Effect of pellet quality and biochar litter amendment on male turkey performance

Bedding (litter) is essential to poultry performance and health and can have an environmental impact after use in the poultry facility such as a soil amendment or as an alternative energy source. Pine shavings are the most common bedding used for turkey production. However, the increase in its price and its increasing scarcity in some areas have created new research opportunities for reusing litter as bedding. Improvement in feed pellet quality has been reported to improve poultry performance. However, the reports for turkeys are limited and dated. This study's objective was to determine how the improvement of feed pellet quality and the use of biochar added to a combination of used turkey brooder house litter and Miscanthus grass as bedding affects turkey performance, small intestine morphology, and ammonia production. Nicolas Select (Aviagen Turkeys, Lewisburg, WV) male poults (816) were randomly assigned to 48 concrete litter floor pens on the day of hatch. The experiment used a completely randomized block design with a 2 × 4 factorial arrangement of treatments: 2 levels of fines in the feed and 4 bedding treatments. The bedding treatments were a constant level of used turkey brooder house litter combined with a varying combination of biochar and Miscanthus grass. Turkey's body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were determined. Differences in treatment means were considered to be statistically significant at P ≤ 0.05 using a mixed model in SAS 9.4. Turkeys fed the feed with improved pellet quality had a higher BW from 3 to 17 wk (17.0 ± 0.1 kg) than turkeys fed an increased abundance of fines (16.72 ± 0.1 kg). Turkeys fed feed with increased pellet quality had a lower FI (45.6 vs. 48.1 ± 0.4 kg) and improved FCR (2.20 vs. 2.31 ± 0.01) from 0 to 20 wk. Litter treatment with 20% biochar resulted in higher BW at 20 wk (20.91 ± 0.16 kg) because of increased BWG at 11 wk over the rest of the biochar levels (3.7 ± 0.1 kg). Strategies to reduce the abundance of fines in feed through feed formulation, feed manufacturing, feed transport, and in-house feed management should be considered to increase male turkeys' performance. There may be opportunities to use biochar as a litter amendment to improve turkey health and performance.

Transcriptome analysis of turkey (Meleagris gallopavo) reproductive tract revealed key pathways regulating spermatogenesis and post-testicular sperm maturation

The application of transcriptomics to the study of the reproductive tract in male turkeys can significantly increase our current knowledge regarding the specifics of bird reproduction. To characterize the complex transcriptomic changes that occur in the testis, epididymis, and ductus deferens, deep sequencing of male turkey RNA samples (n = 6) was performed, using Illumina RNA-Seq. The obtained sequence reads were mapped to the turkey genome, and relative expression values were calculated to analyze differentially expressed genes (DEGs). Statistical analysis revealed 1,682; 2,150; and 340 DEGs in testis/epididymis, testis/ductus deferens, and epididymis/ductus deferens comparisons, respectively. The expression of selected genes was validated using quantitative real-time reverse transcriptase-polymerase chain reaction. Bioinformatics analysis revealed several potential candidate genes involved in spermatogenesis, spermiogenesis and flagellum formation in the testis, and in post-testicular sperm maturation in the epididymis and ductus deferens. In the testis, genes were linked with the mitotic proliferation of spermatogonia and the meiotic division of spermatocytes. Histone ubiquitination and protamine phosphorylation were shown to be regulatory mechanisms for nuclear condensation during spermiogenesis. The characterization of testicular transcripts allowed a better understanding of acrosome formation and development and flagellum formation, including axoneme structures and functions. Spermatozoa motility during post-testicular maturation was linked to the development of flagellar actin filaments and biochemical processes, including Ca2+ influx and protein phosphorylation/dephosphorylation. Spermatozoa quality appeared to be controlled by apoptosis and antioxidant systems in the epididymis and ductus deferens. Finally, genes associated with reproductive system development and morphogenesis were identified. To the best of our knowledge, this is the first genome-wide functional investigation of genes associated with tissue-specific processes in turkey reproductive tract. A catalog of genes worthy of further studies to understand the avian reproductive physiology and regulation was provided.

The Effect of Using New Synbiotics on the Turkey Performance, the Intestinal Microbiota and the Fecal Enzymes Activity in Turkeys Fed Ochratoxin A Contaminated Feed

The feed supplementation of probiotic microorganisms is a promising method for detoxification of ochratoxin A (OTA) in poultry. The aim of the study was to investigate the effect of newly elaborated synbiotics on the turkey performance, the intestinal microbiota and its enzymatic activity in turkeys (0-15 weeks) fed OTA contaminated feed (198.6-462.0 µg/kg) compared to control group (OTA-free feed). The studies determined the composition of intestinal microorganisms by the culture method and the activity of fecal enzymes by spectrophotometry. It was found that OTA had an adverse effect on the body weight, the intestinal microbiota and the fecal enzymes activity in turkeys. On the other hand, synbiotics resulted in an increase in the count of beneficial bacteria while reducing the number of potential pathogens in the digestive tract. Moreover, synbiotics caused an increase in the activity of α-glucosidase and α-galactosidase, while decreasing the activity of potentially harmful fecal enzymes (β-glucosidase, β-galactosidase, β-glucuronidase) in the turkey's excreta. Results indicate a beneficial effect of elaborated synbiotics on the health of turkeys and a reduction of the negative impact of OTA contaminated feed. These synbiotics can be successfully used as feed additives for turkeys.

Effects of different levels of arginine and methionine in a high-lysine diet on the immune status, performance, and carcass traits of turkeys

We postulated that the use of appropriate levels and proportions of arginine (Arg) and methionine (Met) in compound feed with high lysine content (Lys) would make it possible to fully exploit the growth potential of modern fattening turkey crossbreds, without compromising their immune system. The aim of this study was to determine the effect of different ratios of Arg and Met in diets with high Lys content on the performance and immune status of turkeys. The turkeys were assigned to 6 groups with 8 replicates per group and 18 birds per replicate. Six feeding programs, with 3 dietary Arg levels (90, 100, and 110%) and 2 dietary Met levels (30 and 45%) relative to dietary Lys content, were compared. During each of 4 feeding phases (weeks 0–4, 5–8, 9–12, and 13–16), birds were fed ad libitum isocaloric diets containing high level of Lys, approximately 1.83, 1.67, 1.49, and 1.20%, respectively. The dietary treatments had no effect on daily feed intake or body weight at any stage of the study. The protein content of the breast meat was higher in the treatments with the highest Arg level (110%) compared with the lowest Arg level (90%). Similarly, protein content was higher in the treatments with the higher Met level compared with the lower Met level. Higher plasma levels of tumor necrosis factor, interleukin 6 (IL-6), and immunoglobulin Y were found in turkeys fed diets with the lowest Arg content. An increase in Met content resulted in a decrease in plasma content of IL-6. In growing turkeys fed diets high in Lys, an Arg level of 90% relative to Lys can be used without negatively affecting production results and immune system. Regardless of dietary Arg levels, an increase in Met content does not stimulate the immune defense system and shows no effect on growth performance of turkeys in current trial.

Growth performance and gastrointestinal responses in heavy Tom turkeys fed antibiotic free corn-soybean meal diets supplemented with multiple doses of a single strain Bacillus subtilis probiotic (DSM29784)1

Growth performance and gastrointestinal (GIT) responses to a single-strain of Bacillus subtilis (SSB) were investigated using 960 Hybrid Converter Toms. A total of 4 iso-caloric and iso-nitrogenous corn-soybean meal-based diets were allocated to 12 replicate cages/pens and fed (ad libitum) in a four-phase feeding program (starter; days 0 to 28, grower-1; days 29 to 56, grower-2; days 57 to 84, and finisher; days 85 to 126). The diets had either 0 (control), 1E+08 (low), 2E+08 (mid) or 1E+09 (high) cfu B. subtilis/kg. Feed intake (FI) and BW were recorded by phase. Excreta samples were collected towards the end of starter and grower-1 phases for apparent retention (AR) of components by marker method and litter moisture, respectively. Selected birds were necropsied on days 28 and 56 for GIT weight and samples for jejunal histomorphology and ceca digesta short chain fatty acids (SCFA). Supplemental SSB had linear and non-linear (P < 0.05) response on BW gain (BWG). Specifically, relative to the control, birds fed low SSB had higher BWG in starter and grower-1 phases whereas bird fed mid and high SSB had lower BWG in grower-2 and birds fed low and mid SSB had higher BWG in finisher phase. Consequently, birds fed low and mid SSB doses were heavier (P < 0.05) than control fed birds at the end of trial. The FCR response to SSB was linear and non-linear (P < 0.05) with birds fed low SSB showing lower FCR than control fed birds in starter, grower-1 and finisher phases. Supplemental SSB had linear and non-linear (P < 0.05) effects on AR of components (DM, ash, crude protein, crude fat, neutral detergent fiber, and gross energy), litter moisture, GIT weight, jejunal histomorphology, and SCFA. Relative to control, birds fed high SSB showed higher AR of components, villi height, day 56 ceca digesta total SCFA concentration, and lower litter moisture. In conclusions, under condition of the current study, growth performance was optimized by low to mid SSB. Improved nutrient retention and indices of gut health suggested higher SSB doses may optimize growth performance under challenging farm conditions.

