Itaconic acid and dimethyl itaconate exert antibacterial activity in carbon-enriched environments through the TCA cycle.

Itaconic acid (IA), a metabolite generated by the tricarboxylic acid (TCA) cycle in eukaryotic immune cells, and its derivative dimethyl itaconate (DI) exert antibacterial functions in intracellular environments. Previous studies suggested that IA and DI only inhibit bacterial growth in carbon-limited environments; however, whether IA and DI maintain antibacterial activity in carbon-enriched environments remains unknown. Here, IA and DI inhibited the bacteria with minimum inhibitory concentrations of 24.02 mM and 39.52 mM, respectively, in a carbon-enriched environment. The reduced bacterial pathogenicity was reflected in cell membrane integrity, motility, biofilm formation, AI-2/luxS, and virulence. Mechanistically, succinate dehydrogenase (SDH) activity and fumaric acid levels decreased in the IA and DI treatments, while isocitrate lyase (ICL) activity was upregulated. Inhibited TCA circulation was also observed through untargeted metabolomics. In addition, energy-related aspartate metabolism and lysine degradation were suppressed. In summary, these results indicated that IA and DI reduced bacterial pathogenicity while exerting antibacterial functions by inhibiting TCA circulation. This study enriches knowledge on the inhibition of bacteria by IA and DI in a carbon-mixed environment, suggesting an alternative method for treating bacterial infections by immune metabolites.

Probiotic characterization and comparison of broiler-derived lactobacillus strains based on technique for order preference by similarity to ideal solution analysis.

A total of 10 lactobacillus strains were isolated from broiler chickens and their probiotic properties including tolerance to gastrointestinal fluids and heat treatment, antimicrobial activity, adhesion capacity to intestinal cells, surface hydrophobicity, autoaggregation, antioxidative activity, and immunomodulatory effects on chicken macrophages were evaluated. The Limosilactobacillus reuteri (LR) was the most frequently isolated species, followed by Lactobacillus johnsonii (LJ) and Ligilactobacillus salivarius (LS). All isolates showed good resistance to simulated gastrointestinal conditions and antimicrobial activity against 4 indicator strains including Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae, and Proteus mirabilis LR 21 exhibited excellent performances on autoaggregation, hydrophobicity and adhesion capacity to Caco-2 intestinal cells. In the meantime, this strain also possessed considerable tolerance to heat treatment, which indicated great potential to be used in the feed industry. However, LJ 20 strain had the highest free radical scavenging activity compared with the other strains. Furthermore, qRT-PCR results revealed that all isolated strains significantly increased the transcriptional levels of proinflammatory genes and tended to induce the M1-type polarization on HD11 macrophages. Particularly, the technique for order preference by similarity to ideal solution (TOPSIS) was adopted in our study to compare and select the most promising probiotic candidate based on in vitro evaluation tests.

Effects of early post-hatch feeding on the growth performance, hormone secretion, intestinal morphology, and intestinal microbiota structure in broilers.

This study aimed to investigate the effects of time access to post-hatch feeding on the growth performance, hormone secretion, intestinal morphology, and intestinal microbiota structure of broilers. A total of 900 broilers were randomly allocated to 3 treatment groups, with 6 replicates of 50 broilers each. The 3 treatments were: immediate feeding (Group 2 h), delayed access to feed for 24 h (Group 24 h), and delayed access to feed for 48 h (Group 48 h). The experiment lasted for 50 d. Results revealed that Group 2 h had a higher average daily gain (ADG) and average daily feed intake (ADFI) as well as a lower feed-to-gain ratio (F/G) than Group 48 h during the starter period (P < 0.05). Compared with Group 48 h, broilers in Group 2 h exhibited significantly elevated villus height (VH) and villus height to crypt depth ratio (VH: CD) in the duodenum, increased Occludin, and Claudin-1 mRNA expression in the jejunum but decreased crypt depth (CD) in the duodenum at 50 d (P < 0.05). Meanwhile, broilers in Groups 2 h and 24 h had increased glycogen (Gn) and protein (Pro) levels in breast muscle and TG levels in the liver, as well as a higher concentration of serum T3, T4, and IGF-1 compared with Group 48 h at 21 d (P < 0.05). Besides, intestinal microbiota consisted primarily of Firmicutes, Bacteroidetes, and Proteobacteria at the phylum level at 21 d and 50 d; at the genus level, broilers in Group 2 h displayed significantly reduced abundance of Escherichia at 21 d and Bacteroides at 50 d compared with Group 48 h (P < 0.05). Collectively, these findings signal that early post-hatch feeding measures, especially at 21 d, improve hormone secretion, intestinal morphology, and the growth performance of broilers by enhancing intestinal health and modulating the intestinal microbiota.

