Antioxidant status in the blood, liver, and muscle tissue of turkey hens receiving a diet with alfalfa protein concentrate.

This study aimed to investigate the impact of the oxidative potential of turkeys fed a diet with alfalfa protein concentrate (APC), used throughout the rearing period or periodically at 2-wk intervals. The research material consisted of 6-wk-old BIG 6 turkey hens kept in pens, 5 birds per pen in 6 replicates. The experimental factor was the addition of APC to the diet in the amount of 15 or 30 g/kg of diet. APC was administered in 2 ways: birds received a diet with APC throughout the experiment or periodically. In the latter case, the birds received the diet with APC for 2 wk, and then for 2 wk they received the standard diet without APC. Levels of nutrients in the diet; flavonoids, polyphenols, tannins, and saponins in APC; uric acid, creatinine, bilirubin, and some antioxidants in the blood; and enzyme parameters in the blood and tissues of turkeys were determined. The use of APC in the diet stimulated antioxidant processes, which could be seen in the values of the pro-oxidant-antioxidant parameters of the tissues and blood plasma of turkeys. The significant reduction in the H2O2 level (P = 0.042) and slight reduction in the MDA level (P = 0.083), accompanied by an increase in catalase (P = 0.046) activity in the turkeys continuously receiving APC in the amount of 30 g/kg of diet, as well as the increase in plasma antioxidant parameters (vitamin C, P = 0.042 and FRAP, P = 0.048) in these birds, reflects improvement in their antioxidant status. Thus continuous use of the APC supplement in the amount of 30 g/kg of diet proved to be a better feeding practice to optimize oxidative potential than periodic inclusion of APC.

The sarcoplasmic protein profile of breast muscle in Turkeys in response to different dietary ratios of limiting amino acids and Clostridium perfringens-induced inflammation.

In this study, the effects of the Arginine/Lysine (Arg/Lys) ratio in low- and high-methionine (Met) diets on the sarcoplasmic protein profile of breast muscles from turkeys reared under optimal or challenge (Clostridium perfringens infection) conditions were determined. One-day-old Hybrid Converter female turkey poults (216 in total) obtained from a commercial hatchery on hatching day, and on the basis of their average initial body weight were randomly allocated to 12 pens (4 m2 each; 2.0 m × 2.0 m) containing litter bedding and were reared over a 42-day experimental period. Diets with high levels of Lys contained approximately 1.80% and 1.65% Lys and were offered in two successive feeding periods (days 1-28 and days 29-42). The supplemental levels of Lys were consistent with the nutritional specifications for birds at their respective ages as established in the Management Guidelines for Raising Commercial Turkeys. The experiment was based on a completely randomized 3 × 2 × 2 factorial design with three levels of Arg (90%, 100% and 110%) relative to the content of dietary Met (30 or 45%) and without (-) or with (+) C. perfringens challenge at 34, 36, or 37 d of age. Meat samples were investigated in terms of pH, color, and sarcoplasmic protein profile. The experimental factors did not influence meat quality but the dietary Arg content affected meat color. The sarcoplasmic protein profile was influenced by all studied factors, and glycolytic enzymes were the most abundant. This study evidenced strong association between the challenge conditions and the involvement of glycolytic enzymes in cell metabolism, particularly in inflammatory processes, and DNA replication and maintenance in turkeys. The results showed an effect of C. perfringens infection and feeding with different doses of Arg and Met may lead to significant consequences in cell metabolism.

The localization and expression of gonadotropin inhibitory hormone in the hypothalamus of turkey hens during the prepubertal, pubertal and postpubertal phases.

Gonadotropin inhibitory hormone (GnIH), initially discovered in birds as a hypothalamic neuropeptide, inhibits the synthesis and release of gonadotropins by affecting GnRH neurons and gonadotropes. Therefore, it may be a key neuropeptide in reproduction in birds. The aim of the present study was to investigate the prepubertal, pubertal, and postpubertal localization of GnIH and changes in hypothalamic GnIH expression in British United Turkey hens. In prepubertal, pubertal, and postpubertal periods, the brains of turkey hens (n = 15) were removed after fixation. Sections (30 µm) were prepared from the entire hypothalamus and stained immunohistochemically against GnIH antibody. Gonadotropin inhibitory hormone-immunoreactive neurons were observed in the paraventricular nucleus. These neurons were significantly more abundant in the prepubertal turkeys than pubertal and postpubertal turkeys (P < 0.05). The results suggested that GnIH neurons have an important role in regulating the pubertal events in British United Turkey hens.