Effects of brooding periods on performance of poults and grow-out small bronze turkeys in hot humid tropical environment

A study was conducted to determine the effects of varied brooding regimes on the performance of small bronze turkey poults and their grow-outs. One hundred and twenty (n = 120) poults were subjected to four brooding regimes of 0-5, 0-6, 0-7, and 0-8 weeks, designated as T₁, T₂, T₃, and T₄. Each brooding regime (treatment) was applied to 3 replicates of 10 poults/replicate in a completely randomized design. The feed intake of T₁ poults was higher (P < 0.05) than that of the T₂, T₃, and T₄ groups. There was no difference in the daily weight gain among all treatment groups. The T₁ poults had a higher (P < 0.05) feed conversion ratio (FCR) than the T₄ poults while the T₁, T₂, and T₃ had similar FCR. The T₁ group also had the highest feed/heating cost (USD 2.14) while the T₄ recorded the lowest feed/heating cost (USD 2.01) resulting in 5.86% reduction in feed/heating cost. There were no differences in performance of the grow-out turkeys in all the production parameters measured, as well as in the feed cost per kilogram weight gain of the treatment groups. This result shows that small bronze-type turkeys brooded from 0 to 8 weeks had higher efficiency in terms of feed intake, FCR, and lower economic costs compared to those brooded from 0 to 5, 0-6, and 0-7 weeks at the poult stage. However, at grow-out stage, the period of brooding did not have any effects on their performance.

The effect of dietary faba bean and non-starch polysaccharide degrading enzymes on the growth performance and gut physiology of young turkeys

The aim of this study was to investigate the effect of dietary replacement of soya bean meal (SBM) with faba bean (FB) and a blend of non-starch polysaccharide (NSP) degrading enzymes on the gastrointestinal function, growth performance and welfare of young turkeys (1 to 56 days of age). An experiment with a 2×2 factorial design was performed to compare the efficacy of four diets: a SBM-based diet and a diet containing FB, with and without enzyme supplementation (C, FB, CE and FBE, respectively). In comparison with groups C, higher dry matter content and lower viscosity of the small intestinal digesta were noted in groups FB. The content of short-chain fatty acids (SCFAs) in the small intestinal digesta was higher in groups FB, but SCFA concentrations in the caecal digesta were comparable in groups C and FB. In comparison with control groups, similar BW gains, higher feed conversion ratio (FCR), higher dry matter content of excreta and milder symptoms of footpad dermatitis (FPD) were noted in groups FB. Enzyme supplementation increased the concentrations of acetate, butyrate and total SCFAs, but it did not increase the SCFA pool in the caecal digesta. The enzymatic preparation significantly improved FCR, reduced excreta hydration and the severity of FPD in turkeys. It can be concluded that in comparison with the SBM-based diet, the diet containing 30% of FB enables to achieve comparable BW gains accompanied by lower feed efficiency during the first 8 weeks of rearing. Non-starch polysaccharide-degrading enzymes can be used to improve the nutritional value of diets for young turkeys, but more desirable results of enzyme supplementation were noted in the SBM-based diet than in the FB-based diet.

Ameliorative Effects of Neutral Electrolyzed Water on Growth Performance, Biochemical Constituents, and Histopathological Changes in Turkey Poults during Aflatoxicosis

Different in vitro and in silico approaches from our research group have demonstrated that neutral electrolyzed water (NEW) can be used to detoxify aflatoxins. The objective of this investigation was to evaluate the ability of NEW to detoxify B-aflatoxins (AFB₁ and AFB₂) in contaminated maize and to confirm detoxification in an in vivo experimental model. Batches of aflatoxin-contaminated maize were detoxified with NEW and mixed in commercial feed. A total of 240 6-day-old female large white Nicholas-700 turkey poults were randomly divided into four treatments of six replicates each (10 turkeys per replicate), which were fed ad libitum for two weeks with the following dietary treatments: (1) control feed containing aflatoxin-free maize (CONTROL); (2) feed containing the aflatoxin-contaminated maize (AF); (3) feed containing the aflatoxin-contaminated maize detoxified with NEW (AF + NEW); and (4) control feed containing aflatoxin-free maize treated with NEW (NEW). Compared to the control groups, turkey poults of the AF group significantly reduced body weight gain and increased feed conversion ratio and mortality rate; whereas turkey poults of the AF + NEW group did not present significant differences on productive parameters. In addition, alterations in serum biochemical constituents, enzyme activities, relative organ weight, gross morphological changes and histopathological studies were significantly mitigated by the aflatoxin-detoxification procedure. From these results, it is concluded that the treatment of aflatoxin-contaminated maize with NEW provided reasonable protection against the effects caused by aflatoxins in young turkey poults.

Comparative Quantitative Studies on the Microvasculature of the Heart of a Highly Selected Meat-Type and a Wild-Type Turkey Line

In this study the macroscopic and microscopic structure of the heart of a fast growing, meat-type turkey line (British United turkeys BUT Big 6) and a wild-type turkey line (Canadian Wild turkey) were compared. At 8 and 16 weeks of age, 10 birds of each genotype and sex were sampled. The body mass and heart mass of the meat-type turkey both increased at a faster rate than those of the wild-type turkey. However in both turkey lines, the relative heart mass decreased slightly with age, the decrease was statistically significant only in the male turkeys. Furthermore meat-type turkeys had a significantly (p < 0.01) lower relative heart mass and relative thickness of the left ventricle compared to the wild-type turkeys of the same age. The wild-type turkeys showed no significant change in the size of cardiomyocytes (cross sectional area and diameter) from 8 weeks to 16 weeks. In contrast, the size of cardiomyocytes increased significantly (p < 0.001) with age in the meat-type turkeys. The number of capillaries in the left ventricular wall increased significantly (p < 0.001) in wild-type turkeys from 2351 per mm² at the age of 8 weeks to 2843 per mm² at 16 weeks. However, in the meat-type turkeys there were no significant changes, capillary numbers being 2989 per mm² at age 8 weeks and 2915 per mm² at age 16 weeks. Correspondingly the area occupied by capillaries in the myocardium increased in wild-type turkeys from 8.59% at the age of 8 weeks to 9.15% at 16 weeks, whereas in meat-type turkeys this area decreased from 10.4% at 8 weeks to 9.95% at 16 weeks. Our results indicate a mismatch in development between body mass and heart mass and a compromised cardiac capillary density and architecture in the meat-type turkeys in comparison to the wild-type turkeys.

Bioavailability of Cu, Zn and Mn from Mineral Chelates or Blends of Inorganic Salts in Growing Turkeys Fed with Supplemental Riboflavin and/or Pyridoxine

An 84-day feeding trial was conducted in growing turkeys to measure the bioavailability of Cu, Zn and Mn from a commercial mineral chelate and corresponding inorganic salts in composite feeds containing supplemental riboflavin (B2) and/or pyridoxine (B6). A total of 320, 28-day-old British United Turkeys (BUT) were assigned to eight dietary treatments in a 2 × 4 factorial arrangement comprising two trace mineral sources: chelated trace mineral blend (CTMB) and its corresponding inorganic trace minerals blend (ITMB) fed solely or with supplements of vitamin B2 (8 ppm) or B6 (7 ppm) or 8 ppm B2 + 7 ppm B6. Each treatment was replicated four times with 10 turkeys each. It was observed that turkeys fed with diets supplemented solely with ITMB elicited higher (P < 0.05) Zn excretion than their counterparts fed with diets containing ITMB with supplements of vitamins B2 and/or B6. Manganese retention was lower (P < 0.05) in turkeys fed with diets supplemented solely with ITMB than those fed with diets containing vitamins B2 and/or B6 additives. Combination of CTMB or ITMB with B6 improved (P < 0.05) the concentration of Mn in the liver and Cu in the bone. It was concluded that the minerals in CTMB were more available to the animals than ITMB. Furthermore, vitamins B2 and/or B6 supplementation improved the bioavailability of the inorganic Cu, Zn and Mn in growing turkeys and tended to reduce the concentration of these trace elements in birds' excreta.

