The effect of different dietary ratios of lysine, arginine and methionine on protein nitration and oxidation reactions in turkey tissues and DNA.

An assumption was made in the study that the optimal inclusion levels and ratios of lysine (Lys), arginine (Arg) and methionine (Met) in diets with Lys content consistent with National Research Council (NRC) recommendations (1994) contribute to stimulate the antioxidant defense system and prevent disorders resulting from the oxidation and nitration of biologically important molecules. The experiment was carried out on 864 one-day-old Hybrid Converter turkeys divided into six experimental groups (8 replicates per group and 18 birds per replicate) receiving different levels of Arg and Met. Chickens from group Arg90Met30 received 90% Arg and 30% Met relative to Lys; Arg90Met45 - 90% Arg and 45% Met relative to Lys; Arg100Met30 - 100% Arg and 30% Met relative to Lys; Arg100Met45 - 100% Arg and 45% Met relative to Lys; Arg110Met30 - 110% Arg and 30% Met relative to Lys and Arg110Met45 - 110% Arg level and 45% Met level relative to the content of dietary Lys. In comparison with turkeys fed diets with moderate Arg content (100% of Lys content), a decrease in dietary Arg level (90% of Lys content) led to a decrease in plasma 3-nitrotyrosine (3-NT) concentration (163.6 vs. 141.0), whereas an increase in dietary Arg level (110% of Lys content) led to an increase in plasma 3-NT concentration (163.6 vs. 202.6). In comparison with turkeys fed diets with moderate Arg content (100% of Lys content), the lowest dietary Arg level (90% of Lys content) decreased superoxide dismutase (SOD) activity in the intestinal wall (19.68 vs. 17.41) and in the liver (11.51 vs. 7.94), increased SOD activity in the blood (507.6 vs. 961.4) and in breast muscles (6.26 vs. 7.43) and increased the concentration of malondiadehyde in breast muscles (1.10 vs. 1.50). An increase in dietary Met content from 30 to 45% of Lys content caused a decrease in plasma protein carbonyl concentration (4.33 vs. 3.8) and catalase activity in breast muscles (54.70 vs. 49.66), and an increase in SOD activity in the liver (8.90 vs. 10.41). The highest dietary Arg level (110% of Lys content) did not induce the oxidation of lipids, proteins or DNA, but it increased the risk of protein nitration. The lowest dietary Arg level (90% of Lys content) deteriorated the antioxidant status of turkeys. Regardless of dietary Arg levels, an increase in Met content from 30 to 45% of Lys content stimulated the antioxidant defense system of turkeys.

The effect of raw and fermented rapeseed cake on growth performance, carcass traits, and breast meat quality in turkey.

The objective of this study was to determine the effect of including 15% of raw or fermented rapeseed cake (RRC or FRC) in turkey diets on growth performance, carcass traits, and breast meat characteristics. A total of 1,350 day-old female Hybrid Converter turkeys were allocated to 3 dietary treatments (9 replicates per treatment and 50 birds each) and fed complete isocaloric and isonitrogenous diets. In the control group, soybean meal was the main source of dietary protein, whereas the experimental groups were fed diets containing 15% of RRC or FRC. The fermentation of rapeseed cake reduced the content of glucosinolates and phytate-phosphorus. In comparison with RRC, turkeys receiving FRC achieved significantly higher final BW, comparable with that noted in the control group. The experimental factor had no effect on carcass dressing percentage or carcass fat content, whereas turkeys fed diets containing rapeseed cake were characterized by lower relative weight of breast muscles and higher relative gizzard weight. The muscles of birds from groups RRC and FRC had also significantly lower cholesterol concentration. In comparison with control diet, diets RRC and FRC contributed to a significant decrease in the levels of saturated fatty acids and an increase in the share of n-6 polyunsaturated fatty acids in the total fatty acid pool in breast meat. The highest concentrations of n-3 polyunsaturated fatty acids and the most desirable n-6/n-3 polyunsaturated fatty acid ratio were noted in the breast muscles of RRC group turkeys. Both RRC and FRC reduced catalase and superoxide dismutase activity, and decreased the malondialdehyde content of muscle tissue. In conclusion, the replacement of RRC with FRC in diets led to an increase in the final BW of turkeys, but it had no influence on carcass quality and the majority of meat quality traits. The inclusion of rapeseed products in turkey diets positively affected meat quality, improving the fatty acid profile and antioxidant status, but it also decreased the yield of breast muscles.

