period in an Avian Model. PLoS ONE 9(4): e94902.
Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana (Bertoni) Bertoni. T... more Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana (Bertoni) Bertoni. The literature about Stevia, the occurrence of its sweeteners, their biosynthetic pathway and toxicological aspects are discussed. Injection experiments or perfusion ...
Comparative Biochemistry and Physiology: Pharmacology, Toxicology and Endocrinology, 1994
The disappearance rates for glycosylated (GcGH) and non-glycosylated chicken growth hormone (NGcG... more The disappearance rates for glycosylated (GcGH) and non-glycosylated chicken growth hormone (NGcGH) were compared following their intravenous injection into anaesthetized adult laying hens. The metabolic clearance rate of GcGH was about 20% lower (P = 0.13) compared to NGcGH. Similarly, there was a tendency towards a longer half-life for GcGH. No major physiological significance could be attributed to the glycosylation state of the preparations as far as their effects on circulating insulin-like growth factor I and iodohormone levels were concerned.
The health benefits of omega-3 polyunsaturated fatty acids (n−3 PUFA) are generally recognized. U... more The health benefits of omega-3 polyunsaturated fatty acids (n−3 PUFA) are generally recognized. Unfortunately, in most western countries, the recommended daily intake of these compounds is rarely met. Therefore, enrichment of commonly occurring foods can boost intake of these fatty acids. In this regard, eggs are an interesting target, as they form an integral part of the diet. Their n−3 PUFA profile can be modified through feed supplementation. A traditional n−3 PUFA source to be added to hens' diet is flaxseed, a plant source rich in α-linolenic acid. Alternatively, hens are often fed fish oil, which is rich in long chain n−3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A more recent trend is feed supplementation with microalgae as a source of EPA and/or DHA. In this paper, recent scientific literature concerning n−3 PUFA enrichment in eggs is reviewed, giving an overview of advantages and disadvantages of the different approaches.
Sixteen Holstein cows were assigned to 2 groups to evaluate the caloric and metabolic effect of f... more Sixteen Holstein cows were assigned to 2 groups to evaluate the caloric and metabolic effect of feeding marine algae (ALG) from 3 wk prepartum until 12 wk postpartum. Milk production characteristics and the profiles of hormones and metabolites in the serum were monitored from −7 to 46 d in milk (DIM) and in follicular fluid (FF) from 14 to 46 DIM. All cows received a corn-and grass silage-based partially mixed ration supplemented with concentrate and protein supplement. In the diet of the ALG group, 2 kg of the concentrate was replaced by a concentrate containing ALG (44 g/d of docosahexaenoic acid). Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. The ALG diet increased milk yield (41.2 vs. 38.2 kg/d) and decreased milk fat yield (1.181 vs. 1.493 kg/d) and milk fat content (31.6 vs. 40.7 g/kg). Protein yield (1.336 vs. 1.301 kg/d) was not affected but a tendency toward decreased milk protein content (32.8 vs. 34.7 g/kg) was observed. Marine algae supplementation increased the β-hydroxybutyric acid (BHBA) concentration in FF of the ALG cows compared with that in the controls (0.992 vs. 0.718 mmol/L). The total protein concentration in FF was decreased in ALG (62.9 vs. 67.6 g/L). Plasma and serum metabolites did not significantly differ between treatments except for a tendency toward a lower concentration of urea in the serum of the control compared with ALG (4.69 vs. 5.13 mmol/L). Based on metabolizable energy calculations, a daily energy-sparing effect of 3.48 Mcal was obtained due to milk fat depression (MFD). The concomitant increase in milk yield suggests that at least part of this spared energy is used to stimulate milk production. Theoretically, 3.48 Mcal of ME could lead to an increase in milk yield of 7.43 kg/d, which is higher than the observed 3 kg/d. However, when evaluating nutrient requirements during MFD in early lactation, we calculated that increased milk production is caused by a propionate-saving effect of 2.71 mol in the udder when milk fat is depressed. Concurrent increased BHBA concentrations in FF in the ALG group cannot be attributed to a worsened energy status of the animals because all other indicators contradict any change in energy balance, indicating that BHBA might not be an appropriate metabolic parameter to estimate the energy balance in early lactating dairy cows during MFD.
Insulin resistance in horses is an emerging field of interest as it is thought to be a contributi... more Insulin resistance in horses is an emerging field of interest as it is thought to be a contributing factor in the pathogenesis of many equine conditions. The objectives of the present study were to determine the effects of long-term oral administration of L-carnitine on insulin sensitivity, glucose disposal, plasma leptin concentrations and acylcarnitine spectrum both in plasma and urine. Six 3-year-old healthy warmblood geldings were used. In a double blind 2 × 2 Latin square design at a dosage of 100 mg/kg body weight (BW)/day for 28 days the effects of oral supplementation of L-carnitine (as fumarate) were assessed. Glucose disposal and insulin sensitivity were measured by means of the euglycemic-hyperinsulinemic clamp technique. Radioimmunoassays were used to determine plasma leptin and insulin concentrations. Electrospray tandem mass spectrometry was used to assess acylcarnitines both in plasma and urine. Statistical analysis was performed using a linear mixed-effects model and...