Effect of protein source and protease addition on performance, blood metabolites and nutrient digestibility of turkeys fed on low-protein diets from 28 to 55 d post hatch

The objective of this study was to investigate the effect of a monocomponent protease and dietary inclusion of canola meal (CM) and poultry by-product meal (PBM) on growth performance, carcass characteristics and blood metabolites of turkeys fed on low crude protein (CP) diets from 28 to 55 d post hatch. Experimental treatments included control, maize-soybean meal diet including 258.3 g/kg CP; negative control 1 (NC1), maize-soybean meal diet with reduced CP (232.4 g/kg); NC2, control diet (CP, 258.3 g/kg) including CM (80 g/kg) and PBM (80 g/kg); NC3, maize-soybean meal diet with reduced CP (232.4 g/kg) including CM (80 g/kg) and PBM (80 g/kg). Also, the NC1 + P and NC3 + P diets were created by addition of protease enzyme (30 000 units/kg of diet) to the NC1 and NC3 diets, respectively. The NC3 group had lower body weight gain (BWG) compared to those fed on the control diet, and no improvement with enzyme addition (NC3 + P) was achieved. The protease addition to the NC1 diet (NC1 + P) improved BWG to the level of the control diet. The NC1 group had higher feed conversion ratio (FCR) compared to the control and NC3 + P, but protease addition to the NC1 diet improved FCR. Protease addition to the low CP diets resulted in higher nitrogen (N) retention than in the control and NC2 groups. Also, the NC1 + P and NC3 + P diets increased apparent ileal digestibility (AID) of CP compared to the control group. It was concluded that addition of CM (up to 80 g/kg) and PBM (up to 80 g/kg) to turkey diets had no negative effect on growth performance from 28 to 55 d of age. The NC1 + P group achieved the BWG of the control group which was partially due to increases in N retention and AID of CP, but the NC3 + P group failed to recover the growth losses. This difference implies that the efficacy of the protease may depend upon the protein source in the ration.

Selenoprotein Transcript Level and Enzyme Activity as Biomarkers for Selenium Status and Selenium Requirements in the Turkey (Meleagris gallopavo)

The current National Research Council (NRC) selenium (Se) requirement for the turkey is 0.2 μg Se/g diet. The sequencing of the turkey selenoproteome offers additional molecular biomarkers for assessment of Se status. To determine dietary Se requirements using selenoprotein transcript levels and enzyme activities, day-old male turkey poults were fed a Se-deficient diet supplemented with graded levels of Se (0, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0 μg Se/g diet) as selenite, and 12.5X the vitamin E requirement. Poults fed less than 0.05 μg Se/g diet had a significantly reduced rate of growth, indicating the Se requirement for growth in young male poults is 0.05 μg Se/g diet. Se deficiency decreased plasma GPX3 (glutathione peroxidase), liver GPX1, and liver GPX4 activities to 2, 3, and 7%, respectively, of Se-adequate levels. Increasing Se supplementation resulted in well-defined plateaus for all blood, liver and gizzard enzyme activities and mRNA levels, showing that these selenoprotein biomarkers could not be used as biomarkers for supernutritional-Se status. Using selenoenzyme activity, minimum Se requirements based on red blood cell GPX1, plasma GPX3, and pancreas and liver GPX1 activities were 0.29–0.33 μg Se/g diet. qPCR analyses using all 10 dietary Se treatments for all 24 selenoprotein transcripts (plus SEPHS1) in liver, gizzard, and pancreas found that only 4, 4, and 3 transcripts, respectively, were significantly down-regulated by Se deficiency and could be used as Se biomarkers. Only GPX3 and SELH mRNA were down regulated in all 3 tissues. For these transcripts, minimum Se requirements were 0.07–0.09 μg Se/g for liver, 0.06–0.15 μg Se/g for gizzard, and 0.13–0.18 μg Se/g for pancreas, all less than enzyme-based requirements. Panels based on multiple Se-regulated transcripts were effective in identifying Se deficiency. These results show that the NRC turkey dietary Se requirement should be raised to 0.3 μg Se/g diet.

Concentrations of the adrenocorticotropic hormone, corticosterone and sex steroid hormones and the expression of the androgen receptor in the pituitary and adrenal glands of male turkeys (Meleagris gallopavo) during growth and development

Androgens take part in the regulation of puberty and promote growth and development. They play their biological role by binding to a specific androgen receptor (AR). The aim of this study was to evaluate the expression of AR mRNA and protein in the pituitary and adrenal glands, to localize AR protein in luteinizing hormone (LH)-producing pituitary and adrenocortical cells, to determine plasma concentrations of adrenocorticotropic hormone (ACTH) and corticosterone and the concentrations of corticosterone, testosterone (T), androstenedione (A4) and oestradiol (E2) in the adrenal glands of male turkeys at the age of 4, 8, 12, 16, 20, 24 and 28weeks. The concentrations of hormones and the expression of AR varied during development. The expression of AR mRNA and protein in pituitary increased during the growth. The increase of AR mRNA levels in pituitary occurred earlier than increase of AR protein. The percentage of pituitary cells expressing ARs in the population of LH-secreting cells increased in week 20. It suggests that AR expression in LH-producing pituitary cells is determined by the phase of development. The drop in adrenal AR mRNA and protein expression was accompanied by an increase in the concentrations of adrenal androgens. Those results could point to the presence of a compensatory mechanism that enables turkeys to avoid the potentially detrimental effects of high androgen concentrations. Our results will expand our knowledge of the role of steroids in the development of the reproductive system of turkeys from the first month of age until maturity.

Expression of the androgen receptor in the testes and the concentrations of gonadotropins and sex steroid hormones in male turkeys (Meleagris gallopavo) during growth and development

Androgens, including testosterone (T) and androstenedione (A4), are essential for puberty, fertility and sexual functions. The biological activity of those hormones is mediated via the androgen receptor (AR). The regulation of androgen action in birds is poorly understood. Therefore, the present study analysed mRNA and protein expression of AR in the testes, plasma concentrations of the luteinizing hormone (LH), follicle-stimulating hormone (FSH), T, A4 and oestradiol (E2), as well as the levels of T, A4 and E2 in testicular homogenates of male turkeys (Meleagris gallopavo) at the age of 4, 8, 12, 16, 20, 24 and 28weeks. Plasma concentrations of LH and FSH, as well as plasma and testicular levels of T and A4 began to increase at 20weeks of age. The lowest plasma levels of E2 were noted at 20weeks relative to other growth stages. The 20th week of life seems to be the key phase in the development of the reproductive system of turkeys. The AR protein was found in the nuclei of testicular cells in all examined growth stages. Higher expression of AR protein in the testes beginning at 20weeks of age was accompanied by high plasma concentrations of LH and high plasma and testicular levels of androgens. This relationship seems to be necessary to regulate male sexual function.

Estimation of the population size of Canadian commercial poultry farms by log-linear capture-recapture analysis

The objective of this study was to estimate the population size of Canadian poultry farms in 3 subpopulations (British Columbia, Ontario, and Other) by poultry category. We used data for 2008 to 2011 from the Canadian Notifiable Avian Influenza (NAI) Surveillance System (CanNAISS). Log-linear capture-recapture models were applied to estimate the number of commercial chicken and turkey farms. The estimated size of farm populations was validated by comparing sizes to data provided by the Canadian poultry industry in 2007, which were assumed to be complete and exhaustive. Our results showed that the log-linear modelling approach was an appropriate tool to estimate the population size of Canadian commercial chicken and turkey farms. The 2007 farm population size for each poultry category was included in the 95% confidence intervals of the farm population size estimates. Log-linear capture-recapture modelling might be useful for estimating the number of farms using surveillance data when no comprehensive registry exists.

Future considerations in poultry nutrition

Following is invited commentary on the symposium "A Crystal Ball Look into the Future of…" delivered July 16, 2011, at the Poultry Science Association's 100th annual meeting, St. Louis, Missouri. The symposium examined various aspects that will impact the future of poultry production over the next 10 to 20 yr. Topics included genetics, nutrition, incubation, and bird health. This paper deals with various aspects of future issues affecting global feeding and nutrition of poultry.

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.

Evaluation of phytase concentration needed for growing–finishing commercial turkey toms

1. Growth performance, serum bone markers, and bone strength and mineralisation were determined in tom turkeys grown from 9 to 17 weeks of age. 2. Dietary non-phytate phosphorus was formulated to be reduced by 1.0 g/kg in the low phosphorus diet compared to a control diet and phytase was added to provide 0, 150, 300, 450 or 600 units/kg activity to the low phosphorus diet. 3. From 9 to 12 weeks of age, body weight and gain:food were reduced by the low phosphorus diet without added phytase, compared to the adequate phosphorus diet. Increasing the concentration of phytase linearly increased these growth parameters. There were no significant growth responses at 17 weeks of age. 4. Serum osteocalcin was reduced by increasing dietary phosphorus at 12 weeks of age when growth was affected, but not at later ages. Serum pyridinoline was reduced by higher dietary phosphorus and decreased linearly with increasing phytase activity at 17 weeks of age. 5. Fracture force of the ulna and femur increased linearly with increasing phytase activity but bone strength was not affected when corrected for bone cross-sectional area. Bone strength of the ulna and ash concentration of the ulna and tibia were increased by higher dietary phosphorus. Humerus and ulna ash increased linearly with increasing phytase activity. 6. Water-soluble phosphorus content of the litter was increased by higher dietary phosphorus and addition of phytase to the low phosphorus diet. The increase in water-soluble phosphorus content of the litter when phytase was fed may indicate that phosphorus could be fed at a lower concentration than used in this trial, at least in the finisher diet when phytase is added to the food. 7. Bone fracture force, strength and ash were generally optimised when 450 units/kg phytase activity was added to the low phosphorus diet. However, growth performance was best in the grower I (9 to 12 weeks) phase when 600 units/kg phytase was added to the diet.