Effects of posthatch feed deprivation on residual yolk absorption, macronutrients synthesis, and organ development in broiler chicks.

The aim of the research was to evaluate the dynamic changes of early posthatch starvation on residual yolk absorption, synthesis of macronutrients (protein, lipid, and glycogen), and organ development in broiler chicks. A total of 720 1-day-old chicks (Lingnan Yellow) were randomly assigned to 3 treatments: group A (nonfasted), group B (fasting for 24 h after placement), and group C (fasting for 48 h after placement). The trial lasted for 168 h, and water was provided ad libitum all the time. Sampling was performed at 0, 24, 48, 72, 120, and 168 h. Nonfasting (group A) promoted (P < 0.05) the absorption of amino acids, fatty acids, mineral elements, protein, and maternal antibody in the residual yolk of broiler chicks. The concentration of insulin-like growth factor 1 in plasma and the liver was higher (P < 0.05) in group A. Nonfasting enhanced (P < 0.05) the synthesis of protein and glycogen in the breast muscle and liver; the relative weights of the liver, pancreas, and spleen; and body weight, but retarded (P < 0.05) the synthesis of triglyceride in the liver. The results indicated that nonfasting (group A) after placement promoted the absorption of residual yolk and synthesis of protein and glycogen in the breast muscle and liver, whereas early feed deprivation promoted the synthesis of lipid in the liver. Thereby, nonfasting after placement promoted organ development and body growth of broiler chicks.

Effect of night light regimen on growth performance, antioxidant status and health of broiler chickens from 1 to 21 days of age.

OBJECTIVE: The study was conducted to evaluate the effects of night light regimen on growth performance, antioxidant status and health of Lingnan Yellow broiler chickens from 1 to 21 days of age. METHODS: A completely randomized factorial design involved 2 photoperiods (constant lighting [CL], 24 L:0 D and intermittent lighting [INL], 17 L:3 D:1 L:3 D)×2 light intensities (10 lx and 30 lx). A total of one thousand six hundred and eighty 1-d-old Lingnan Yellow broiler chicks were randomly divided into 4 treatments with 6 replicates (70 birds per replicate). The experiment lasted for 21 d. RESULTS: Photoperiods and light intensities had no effect on average daily gain, feed conversion ratio, and mortality of the broiler chickens (p>0.05). The INL had a significant effect on average daily feed intake (p<0.05) of broiler chickens compared with CL. Photoperiod and light intensity had an interactive effect on melatonin (MT) concentration (p<0.05). At CL, reducing light intensity increased MT concentration; INL birds had higher MT but MT concentration was not affected by light intensity. There was an interactive effect on glutathione peroxidase (GPx) and catalase (CAT) in serum and total antioxidant capability (T-AOC) in liver between photoperiod and light intensity. With the decrease of light intensity, the activities of GPx and CAT in serum and T-AOC in liver increased in CL group (p<0.05). Broiler chickens reared under INL had better antioxidant status and 10 lx treatments had higher activities of CAT in serum than 30 lx (p<0.05). Different photoperiods and light intensities had no effect on malondialdehyde. There was an interaction between photoperiod and light intensity on serum creatine kinase (CK) concentration (p<0.05). At CL, the elevated light intensity resulted in an increase in CK content; INL birds had lower CK concentration especially in low light intensity group. Besides, INL and low light intensity significantly reduced the concentration of serum corticosterone and heat shock protein 70 (p<0.05). Serum immunoglobulin M contents were increased in broiler chickens reared under the INL compared with CL group (p<0.05). CONCLUSION: Results above suggest that the night light regimen of INL and 10 lx could be beneficial to the broiler chickens from 1 to 21 days of age due to the better health status and electricity savings.