Aims: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus... more Aims: To investigate the spatial organization of endogenous and exogenously applied Lactobacillus communities at specific locations in the adult gastrointestinal tract of different hosts. Methods and Results: Samples of the human, murine and avian gastrointestinal tract of subjects that received or not received a Lactobacillus probiotic were analysed by fluorescence in situ hybridization (FISH) with rRNA-targeted probes. High levels of endogenous lactobacilli were observed on the nonsecretory, stratified squamous epithelia present in the forestomach of mice and crop of chickens, respectively. These epithelial associations showed characteristics of bacterial biofilms, i.e. bacteria attached to a surface and embedded in a matrix of extracellular polymeric substances. In other regions of the analysed intestines, lactobacilli seemed to occur mainly as dispersed bacterial cells or as microcolonies. Exogenous administration of a Lactobacillus probiotic did increase the levels of loosely adherent Lactobacillus cells detected. However, the probiotic strains were unable to establish themselves inside the gastrointestinal biofilms. Conclusions: Gastrointestinal biofilms of lactobacilli occur only in specific niches in certain hosts, such as the murine forestomach and avian crop. Significance and Impact of the Study: Biofilm formation by lactobacilli in specific parts of animal gastrointestinal tracts was documented for the first time by FISH.
ABSTRACT Based on its described beneficial effects on small and large intestinal epithelium, buty... more ABSTRACT Based on its described beneficial effects on small and large intestinal epithelium, butyrate can be a very good alternative to antimicrobial growth promoters. Effective dietary application requires coating because the majority of uncoated butyrate is purportedly absorbed before reaching the proximal small intestine. Several studies using different protocols reported varying stomach passage times in chickens. In the present study, we compared feeding uncoated vs. fat coated [1-13C] labeled Ca butyrate, and compared the effect of butyrate coating with [1-13C] labeled octanoic acid which is an established indicator of stomach passage. By monitoring 13CO2 expiration continuously, we show that the majority (about 80%) of uncoated Ca butyrate is oxidized proximally of the small intestine, and that base line levels were reached after 6 h. Fat coating of Ca butyrate resulted in reduced proximal oxidation (from about 80% to about 45%), and in an extended release pattern of 13CO2 from butyrate similar to that of octanoic acid, and that the return to base line levels was extended to 12 h. This indicated that fat coating of butyrate results in absorption along the entire intestinal tract in broilers, offering an explanation for the described beneficial effects as a growth promoter.
Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology, 1997
Ten broiler-type chickens at 2 weeks of age were injected daily with 0.5 ml of normal sheep serum... more Ten broiler-type chickens at 2 weeks of age were injected daily with 0.5 ml of normal sheep serum while 10 others were similarly injected with 0.5 ml of a sheep anti-IGF-2 serum. Immunization with anti-IGF-2 serum had no significant effect upon body weight gain, on carcass composition, on appetite or food conversion. Liver weight was significantly increased (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05)
Journal of animal physiology and animal nutrition, 2015
Breeder age and nutrition are amongst the most important factors affecting progeny growth and dev... more Breeder age and nutrition are amongst the most important factors affecting progeny growth and development. The present experiment was carried out to evaluate the effects of n-3 fatty acid (FA), with special emphasis on the ratio of eicosapentaenoic (EPA, 20:5 n-3) and docosahexaenoic (DHA, 22:6 n-3) acid, provided to the diet of ageing broiler breeder hens at different ratios, on the incubation parameters and the performance of the offspring. Four hundred and eighty Ross-308 broiler breeder hens were fed one of four different diets (120/treatment), with an equal fat content. The control diet was a basal diet, rich in n-6 FAs (CON). Blends of fish oil were used to enrich the three other diets in n-3 FA and to obtain different EPA/DHA ratios of 1/1 (EPA=DHA), 1/2 (DHA) or 2/1 (EPA). Every 5 weeks, incubation parameters were assessed. Every 15 weeks, offspring was reared until slaughter age on a standard diet. Breeder age affected almost all incubation and post-hatch parameters, wherea...
Journal of animal physiology and animal nutrition, Jan 3, 2015
In this study, we tested the hypothesis that in ovo feeding (IOF) of L-arginine (L-Arg) enhances ... more In this study, we tested the hypothesis that in ovo feeding (IOF) of L-arginine (L-Arg) enhances nitric oxide (NO) production, stimulates the process of myogenesis, and regulates post-hatching muscle growth. Different doses of L-Arg were injected into the amnion of chicken embryos at embryonic day (ED) 16. After hatching, the body weight of individual male chickens was recorded weekly for 3 weeks. During in vitro experiments, myoblasts of the pectoralis major (PM) were extracted at ED16 and were incubated in medium containing 0.01 mm L-Arg, 0.05 mm L-Arg, and (or) 0.05 mm L-nitro-arginine-methyl-ester (L-NAME), an inhibitor of nitric oxide synthase (NOS). When 25 mg/kg L-Arg/initial egg weight was injected, no difference was observed in body weight at hatch, but a significant decrease was found during the following 3 weeks compared to that of the non-injected and saline-injected control, and this also affected the growth of muscle mass. L-NAME inhibited gene expression of myogenic d...
Journal of animal physiology and animal nutrition, Jan 3, 2014
Small-scale urban dairy farms (n = 16) in and around Jimma, Ethiopia with cross-bred (Bos indicus... more Small-scale urban dairy farms (n = 16) in and around Jimma, Ethiopia with cross-bred (Bos indicus × Bos taurus) cows were enrolled in a double-blinded intervention study to investigate the effect of a trace element supplementation programme on trace element status and milk concentrations as well as performance [body condition score (BCS), milk yield, leptin], milk composition, antioxidant status (ferric-reducing ability of plasma (FRAP), thiobarbituric acid-reactive substances (TBARS)], blood biochemistry, serum proteins and immune response (antibody titre upon rabies vaccination). The farms were allocated to a (1) placebo or (2) Cu, Zn, Se, Co and I supplementation treatment for 150 d. On days 0 and 120, four lactating cows per farm were sampled for milk and plasma, and on day 150 for serum, following primo-vaccination. Cu deficiency was present in 17% and marginal Se deficiency in 30% of initially sampled cows, while no Zn shortage was detected. Over 120 days, trace element supple...
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Papers by J. Buyse