Application of soybean meal, soy protein concentrate and isolate differing in α-galactosides content to low- and high-fibre diets in growing turkeys

The aim of this experiment was to investigate the physiological and growth response of young turkeys (up to 8 weeks of age) to dietary replacement of soybean meal (SBM) by soy protein concentrate (PC) or protein isolate (PI). This replacement resulted in a differentiated dietary concentration of α-galactosides of over 2.5% in the SBM diet, approximately 2% with a mixture SBM and PC, 1% with a PC diet and 0.1% with a PI diet. Each treatment was applied in two ways: with lower (3.5%) or higher (5.3%) dietary crude fibre content, made by supplementation with soybean hulls. The highest and lowest body weight of turkeys was recorded both after the first and second 4-week half of the study in the PC and PI-type diets respectively. A gradual withdrawal of α-galactosides from a diet was accompanied by a decline in ileal tissue mass, ileal viscosity and activity of endogenous maltase (the latter was found to be significant at 4 weeks of age). At the same time, two-way anova revealed that an elevated level of crude fibre (HF treatment) caused an increase in ileal tissue mass (p < 0.05 after 4 weeks of feeding) as well as a decrease in activity level of intestinal sucrase and maltase. The presence of raffinose family oligosaccharides in a diet, in contrast to dietary crude fibre level, significantly affected the caecal metabolism. The rate of bacterial production of short-chain fatty acids in the caeca was distinctly diminished by dietary withdrawal of α-galactosides. In conclusion, the soy protein concentrate, in contrast to the protein isolate preparation, exerted positive effects on the turkeys' growth and gastrointestinal tract physiology and should be considered as an effective SBM substitute.

The effect of dietary fibre on the small intestines and apparent digestion in the turkey

1. In order to determine the feasibility of using high fibre diets in turkey rations, three crude fibre dietary concentrations were fed to turkey hens at three ages and performance, fibre digestibility and small intestinal morphology were determined. 2. Growth rate and feed efficiency decreased when diets contained 80 to 90 g crude fibre/kg; however, growth did not change when 60 g crude fibre/kg was fed between 1 and 4 weeks or between 6 and 8 weeks and was enhanced between 11 and 14 weeks of age. 3. Digestibilities of crude protein, fat and gross energy (GE) were depressed at fibre intakes of 80 to 90 g/kg between 1 and 4 weeks but not at later ages. Crude fibre digestibility increased with age and decreased with dietary fibre content. 4. Total small intestinal length and surface area were increased by high dietary crude fibre intake between 11 and 14 weeks. Small but inconsistent changes in the length, diameter and number of villi, villus size and area were observed in the duodenum, jejunum and ileum at the different ages as a result of feeding the different crude fibre concentrations. 5. Crude fibre can be utilised to some extent by turkeys and concentrations of 60 g fibre/kg in the diet did not result in decreased performance after 6 weeks of age.

[Turkey fattening under extensive rearing conditions--selected parameters concerning health, performance and behavior]

Within two consecutive studies (study I and study II), each involving a summer (su) and a winter mast (wi), 36 male turkeys per B.U.T. Big 6 (BUT) and Kelly Bronze (KB) origin were set on two seperated areas in free range and fatted over a period of 20 (winter mast in study II) and 22 weeks respectively. Aim of both studies was to analyze the effects of extensive rearing conditions on these two turkey origins concerning health, performance and behavior and whether seasonal climatic differences had any additional influence. Besides the aim in study II was to detect how intensely environmental enrichment (plateau and perches) was accepted by the turkeys and if co-housing of BUT and KB turkeys was possible. The occurence of skin lesions in the breast area (breast blisters and/or breast buttons) was significantly influenced by season (su > wi) and origin (BUT > KB). Malposition of the hind extremities was found significantly more often in the BUT origin, whereas the X-leg position was the most common observed leg abnormality. The mortality rate remained beneath 6% during three of the four fattening periods. Due to their genetical determination, the BUT constantly gained higher weights than the KB (wi > su).The intensity of acceptance of the structural elements was influenced by season (su > wi), forage (ecological > commercial) and time of day (night > day).The results of the studies lead to the conclusion that turkeys of the BUT origin can certainly be fattened under extensive rearing conditions alongside the KB origin, while providing good performance.

The influence of methisoprinol applied in ovo upon hatchability and health status of turkeys

A study was undertaken to determine the effect of a synthetic immunomodulator, i.e. methisoprinol applied in ovo, upon the hatchability of turkey poults under conditions of a standard hatchery as well as on their health status evaluated based on analyses of selected biochemical indices in their blood serum. Experiments were conducted on 5 groups of BUT 9 turkeys at the age of 5 days (35 birds in each group) hatched from eggs to which methisoprinol (VetAgro, Lublin, Poland) was applied in ovo at a dose of 5 mg (group I), 10 mg (group II) or 20 mg per egg (group III) on the 26th day of incubation. Turkeys hatched from eggs to which a physiological solution of NaCl was applied on the same day at a dose of 0.1 ml per egg (group IV) as well as those hatched from eggs without in ovo injection (group V) served as controls. Five hundreds eggs were used in each group. Hatchability was evaluated based on the number of hatched poults in respect of the number of eggs with live embryos transferred from the setting compartment to the hatching compartment, that were subjected to in ovo administration of the preparations according to the experimental design. Blood serum of the 5-day-old turkey poults was analyzed for activities of AST, ALP, LDH-L, CK, lysozyme and ceruloplasmine as well as for total protein and albumin contents. Analyses were also conducted for the immune system organ index - percentage contribution of organs of the immune system (spleen, thymus and the bursa of Fabricius) in the body weight of turkeys. The study demonstrated that methisoprinol administered to turkey embryos in ovo on day 26 of incubation at doses of 5, 10 or 20 mg per embryo did not induce any disturbances in the hatching process or affect its final result. In addition, it was shown not to exert any negative effect on the health status of the reared turkey poults.

Cardiovascular system diseases in turkeys

Genetic manipulation conducted for many years has resulted in breeding turkeys with very intensive growth rate and high percentage of muscle tissue. These features promote dysfunctions in the cardiovascular system. The aim of this article was to present current data on the etiology of cardiovascular system diseases in turkeys. In this paper the most recent data on dilated cardiomyopathy (round heart disease), spontaneous aortic rupture and perirenal hemorrhage syndrome are described.

Lipogenesis in turkeys and chickens: A study of body composition and liver lipogenic enzyme activities

1. Carcase composition, fat deposition and the activities of three liver lipogenic enzymes were compared in turkeys and chickens fed ad libitum on two different isocaloric diets, respectively adapted to chickens (C) and to turkeys (T). Diets differed in their protein content, being higher by 60 g/kg in diet T. 2. Chickens were much fatter than turkeys and exhibited higher activities of acetyl-coenzyme A carboxylase (EC 6.4.1.2) and malic enzyme (EC 1.1.1.40). 3. The carcase composition of turkeys was not influenced by the type of diet administered, while chickens fed on diet C were fatter than chickens fed on diet T. Compared to diet T, diet C enhanced malic enzyme activity, whatever the species and age. 4. A good correlation between abdominal fat and total fatness was observed in both species but especially in turkeys. 5. In conclusion, hepatic lipogenesis is much lower in turkeys than in chickens.

Alkaline phosphatase reactivity in the vagina and uterovaginal junction sperm-storage tubules of turkeys in egg production: implications for sperm storage

1. Currently there remains contradictory information on the localisation and possible role of alkaline phosphatase (AP) in the chicken and Japanese quail oviducts. 2. Using turkeys with a hard-shelled egg in their uteri, vaginal and uterovaginal junction mucosae were stretched and fixed as whole mounts prior to the histochemical localisation of AP activity. 3. Scattered AP reactive cells were observed in the vaginal and uterovaginal junction surface epithelia and intense AP reactivity of the sperm-storage tubule (SST) epithelium, localised to its apical border. 4. We suggest that such AP reactivity in hens in egg production may reflect cell differentiation and proliferation in the vagina and SST and possibly a mechanism for the transfer of lipid from the SST epithelia to resident sperm.