Antagonistic effects of different selenium sources on growth inhibition, oxidative damage, and apoptosis induced by fluorine in broilers.

Fluorosis can induce oxidative stress through leading to reactive oxygen species (ROS) generation. Selenium (Se) can eliminate ROS by direct and indirect manners. In this study, therefore, we investigated the possible protective effects of sodium selenite (SS) and selenomethionine (Se-Met) on fluorine (F)-induced oxidative stress in broilers. A total of 720 1-day-old Lingnan Yellow broilers were allotted to 4 groups (6 replicates of 30 birds each group) and fed with basal diet (control group), 800 mg/kg F (high F group), 800 mg/kg F+0.15 mg Se/kg as SS (SS group), or Se-Met (Se-Met group), respectively. The experiment lasted 50 d. High F group significantly decreased (P < 0.05) the average daily gain (ADG) and feed efficiency (FE) in comparison with control group. The contents of ROS, malondialdehyde, 8-hydroxydeoxyguanosine, protein carbonyl, and cysteinyl aspartate specific proteinases 3 in serum, liver, and kidney were higher (P < 0.05) in high F group than those in control group. Compared with control group, the decreased (P < 0.05) activities of glutathione peroxidase (GSH-Px) and cytoplasmic thioredoxin reductase (TrxR1) as well as contents of selenoprotein P (SelP), total protein (TP), and B-cell lymphoma-2 in serum and tissues were observed in high F group. Moreover, the pathological lesions of liver and kidney in high F group were more than those in control group. However, supplementation with SS and Se-Met could improve ADG and FE, increase SelP and TP concentrations, elevate GSH-Px and TrxR1 activities, minimize the changes of oxidative stress and apoptosis parameters as well as ultrastructure of liver and kidney, whereas the effects of Se-Met were better than those of SS. The results indicated that excess F could result in growth inhibition of broilers through inducing oxidative stress and subsequently caused oxidative damage to biological macromolecules and soft tissues as well as apoptosis, whereas dietary SS and Se-Met supplementation could antagonize high F induced growth retardation by inhibiting oxidative stress and a mechanism of apoptosis regulation and the impact was more with Se-Met.

Effects of different selenium sources and levels on antioxidant status in broiler breeders.

OBJECTIVE: This study was conducted with the objectives to examine the impacts of inorganic selenium (Se) and different types and levels of organic selenium on the serum and tissues Se status and antioxidant capacity in broiler breeders. METHODS: Five hundred and forty 48-wk-old Lingnan Yellow broiler breeders were randomly assigned to 6 dietary treatments, provided same basal diet (0.04 mg/kg of Se) with 0.15 mg/kg, or 0.30 mg/kg of Se from sodium selenite (SS) or from selenium-enriched yeast (SY) or from selenomethionine (SM). The broiler breeders were slaughtered after an 8-wk experiment. RESULTS: The results showed that SM was better than SY and SS, 0.30 mg/kg level was better than 0.15 mg/kg level in Se deposition (p<0.05) in serum, liver, kidney, pancreas and muscle; in antioxidant status, organic selenium had better effects than SS in broiler breeders (p<0.05), but SM and SY had a similar result, and 0.15 mg/kg level was better than 0.30 mg/kg (p<0.05). CONCLUSION: The results demonstrated the evident advantage of supplementation of broiler breeders with 0.15 mg/kg SM, which improved tissue Se concentrations and antioxidant status, and can be considered as the best selenium source.