The effect of manganese nanoparticles on performance, redox reactions and epigenetic changes in turkey tissues.

The hypothesis of the research was the assumption, that manganese nanoparticles can affect the body in the same way as macromolecules. Their smaller size and greater biological reactivity will potentially allow the Mn addition to the diet to be reduced and, consequently, less excretion of this element into the environment. The aim of the study was to determine whether the use of Mn nanoparticles would make it possible to reduce the level of this micronutrient added to turkey diets without adversely affecting redox reactions in cells and epigenetic changes. The experiment was conducted on six groups with 10 replications, in a two-factor design with three dosages of manganese: 100, 50 and 10 mg/kg, and two sources: manganese oxide (MnO) and manganese nanoparticles (NP-Mn2O3). Markers of oxidative stress determined in the blood, that is, the concentration of lipid hydroperoxides, malondialdehyde, protein carbonyl derivatives, 3-nitrotyrosine, 8-hydroxydeoxyguanosine, total glutathione, superoxide dismutase, glutathione peroxidase, catalase, ceruloplasmin, total antioxidant status, albumin and vitamin C content. The level of epigenetic changes in the blood was determined by analysing global DNA methylation. In the experiment, in which the diet of turkeys was supplemented with two forms of Mn (MnO or NP-Mn2O3) at three dosages: 100, 50 and 10 mg/kg, the 10 mg/kg dose, especially in the form of NP-Mn2O3, induced lipid oxidation reactions to the greatest extent. Irrespective of the dosage of Mn in the turkey diet, Mn in the form of NP-Mn2O3 was found to reduce protein nitration more than Mn in the form of MnO. Reducing the Mn dosage in the diet from 100 to 50 mg/kg and then to 10 mg/kg is unfavourable because proportionally increases protein and DNA oxidation in cells, decreases the activity of antioxidant enzymes, and increases the level of glutathione. Reducing the dosage from 100 to 10 mg/kg increases global DNA methylation. The reduction of the Mn level, regardless of the form used, is disadvantageous, because it weakens the defense of the antioxidant system, which consequently can induce oxidative processes in the cells. Although Mn in the form of NP-Mn2O3 reduce protein nitration better than in MnO form, the use of manganese nanoparticles in turkey feeding (even in lower doses) requires further study.

Metabolic parameters in young turkeys fed diets with different inclusion levels of copper nanoparticles.

The aim of this study was to verify the hypothesis postulating that the supplementation of turkey diets with Cu nanoparticles can lower dietary inclusion levels of Cu without compromising the growth rate and antioxidant status of turkeys. The experiment was carried out on 648 one-day-old Hybrid Converter turkeys divided into 6 groups with 6 replicates per group, in a two-factorial design with 3 dietary inclusion levels of Cu (20, 10 and 2 mg/kg) and 2 dietary sources of Cu - copper sulfate (Cu-SUL) and Cu nanoparticles (Cu-NP). At 42 days of age, blood samples were collected from 2 birds per replicate (12 birds per group), after slaughter livers were collected for analyses. Blood and liver samples were assayed for: Cu, Zn, Ca, P, Mg, GLU, TP, ALB, UREA, TAG, TC, UA, ALT, AST, ALT, GGT, ALP, SOD, GPx, CAT, VIT C, FRAP, GSH+GSSG, LOOH, MDA. The results of this experiment demonstrate that a decrease in the dietary inclusion levels of Cu from 10 mg/kg to 2 mg/kg does not compromise the growth performance of turkeys, but weakens antioxidant defense mechanisms. A Cu dose of 20 mg/kg induces oxidation reactions and has a much more inhibitory effect on the antioxidant defense system than dietary Cu content of 2 mg/kg. In turkeys, dietary supplementation with Cu-NP has a more beneficial effect on carbohydrate metabolism and antioxidant status compared with Cu-SUL. The results of analyses examining the antioxidant and metabolic status of young turkeys indicate that 10 mg/kg is the optimal dietary inclusion level of Cu.

Differences in aromatase expression and steroid hormone concentrations in the reproductive tissues of male domestic turkeys (Meleagris gallopavo) with white and yellow semen.