Effect of Age and Method on Ileal Endogenous Amino Acid Flow in Turkey Poults

Ileal endogenous amino acid (IEAA) flow in turkey poults was determined at 2 experimental locations on d 5, 15, and 21 posthatch using 3 methods, namely a N-free diet (NFD), a highly digestible protein (casein), and the regression method, obtained by regressing IEAA flow against dietary casein levels. The diets were semipurified and contained 0, 50, 100, or 150 g of casein/kg of diet as the sole source of dietary protein. Each diet was fed for 5 d to 6 replicate cages of 30 (d 5), 10 (d 15), or 8 (d 21) birds per cage. There was no interaction between locations and age or locations and diet, so the data from both locations were pooled. Ileal endogenous amino acid flow on d 5 (NFD method) was higher (P < 0.05) than on d 15 or 21. Ileal endogenous amino acid flow estimated from the NFD and the regression methods was different on d 5 (P < 0.05), but there were no differences in IEAA flow for most of the amino acids on d 15 and 21. Increasing the level of casein resulted in a linear (P < 0.05) increase in IEAA flow. The amino acids with the lowest flow were Trp and Met, whereas Glu had the greatest flow. The results obtained from this study indicate that data generated across laboratories were repeatable. The results also suggest that about twice as much amino acids of endogenous origin are found in the digesta of poults on d 5 relative to d 21. Also, as poults age, there is a decrease in IEAA flow from d 5 to 15, but flows from d 15 to 21 are not different. These observations suggest that apparent digestibility coefficients for poults on d 5 and d 15 or 21 could be significantly influenced by the level of endogenous amino acids, more so on d 5.

Performance of Turkey Poults Fed Different Doses of Aflatoxins in the Diet

This work was conduced to determine the performance parameters of initial-phase turkey poults fed 7 different doses of aflatoxins in the diet. Three hundred thirty-six 1-d-old male turkey poults were used in this research. Turkeys were divided into 7 treatments according to aflatoxin doses (T1 = control; T2 = 20 ppb aflatoxins; T3 = 50 ppb; T4 = 100 ppb; T5 = 200 ppb; T6 = 500 ppb; T7 = 1,000 ppb). Birds were killed in 2 periods: half of them after 21 d of experiment and the remaining birds after 42 d of experiment. In both periods, the evaluated parameters were as follows: feed consumption, BW, relative weights of organs (liver, gizzard, heart, and bursa of Fabricius) and meat (breast and thighs), and clinical biochemistry parameters (total plasmatic proteins, albumin, uric acid, cholesterol, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase). At 21 d of experiment, both feed consumption and BW were significantly affected by the aflatoxins present in the diet. Nevertheless, gizzard relative weight, total plasmatic proteins, and cholesterol levels were also affected. At the 42-d evaluation, besides feed consumption and BW, gizzard and liver relative weights and cholesterol levels were also affected by the presence of aflatoxins in the diet. Turkey poults are very sensitive to aflatoxin poisoning, because they are at least 3 to 6 times more sensitive to these contaminants than broilers.

Evidence of a different dose response in turkeys when fed 2-hydroxy-4(methylthio) butanoic acid versus DL-methionine

In broilers, 2-hydroxy-4(methylthio) butanoic acid (HMTBA) can elicit a different dose response relative to dl-Met (DLM) such that birds could have lower gain responses at deficient TSAA concentrations but greater gain responses at maximum response concentrations. Two experiments tested if the 2 Met sources have a different dose response in 1-d-old turkeys using a 2 x 4 factorial plus a control design with 8 replicates of 12 toms per treatment. 2-Hydroxy-4(methylthio) butanoic acid and DLM were supplemented at equimolar concentrations of 0.05, 0.10, 0.15, and 0.20% or 0.04, 0.08, 0.16, and 0.32% for experiments 1 and 2, respectively, in commercial-type TSAA-deficient (0.99 to 1.02%) diets for 21 d. No differences in any performance parameter tested were found between HMTBA and DLM in either trial by ANOVA. Linear (LIN), quadratic (QUAD), and exponential regressions were fitted to the gain response of birds fed HMTBA or DLM. Equations with better goodness of fit as determined by Schwarz's Bayesian information criteria index were used for further calculations of predicted differences between HMTBA and DLM. In both trials, the shape of the dose response differed according to the Met source used, and best-fit equations were obtained when using Met intake over control rather than dietary Met concentration as the dependent variable. In experiment 1, the best-fit equations were an inverse QUAD for HMTBA and a LIN for DLM, and in experiment 2 with higher Met concentrations, the best-fit equations were a QUAD for DLM and a LIN for HMTBA. Feeding HMTBA at deficient TSAA resulted in lower (P <0.05) gains in experiment 1 but greater gains at maximum response concentrations (P <0.05) in both experiments. Plasma-free Met increased at 3 times the rate for DLM than HMTBA (P <0.01) with increasing Met concentration, which may play a role in the evolution of different dose responses at the extremes of the Met dose response. These results demonstrate that Met sources elicit a differential dose response in turkeys such that feeding HMTBA at deficient TSAA concentrations can be lower than DLM and can reach a higher maximum performance than with DLM.

Endochondral ossification process of the turkey (Meleagris gallopavo) during embryonic and juvenile development

The long bones of the developing skeleton arise from the process of endochondral ossification, which begins during the embryonic stages and resumes later in the growth plates located at the extremities of the long bones. This process includes commitment of cells to the chondrocytic lineage and further differentiation into hypertrophic chondrocytes, which subsequently undergo apoptosis and are replaced by osteoblasts laying down the trabecular bone. In this study we characterize, for the first time, the endochondral bone development of the turkey during embryonic and juvenile stages. Turkey tibias were collected on embryonic d 11, 14, and 18; and at 3 and 7 d posthatching, alcian blue and Von Kossa staining, alkaline phosphatase activity, and in situ expression of collagen types II and X were studied in these samples. We showed that the principles of bone development in the turkey follow the known vertebrate pattern, and that the initiation of ossification is related to the perichondrium and compact bone. These results increase the knowledge about this process in the turkey, which is an important animal in the agricultural industries.

Matrix metalloproteinase expression and localization in turkey (Meleagris gallopavo) during the endochondral ossification process1

Vertebrate long bones are formed by endochondral ossification, a process accompanied by changes in extracellular matrix synthesis and remodeling, performed mainly by the matrix metalloproteinases (MMP). The temporal/spatial expression patterns of 5 members of the MMP family known to be important for endochondral ossification were studied, for the first time, in the turkey growth plate during embryonic and juvenile stages. The expression of MMP-2 was detected in the proliferative zone, MMP-3, MMP-9, and MMP-13 in cells lining the blood vessels; MMP-13 was also detected in hypertrophic chondrocytes. The MMP-16 expression was detected in the reserve zone of the growth plate. These results present a detailed survey of turkey MMP, serving as a data source (atlas) for further studies in this subject.

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).

Gastrointestinal Maturation is Accelerated in Turkey Poults Supplemented with a Mannan-Oligosaccharide Yeast Extract (Alphamune)

Alphamune, a yeast extract antibiotic alternative, has been shown to stimulate the immune system, increase BW in pigs, and reduce Salmonella colonization in chickens. The influence of Alphamune on gastrointestinal tract development has not been reported. Two trials were conducted to evaluate the effects of Alphamune on gut maturation of 7- and 21-d-old turkey poults. Poults were fed a standard control unmedicated turkey starter diet or the same diet supplemented with either 1 or 2 lb/ton of Alphamune (n = 18/group). Poults were weighed on d 7 and 21, euthanized, and a 2-cm section was collected from the midpoint of the duodenum, jejunum, and ileum of each bird (9 poults/d per treatment) and fixed in a 10% formalin solution for 72 h and then stained. Twenty measurements of villus height, villus surface area, lamina propria thickness, crypt depth, and density of neutral, sialomucin, and sulfomucin goblet cells were taken per section per poult. On d 7, BW were higher for the poults given the Alphamune treatments compared with control poults; however, no differences were observed on d 21. Alphamune supplementation influenced intestinal morphology differently based on gut location. Ileum villus height, surface area, lamina propria thickness, crypt depth, and neutral, sialomucin, and sulfomucin goblet cell density were enhanced with Alphamune treatments on d 7 and 21 (P < 0.05) and in a dose-dependent manner for many of the parameters evaluated. Jejunum results were mixed. Surface area, crypt depth, and sialomucin and sulfomucin goblet cells were consistently higher for the 2 lb/ton of Alphamune groups compared with the control group on d 7 and 21. Duodenum villus height, surface area, and goblet cell density were higher for the 2 lb/ton of Alphamune groups on d 7; however, intestinal morphology of the duodenum was not different between the control and treated birds on d 21. These results suggest that feed supplemented with Alphamune can accelerate gastrointestinal maturation in turkey poults and is more pronounced in the ileum than in other portions of the small intestine.