Transcriptome analysis of the hypothalamus and pituitary of turkey hens with low and high egg production.

BACKGROUND: High egg producing hens (HEPH) show increased hypothalamic and pituitary gene expression related to hypothalamo-pituitary-gonadal (HPG) axis stimulation as well as increased in vitro responsiveness to gonadotropin releasing hormone (GnRH) stimulation in the pituitary when compared to low egg producing hens (LEPH). Transcriptome analysis was performed on hypothalamus and pituitary samples from LEPH and HEPH to identify novel regulators of HPG axis function. RESULTS: In the hypothalamus and pituitary, 4644 differentially expressed genes (DEGs) were identified between LEPH and HEPH, with 2021 genes up-regulated in LEPH and 2623 genes up-regulated in HEPH. In LEPH, up-regulated genes showed enrichment of the hypothalamo-pituitary-thyroid (HPT) axis. Beta-estradiol was identified as an upstream regulator regardless of tissue. When LEPH and HEPH samples were compared, beta-estradiol was activated in HEPH in 3 of the 4 comparisons, which correlated to the number of beta-estradiol target genes up-regulated in HEPH. In in vitro pituitary cell cultures from LEPH and HEPH, thyroid hormone pretreatment negatively impacted gonadotropin subunit mRNA levels in cells from both LEPH and HEPH, with the effect being more prominent in HEPH cells. Additionally, the effect of estradiol pretreatment on gonadotropin subunit mRNA levels in HEPH cells was negative, whereas estradiol pretreatment increased gonadotropin subunit mRNA levels in LEPH cells. CONCLUSIONS: Up-regulation of the HPT axis in LEPH and upstream beta-estradiol activation in HEPH may play a role in regulating HPG axis function, and ultimately ovulation rates. Thyroid hormone and estradiol pretreatment impacted gonadotropin mRNA levels following GnRH stimulation, with the inhibitory effects of thyroid hormone more detrimental in HEPH and estradiol stimulatory effects more prominent in LEPH. Responsiveness to thyroid hormone and estradiol may be due to desensitization to thyroid hormone and estradiol in LEPH and HEPH, respectively, due to up-regulation of the HPT axis in LEPH and of the HPG axis in HEPH. Further studies will be necessary to identify possible target gene desensitization mechanisms and elicit the regulatory role of the HPT axis and beta-estradiol on ovulation rates in turkey hens.

Comparative aspects of phytase and xylanase effects on performance, mineral digestibility, and ileal phytate degradation in broilers and turkeys.

Two experiments were performed, using broilers or turkeys, each utilizing a 3 × 2 factorial arrangement, to compare their response to phytase and xylanase supplementation with growth performance, nutrient digestibility, and ileal phytate degradation as response criteria. For both experiments, 960 Ross 308 or 960 BUT 10 (0-day-old) birds were allocated to 6 treatments: (1) control diet, containing phytase at 500 FTU/kg; (2) the control diet with xylanase (16,000 BXU/kg); (3) the control diet supplemented on top with phytase (1,500 FTU/kg); (4) diet supplemented with 1,500 FTU/kg phytase and xylanase (16,000 BXU/kg); (5) the control diet supplemented with phytase (3,000 FTU/kg); and (6) diet supplemented with 3,000 FTU/kg phytase and xylanase (16,000 BXU/kg). Each treatment had 8 replicates of 20 birds each. Water and diets based on wheat, soybean meal, oilseed rape meal, and barley were available ad libitum. Body weight gain and feed intake were measured from 0 to 28 D, and feed conversion ratio (FCR) corrected for mortality was calculated. Ileal digestibility for dry matter and minerals on day 7 and 28 were analyzed in addition to levels of inositol phosphate esters (InsP6-3) and myo-inositol. Statistical comparisons were performed using ANOVA. Xylanase supplementation improved 28D FCR in broilers and turkeys. Increasing doses of phytase reduced FI and improved FCR only in broilers. In broilers, the age × phytase interaction for phosphorous digestibility showed that increasing phytase dose was more visible on day 7, than on day 28. Mineral digestibility was lower in 28-day-old turkey compared with 7-day-old turkey. InsP6 disappearance increased with increasing phytase levels in both species, with lower levels analyzed in turkeys. InsP6 disappearance was greater in younger turkeys (day 7 compared with day 28). In conclusion, although broilers and turkeys shared several similarities in their growth and nutrient utilization responses, the outcomes of the 2 trials also differed in many aspects. Whether this is because of difference in diets (InsP or Ca level) or differences between species needs further investigation.