Modulation of broilers' caecal microflora and metabolites in response to a potential probiotic Bacillus amyloliquefaciens.

Studies have found that a dietary supplement of Bacillus amyloliquefaciens improved the growth performance, increased the nutrient digestibility of hosts and modulated the intestinal microflora. A total of 360 1-day-old Ross broilers were randomly divided into three treatments: a control group with a basal diet, an antibiotic group with a basal diet and added colistin sulphate, and a probiotics group with a basal diet and added Bacillus amyloliquefaciens. The HiSeq high-throughput sequencing analysis of 16S rRNA was used to investigate the differences in birds' caecal microflora, and metabolomics was used to analyse changes in caecal metabolites. Results showed that the supplementation of Bacillus amyloliquefaciens significantly improved the BW and ADG compared with the control birds. Results of sequencing indicated that (i) 645, 670, 596 unique operational taxonomic units (OTUs) were found in birds supplemented with Bacillus amyloliquefaciens on day 7, 21 and 42, separately, (ii) due to the diversity and relative abundance of the birds' caecal microflora, the OTUs of the caecal microflora clustered according to age and treatment, except on day 42, (iii) among the six predominate families (Ruminococcaceae, Lachnospiraceae, Enterobacteriaceae, Erysipelotrichaceae, Lactobacillaceae and Rikenellaceae), the supplementation of Bacillus amyloliquefaciens significantly increased Enterobacteriaceae on day 42, (iv) Bacillus amyloliquefaciens increased the relative abundance of Faecalibacterium and Ruminococcus on day 21, increased the Faecalibacterium and Blautia and decreased the Ruminococcus on day 42. The metabolomics of caecal metabolites showed that the dietary Bacillus amyloliquefaciens changed the caecal metabolites involved of amino acid metabolism and glyceride metabolism, and the antibiotics changed the caecal metabolites that were related to carbohydrates and amino acid metabolism on day 21.

Effects of first feed intake time on growth performance, nutrient apparent metabolic rate and intestinal digestive enzyme activities in broilers.

OBJECTIVE: This experiment studied the effects of first feed intake time post-hatch on growth performance, nutrient apparent metabolic rate and intestinal digestive enzyme activities in broilers. METHODS: Two thousand five hundred and twenty LingNan Yellow broilers were randomly allotted to seven treatments with six replicates of 60 each. The only experimental factor was the first feed intake time which was 18, 24, 30, 36, 42, 48, and 54 hours after hatching. The whole experiment lasted for 21 days. RESULTS: During the whole period, the 30 h treatment had the best body weight and average daily gain (p<0.05), followed by the 24 h group performance optimization. Also, the 30 h group was observed to have the best apparent metabolic rate for ether extract (p<0.05) and crude protein (p<0.05) and the highest activities of amylase, lipase and trypsin in small intestine. And the 24 h group was second only to the 30 h group in terms of the above two measures. CONCLUSION: These results indicated that the appropriate first feeding time of LingNan Yellow broilers was 24 to 30 hours after hatching.

[Clinical analysis of laparoscopic surgery in patients with maintenance hemodialysis and colon cancer].

OBJECTIVE: To explore the safety of laparoscopic assisted radical resection of colon cancer in uremic patients. METHODS: Retrospective analysis of Zhejiang Jinhua Guangfu hospital 2012 March to 2015 March 5 cases of uremia patients complicated with colon cancer underwent laparoscopic assisted colorectal cancer radical resection, and compared with 10 cases, observing two groups of operative time, intraoperative bleeding volume, postoperative drainage volume, lymph nodes dissect, anal exhaust time, postoperative complications, postoperative hospitalization time and postoperative pathological staging. RESULTS: Before operation two groups of age, gender, tumor location was no significant difference (P>0.05). In preoperative comorbidities uremic patients were significantly more than that of ordinary patients, mainly in cardiovascular complications, and patients in the two groups in operation time, intraoperative bleeding, post operative drainage volume, lymph node dissection numbers were no significant difference, the postoperative gastrointestinal function recovery was almost no difference, but postoperative hospitalization time significantly prolonged (P<0.05). CONCLUSIONS: Patients with uremia as long as full preoperative preparation, perioperative management, plus timely hemodialysis, uremia patients undergoing laparoscopic assisted radical surgery is safe and feasible, and it is worth promoting.