Influence of Hen Age on the Response of Turkey Poults to Cold Stress, Escherichia coli Challenge, and Treatment with a Yeast Extract Antibiotic Alternative

Two battery experiments were conducted to evaluate a commercial yeast extract feed supplement, Alphamune, in a cold stress-Escherichia coli challenge of 1-wk-old turkeys. Experiment 1 used 1-d-old male poults that were the progeny of 33-wk-old hens in their second week of lay. Experiment 2 used male poults of the same genetic line from 40-wk-old hens in their eighth week of lay. Poults were fed a standard unmedicated turkey starter diet or the same diet with either a low level (504 g/t) or a high level (1,008 g/t) of yeast extract. Challenged birds were exposed to intermittent cold stress during wk 1 to 3 and to a respiratory E. coli challenge at 1 wk of age. In both experiments, BW at wk 1 was increased by feeding yeast extract. In experiment 1, challenged, control-fed birds had decreased BW at wk 3 and feed conversion was protected by both levels of yeast extract supplementation. In experiment 2, challenge had no effect on control-fed birds; however, yeast extract decreased the BW of challenged birds. In experiment 1, total leukocyte numbers were decreased by challenge of control-fed birds only, and there was no effect of challenge on the heterophil/lymphocyte ratio. In experiment 2, total leukocyte numbers were decreased and the heterophil/lymphocyte ratio was increased in challenged, control-fed birds. Percentage mortality was not affected by challenge in experiment 1; however, in experiment 2, mortality was increased by challenge of control-fed birds and those fed the lower level of yeast extract. These results suggest that hen age should be considered when designing studies to evaluate antibiotic alternatives and in making decisions for incorporating such alternatives into production.

Comparison of the performance of 1966- versus 2003-type turkeys when fed representative 1966 and 2003 turkey diets: growth rate, livability, and feed conversion

Body weight, livability, and feed conversion of a randombred control turkey line (RBC2) started in 1966 at The Ohio State University was compared with that of modern commercial turkeys hatched in 2003 when fed representative 1966- and 2003-type diets from hatch (March 5, 2003) through 196 d of age. Each pen of modern turkeys consisted of 5 birds each of the Nicholas, British United Turkeys of America, and Hybrid strains. Eight groups (i.e., 2 strains (RBC2 vs. modern), 2 sexes, and 2 dietary regimens) were randomly assigned into each of 4 blocks of 8 litter floor pens (32 total) for growout. Using the BW performance of the 2 strains on the modern feed as the basis, the study showed that the 2003 turkeys were approximately twice as heavy as the 1966 RBC2 at the 4 slaughter ages and that tom weights have increased by 186, 208, 227, and 241 g/yr, and hen weights have increased by 164, 179, 186, and 205 g/yr at 112, 140, 168, and 196 d of age, respectively, over the past 37 yr. Cumulative feed conversion (kg of feed/kg of BW) was approximately 20% better in the 2003 tom turkey on the 2003 feed (2.638) than in the RBC2 tom on the 1966 feed (3.278) at 20 wk of age. Feed efficiency to 11 kg of BW in the 2003 toms (2.132 at 98 d of age) was approximately 50% better than in the RBC2 toms (4.208 at 196 d of age). The number of days to reach that weight was halved during this period of time. Growth performance during the different periods of the study appeared to be strongly affected by type of feed used and seasonal changes in ambient temperature. Overall livability was very good for all groups, but the mortality level of the RBC2 was consistently higher, although not significantly so, than for the modern birds.

Genetic Control of Neonatal Growth and Intestinal Maturation in Turkeys

Turkey experimental lines E (selected 44 yr for increased egg production) and F (selected 38 yr for increased 16-wk BW) were mated reciprocally with the randombred control lines from which they were derived (RBC1 and RBC2, respectively), and the pure line and reciprocal cross poults were compared according to their hatch, 3- and 7-d BW, jejunum weight, jejunum length, and jejunal maltase and alkaline phosphatase activities. Orthogonal contrasts of the data from the pure line and reciprocal cross-poult data were used to estimate additive genetic effects, reciprocal effects (confounded maternal and sex-linked effects), and heterosis for each of the traits measured. Body weights at hatch and at 3 and 7 d of age were increased in the F line relative to the RBC2 line and were decreased in the E line relative to the RBC1 line. The genetic changes from long-term selection in the E and F lines have had concomitant effects on jejunum growth and function that parallel the changes in growth rate. The increased BW of the F line poults and the decreased BW of the E line poults relative to their randombred controls may be due to increases in the absorption of nutrients because of greater intestinal mass rather than to differences in glucose digestion. Concomitant changes in egg weight in the 2 selected lines appear to have resulted in maternal effects that have significantly affected neonatal BW and digestive system maturation.

Supplementation of Avizyme 1502 to corn-soybean meal-wheat diets fed to turkey tom poults: the first fifty-six days of age

A study was designed to determine the effects of enzyme supplementation on poults fed commercially based diets that included corn, soybean meal, and ground wheat with meat and bone meal (0 to 21 d) or Pro-Pak (22 to 56 d). Day-old turkey poults (n = 3,850) were divided into 35 pens and fed 1 of 5 dietary treatments for 56 d. Treatments were a positive control, a negative control (corn matrix adjustment of 140 kcal), and negative control diets supplemented with Avizyme 1502 at 250, 500, or 750 g/tonne. Feed intake, live weight gain, feed conversion ratio, and mortality were measured for the periods 0 to 21 d, 21 to 42 d, and 42 to 56 d, as well as for the cumulative 0 to 56 d. The 0- to 21-d period was further divided into subperiods (0 to 4 d, 4 to 8 d, 8 to 12 d, 12 to 16 d, 16 to 21 d) to evaluate early nutritional development. Ileal contents along with duodenal, jejunal, and ileal sections (n = 7/treatment) were sampled to determine apparent digestibility and morphology. In most instances, production response differences between the positive and negative controls were not significant, making definitive interpretation of enzyme addition difficult. Energy and protein ileal digestibilities of the negative control diets were lower than those of the positive control diet at 4, 8, 12, 16, and 42 d. Enzyme supplementation significantly improved energy and protein beyond that of the PC diet on d 42. Villus height and crypt depth did not respond to dietary treatment, although there was a significant interaction of age by treatment on jejunal villus height. The similarity between the controls, as well as the high inclusion of CuSO(4), may be responsible for the low response with enzyme inclusion.

On the interactions betweenFusariumtoxin-contaminated wheat and non-starch-polysaccharide hydrolysing enzymes in turkey diets on performance, health and carry-over of deoxynivalenol and zearalenone

1. Diets with increasing proportions of Fusarium toxin-contaminated wheat (0, 170, 340 and 510 g CW/kg) were fed to male turkeys (BUT Big 6) from d 21 to d 56 of age. Each diet was tested with or without a non-starch-polysaccharide (NSP) hydrolysing enzyme preparation. Dietary deoxynivalenol (DON) and zearalenone (ZON) concentrations were successively increased up to approximately 5.4 and 0.04 mg/kg, respectively. 2. Weight gain decreased slightly with increasing proportions of CW, by 1.6, 0.7 and 3.6%, whereas other performance parameters remained unaffected. NSP enzyme supplements to the diets had no influence. 3. The weight of the emptied jejunum plus ileum, relative to live weight, decreased in a dose-related fashion whereby the NSP enzyme exerted an additional weight-decreasing effect. A similar weight-decreasing NSP enzyme effect was noted for heart weights. Activity of glutamate dehydrogenase in serum was significantly increased in groups fed the diets with the highest CW proportion, whereas gamma-glutamyl-transferase remained unaltered. 4. Viscosity in the small intestine was significantly reduced by supplementing the diets with the NSP enzyme. This effect successively decreased with increasing proportions of the CW. 5. Concentrations of DON and of its de-epoxidised metabolite de-epoxy-DON in plasma, liver and breast meat were lower than the detection limits of 2 ng/ml (plasma) and 4 ng/g, respectively, of the applied HPLC method. DON concentration in bile reached up to 13 to 23 ng/ml whereas de-epoxy-DON concentration was lower than 4 ng/ml. 6. ZON or its metabolites were not detectable in plasma, liver or breast meat (detection limits of the HPLC method were 1, 0.5 and 5 ng/g for ZON, alpha-zearalenol (ZOL) and beta-ZOL, respectively). Concentrations of ZON and alpha-ZOL in bile increased with dietary ZON concentration. The mean proportions of ZON, alpha-ZOL and beta-ZOL of the sum of all three metabolites were 19, 77 and 4%, respectively.

Turkey breeder hen age affects growth and systemic and intestinal inflammatory responses in female poults examined at different ages posthatch

This trial examined the effect of 2 turkey breeder hen ages (33 or 55 wk of age) on performance, intestinal histology, and inflammatory immune response of female turkey poults grown to market weight. Using a randomized design, female poults were separated by breeder flock age (n = 8 floor pens/breeder flock age; n = 26 poults/pen; 0.195 m(2)/bird), fed identical commercial diets (9 phases), and grown to market weight (approximately 11.4 kg/ bird). At young ages, poults from the older breeder flock tended to have higher BW (P < 0.01 for d 7, P < 0.09 for d 63), although feed consumed was not significantly different due to breeder flock age (P > 0.20 for all ages). After approximately 63 d posthatch, no difference in BW was observed, suggesting that poults from the younger breeder flock were eventually able to compensate for initial reductions in performance. In addition to growth measurements on d 10, 24, and 65 posthatch, poults were vaccinated with lipopolysaccharide (LPS, from Salmonella Typhimurium; 0.5 mg/kg of BW intraabdominally) or not vaccinated (control), and intestinal histology and plasma haptoglobin were assessed at 24 h postadministration. In control birds, intestinal villus length was greater for poults from the older breeder flock (P < 0.05), as was crypt depth (P < 0.05 for d 11 and 25). Plasma haptoglobin levels did not change in 11-d-old poults after LPS administration, but they increased with LPS at d 25 and 66 posthatch (P < 0.05 for each). At d 66 posthatch, poults from the younger flock had increased haptoglobin levels post-LPS compared with those from the older breeder flock (P < 0.05). In general, LPS administration increased villus width in the jejunum and ileum (P < 0.05 for each), increased lamina propria width in the duodenum and ileum (P < 0.05 for each), and decreased ileum crypt depth (P < 0.05). Overall, poults from the older breeder flock had reduced inflammatory responses, even at 9 to 10 wk posthatch, even though performance was similar in poults from the 2 flocks by this age.