The effect of different dietary ratios of arginine, methionine, and lysine on the performance, carcass traits, and immune status of turkeys.

The research hypothesis postulated that the optimal dietary inclusion levels and ratios of lysine (Lys), arginine (Arg), and methionine (Met) can increase the growth potential of hybrid turkeys and limit metabolic disorders that weaken immune function. The experiment was carried out in a full rearing cycle, from 1 to 16 wk of age, in a two-factorial randomized design with 3 levels of Arg and 2 levels of Met (90, 100 and 110% of Arg, and 30 or 45% of Met, relative to the content of dietary Lys), with 6 groups of 8 replicates per group and 18 turkeys per replicate. In the first and second month of rearing, a significant dietary Arg-by-Met interaction was noted for daily feed intake and body weight gain, and a more beneficial effect was exerted by higher Met content and medium Arg content. Throughout the experiment, the higher dietary Met level increased the final body weight (BW) of turkeys (P = 0.001). Different dietary Arg levels had no influence on the growth performance of turkeys, but the lowest level decreased dressing yield (P = 0.001), and the highest level increased the percentage of breast muscles in the final BW of turkeys (P = 0.003). The lowest Arg level (90% of Lys content) undesirably increased the concentration of the proinflammatory cytokine IL-6 (P = 0.028) and decreased globulin concentration (P = 0.001) in the blood plasma of turkeys. The higher dietary Met level (45% of Lys content) increased plasma albumin concentration (P = 0.016). It can be concluded that higher dietary levels of Met (45 vs. 30% of Lys content) and Arg (100 and 110 vs. 90% of Lys content) have a more beneficial effect on the growth performance and immune status 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.

Effect of 25-hydroxycholecalciferol supplementation on turkey performance and immune cell parameters in a coccidial infection model.

This study was conducted to identify the effects of 25-OH cholecalciferol supplementation to turkeys on the immune cells parameters, fecal coccidial oocyst shedding, macrophage nitric oxide production, T regulatory cell cytokine production, and production parameters during a coccidial challenge. A total of 200 1-day-old turkey poults were supplemented with 27.5, 55, 82.5, or 110 µg/kg 25-OH cholecalciferol and challenged or not challenged with coccidial oocysts in a 4 × 2 factorial set up of treatments. Birds fed 110 µg/kg of 25-OH cholecalciferol and infected with coccidial oocyst had 41% lower (P < 0.05) fecal oocyst and 53% higher (P < 0.05) macrophage nitric oxide production than the birds fed 27.5 µg/kg of 25-OH cholecalciferol and infected with coccidial oocyst at 5 d post-coccidial infection. Birds fed 82.5 µg/kg 25-OH cholecalciferol and infected with coccidial oocyst had 5-fold higher (P < 0.05) IL-1 mRNA amounts than the birds fed 27.5 µg/kg of 25-OH cholecalciferol and infected with coccidial oocyst. Birds fed 110 µg/kg 25-OH cholecalciferol and infected with coccidial oocyst had 5.3-fold higher (P < 0.05) IL-10 mRNA amounts than the birds fed 27.5 µg/kg of 25-OH cholecalciferol and infected with coccidial oocyst at 5 d post-coccidial infection. CD4+CD25+ cells from birds fed 110 µg of 25-OH cholecalciferol and infected with coccidial oocyst had 12-fold higher (P < 0.05) IL-10 mRNA than that from the birds fed 27.5 µg/kg of 25-OH cholecalciferol and infected with coccidial oocyst. In conclusion, supplementing birds with 101 µg/kg 25-OH cholicalciferol decreases coccidial oocyst shedding in the feces and could be a nutritional strategy to reduce the coccidial infection and spread in turkeys.

The effect of different dietary levels of DL-methionine and DL-hydroxy analogue on the antioxidant status of young turkeys infected with the haemorrhagic enteritis virus.