Different sources of maternal selenium affect selenium retention, antioxidant status, and meat quality of 56-day-old offspring of broiler breeders.

The maternal effect of different Se source in offspring of young broiler breeders has been reported, but the lasting maternal effect of different sources of Se on offspring of breeders has received limited attention, so this study was conducted to investigate the effects of different maternal Se sources on Se retention, antioxidant status, and meat quality of 56-d-old offspring of broiler breeders. A total of two hundred forty 39-wk-old Lingnan Yellow broiler breeders were randomly distributed into 2 treatments, each of which was replicated 3 times with 40 birds per replicate, with a 14-d pretreatment and 56-d trial period. The treatments were fed a basal corn-soybean diet (0.04 mg∙kg⁻¹ Se) supplemented with 0.3 mg∙kg⁻¹ sodium selenite (SS) or selenomethionine (Se-Met). Fertile eggs were collected for incubation, after which 180 healthy chicks from each treatment were selected and randomly allocated into 3 replicates, with 60 birds per replicate. All the chicks were fed the same basal diet (0.04 mg∙kg⁻¹ Se) for 56 d. The Se concentrations in serum and tissues (liver, kidney, and breast muscle) of the 56-d-old offspring were significantly (P < 0.01) increased by maternal Se-Met intake compared with maternal SS intake. The antioxidant status of the 56-d-old offspring was greatly improved by maternal Se-Met supplementation in contrast with maternal SS supplementation, which was shown by increased glutathione peroxidase activity in serum and breast muscle (P < 0.01), glutathione concentration in serum (P < 0.05), and total antioxidant capability in pancreas (P < 0.01), as well as cytosolic glutathione peroxidase mRNA abundance in breast muscle, liver (P < 0.01), and pancreas (P < 0.05). The maternal Se-Met treatment was more effective in maintaining the shape of liver and pancreas cells, cell nuclei, chromatin, as well as cell membrane structure, and more organelles were observed in liver cells. The maternal Se-Met treatment had significant (P < 0.05) reduced the 48-h drip loss of 56-d-old offspring in comparison with maternal SS treatment. The results suggest that maternal Se-Met diet is superior to maternal SS diet in increasing Se retention and improving antioxidant status and meat quality of 56-d-old offspring.

Regulation of selenoprotein P concentration and expression by different sources of selenium in broiler breeders and their offspring.

An 8-wk experiment using 180 Lingnan Yellow broiler breeders was conducted to investigate the effect of different sources of Se on the concentration and gene expression of selenoprotein P (SEPP1) in broiler breeders and their offspring. After receiving a low-Se basal diet for 8 wk, broiler breeders were randomly allocated to 3 treatments (6 replicates per treatment) and fed corn-soy-based diets supplemented with 0.15 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SY), and selenomethionine (SM), respectively. Fertile eggs from different replicates were collected during the last week of the experiment and then incubated in different incubator trays in the same incubator. The concentrations and mRNA levels of SEPP1 were determined in liver and kidney of broiler breeders and their offspring, as well as the serum SEPP1 concentration. Compared with SS, both SY and SM significantly increased (P < 0.05) the concentration and mRNA level of SEPP1 in 1-d-old chicks. In broiler breeders, the serum and liver SEPP1 concentrations were notably increased by the use of organic Se (P < 0.05), whereas no differences were found in the kidney. Moreover, the SEPP1 mRNA level in the liver was remarkably elevated (P < 0.05) in organic Se treatments, but also no differences were observed in the kidney. Results of this study indicate that the use of organic Se (SY or SM) in maternal diets is very effective for increasing the concentration and mRNA level of SEPP1, especially in their offspring. No differences between SY and SM were observed.