Comparison of Plasma Uric Acid Levels in Five Varieties of the Domestic Turkey, Meleagris gallopavo

Plasma uric acid (PUA) is a consensus physiological biomarker for many phenotypes in vertebrates because it is a reliable indicator for processes such as oxidative stress and tubular function. In birds, it is considered a major antioxidant and is also the primary endproduct of nitrogen metabolism. Despite this importance, knowledge of baseline levels of PUA in physiologically normal birds, including the turkey, Meleagris gallopavo, is limited. Here, we compared PUA levels in a total of 106 apparently normal male and female birds at 8 and 32 wk of age from 5 strains of the domestic turkey, including Bourbon Red, Narragansett, Blue Slate, Royal Palm, and Spanish Black. Though differences in PUA were not significant at 8 and 32 wk of age, BW, variety, and sex effects were highly significant. When adjusted for BW, female birds had, on average, a higher PUA per kilogram of BW than male birds. When adjusted for both sex and BW, Royal Palm birds had the lowest average PUA, and Blue Slate had the highest PUA. Results of these investigations represent the first comparative analysis of PUA in physiologically normal turkey varieties. They suggest that differences in basal plasma levels of uric acid in physiologically normal turkeys are influenced by sex, weight, and genetic background but may be independent of age.

Genetics of growth and reproduction in the turkey. 16. Effect of repeated backcrossing of an egg line to a commercial sire line

The turkey industry's view of the relative economic importance of growth and egg production has changed rapidly, and genetic changes by selection within lines may not be rapid enough to meet the changing needs. The objective of the present study was to determine the feasibility of rapidly increasing the BW of dam lines by repeated backcrossing of a dam line (E) to a commercial sire line (B). The experimental E line was selected long-term for increased egg production and was used as the model for a turkey dam line. The B line was larger (more than 3-fold) in BW at 8, 16, and 20 wk of age, had wider breasts (approximately 1.8-fold) at 16 wk of age, and had lower egg production for 180 d (about 3-fold) than the E line. Based on additive genetic variation, males in the F1 generation of the B x E cross did not differ from expected in BW at any age, but females of this cross had BW less than expected at 16 and 20 wk of age. In the F1 generation, breast width of the cross did not differ from the expected value, but egg production for 180 d was greater than expected (126.6 vs.102.3 eggs/hen). After 3 generations of backcrossing, the backcrosses exhibited a gain in 20-wk BW of 12.5 and 8.8 kg, respectively, for males and females; a gain of 5.9 and 5.3 cm in breast width at 16 wk of age for males and females, respectively; and a loss of 74.1 eggs per hen over a 180-d production period. Based on the results of the current and a previous study, limited backcrossing of a dam line to a sire line may be an economically feasible method to greatly increase the BW of dam lines without unduly sacrificing egg production. For maximum gains per generation, backcrossing probably should be used for a maximum of 2 or 3 generations.

Dietary putrescine (1,4-diaminobutane) influences recovery of Turkey poults challenged with a mixed coccidial infection

Exogenous dietary putrescine (1,4-diaminobutane) can increase growth rates of neonatal animals, including calves, chicks, and piglets, under nutritional stress. Turkey poults often have a high mortality rate and this may be due to poor initial feeding behavior and inadequate development of the intestinal tract. We conducted an experiment to determine the effect of dietary putrescine supplementation on growth performance and the role of dietary putrescine in prevention and recovery from a coccidial challenge. A total of 160 1-d-old turkey poults were fed a corn and soybean meal-based starter diet supplemented with 0.0 (control), 0.1, 0.2, and 0.3 g/100 g purified putrescine (8 birds/pen, 5 pens/diet). At 14 d of age, half the birds were infected with approximately 43,000 sporulated oocysts. The experiment lasted 24 d. Fecal samples were gathered from d 3 to d 5 postinfection by total collection. Ten control and 10 infected birds fed each diet were sampled on d 6 and d 10 postinfection. The induced infection produced significant depressions in growth and feed intake and detrimental morphological changes in the small intestine of poults in the absence of mortality. Weight gains, protein content of jejunum, and morphometric indices of duodenum, jejunum, and ileum were greater in challenged poults fed 0.3 g/100 g putrescine than in controls. We conclude that dietary putrescine supplementation may be beneficial to poult growth, mucosal development of the small intestine, and to recovery from subclinical coccidiosis.

Effect of myostatin on turkey myogenic satellite cells and embryonic myoblasts

Myostatin (GDF-8) inhibits the activation, proliferation, and differentiation of myogenic satellite cells. The relative importance of this growth factor is demonstrated in myostatin-null mice and cattle possessing defective myostatin genes. These defects result in greatly enhanced musculature. In the present study, we examined the effect of myostatin on turkey myogenic satellite cells and embryonic myoblasts. Compared with controls (P<0.05), proliferation of both turkey embryonic myoblasts and satellite cells was inhibited between 26 and 45% in serum-free medium containing 20 ng/mL myostatin. While individual turkey satellite cell clones differed in their responsiveness to myostatin, there were no significant differences in the responsiveness of fast and slow growing cells as groups (P>0.05). A slow growing clone that exhibited the greatest response to myostatin also exhibited the greatest depression of differentiation with this growth factor (P<0.05). All other turkey satellite cell clones exhibited similar responses to the differentiation depressing effects of myostatin (P>0.05). However, myostatin had no effect on differentiation of turkey embryonic myoblasts (P>0.05). When exposed to myostatin, 4 of 6 proliferating clones and all differentiating clones increased their expression of decorin, a growth inhibitor (P<0.05). The present study demonstrates that myostatin inhibits the proliferation and differentiation of satellite cells and suggests a role for decorin in myostatin action in muscle development.

Effect of conventional and organic production practices on the prevalence and antimicrobial resistance of Campylobacter spp. in poultry

Intestinal tracts of broilers and turkeys from 10 conventional broiler farms and 10 conventional turkey farms, where antimicrobials were routinely used, and from 5 organic broiler farms and 5 organic turkey farms, where antimicrobials had never been used, were collected and cultured for Campylobacter species. A total of 694 Campylobacter isolates from the conventional and organic poultry operations were tested for antimicrobial resistance to nine antimicrobial agents by the agar dilution method. Although Campylobacter species were highly prevalent in both the conventional and organic poultry operations, the antimicrobial resistance rates were significantly different between the organic operations and the conventional operations. Less than 2% of Campylobacter strains isolated from organically raised poultry were resistant to fluoroquinolones, while 46% and 67% of Campylobacter isolates from conventionally raised broilers and conventionally raised turkeys, respectively, were resistant to these antimicrobials. In addition, a high frequency of resistance to erythromycin (80%), clindamycin (64%), kanamycin (76%), and ampicillin (31%) was observed among Campylobacter isolates from conventionally raised turkeys. None of the Campylobacter isolates obtained in this study was resistant to gentamicin, while a large number of the isolates from both conventional and organic poultry operations were resistant to tetracycline. Multidrug resistance was observed mainly among Campylobacter strains isolated from the conventional turkey operation (81%). Findings from this study clearly indicate the influence of conventional and organic poultry production practices on antimicrobial resistance of Campylobacter on poultry farms.

Effects of glypican-1 on turkey skeletal muscle cell proliferation, differentiation and fibroblast growth factor 2 responsiveness

The heparan sulfate proteoglycan, glypican-1, is a low affinity receptor for fibroblast growth factor 2 (FGF2). Fibroblast growth factor 2 is a potent stimulator of skeletal muscle cell proliferation and an inhibitor of differentiation. Heparan sulfate proteoglycans like glypican-1 are required for FGF2 to transduce an intracellular signal. Understanding the role of glypican-1 in the regulation of FGF2-mediated signaling is important in furthering the understanding of the biological processes involved in muscle development and growth. In the current study, a turkey glypican-1 expression vector construct was transfected into turkey myogenic satellite cells resulting in the overexpression of glypican-1. The proliferation, differentiation, and responsiveness to FGF2 were measured in control and transfected cell cultures. The overexpression of glypican-1 in turkey myogenic satellite cells increased both satellite cell proliferation and FGF2 responsiveness, but decreased the rate of differentiation. The current data support glypican-1 modulation of both proliferation and differentiation through an FGF2-mediated pathway.