BACKGROUND: The results of experiments involving broiler chickens and turkeys indicate that increased dietary methionine (Met) levels may improve the antioxidant protection of tissues in fast-growing birds. This is an important consideration since viral infections induce oxidative stress. The aim of this study was to verify the hypothesis that turkey diets with increased Met content can suppress oxidation processes induced by infection caused by the haemorrhagic enteritis virus (HEV), and that the noted effect is determined by the chemical form of this amino acid: DL-methionine (DLM) or DL-hydroxy analogue of Met (MHA). RESULTS: Dietary Met content above 40% higher than the level recommended by the NRC (1994) intensified lipid peroxidation in the small intestine, leading to an increase in malondialdehyde (MDA) and lipid peroxide (LOOH) levels, but it also stimulated antioxidant mechanisms in the blood and liver of turkeys infected with HEV. In comparison with DLM, MHA contributed to more severe symptoms of oxidative stress, such as elevated MDA levels in the intestines, and a decrease in glutathione peroxidase (GPx) activity and ferric-reducing ability of plasma (FRAP). CONCLUSIONS: In HEV-infected turkeys, diets with increased Met content did not exert a clear antioxidant effect, which was noted in uninfected birds. The prooxidant activity of Met observed in the small intestinal wall was suppressed in the blood and liver of turkeys, most likely due to intensified synthesis of uric acid and glutathione. In comparison with MHA, DLM had a more beneficial influence on the analysed parameters of the redox status in the small intestine, blood and liver of turkeys.

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.

Evaluation of novel protease enzymes on growth performance and apparent ileal digestibility of amino acids in poultry: enzyme screening.

Three experiments were conducted to evaluate eight neutral and six acid proteases on growth performance and apparent ileal amino acid digestibility (AID) of poults (Experiment 1) or chicks (Experiments 2 and 3). Two basal diets were formulated: a nutrient adequate positive control (PC), which met or exceeded the nutrient requirements for poults (Experiment 1) or chicks (Experiments 2 and 3) and a negative control (NC) formulated to achieve 85% (Experiments 1 and 2) or 80% (Experiments 3) of the requirement for protein and amino acids. Phytase was included in all diets to provide 500 phytase units (FTU)/kg and xylanase was included in all diets to provide 10,000 (Experiments 1 and 2) or 16,000 (Experiments 3) xylanase units (BXU)/kg. Proteases were supplemented in the NC diet at an equivalent amount of enzyme protein to create 16 experimental diets. There were five birds/pen and 10 replicate pens per treatment in each experiment. In experiment 1, birds fed the PC diet gained more (P < 0.05) than birds fed the NC. There were no differences in growth performance in birds fed the PC or NC in experiments 2 or 3. In all three experiments, birds fed the NC supplemented with neutral protease 1 had reduced (P < 0.05) feed intake (FI) or body weight gain (BWG) and increased (P < 0.05) feed conversion ratio (FCR) compared with birds fed the NC. Birds fed the NC diet supplemented with neutral protease 3, 7 (Experiment 1), or acid protease 4 (Experiment 3) had increased (P < 0.05) FCR and birds fed neutral protease 6 (Experiment 2) had reduced (P < 0.05) BWG compared with birds fed the NC. Apparent ileal amino acid digestibility was improved (P < 0.05) with protease supplementation to the NC diets (Experiment 1 or 3), but this was dependent on the protease and the amino acid. In conclusion, novel protease supplementation improved AID of amino acids but this was not reflected in improvements in growth performance of poults or chicks.

The premammillary nucleus of the hypothalamus is not necessary for photoperiodic timekeeping in female turkeys (Meleagris gallopavo).

In birds, seasonal reproduction is regulated by day length, with long days in the spring activating the hypothalamic-pituitary-gonadal axis and reproductive behaviors. The photoreceptors mediating this process remain unknown, but recently, the premammillary nucleus (PMM) of the hypothalamus has been implicated as the site of photoperiodic signaling in turkeys. We performed electrolytic lesions of the PMM to elucidate its role in the photoactivation and maintenance of egg production in female turkeys. Our results show that ablation of the PMM does not alter the normal lay cycle. No differences were found between lesioned birds and sham controls in the latency to lay following photostimulation, nor in subsequent egg production over a period of 29 weeks. No differences in the incidence of gonadal regression were found, indicating that the PMM is not essential for the termination of breeding. We conclude that any role of the PMM in photoperiodic regulation, if it exists, is redundant with other components of the system.