Effect of selenium sources on the expression of cellular glutathione peroxidase and cytoplasmic thioredoxin reductase in the liver and kidney of broiler breeders and their offspring.

In total, 180 Lingnan Yellow broiler breeders were used to investigate the effect of different sources of selenium (Se) on the expression of cellular glutathione peroxidase (GPx1) and cytoplasmic thioredoxin reductase (TrxR1) in the liver and kidney of broiler breeders and their offspring by quantitative real-time PCR. There were 6 replicates of 3 dietary treatments. Broiler breeders were fed corn-soy-based diets supplemented with 0.15 mg/kg of Se from sodium selenite, Se-enriched yeast (SY), or selenomethionine (SM). At the end of the feeding trial, liver and kidney mRNA levels of GPx1 and TrxR1 were determined by quantitative real-time PCR, as well as the activity of GPx1 and TrxR1 in liver and kidney of breeders and their offspring. The results showed that, compared with sodium selenite, SY or SM significantly increased (P < 0.05) the activity of TrxR1 in the liver and kidney of broiler breeders and their offspring but not the GPx1 activity. The liver GPx1 and TrxR1 mRNA levels in SY or SM groups were higher (P < 0.05) than that in the sodium selenite group. And the kidney TrxR1 mRNA levels were also significantly increased (P < 0.05) by using SY or SM, whereas there was no significant difference in the kidney GPx1 mRNA levels between the organic or inorganic sources of Se used.

Effect of early feed restriction on metabolic programming and compensatory growth in broiler chickens.

The effect of early feed restriction on metabolic programming and compensatory growth was studied in broiler chickens. A total of 480 female 1-d-old broiler birds (Aconred) were randomly allocated to ad libitum and feed-restricted groups, each of which was replicated 6 times with 40 birds per replicate. Broilers were provided commercial diets. Feed-restricted broilers were deprived of feed for 4 h per day from 1 to 21 d of age. Effects of treatments were determined at 21 and 63 d of age. In feed-restricted birds at 21 d of age, BW, average daily gain and average daily feed intake, breast muscle (P < 0.01), carcass yield (P < 0.05), and abdominal fat (P < 0.05) were decreased. Ether extract content in breast muscle was increased (P < 0.01), whereas CP content was slightly decreased. Triiodothyronine (P < 0.01) and thyroxine (P < 0.05) were decreased in serum. Free fatty acid and very low density lipoprotein were slightly increased in serum, whereas triglyceride and glucose were decreased (P < 0.01). Activities of NADPH-generating enzymes in liver including malic dehydrogenase, isocitrate dehydrogenase, and glucose-6-phosphate remained unchanged in ad libitum birds, whereas hormone-sensitive lipase activity was increased (P < 0.01). In feed-restricted birds at 63 d of age, BW, average daily gain, average daily feed intake, carcass yield, breast muscle yield, and serum triiodothyronine and thyroxine remained as ad libitum birds, whereas abdominal fat yield was increased (P < 0.05). Ether extract content in breast muscle was decreased (P < 0.01), whereas CP content was increased (P < 0.05). Activities of NADPH-generating enzymes were significantly increased, except abdominal malic dehydrogenase and hormone-sensitive lipase activity was decreased (P < 0.01) in liver and abdominal fat. Lipoprotein lipase activity was increased (P < 0.05) in abdominal fat. In summary, feed restriction severely affected growth performance and lipid metabolism in broilers in the early period. Because there was no statistical difference among the final BW, near full compensatory growth was achieved. In addition, early feed restriction might have induced prolonged metabolic programming in chicks and led to adult obesity.

Effects of methionine and betaine supplementation on growth performance, carcase composition and metabolism of lipids in male broilers.

