Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Turkeys”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed2000

Effect of current frequency during electrical stunning in a water bath on somatosensory evoked responses in turkey's brain.

Somatosensory evoked responses (SEP) in a turkey's brain were determined after water-bath stunning with a 150-mA (constant current) delivered with 50, 300 or 600 Hz, or with 75 mA, delivered with 50-Hz alternating current (AC) in order to evaluate the effectiveness of stunning. Ninety-four BUT 9 turkey hens 12 weeks of age were surgically implanted with EEG recording and left wing nerve stimulating electrodes 4 hours before stunning. They were individually stunned by immersion of the head and upper part of the neck in a water bath for 4 s. Using a 150-mA current, all birds stunned at 50 Hz showed cardiac arrest and a flat EEG immediately after the stun with no SEP recovery. The incidence of cardiac arrest at stunning decreased with increasing current frequency but SEP were lost in all birds. In birds that survived the stun, the duration of SEP abolition was on average 69 and 34 seconds at 300 and 600 Hz, respectively. Stunning with a 75-mA AC, delivered with 50 Hz, induced cardiac arrest in 32 per cent of turkeys. SEP were abolished in only 71 per cent of the birds that survived the stun, with an average duration of SEP of 66 seconds. The results indicate that increasing the frequency of a 150-mA AC current leads to a decreased stunning efficiency. A current of 75 mA per bird is unacceptable since 29 per cent of the birds do not show SEP abolition.

Animals↗
PubMed1976

Affinity label for beta-adrenergic receptor in turkey erythrocytes.

The compound N-[2-hydroxy-3-(1-naphthoxy)-propyl]-N'-bromoacetylethylenediamine (NHNP-NBE) was found to label covalently the beta-adrenergic receptor in turkey erythrocytes. The compound inhibits irreversibly 1-epinephrine-dependent adenylate cyclase activity [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] in the whole turkey erythrocyte as well as in the erythrocyte membranes possessing the beta-receptor. The affinity label blocks, also irreversibly, the specific [3H] propranolol binding, whereas other bromoacetyl compounds tested have no effect on binding, even at high concentrations, which cause enzyme inactivation. 1-Epinephrine and propranolol offer protection against the affinity label in whole turkey erythrocytes as well as in membranes prepared from these cells. The potential usefulness of an irreversible beta-antagonist is discussed.

Adenylyl Cyclase Inhibitors↗
PubMed1984

Phorbol ester induces desensitization of adenylate cyclase and phosphorylation of the beta-adrenergic receptor in turkey erythrocytes.

Incubation of turkey erythrocytes with the phorbol ester phorbol 12-myristate 13-acetate (PMA) results in a dose- and time-dependent desensitization of isoproterenol-stimulated adenylate cyclase activity. Compared to controls, membranes from PMA-treated cells have an isoproterenol-stimulated adenylate cyclase activity that is decreased 20%-40%, with little effect on forskolin or fluoride activation of adenylate cyclase. No change in beta-adrenergic receptor number is observed after PMA treatment, indicating that the major effect of PMA is to uncouple receptor interactions with Ns, the stimulatory guanine nucleotide regulatory protein of adenylate cyclase. Purification of beta-adrenergic receptors from 32Pi-labeled turkey erythrocytes, incubated in the presence or absence of PMA, indicates that the phorbol ester is capable of inducing a 3-fold increase in phosphorylation of the beta-adrenergic receptor. The PMA effect is similar to the phosphorylation of the beta-adrenergic receptor during isoproterenol- and dibutyryl cAMP-induced desensitization of adenylate cyclase in turkey erythrocytes. The findings indicate that decreased receptor-Ns coupling is correlated with receptor phosphorylation and that phorbol esters can influence the responsiveness of hormone-sensitive adenylate cyclase in certain cell types.

Adenylyl Cyclases↗
PubMed2002

Exon skipping in cardiac troponin T of turkeys with inherited dilated cardiomyopathy.

Troponin T is a central component of the thin filament-associated troponin-tropomyosin system and plays an essential role in the Ca(2+) regulation of striated muscle contraction. The importance of the structure and function of troponin T is evident in the regulated isoform expression during development and the point mutations resulting in familial hypertrophic and dilated cardiomyopathies. We report here that turkeys with inherited dilated cardiomyopathy and heart failure express an unusual low molecular weight cardiac troponin T missing 11 amino acids due to the splice out of the normally conserved exon 8-encoded segment. The deletion of a 9-bp segment from intron 7 of the turkey cardiac troponin T gene may be responsible for the weakened splicing of the downstream exon 8 during mRNA processing. The exclusion of the exon 8-encoded segment results in conformational changes in cardiac troponin T, an altered binding affinity for troponin I and tropomyosin, and an increased calcium sensitivity of the actomyosin ATPase. Expression of the exon 8-deleted cardiac troponin T prior to the development of cardiomyopathy in turkeys indicates a novel RNA splicing disease and provides evidence for the role of troponin T structure-function variation in myocardial pathogenesis and heart failure.