Propolis supplementation attenuates the negative effects of oxidative stress induced by paraquat injection on productive performance and immune function in turkey poults.

Paraquat (PQ) is used as a herbicide in agriculture and causes oxidative and inflammatory damage to animal tissues. The current study was conducted to investigate the positive effects of dietary propolis (PR), as a potent naturally produced antioxidant, on growth performance and immune function of turkey poults exposed to oxidative stress induced by PQ injection. Native male turkey poults (n = 120, 49-d-old) were randomly assigned into 4 groups: poults received a basal diet with a daily subcutaneous PQ injection of 5 mg/kg BW for 7 consecutive days (PQ group), an experimental diet containing 1 g/kg PR with a daily subcutaneous PQ injection for 7 days (PR+PQ group), or received the experimental PR diet with a daily subcutaneous injection of 0.5 mL sterile saline for 7 days (PR group); while the control poults received a basal diet with a daily subcutaneous saline injection for 7 consecutive days (C group). The productive performance in the PQ group showed a significant (P < 0.05) reduction in the weight gain (WG) and feed intake (FI), and impaired feed conversion ratio (FCR). Propolis supplementation in the PR+PQ group significantly ameliorated the PQ effects on WG and FCR. Turkey poults of the PQ and PR+PQ groups had a significant augmentation in the blood malondialdehyde (MDA), tumor necrosis factor-α (TNFα), and corticosterone levels, and in contrast, a significant reduction in the triiodothyronine (T3), when compared to the C group. While propolis significantly reduced the MDA and corticosterone, and increased the T3 levels in the PR+PQ group compared to the PQ group. Furthermore, the dietary PR supplementation significantly limited the PQ-suppressive effects on cell- and humoral-mediated immunity and lymphocyte proliferation of turkey poults. In addition, propolis supplementation in the PR and PR+PQ groups markedly reversed the PQ-induced DNA fragmentation and heat shock protein 70 (Hsp70) over-expression in blood cells. It can be concluded that PR could improve turkey immunity and performance, particularly under inflammation and oxidative stress induced by PQ exposure.

Effect of dietary supplementation with clay-based binders on biochemical and histopathological changes in organs of turkey fed with aflatoxin-contaminated diets.

This study was carried out to investigate the effect of dietary supplementation with molecular or nano-clay binders on biochemical and histopathological examination of organs of turkeys fed diets contaminated with aflatoxin B1. Two hundred and sixteen unsexed 1-day-old British United Turkeys were randomly allotted to nine diets in a 3 × 3 factorial arrangement of diets supplemented with no toxin binder, molecular toxin binder (MTB) and nano-clay toxin binder, each contaminated with 0, 60 and 110 ppb aflatoxin B1 respectively. There were three replicates per treatment with eight turkeys per replicate. Biochemical analyses, organ weights and histopathological changes of some organs were examined at the end of the study which lasted for 84 days. Turkeys fed diets supplemented with molecular and nano-binders showed higher (p < 0.001) total serum protein, reduced (p < 0.001) serum uric acid and GGT concentration values when compared with those fed aflatoxin-contaminated diets supplemented with no binder. Turkeys fed aflatoxin-contaminated diets supplemented with no binder had increased (p < 0.001) AST and ALT concentration when compared with other treatments. The heaviest (p < 0.001) liver and intestinal weight was noticed with turkeys fed diets supplemented with no binder and contaminated with 110 ppb aflatoxin B1 . Pathologically, there was no visible morphological alteration noticed in all turkeys fed uncontaminated diets and nano-clay-supplemented group. Hepatic paleness, hepatomegaly and yellowish discolouration of the liver were observed with turkeys fed diets containing no binder but contaminated with 60 and 110 ppb aflatoxin B1. Intestinal histopathological changes such as goblet cell hyperplasia, villous atrophy and diffuse lymphocytic enteritis were more prominent in turkeys fed diets containing no toxin binder and MTB. In conclusion, there were improved biochemical parameters and reduced deleterious effects of aflatoxin B1 in turkeys fed diet supplemented with clay binders. However, the improvement was more conspicuous in the nano-clay-supplemented group than molecular clay group.

Ascorbic Acid Differentially Affects Stress Response and Resistance to Colibacillosis in Turkeys from Genetic Lines Differing in Growth Rate.