1. This study was conducted to investigate the effects of methionine and betaine supplementation on growth performance, carcase composition and lipid metabolism in growing broilers. 2. A total of 450 commercial broilers, 22 d of age, were randomly allocated to three groups, each of which included three replicates (50 birds per replicate). The groups received the same methionine-deficient diet supplemented with 0 or 1 g/kg methionine, or 0.5 g/kg betaine, respectively. 3. Methionine and betaine supplementation significantly improved weight gain and feed conversion. Supplemental methionine and betaine also significantly increased breast muscle yield and decreased abdominal fat content. Meanwhile, addition of methionine and betaine significantly increased the contents of creatine and free carnitine in liver, the activity of hormone-sensitive lipase in abdominal fat and the concentration of free fatty acid in serum, whereas uric acid concentration in serum was significantly decreased. 4. The results of this study suggest that betaine can spare methionine in its function as an essential amino acid and is as effective as methionine in improving performance and carcase quality of growing broilers if the diet is moderately deficient in methionine. The decrease in abdominal fat may be due to the increased carnitine synthesis in liver and hormone-sensitive lipase activity in abdominal fat.

Effects of dietary fructooligosaccharide on digestive enzyme activities, intestinal microflora and morphology of male broilers.

Two hundred forty male Avian Farms broiler chicks, 1 d of age, were randomly allocated to four treatments, each of which had five pens of 12 chicks per pen. The chicks were used to investigate the effects of fructooligosaccharide (FOS) on digestive enzyme activities and intestinal microflora and morphology. The chicks received the same basal diet based on corn-soybean meal, and FOS was added to the basal diet at 0, 2.0, 4.0, and 8.0 g/kg diet at the expense of corn. Addition of 4.0 g/kg FOS to the basal diet significantly increased average daily gain of broilers. The feed-to-gain ratios were significantly decreased for the birds fed diets with 2.0 and 4.0 g/kg FOS versus the control. Addition of 4.0 g/kg FOS enhanced the growth of Bifidobacterium and Lactobacillus, but inhibited Escherichia coli in the small intestinal and cecal digesta. Supplementation of 2.0 or 4.0 g/kg FOS to chicks significantly improved the activities of amylase compared to the control (12.80 or 14.75 vs. 8.42 Somogyi units). A significant increase in the activities of total protease was observed in 4.0 g/kg FOS-treated birds versus controls (83.91 vs. 65.97 units). Morphology data for the duodenum, jejunum, and ileum showed no significant differences for villus height, crypt depth, or microvillus height at the duodenum. By contrast, addition of 4.0 g/kg FOS significantly increased ileal villus height, jejunal and ileal microvillus height, and villus-height-to-crypt-depth ratios at the jejunum and ileum and decreased crypt depth at the jejunum and ileum. However, addition of 8.0 g/kg FOS had no significant effect on growth performance, digestive enzyme activities, intestinal microflora, or morphology.

Effects of L-carnitine on growth performance, carcass composition, and metabolism of lipids in male broilers.

We studied the effects of L-carnitine on growth performance, carcass composition, and lipid metabolism in male broilers. Six hundred male commercial broilers were allotted to five groups, each of which included three replicates (40 birds per replicate). The groups received the same basal diet supplemented with 0, 25, 50, 75, or 100 mg/kg L-carnitine, respectively. The feeding trial showed that L-carnitine had no significant effect on daily gain or feed conversion. Supplementation with L-carnitine (above 25 mg/kg) in the diet increased breast muscle yield (P < 0.05) and crude fat content of the muscles and decreased abdominal fat content (P < 0.05). Addition of 50, 75, or 100 mg/kg L-carnitine to the diet decreased total activities of glucose-6-phosphate dehydrogenase, malic dehydrogenase, isocitrate dehydrogenase, and lipoprotein lipase (P < 0.05) in the subcutaneous fat and total activity of carnitine palmitoyltransferase-I (P < 0.05) in breast muscles. The results of this study indicate that L-carnitine could reduce the deposit of subcutaneous fat by decreasing total activities of enzymes in the fat and enhance intramuscular fat by decreasing the activity of carnitine palmitoyltransferase-I in breast muscles.