1. To show hormonal differences between male turkeys with yellow semen syndrome (YSS) and white, normal semen (WNS), the expression of aromatase, oestrogen receptor α (ERα), and oestrogen receptor ß (ERß) as well as testosterone and oestradiol concentrations in YSS and WNS testes, epididymis, and ductus deferens were examined. 2. To measure gene expression levels of aromatase and oestrogen receptors (ERs), three complementary techniques (real-time PCR, Western blot, and immunohistochemistry) were used, whereas steroid hormone levels were determined radio-immunologically. 3. Upregulation of aromatase and ERα mRNAs in YSS testes (P < 0.05; P < 0.01), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.05; P < 0.01) compared to those of WNS tissues was detected. Significant increases in the levels of aromatase and ERα proteins were detected in YSS testes (P < 0.001; P < 0.05), epididymis (P < 0.001; P < 0.001), and ductus deferens (P < 0.001; P < 0.05). The expression of ERß mRNA and protein level was upregulated in the testes (P < 0.05; P < 0.01) and epididymis (P < 0.001; P < 0.01) but not in ductus deferens where it was downregulated (P < 0.01; P < 0.01). Increased intensity of immunoreactive proteins in YSS versus WNS reproductive tissues corroborated gene expression results. 4. Testosterone concentration diminished in YSS epididymis (P < 0.05) and ductus deferens (P < 0.05), but not in the testes, remaining at high level (P < 0.05) compared to WNS values. Concomitantly, increased oestradiol concentration was found in YSS testes (P < 0.05) and epididymis (P < 0.05) but decreased in the ductus deferens (P < 0.05). 5. From the published literature, this study is the first to demonstrate the ability for androgen aromatisation in the turkey reproductive tissues and to show the cellular targets for locally produced oestrogens. The data suggested that the androgen/oestrogen ratio is a mechanistic basis for amplification of differences between turkeys with white and yellow semen and that these results can have a relevance in applied sciences to widen the knowledge on domestic bird reproduction.

The effect of DL-, L-isomers and DL-hydroxy analog administered at 2 levels as dietary sources of methionine on the metabolic and antioxidant parameters and growth performance of turkeys.

A hypothesis was verified that dietary methionine (Met) improves the growth and antioxidant status of turkeys, and that its effects depend on dietary inclusion levels and sources. A total of 816 female Hybrid Converter turkeys was fed wheat-soybean meal-based diets supplemented with 3 sources of Met: DL-, L-isomers and DL-hydroxy analog (DLM, LM, and MHA, respectively). In 4 4-week periods (from one to 16 wk of age), dietary Met content corresponded to NRC (1994) recommendations or was increased by approximately 50% (in one to 8 wk by 44 to 46% and in 9 to 16 wk by 55 to 56% vs. the NRC guidelines) to match the recommendations of some breeding companies. Increased Met content resulted in higher final body weights of turkeys (P = 0.002), an improved feed conversion ratio (P = 0.049), increased total glutathione concentration and ferric reducing ability of plasma (FRAP) values, and decreased malondialdehyde (MDA) concentration (all P < 0.001) in the blood plasma of turkeys. In comparison with DLM, LM and MHA contributed to an increase in plasma glutathione concentration (P = 0.001), a decrease in plasma triacylglycerol (P = 0.003) and uric acid (P = 0.001) concentrations, and a decrease in liver MDA (P = 0.001) levels. A decrease in plasma MDA (vs. DLM) and lipid peroxides (LOOH) (vs. DLM and LM) concentrations as well as a decrease in plasma superoxide dismutase (SOD) activity (vs. DLM and LM) also were noted in the MHA treatment (P = 0.016, P = 0.001 and P = 0.011, respectively). In conclusion, the results of the study indicate that the antioxidant status of turkeys could be affected by dietary Met levels and sources. The dietary Met content increased by 50% relative to NRC recommendations, improved the growth performance of turkeys, and strengthened their antioxidant defense system. In comparison with DLM, LM and MHA could be considered positive nutritional factors as manifested by a beneficial decrease in plasma and hepatic MDA concentrations as well as an increase in plasma glutathione levels, and the effect of MHA was more pronounced.

The effect of different dietary levels of vitamin E and selenium on antioxidant status and immunological markers in serum of laying hens.