Genetic selection for fast growth can affect the ability of male turkeys to cope with stressors, resulting in decreased immunity to opportunistic bacterial infection. The purpose of the current study was to compare the effects of ascorbic acid (AA) on the stress response and resistance to Escherichia coli challenge of birds selected for increased 16-wk body weight (BW; F-line) with their random-bred parent line (RBC2). Male turkeys were raised in duplicate floor pens in a two line×two AA treatment×two stress challenge (SC) design. At 5 wk of age, AA (1200 ppm) was provided in drinking water for a 24-hr period, during which all birds were weighed. After AA treatment, the SC group was subjected to a transport stress protocol. Six hours after the start of transport, SC birds were also inoculated in the thoracic air sac with 1×10(4) colony-forming units of E. coli. The following morning four birds from each pen were bled, and all birds were weighed and necropsied 2 days later. BW and gain after SC were decreased in the F-line but not the RBC2 line, and there were no AA effects on BW. The weight of the bursa of Fabricius relative to BW was higher in the RBC2 line than in the F-line, was decreased by SC, and was not affected by AA. The heterophil∶lymphocyte ratio was higher in the SC F-line as compared to the SC RBC2 and was decreased by AA only in the SC F-line. Corticosterone (C) levels were increased by SC only in the F-line, and AA decreased C levels only in the RBC2 line. Airsacculitis scores were increased in the F-line SC birds. The challenge strain of E. coli was only detected in the air sac and liver of the AA-treated F-line SC birds and in the liver of the no-AA F-line birds. These results suggest that SC at 5 wk of age had a more deleterious effect on the fast-growing F-line than on its parent line and that AA may have increased susceptibility to colibacillosis in the SC F-line birds.

Evaluation of inclusion level of wheat distillers dried grains with solubles with and without protease or ß-mannanase on performance and water intake of turkey hens.

It is becoming a common practice to use higher levels of wheat distillers dried grains with solubles (wDDGS) in poultry diets. The objective of this study was to determine the effects of level of inclusion of wDDGS with or without enzyme (E-, i.e., wDDGSE-) supplementation on performance and water consumption of turkey hens (0 to 72 d). Two diets (0 or 30% wDDGS) were formulated to meet the nutrient requirements of Hybrid Converter turkeys. Diets (0 or 30% wDDGS; starter, grower, and finisher) were then blended to obtain a different level of inclusion (15%) of wDDGS. The 30% wDDGS diet was divided into 3 fractions and 2 fractions supplemented with either protease (P+, i.e., wDDGSP+; 0.126 g/kg) or ß-mannanase (M+, i.e., wDDGSM+; 0.05 g/kg). All 5 diets were fed ad libitum as mash. The 700 0-d turkey hens were randomly allocated into groups of 35 birds per replicate with 4 replicate floor pens per treatment, in a completely randomized design. Water consumption per pen was recorded beginning at 7 d. There was no effect of dietary treatment on feed intake. BW of turkey hens (52 d; grower) was significantly higher for 30% wDDGSP+ as compared to 0% wDDGSE- or 15% wDDGSE- diets; but was not different from 30% wDDGSE- or 30% wDDGSM+ diets. FCR (P < 0.01; 28 to 52 d), and total FCR (P < 0.05; 0 to 72 d) was significantly improved for birds fed 15 or 30% wDDGS regardless of enzyme treatment compared to 0% wDDGSE-. Water intake (WI, in mL per bird per day) tended to be higher (P = 0.08) between 7 and 28 d for 30% wDDGSP+ diets compared to other treatments. Similarly, WI of birds fed 30% wDDGSP+ was higher (P < 0.05; 28 to 52 and 52 to 72 d) and total WI (P = 0.07; 7 to 72 d) tended to be higher than other treatments. This study is the first to report the impact of wDDGS on WI. As high as 30% wDDGS can be substituted in turkey hen diets. No effect of P+ or M+ at the inclusion level tested was found on performance.

The effects of extrusion of wheat distillers dried grains with solubles with or without an enzyme cocktail on performance of turkey hen poults.