Animals↗
PubMed1996

Effects of supplemental phytase and phosphorus on histological, mechanical and chemical traits of tibia and performance of turkeys fed on soyabean-meal-based semi-purified diets high in phytate phosphorus.

Tibial traits were investigated for turkey poults fed on soyabean-meal-based semi-purified diets high in phytate P (2.2 g/kg) with added phytase and inorganic P. Dietary treatments were: (1) 2.7 g non-phytate P (nP)/kg; (2) diet 1 + 1000 U phytase/kg diet; (3) 3.6 g nP/kg; (4) diet 3 + 800 U phytase; (5) 4.5 g nP/kg; (6) diet 5 + 600 U phytase; (7) 6.0 g nP/kg. Added phytase and nP increased (P < 0.006) tibial dry matter, ash weight and content, body-weight gain, feed intake and gain:feed. The Mg and Zn concentrations in the tibial ash were also increased (P < 0.001 and P < 0.09 respectively) by added phytase or nP; tibial P and Ca concentrations tended to be increased. Hypertrophy zone width of the tibial proximal end decreased (P < 0.001), while proliferating zone width, tibial length, and widths at the long and short axes increased (P < 0.003) as phytase and nP were added. The addition of phytase also tended to enlarge the cartilaginous zone width, which was linearly increased (P < 0.05) by added nP. Disorganization scores of the hypertrophy zone and trabecular bone were low, approaching normal (P < 0.05), for turkey poults fed on diets with phytase supplementation, and tibial abnormality scores were linearly decreased (P < 0.001) as nP levels increased (zero score is considered normal). Adding phytase and nP improved the orderliness of development, mineralization and arrangement of cartilage and bone cells, and alleviated the effects of P deficiency on the histological and gross structure of the tibias. Tibial shear stress increased (P < 0.04) as phytase and nP were added. In summary, similar improvements in bone characteristics were achieved for turkey poults fed on a P-deficient diet supplemented with either phytase or nP.

6-Phytase↗
PubMed2004

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

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

Adaptation, Physiological↗
PubMed2001

Effect of retail light sources on the appearance of processed turkey products.

1. The effect of using incandescent (INC), fluorescent (FL) and metal halide (MH) light sources on panel preference of three turkey products was investigated. 2. For the bologna, smoked turkey and turkey breast, INC was the preferred light source. There was no significant difference in preference between the FL and MH light sources. 3. Relative luminance data, collected with a fibre optic probe connected to a photodiode array, demonstrated that the reason was a minimal red light output in the commercially used FL and MH light sources, which resulted in a lack of redness in the products.

Animals↗
PubMed2003

Isolation and characterisation of Salmonella in a turkey production facility.

1. A comprehensive ecological survey was conducted from April 1997 to June 1999 on 4 turkey flocks (F1 to F4) to identify key pre-harvest sources/vectors of Salmonella colonisation. 2. Turkey caecal and crop content, litter, drinker, air, feed, feeder and environmental swab samples were collected. Conventional microbiological and serological procedures were used to isolate, identify, and confirm the presence or absence of Salmonella. 3. Salmonella was isolated from 13% of litter, 11% of turkey caeca, 10% of drinker, 5% of environmental swab, 3% of feed and 1% of feeder samples. Salmonella heidelberg (65%), S. senftenberg (19%), S. muenster (10%), S. anatum (3%), and S. worthington (3%) were identified. 4. Identifying environmental sources associated with Salmonella colonisation and characterising serotypes would assist in designing pre-harvest controls for this poultry-borne pathogen. Integrators and poultry producers may be able to design hazard analysis and critical control point (HACCP) protocols to reduce the incidence of Salmonella arriving at the processing plant.

Animal Husbandry↗
PubMed2003

Effect of xylanase and beta-glucanase supplementation of wheat- or wheat- and barley-based diets on the performance of male turkeys.

The efficiency of a mixture of xylanase and beta-glucanase enzymes was evaluated in two separate experiments on growing turkeys offered diets based on wheat or wheat and barley. 2. In the first experiment, the addition of 560 and 2800 IU of xylanase and beta-glucanase, respectively, per kg of diet significantly improved feed efficiency in turkeys fed on wheat- and barley-based diet throughout the entire experiment (42 d). 3. In the second experiment, the enzyme mixture significantly increased N-corrected apparent metabolisable energy (AMEN) by approximately 5%. 4. Furthermore, the combination of xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Feed efficiency was increased by 2.94, 2.47 and 5.91% in diets based on 500 then 540 g of wheat/kg of diet, 394 then 384 g of wheat and 100 then 150 g of barley/kg of diet and 180 g of wheat and 300 then 350 g of barley/kg of diet, respectively. 5. This enzyme mixture decreased in vitro viscosity of wheat, barley and soybean meal, the effect being larger for wheat and barley than for soybean meal. 6. In conclusion, the supplementation of diets based on wheat and barley with xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Therefore, wheat and barley could be used more efficiently by turkeys in the presence of an appropriate enzyme preparation.