The effect of different dietary levels of selenium (Se) and vitamin E on egg production, the antioxidant status and the immune system response of hens was investigated in the current study. A total of 32 Lohman Brown hens were divided into four groups and were fed diets with 5% of soybean oil and two levels of Se (0.15 and 0.30 mg/kg) and vitamin E (30 and 60 mg/kg). During 10 weeks of experimental feeding, the body weights of hens and egg production were similar in all dietary treatments, but a higher Se content of diets contributed to a significant increase in egg weight. A higher vitamin E level significantly increased alpha-tocopherol concentrations (2.71 vs. 2.05 microg/mL, p = 0.001), superoxide dismutase (SOD) activity (43.3 vs. 39.9 U/mL, p = 0.049) and the ferric reducing ability of serum (FRAP) (123.0 vs. 105.7 micromol/L, p = 0.029). A higher Se content increased the concentrations of ascorbic acid (0.309 vs. 0.073 microg/L, p = 0.001), retinol (1.48 vs. 1.15 microg/mL, p = 0.001) and alpha-tocopherol (2.86 vs. 1.90 microg/mL, p = 0.001), the activity levels of catalase (3.40 vs. 2.98 U/L,p = 0.010) and SOD (43.4 vs. 30.8 U/mL, p = 0.040) as well as the total antioxidant status (TAS) of serum (0.38 vs. 0.28 mmol/L, p = 0.026). There were no significant differences in the concentrations of tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6) between treatments, while a higher vitamin E content of diets increased serum immunoglobulin A (IgA) concentrations (370.6 vs. 321.3 microg/mL, p = 0.026). Higher dietary levels of vitamin E and Se increased the serum concentrations of retinol (1.66 vs. 2.20 microg/mL, p = 0.013) and a-tocopherol (3.33 vs. 1.71, p = 0.014), but they had no effect on the other physiological parameters. It is recommended that the levels of both supplements, Se and vitamin E, be increased in laying hen diets as they have a beneficial effect on the serum concentrations of retinol and alpha-tocopherol.

Effects of dietary probiotic (Pediococcus acidilactici) supplementation on performance, nutrient digestibility, egg traits, egg yolk cholesterol, and fatty acid profile in laying hens.

The objective of this study was to determine the effect of dietary probiotic Pediococcus acidilactici (PA) strain MA18/5M on performance, egg traits, egg cholesterol content, and fatty acid composition in laying hens during a 24-wk period. A total of 222 Hy-Line Brown laying hens, 22 wk of age, were divided into 3 treatment groups. Control group (C) hens were fed a basal diet with no probiotic added. In group PA1, the basal diet was supplemented with PA at 100 mg.kg(-1) of feed for the first 12 wk and 50 mg.kg(-1) feed for the next 12 wk, whereas treatment PA2 was supplemented with 100 mg.kg(-1) feed for the whole trial period. Dietary treatments did not significantly affect the BW, feed intake, and egg production of hens. Pediococcus acidilactici supplementation increased egg weight (P < 0.05), eggshell thickness, eggshell relative weight, and egg specific gravity, and it improved feed efficiency ratio per kilogram of eggs (P < 0.01). Moreover, PA dietary supplementation resulted in a significant (P < 0.05) decrease in the number of broken eggs and eggs without the shell, leading to a significant (P < 0.01) reduction in the number of downgraded eggs (39% for PA1 and 52% for PA2). After 6 mo of probiotic supplementation, significant differences were also found in the fatty acid composition and cholesterol content of egg yolk. The yolk cholesterol content, regardless of PA dose, decreased by more than 10%. The concentrations of total polyunsaturated fatty acids, including linoleic acid and linolenic acid, were significantly higher in treatment PA2 (6.5% increase) than in C and PA1. In conclusion, dietary supplementation of Pediococcus acidilactici MA 18/5M at 100 mg.kg(-1) has potential commercial applications for improvements in hen performance and eggshell quality during the early laying period.

The effect of different dietary sodium levels on blood mineral concentrations and tibia mineralization in turkeys.