Two experiments were conducted to determine if extrusion (EX) or enzymes (E) could overcome the restrictions (e.g., high fiber) of feeding wheat distillers dried grain with solubles (wDDGS) and improve its nutritional value for feeding turkeys. Two starter diets with either 0 or 30% wDDGS were formulated to meet or exceed the nutrient requirements of the Hybrid Converter female turkeys. The 30% wDDGS diet was substituted with either non-extruded (EX-) or extruded (EX+) wDDGS to produce three basal diets [0% wDDGS (EX-) or 30% wDDGS (EX-/EX+)]. Diets were blended to obtain 15% wDDGS. In the respective treatments, only wDDGS was extruded (temperature; 118°C, retention; 15 sec, total moisture; 25% and pressure 33 bar). The respective experimental diets were supplemented with/without an enzyme cocktail (E; 0.5 g/kg). Test diets were fed from 7-21 d in a completely randomized design. In Experiment 1, a total of 210 turkey hen poults were fed diets containing 0, 15, or 30% wDDGS (EX-) with or without enzyme (E+/E-). Body weight (BW) and feed intake (FI) were significantly higher for 0% wDDGSE-. Nitrogen retention (NR) and apparent metabolizable energy (AME) for the 30% wDDGSE- was significantly higher than other treatments at 21 d. The results indicated significant main effects of E and an interaction between wDDGS level and E. In Experiment 2, 280 turkey hen poults were fed 8 diets [15/30% wDDGS (E+/E-), (EX-/EX+)]. The level of wDDGS had a significant effect on BW, FI and gain:feed; 15% inclusion was superior to 30%. There were significant 2- and 3-way interactions for AME and NR at 21 d due to differences in enzyme response with 15 or 30% wDDGS inclusion and/or extrusion of wDDGS. As high as 15% wDDGS can be incorporated in turkey hen diets. There were no beneficial effects of EX or E on poult performance.

The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of turkey hens.

The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of turkey hens. The experiment was carried out on 240 turkey hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The turkey hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the turkey hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the turkey hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to turkey hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.

Use of organic acids and competitive exclusion product as an alternative to antibiotic as a growth promoter in the raising of commercial turkeys.

A study was conducted to investigate the effects of organic acids (OA) and competitive exclusion product (CE) on growth performance, intestinal morphology, and concentration of volatile fatty acids in the cecal content. The experiment lasted for 10 wk. Four hundred twenty 1-d-old female commercial cross turkey poults (British United Turkeys, BUT Big 9) were distributed into 4 treatments with 5 replicates/pen of 21 birds each. The birds were fed a basal diet without growth promoter (control), diet with lincomycin (44 mg/kg), diet with organic acids (2 g/kg), and diet with product of CE (10(9) cfu/kg). Dietary levels of other nutrients, housing, and general management practices were similar for all treatments. On the first week (d 0-7), the BW and BW gain of the birds that fed diets with OA were lower than in the control group. In the fattening phase (d 28-70), the feed intake of the OA-treated group was lower than compared with the control. The birds that received diet with OA and CE product presented higher concentrations of propionic acid, at 14 d, and butyric acid in cecal content at 28, 56, and 70 d, compared with the control. Dietary inclusion of additives had no significant effects on intestinal villus height, crypt depth, and villus:crypt ratio. Organic acids had negative effects either on early gain or feed intake throughout the study. Because the test was conducted under controlled experimental conditions, the additives that showed results similar to those found by using antibiotics should be studied further in commercial farms to obtain results that can be incorporated into practice.

Supplementary biotin decreases tibial bone weight, density and strength in riboflavin-deficient starter diets for turkey poults.

1. Growth and skeletal responses to different dietary concentrations of riboflavin and biotin were compared in turkey poults from hatch to 21 d of age. The birds were fed on a turkey starter diet with different concentrations of supplementary riboflavin (0, 20 and 40 mg/kg) and biotin (0, 0.3 and 0.6 mg/kg) in a factorial design. 2. Poults fed on diets with no supplementary riboflavin had poor gait scores, decreased times to sit and higher rates of culling compared to poults fed on the control diet (20 mg riboflavin and 0.3 mg biotin/kg [corrected] diet). Histologically, riboflavin deficiency was associated with a peripheral neuropathy similar to that described previously in chicks and, unexpectedly, in growth plate abnormalities. 3. Tibiae of poults fed on the control diet were larger, more dense, stronger and stiffer than the diets with no supplementary riboflavin. 4. Increasing supplementary biotin in poults fed on diets with no supplementary riboflavin was associated with a decrease in tibia weight, density, strength and stiffness. 5. The results demonstrated that riboflavin deficiency in fast-growing turkey poults was associated with growth retardation, growth plate disturbance and peripheral nerve dysfunction leading to an inability to walk.