Effect of in ovo feeding egg white protein, β-hydroxy-β-methylbutyrate, and carbohydrates on glycogen status and neonatal growth of turkeys

In ovo feeding (IOF), injecting dietary components into the amnion about 1 d prior to internal pipping, may enhance growth by altering glycogen status. This hypothesis was evaluated with 5 IOF solutions containing protein, beta-hydroxy-beta-methylbutyrate (HMB), and carbohydrate. Four IOF treatments were arranged as a factorial of 2 levels of egg white protein (EWP; 0 and 18%) and 2 levels of HMB (0 and 0.1%). An IOF solution of carbohydrates (S; 20% dextrin and 3% maltose) was evaluated for contrast purposes. At 23 d of incubation, 1.5 mL of IOF solution was injected into the amnion of 100 eggs per treatment. At hatch, feed and water were provided ad libitum. At hatch and 3 and 7 d of age, BW were determined, and 10 poults per treatment were sampled to determine liver (LG) and pectoralis muscle (PC) glycogen content. Poults on IOF treatments A (18% EWP), B (18% EWP + HMB), and D (HMB) weighed 6.0, 2.7, and 3.3% more than the controls at hatch, respectively (P < 0.05) with an EWP x HMB interaction (P < 0.05) sustained to 3 and 7 d only in treatment D (P < 0.005). At hatch, A and D poults had greater percentages of PC (P < 0.05) than controls, and the percentage of PC in treatment D was sustained until 7 d. Total LG was enhanced by A and B at 7 d (P < 0.05) over the controls, whereas total PC glycogen was enhanced at 7 d by IOF treatment D (P < 0.05). The IOF A and S poults had greater BW than the controls at hatch only (P < 0.05). The IOF treatment A had greater LG at hatch (P < 0.05), but by 7 d, A and S had greater LG than controls (P < 0.05). Poults fed S in ovo had enhanced total PC glycogen over controls, whereas poults on treatment A had less total PC glycogen than controls (P < 0.05). The results of this experiment demonstrate that IOF of A or S poults may enhance hatch BW and glycogen status of poults during the neonatal period by inclusion of HMB.

Protein quality of poultry by-product meal manufactured from whole fowl co-extruded with corn or wheat

Three experiments were conducted with turkey poults to characterize the protein quality of a novel poultry by-product meal composed of aged fowl extruded with either corn (CHM) or wheat (WHM). In Experiment 1, a growth assay was conducted to determine a dietary protein response range for semipurified diets containing CHM or WHM as the sole sources of dietary protein. Diets contained 12, 15, and 18% CP, and there was a linear increase in BW with no significant differences between the 2 sources. The same dietary protein levels were used to determine the protein efficiency ratio (PER), net protein ratio (NPR), and apparent amino acid digestibility of CHM and WHM in Experiments 2 and 3. In Experiment 3, WHM and CHM were also compared with soybean meal (SBM) and meat and bone meal (MBM). In Experiment 2, there were no significant differences between CHM and WHM in PER or NPR, but the variability between levels of CP did account for a significant level of CP x source interaction (P < 0.05). In Experiment 3, there were no significant protein level effects on PER or NPR, but the values for MBM were consistently lower than those for CHM, WHM, and SBM. The apparent amino acid digestibility coefficients for MBM were also consistently lower than those for CHM and WHM. In conclusion, the extruded WHM and CHM products have acceptable protein quality and were better than MBM as single sources of dietary protein.

Differential expression of membrane-associated heparan sulfate proteoglycans in the skeletal muscle of turkeys with different growth rates

Heparan sulfate proteoglycans (HSPG) are key components of the cell membrane and extracellular matrix of skeletal muscle cells. Two major groups of membrane-associated HSPG found in skeletal muscle are syndecans (SYN) and glypicans (GPC), both of which can regulate growth factor activities and, thus, modulate cell proliferation and differentiation. In the current study, the mRNA expression of a group of membrane-associated HSPG (SYN 2 through 4 and GPC 1) was investigated in embryonic pectoralis major muscle [embryonic days (ED) 14, 16, 18, 20, 22, 24] and myogenic satellite cells isolated from males of a turkey genetic line selected for increased 16-wk BW (F line) and an unselected randombred control (RBC2 line) from which the F line was developed. The mRNA expression was measured by a real-time quantitative PCR approach. The SYN 2 and SYN 4 expression exhibited a similar pattern during embryonic p. major muscle development, which remained constant from ED 14 to ED 22 and declined sharply from ED 22 to ED 24 to a very low level. In contrast, the SYN 3 and GPC 1 expression showed a continuous decline from ED 14 to ED 24. The F line had higher SYN 2 (ED 14, 18, 20, 22), SYN 3 (ED 22), and SYN 4 (ED 22) expression than the RBC2 line. In myogenic satellite cells, initiating differentiation resulted in a decrease in SYN 2 expression and an increase in GPC 1 expression. Both SYN 3 and SYN 4 expression stayed almost constant through both the proliferation and differentiation stages. The proliferating satellite cells from the F line displayed higher SYN 4 expression than those from the RBC2 line. Collectively, the results from the current study suggest that membrane-associated HSPG are differentially expressed in both embryonic p. major muscle tissue and satellite cells isolated from F-line and RBC2-line male turkeys, implying their distinct roles in myogenesis and differing influence on muscle growth properties.

Performance and Gastrointestinal Tract Metabolism of Turkeys Fed Diets with Different Contents of Fructooligosaccharides

Different levels of dietary fructooligosaccharide (FOS) administered for 8 wk to commercial male turkeys were evaluated for their efficacy on performance and physiological response in the digestive tract. Special attention was paid to cecal metabolism. The following levels of FOS were used in a diet: 0.5, 1, and 2%. After 8 wk of experimental feeding, the diet intake, body weight, and feed efficiency ratio were similar in all groups examined. The pH of ileal and cecal contents were reduced by dietary treatments, especially when 2% of dietary FOS was used. The highest ammonia and Lowry's protein concentrations were associated with elevated amounts of FOS preparation in a diet (1 and 2%). Bacterial enzyme activity remained statistically unaffected by experimental treatments; however, a slight beneficial decrease in the activity of beta-glucosidase and beta-glucuronidase was observed after ingestion of the FOS preparation. The addition of FOS to a diet did not affect short-chain fatty acid concentration but gave greater short-chain fatty acid pool in the ceca of turkeys, especially in the case of the highest dose of FOS.

Poult Performance as Influenced by Age of Dam, Genetic Line, and Dietary Vitamin E

An experiment was conducted to measure the effects of age of dam, genetic line, and dietary levels of vitamin E on growth and immunocompetence of poults. Age of dam was defined as younger (in early egg production) and older (past peak production); line consisted of a commercial sire and dam line; and dietary vitamin E was supplemented into the diet at 10 and 300 IU/kg of feed. Traits measured included body, liver, gizzard, and yolk sac weights at hatch; BW and feed conversion to 9, 28, and 42 d; response to SRBC, Phaseolus vulgaris agglutinin-P, and Escherichia coli administered at 28 d of age; and response to a cold stress on d 5 posthatch. Differences among genetic lines were evident with growth greater for poults from the sire than from the dam line. Performance of poults from older dams was generally superior to that of poults from younger dams. The higher level of vitamin E resulted in a greater than 7-fold increase in blood plasma vitamin E and reduced mortality. There were interactions among the main effects in which the fitness of poults from younger dams was enhanced by the higher level of vitamin E and the effect of breeder age differed among genetic lines.

Response of Male BUT Big 6 Turkeys to Varying Amino Acid Feeding Programs

Dietary protein is a major cost contributor in turkey nutrition. Therefore, a feeding trial with male BUT Big 6 turkeys to 154 d of age was conducted to examine how live performance and economics are affected when dietary amino acid levels are altered in different phases. Six dietary treatments were run with treatment 1 as the control in which balanced protein levels were according to recommendations during all 6 phases. Treatments 2 through 6 used combinations of balanced protein (based on lysine) that ranged from 90 to 120% of those used in treatment 1. The combinations for the 6 phases of feeding were 120, 120, 120, 120, 90, and 90% for treatment 2; 120, 120, 120, 100, 90, and 90% for treatment 3; 120, 120, 100, 100, 90, and 90% for treatment 4; 120, 120, 120, 120, 100, and 100% for treatment 5; and 90, 90, 90, 100, 100, and 100 for treatment 6. Final BW was highest in treatment 4 and lowest in treatment 2 (P < 0.05), whereas final BW were intermediate and statistically not different in treatments 1, 3, 5, and 6. Breast meat yield was highest in treatment 5 and lowest in treatments 2 and 3 (P < 0.05). Mortality seemed to be reduced in treatment 6 compared with treatments 2, 3, and 5 (P < 0.10). Performance data in combination with economic simulations suggested that the feeding regimens of treatments 4 or 6 might be alternative strategies to treatment 1 to improve overall profitability.