The objective of this study was to determine the effect of different dietary levels of sodium in diets with and without sodium chloride on mineral metabolism, including blood electrolyte levels and tibia mineralization parameters, in young turkeys (to six weeks of age). The influence of diets with a low (L), medium (M) and high (H) sodium content, at 0.34, 1.34 and 2.82 g/kg respectively, was compared. The content of chloride and potassium in turkey diets (1.7 - 5.9 and 11 g/kg, respectively) was above the recommended levels. The sodium-deficient diet L decreased the serum concentrations of sodium, chloride and phosphorus, and it increased the serum levels of calcium and magnesium in turkeys, compared with groups M and H. Relative to group L, different dietary sodium levels in groups M and H contributed to a similar increase in the body weights of birds (1.06 vs. 1.46 and 1.44 kg, p < 0.001) and in the absolute (4.60 vs. 6.83 and 6.62 g, p < 0.001) and relative tibia weight (0.42 vs. 0.46 and 0.46% body weight, p = 0.031). No significant differences were found between groups with respect to the content of ash, calcium and phosphorus in tibia dry matter. Supplemental sodium increased the bone density index (from 50.6 to 68.4 and 66.3 mg/mm in groups L, M and H, respectively, p < 0.001), the maximum bending moment (from 5.27 to 7.40 and 7.33 N/mm, p = 0.002) and the minimum breaking strength of tibia (from 0.136 to 0.191 and 0.189, p = 0.002). In conclusion, our study indicates that the applied dietary treatment with a moderate sodium level (1.34 g/kg) resulted in a rate of bird growth and tibia mineralization similar to those observed with the treatment with much higher Na content (2.82 g/kg).

Metabolic and immune response of young turkeys originating from parent flocks fed diets with inorganic or organic selenium.

The aim of this study was to verify the hypothesis that the health and growth of turkey poults may be improved by supplementing diets fed to parent flocks with available selenium. Experimental poults originated from parent flocks fed with diets containing 0.3 mg/kg inorganic selenium (control group Se(M)) and organic selenium (experimental group Se(O)). Egg yolk selenium content was comparable in both flocks (0.72 and 0.70 mg/kg d.m., respectively). Eggs from the Se(O) flock had a significantly lower content of thiobarbituric acid reactive substances - TBARS (31.13 vs. 53.10 nmol/g, p > 0.001). Se(O) group poults were characterized by higher activity of glutathione peroxidase (7.54 vs. 5.92 U/mL, P = 0.001) and superoxide dismutase (89.30 vs. 79.23 U/mL, P = 0.026). The thigh muscles of Se(O) group birds had significantly higher selenium concentrations (0.74 vs. 0.57, p = 0.045) and a significantly lower TBARS content (38.42 vs. 65.01, p = 0.001). No differences were found between the groups with respect to the content of total protein, albumins and uric acid, and the activites of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (DLH) in day-old poults. On day 28, groups Se(O) and Se(M) differed in the activity of ALT (20.50 vs. 26.33, p = 0.05) and SOD (87.29 vs. 100.02 U/mL, p = 0.035). There were no differences between the groups regarding the percentages of T lymphocyte subpopulations CD4+, CD8+, CD4+CD8+ and B lymphocyte subpopulations (IgM+) at 1 and 28 days of age. Over the experimental period, mortality rates were similar in both groups (7.32 and 8.87%), and so were the final body weights of birds (1108 vs. 1135 g). The results of the study show that the dietary supplementation of organic selenium in turkey parent flocks reduces the rate of oxidation processes in the egg and in the tissues of newly-hatched poults, yet it has no effect on the analyzed parameters of cell-mediated immunity and the growth performance of birds during the first five weeks of their life.

The effect of partial replacement of soyabean meal with sunflower meal on ileal adaptation, nutrient utilisation and growth performance of young turkeys.

1. A 4 x 2 factorial arrangement of treatments was used to investigate the effect of graded levels of sunflower meal (SFM; 0, 70, 140 and 210 g/kg) and enzyme supplementation on gut morphology, nutrient utilisation and growth performance of young turkeys from 0 to 8 weeks of age. The enzyme supplement used in the study contained non-starch polysaccharide (NSP)-degrading activities and supplied 500 U pectinase, 40 U cellulase, 1600 U xylanase, 800 U glucanase, 200 U mannanase, 20 U galactanase per kg diet. 2. The use of SFM resulted in an increase in the height and width of intestinal villi, and a linear decrease in crypt depth. Dry matter digestibility and energy metabolisability decreased in groups fed diets with a moderate (140 g/kg) and high (210 g/kg) SFM content. 3. A decrease in dry matter digestibility and energy metabolisability was most likely the reason for a reduction in body weights of 8-week-old turkeys fed on diets containing 140 g/kg (from 4 x 17 to 4 x 01 kg) and 210 g/kg (from 4 x 17 to 3 x 93?kg) of SFM. 4. The addition of enzyme resulted in a slight increase in villus height, a significant increase in the number of goblet cells and an increase in digestibility coefficients for crude fat. 5. The results of this study demonstrate that turkey diets can be effectively supplemented with high-quality sunflower meal at a concentration of approximately 70 g/kg. It should be noted, however, that at 8 weeks of age the body weight of turkeys fed on diets containing 140 and 210 g/kg of SFM could be lower by 4 and 6%, respectively, than in those receiving the soyabean meal-based diets.