Animal Feed↗
PubMed2003

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.

Aging↗
PubMed2004

Mitochondrial function in turkey skeletal muscle--impact on meat quality.

1. M. iliotibialis (MIT) and M. pectoralis (MP) of the BUT Big 6 and Kelly BBB turkey were characterised with respect to physical properties, mitochondrial function, metabolic state, morphology and meat quality. 2. Mitochondrial enzyme activity and respiration rates in MP declined with increasing age while glycolytic enzyme activity remained nearly constant. 3. There were no major differences between BUT Big 6 and Kelly BBB with respect to histological, histochemical or biochemical variables. In spite of the greater adult weight of BUT Big 6, body proportion was equal in both strains. 4. In agreement with the histochemical findings MIT showed higher oxidative capacities, while glycolytic enzyme activity was higher in MP. 5. Pyruvate was the best substrate for oxidative phosphorylation in MIT, but not in MP. Pyruvate dehydrogenase (PDH) activity was up to 15 times less in MP and blood lactate was correlated with intramuscular pH. 6. Turkey breast muscle was restricted in its ability to oxidise pyruvate, especially in those animals that tended to develop intramuscular acidosis post mortem. 7. It is concluded that the in vivo metabolic environment results in acidosis and impaired meat quality, at least in turkey M. pectoralis.

Acidosis↗
PubMed2005

Effects of Lactobacilli and lactose on Salmonella typhimurium colonisation and microbial fermentation in the crop of the young turkey.

1. Three experiments were performed to examine the effects of Lactobacilli and lactose on microbial fermentation and Salmonella enterica serovar Typhimurium colonisation in the crop of the young turkey. 2. The following carboxylic acids were detected in the crop ingesta: formic, acetic, butyric, lactic, valeric, caproic, oxalic, phenyl acetic, succinic and fumaric; propionic, isobutyric and isovaleric acids were not detectable. 3. At the beginning of the night, there were considerable quantities of ingesta in the crop of young turkeys. During the scotophase, there were progressive reductions in the contents and pH. Moreover, there were linear increases in the concentration of lactic, valeric and caproic acids (by approximately 7-fold over 8 h). Much smaller changes in crop pH were observed in the study where dietary treatments of Lactobacilli were not included. 4. Chronic addition of lactose or Lactobacilli to the diet exerted modest effects on the carboxylic acid concentration in the crop contents but did not consistently influence colonisation of the crop by Salmonella enterica serovar Typhimurium. 5. Young turkeys confine eating to the hours of illumination (photophase) with a peak in consumption prior to the subjective dusk.

Aging↗
PubMed2006

Effects of alpha-tocopheryl acetate and beta-carotene dietary supplementation on the antioxidant enzymes, TBARS and sensory attributes of turkey meat.

1. The aim of the study was to evaluate the effects of alpha-tocopheryl acetate (50 mg/kg) and beta-carotene (15 mg/kg) dietary supplementation on the oxidative status of raw turkey breast and leg muscles assessed by thiobarbituric acid test values, the vitamin E levels and the antioxidant enzyme activities. In parallel, a quantitative descriptive sensory analysis was carried out on cooked, stored and reheated samples. 2. Vitamin E was present in sufficient quantity to reduce oxidation, since iron-induced reactive substances (TBARS) were significantly lower in antioxidant-supplemented treatments. The results suggested that the presence of beta-carotene in the diet limits the accumulation of alpha-tocopherol in turkey muscles. 3. In the present study, there was no conclusive relationship between dietary antioxidant supplementation and endogenous antioxidant enzyme activities. 4. Sensory evaluation showed that a longer supplementation time and dose may be necessary in turkeys to prevent meat from rancidity and warmed-over flavour (WOF). Leg pastiness and stringiness were modified by dietary antioxidant supplementation, indicating the possible synergism between antioxidants and cysteine proteinases in the perception of meat quality. 5. Given the modern trends that lead consumers to increase their consumption of poultry meat, it would be interesting to evaluate the commercial potential and cost effectiveness of routine dietary antioxidant supplementation.

Animal Feed↗
PubMed2006

Genetic parameters for a heavy female turkey line: impact of simultaneous selection for body weight and total egg number.