Effect of organic and inorganic forms of selenium in diets on turkey semen quality.

The effects of Se supplementation and its organic or inorganic form on semen quantitative parameters (ejaculate volume, sperm concentration, and total number of sperm) and biochemical parameters of seminal plasma (protein concentration, acid phosphatase activity, superoxide dismutase activity, and total antioxidant capacity) were investigated over a 25-wk reproductive season. Additionally, DNA fragmentation and motility characteristics of turkey spermatozoa were measured. The parameters of turkey semen in relation to yellow semen syndrome were also determined. Twenty-four males (Big 6) were divided into 3 experimental groups differing in form of Se supplementation (no Se supplementation, 0.3 mg/kg of inorganic Se from sodium selenite and 0.3 mg/kg of organic Se from Sel-Plex, Alltech Inc., Nicholasville, KY). Dietary Se supplementation enhanced the sperm concentration and total number of sperm and did not influence the antioxidative properties of turkey seminal plasma and most biochemical parameters. Only seminal plasma acid phosphatase activity was increased in turkeys fed inorganic Se. The main sperm DNA fragmentation parameters were not affected by dietary Se. The highest percentage of motile spermatozoa (85%) was recorded for the semen of turkeys fed organic Se. Values of the biochemical parameters (acid phosphatase, superoxide dismutase, total antioxidant capacity) of seminal plasma increased during the reproductive season. Yellow semen was characterized by increased biochemical parameters and decreased spermatozoa motility characteristics. However, the percentage of motile spermatozoa did not differ between white and yellow semen. Organic Se seemed to be the preferred form of diet supplementation in comparison with inorganic Se. Biochemical parameters of semen and spermatozoa motility parameters appear to be useful for evaluating the effect of age on semen quality. Monitoring the DNA fragmentation of spermatozoa at the end of the reproductive season could be a useful tool for monitoring turkey semen quality. Increased superoxide dismutase activity can be used as an indicator of yellow semen. A decline in the quality of yellow semen can be related to a decrease in the spermatozoa motility parameters of turkeys.

Effects of dietary addition of Macleaya cordata alkaloid extract on growth performance, caecal indices and breast meat fatty acids profile in male broilers.

The aim of this experiment was to investigate whether a low-dietary application (15 mg/kg) of an alkaloid preparation containing quaternary benzo[c]phenanthridine alkaloids and obtained from Macleaya cordata (Sangrovit) influenced caecal metabolism, growth performance and long-chain fatty acid composition of breast meat. One-day-old broiler chicks (Cobb 500) were fed a diet without supplement or with a 15 mg/kg dose of Sangrovit (C and A groups respectively) for 5 weeks. Although the A treatment was not accompanied by an enhanced final body weight of broilers, the intake of a diet with Sangrovit influenced the caecal microflora activity. The addition of Sangrovit to a diet decreased potentially harmful ß-glucuronidase and ß-glucosidase activities (p<0.05 and p=0.075 respectively), and at the same time led to a significant increase in activities of bacterial glycolytic enzymes α-glucosidase, α-galactosidase, ß-galactosidase in comparison to the control group. The concentration of total short-chain fatty acids in the caecal digesta was increased in the A treatment contributing to the tendency towards lower caecal pH (p=0.078). The analysis of breast meat fatty acids showed that the dietary application of Sangrovit evoked some changes in contents of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) contents. The applied dosage of Sangrovit caused an increase in the sum of MUFA and the tendency towards lower PUFA sum (p<0.05 and p=0.062 respectively) as in relation with the C group. Although the nutritionally relevant n-6/n-3 PUFA and the (PUFA+MUFA)/saturated fatty acids ratios remained similar in both groups, further research is postulated to establish the effect of this preparation on meat quality. To sum up, despite of a lack of the improvement in final body weight, a low dose of dietary Sangrovit was found to exert positive effects on the caecal metabolism of the broilers.

Effects of dietary calcium content and vitamin D source on skeletal properties in growing turkeys.

1. The aim of the study was to investigate the effects of feeding fast growing turkeys with differentiated dietary calcium (Ca) content, and the partial replacement of vitamin D(3) in the feed with 25-hydroxycholecalciferol (25(OH)D(3)), on skeletal properties. 2. One-day-old Big-6 male turkeys (n = 1008) were randomly divided into 4 groups, and two subgroups were created within each group. The groups were differentiated with 4 levels of Ca provision in the feed, namely 85% of the National Research Council (NRC) recommendation (Group Ca(1)); 95% as above (Group Ca(2)); 105% as above (Group Ca(3)); and 115% as above (Group Ca(4)). The first subgroup received the recommended dosage of cholecalciferol (vitamin D(3) subgroup) in the feed, while in the second subgroup (Hy-D subgroup), half of the dosage of cholecalciferol was replaced with 25(OH)D(3). At the ages of 4, 8, 12 and 20 weeks, 7 turkeys from each subgroup were randomly selected and killed to obtain the right tibia for densitometric, geometric and mechanical analyses. 3. This study showed advantageous effects of increased calcium supply in the diet on skeletal system properties, that were increased and produced the most desirable traits in turkeys receiving 95%, 105% and 115% of the NRC calcium recommendation. Benefits resulting from administration of 25(OH)D(3) in the diet were also obtained in the skeletal formation of turkeys, and the most advantageous effects were present in the group receiving 105% of recommended dietary Ca. 4. Effects on the metabolic response of the skeleton of turkeys to manipulation of dietary calcium content and vitamin D(3) source were the most evident in the groups between 4 and 12 weeks of life, and demonstrated a limited ability to induce a positive influence on bone properties at advanced stages of the production cycle by alteration of these dietary factors.

The efficacy of lactic acid bacteria Pediococcus acidilactici, lactose and formic acid as dietary supplements for turkeys.

A feeding trial was performed on 1400 Big-6 turkey toms divided into experimental groups subject to the use of dietary supplements. The ain of this study was to evaluate the efficacy of the probiotic supplement Bactocell, containing lactic acid bacteria Pediococcus acidilactici, and lactose, administered to turkeys separately or in combination, as well as a formic acid supplement. The addition of the probiotic under test (lactic acid bacteria Pediococcus acidilactici) to diets for turkeys contributed to higher daily gains and lower feed consumption per kg weigh gain only during the first 12 weeks of their life. Diet supplementation with lactic acid bacteria and lactose reduced mortality rates. A slaughter value analysis revealed only a slightly (by approximately 1%) higher content of breast muscle and a lower content of thigh muscle in birds fed diets supplemented with lactic acid bacteria. Turkeys receiving lactic acid bacteria or lactose and a combination of both these supplements were characterized by a higher fat content of meat and slightly lower pH values, whereas meat from turkeys fed lactose-supplemented diets was darker in color. The addition of formic acid Acidum formicum to diets for turkeys contributed only to lower mortality rates.

Efficacy of different levels of Escherichia coli phytase in broiler diets with a reduced P content.

Escherichia coli-derived 6-phytase expressed in Pichia pastoris (Optiphos) was added to broiler rations with considerably reduced levels of phosphorus (by 1.5 g/kg). This experiment, performed over a five-week period, involved Ross 308 male chickens kept in battery cages. Each group was divided into 9 subgroups, each of 9 chickens (81 birds per treatment). Birds were allocated to a positive control group (I), a negative control group (II) and three phytase-supplemented groups (III-V--the diet as in group II + 250, 500 and 750 FTU Escherichia coli phytase/kg feed, respectively). The major components of starter and grower diets were corn, soybean and wheat meals. Starter and grower diets (in meal form) contained 6.73 and 6.05 g total P/kg, 4.05 and 3.46 g available P (aP)/kg, respectively, in group I, and 5.23 and 4.55 total P/kg, 2.54 g and 1.95 g aP /kg, respectively, in groups II-V. Phytase efficacy was evaluated based on performance results, carcass quality and bone mineralization. P reduction in group II decreased weight gains by 9.1% and increased feed conversion by approximately 8.4%, compared with group I. Diet supplementation with phytase in groups IV and V significantly compensated for the decrease in performance observed in group II. The differences in dressing percentage between group II and groups III and V were significant. Phosphorus reduction in the diets negatively influenced the process of bone mineralization, which was enhanced by phytase supplementation.

Efficacy of different phytase preparations in broiler rations.