1. The objective of this study was to investigate the strength of the genetic association between growth and reproduction traits in turkeys selected for body weight, conformation and egg production. 2. Two distinct populations but derived from the same heavy turkey female line and situated in different locations (UK and USA), were used to estimate genetic parameters using multivariate REML for the following traits: body weight at 14 (BW14), 19 (BW19) and 24 (BW24) weeks of age and total egg number (EGG). 3. A Box-Cox transformation was applied to egg production data to reduce the impact of non-normality. 4. The heritability estimates for each trait for the UK and USA populations, respectively, were: BW14 0.37 and 0.48; BW19 0.34 and 0.43; BW24 0.28 and 0.43; EGG 0.22 and 0.34. 5. The genetic correlation between the body weight at all ages and the total egg production was strongly negative, reaching a value of -0.75 for the UK and -0.55 for the USA population. 6. The comparison of our results with published estimates in turkeys suggests that the genetic correlation may get stronger in magnitude following selection for increased body weight. 7. This could arise from fixation during selection of genes favouring larger weights but with minimal effect on egg production, leaving the segregating genetic variation dominated by pleiotropic loci with antagonistic effects on the traits. 8. Thus, in order to avoid continued selection for body weight reducing egg production to a point where natural selection offsets selection gains, alternative selection strategies should be considered.

Animals↗
PubMed1980

Circulating growth hormone and prolactin concentrations in turkeys and chickens infected with Histomonas meleagridis.

1. Histomonas meleagridis was inoculated into young chickens and turkeys and the effect of the infection (blackhead) on circulating growth hormone (GH) and prolactin concentrations determined. 2. During the course of the infection in turkeys there was a marked increase in plasma GH concentration which correlated with the severity of the disease, as judged by liver and caecal characteristics. The infection was less severe in chickens and no correlation between plasma GH and the degree of infection was observed. 3. The concentration of plasma prolactin was increased in the chicken, but not in the turkey, during the invasive period of infection.

Animals↗
PubMed1985

Effects of exercise conditioning on semen characteristics from hyper- and hypotensive lines of turkeys.

Twenty-one male Broad Breasted White turkeys which had been selected for high or low blood pressure were put on an exercise regimen to determine its effect on semen quality. Eleven were from the hypertensive line and 10 from the hypotensive line. Eleven (6 hypertensive and 5 hypotensive) turkeys were placed on an exercise regime of walking (herding) about 1 mile daily for 6 weeks before the experiment began, and then for a further 6 weeks during semen collection. Semen was collected from 11 turkeys on the exercise regime and 10 nonexercised control birds which were kept in their experimental pens during the trial. Both hypertensive and exercised groups showed an improved semen colour score at the first collection period (P less than or equal to 0.09). Only the exercised group showed a significantly (P less than or equal to 0.05) better score than the control group during periods 2 and 3. The hypertensive line showed significantly higher spermatozoa count than the hypotensive line during the first collection period. There was no effect of either exercise or selection for high or low blood pressure on semen volume.

Animals↗
PubMed1987

Effect on fertility of low numbers of fowl spermatozoa inseminated in aqueous diluent or semen components of the fowl and turkey.

A study was undertaken to compare the effect on fertility in the fowl of aqueous medium, natural homologous seminal plasma, heterologous turkey seminal plasma and whole turkey semen when whole fowl semen was excessively diluted with these media and inseminated fresh. High dilution with fowl seminal plasma resulted in the best fertility. Dilution with the turkey semen components produced fertility no different from that with aqueous diluent when the dose of spermatozoa was 5 X 5 or 10 X 10(6). The results of this study confirm that 5 X 5 to 10 X 10(6) good quality spermatozoa are sufficient to produce acceptable fertility in weekly inseminations of fresh semen. This enables good quality semen to be highly diluted. However, at high dilution rates there is a need to reconsider the composition of semen diluents, with respect to simulating as yet unknown properties provided by factor(s) in homologous ductus deferens seminal plasma.

Animals↗
PubMed1987

Observations on the size of the follicular hierarchy in the turkey hen and a case of arrested follicular growth.

1. The phase of rapid development of ovarian follicles in turkeys fed ad libitum or given a restricted allocation of food from 6 to 30 weeks of age was determined by feeding a fat soluble dye and counting the number of rings of dye in the yolks of laid eggs. 2. The duration of rapid growth was similar in ad libitum and restricted birds and averaged 11.6 d. The maximum number of yellow follicles greater than 8 mm expected in the hierarchy of the turkey hen is 9 to 10 compared with 6 to 7 in the chicken. 3. Discontinuous growth was observed in a series of follicles from one bird. This is believed to be the first report of arrested follicular growth in the turkey.

Animals↗