Three phytase preparations were added to broiler rations with considerably reduced levels of phosphorus. Birds were allocated to a positive control group (I), a negative control group (II) and three phytase-supplemented groups (III--Aspergillus niger phytase, IV--Penicillium canescens phytase, V--Pichia phytase). Major components of starter and grower diets were wheat, corn and soybean meals. Starter and grower diets (in meal form) contained 6.65 or 6.01 g of total P/kg and 3.98 or 3.68 g available P/kg in group I, and 5.67 or 5.05 of total P/kg and 2.98 g or 2.70 g available P/kg in groups II - V, respectively. This experiment, performed over a five-week period, involved Ross 308 male chickens kept in battery cages. Each group was divided into 9 subgroups, each of 9 chickens (81 birds per treatment). Phytase efficacy was evaluated based on performance results, carcass quality and bone mineralization. Optimal performance levels were achieved in group I (2.149 g body weight, 1.776 kg feed/kg gain). P reduction in group II decreased weight gains by 9% and increased feed conversion by about 5%. Diet supplementation with phytase in groups III - V compensated for the decrease in performance observed in group II. The effect exerted by three microbial phytases was similar. The difference in carcass weight between group II and the other groups was significant. P reduction in the diets negatively influenced the process of bone mineralization, which was enhanced by phytase supplementation.

Effect of a kestose and nystose preparation on growth performance and gastrointestinal tract function of turkeys.

The aim of the present study was to determine the effects of dietary administration of a fructooligosaccharide preparation rich in kestose and nestose on growth performance and gastrointestinal parameters in young turkeys. The kestose and nestose preparation was obtained through bioconversion of sucrose using fungi fructosyl transferase and contained in DM 39.9% of kestose, 17.6% of nystose, as well as 26.5% of glucose and 14.7% of sucrose. Three dietary levels of the sum of kestose and nystose (0.3, 0.6, and 1.2%) were fed to growing turkeys for 8 wk. When compared with the control treatment, addition of the kestose and nestose preparation had no effect on feed intake, feed conversion, and BW. The kestose and nestose-supplemented diet, especially the medium level of kestose and nystose, influenced microbial metabolism, especially in the ceca. Compared with the control group, the medium level of kestose and nestose decreased relative weight of gizzard (from 18.67 to 16.51 g/kg of BW) and weight of small intestine tissue (from 23.3 to 19.6 g/kg of BW) and increased weight of ceca digesta (from 3.51 to 4.77 g/kg of BW) as well as activities of microbial beta-glucosidase (an increase from 0.22 to 0.38 U/g) and alpha-galactosidase (an increase from 0.90 to 1.61 U/g), pH of digesta (a decrease from 6.13 to 5.79), concentration of NH3 (an increase from 0.60 to 0.98 mg/g), and concentration of total short-chain fatty acids (an increase from 81.1 to 107.7 micromol/g) in the cecal digesta. A high content of kestose and nestose in the diet caused a decrease in ileal and cecal pH (to 5.42 and 5.49, respectively).

Performance and caecal adaptation of turkeys to diets without or with antibiotic and with different levels of mannan-oligosaccharide.

A study on turkeys was conducted to evaluate the administration of different levels of mannan-oligosaccharide (MOS) (0.1, 0.25 and 0.5%) to a diet without or with an antibiotic (Flavomycin, 8 mg/kg feed). The growth performance as well as caecal development and metabolism indicators of turkeys after 8 weeks of experimental feeding were estimated. No interactions were noted between the contents of antibiotic and MOS in the diet in any of the parameters examined. During 8 weeks of experimental feeding, the feed intake as well as feed conversion ratio were similar in all experimental groups. The turkeys fed a control diet (without MOS) supplemented with antibiotic were the heaviest, but there were no statistical differences between groups. Depending on dietary dose, MOS had a different influence on caecal digesta parameters. The medium level of dietary MOS (0.25%) resulted in the highest caecal pH, dry matter and protein concentrations as well as the bacterial glycolytic activity (including beta-glucuronidase). Compared to other dietary treatments, the highest amount of MOS (0.5%) reduced ammonia concentration and enhanced volatile fatty acids concentration, especially of acetate and butyrate, in the caecal digesta. The medium level of dietary MOS caused a significant enhancement of propionate, iso-butyrate and iso-valerate concentrations in the digesta. The antibiotic addition to a diet resulted in a lack of birds' response.