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 1,369 records · Page 76Linked to original sources
PubMed1989

Daily changes in plasma prolactin, corticosterone, and luteinizing hormone in the unrestrained, ovariectomized turkey hen.

Plasma concentrations of prolactin (PRL), corticosterone (B), and luteinizing hormone (LH) were determined in hourly samples collected over a 24-h period from unrestrained, long-term ovariectomized (OVX) turkey hens maintained in cages in an isolation room on a 14 h light: 10 h dark photoperiod. Mean plasma concentrations of all three hormones were found to vary significantly with the time of sampling. Mean plasma PRL levels reached a peak (6.50 +/- 1.70 ng/mL, means +/- SEM) during the latter half of the photophase, declined to a nadir (5.22 +/- 1.20 ng/mL) prior to the onset of darkness, and then rose gradually during the scotophase to reach another peak (8.96 +/- 1.80 ng/mL) 1 h prior to lights on. Mean plasma LH levels rose significantly (P less than .001) from a nadir of 4.11 + .29 ng/mL prior to lights out to a peak of 4.74 + .34 ng/mL during the dark period. No evidence of random fluctuations in LH levels was observed in any individual, suggesting that episodic LH release may not occur in OVX turkey hens. Individual patterns of B secretion varied substantially so that, although significant increases and decreases in mean plasma B levels were observed, no clearly defined peaks in mean plasma B levels were identified. Individual secretory profiles revealed that peaks in PRL secretion often coincided with peaks in B secretion, but B peaks were usually more numerous. It is concluded that PRL and LH are secreted in a daily rhythm in the OVX turkey hen, with the highest levels of both hormones occurring during the scotophase.

Animals↗
PubMed1989

Characterization of complement activity in turkeys: evidence for classical and alternative complement pathways.

Complement activity in turkey serum was examined by using inhibitors or activators of mammalian complement. Hemolytic test systems using sheep red blood cells sensitized with specific antibody (SSRBC) and horse red blood cells (HRBC) were developed to measure residual complement activity of turkey sera treated with the various inhibitors or activators. Lysis of SSRBC was blocked by treatment with 6-mM EDTA, 10-mM ethylene glycol-bis-beta aminoethylether N,N,N',N' tetraacetic acid (EGTA), and carrageenan. In contrast, lysis of HRBC was blocked by 6-mM EDTA, but not by 10-mM EGTA or carrageenan. Addition of magnesium to EGTA-chelated serum facilitated the lysis of HRBC but not the lysis of SSRBC. Treatment of serum with zymosan at 1 mg/mL and inulin at 5 mg/mL depleted hemolytic activity against both SSRBC and HRBC, suggesting depletion of components common to both pathways. Differences in the hemolytic activities of sera against SSRBC and HRBC after treatment with the various complement inhibitors and activators demonstrate the presence of two complement pathways in turkeys.

Animals↗
PubMed1989

The absence of sex and age effects on the corticosterone response of turkey poults to adrenocorticotropic hormone and temperature stressors.

A study was undertaken to assess the role of sex and age on the adrenal cortical response of turkey poults during the time period associated with idiopathic poult mortality. Three and 14-day-old tom and hen turkey poults were subjected to the following treatments: saline injection (control), cool water immersion (20 C) for 1 min, cold water immersion (5 C) for 1 min, and 1 IU/kg adrenocorticotrophic hormone (ACTH) injection. Blood was collected 1 and 4 h posttreatment for plasma corticosterone (CS) assay. Temperature treatments did not affect plasma CS in either age or sex. Plasma CS was increased by ACTH after 4 h postinjection in both sexes and at both ages. The hypothalamic-pituitary-adrenal cortical axis of the turkey poult was functional but appeared to be insensitive to temperature stress.

Adrenocorticotropic Hormone↗
PubMed1990

Protein quality and iron bioavailability of mechanically and hand-deboned turkey meat fed to rats.

The protein quality and iron bioavailability of mechanically deboned turkey meat (MDT) and hand-deboned turkey meat (HDT) were determined in rats. The protein, fat, and moisture levels in MDT were similar to those found in HDT. The MDT, however, contained more ash, calcium, and iron than the HDT. The MDT and HDT had similar amino-acid patterns; methionine and cystine were the limiting amino acids for both products. The amino-acid scores were .97 and .98 for MDT and HDT, respectively. The protein efficiency ratio and biological value as well as the values for net protein utilization and nitrogen efficiency for growth for MDT were similar to those for HDT and reference casein (P greater than .05). The hemoglobin-regeneration efficiency values were 40, 39, and 55%, respectively, for MDT, HDT, and FeSO4 (least significant difference = 12%). The MDT contained more bioavailable iron (7.6 mg of iron per kg of meat or 4.1 mg of iron per 1,000 kcal) than the HDT (4.2 mg/kg or 2.4 mg/1,000 kcal). Mechanically deboning turkey meat did not affect its protein quality, but increased the amount of bioavailable iron.

Amino Acids↗
PubMed1990

Hematological indices of turkey embryos incubated at high altitude as affected by oxygen and shell permeability.

Turkey eggs (Meleagris gallopavo) were incubated at an altitude of 1,707 m to test the effects of oxygen supplementation and increased eggshell permeability by removal of shell cuticle on embryonic hematology. Turkey embryo hematological indices measured were red blood cell count (RBC), hemoglobin concentration, packed cell volume, mean cellular volume, mean cellular hemoglobin, and percentage of reticulocytes. Although hemoglobin concentration measured during pipping increased as expected by increasing RBC, no significant differences were observed between oxygenation, or permeability treatments, or their interaction. Under the high altitude conditions of the present experiment, increased hemoglobin concentrations in all treatments corresponded to increased numbers of erythrocytes with constant mean cellular hemoglobin. None of the remaining hematological indices examined was affected by oxygen or permeability treatments. It was concluded that turkey embryos incubating at 1,707-m elevation make no additional changes in hemoglobin concentrations during the plateau stage in oxygen consumption (25, 26, and 27 days of incubation) when exposed to increased oxygen tension (151 mm Hg versus 135 mm Hg) or increased eggshell permeability (19.9 mg H2O/day per mm Hg versus 23.2 mg H2O/day per mm Hg).

Altitude↗
PubMed1991

Correlations of organ weights, hematocrit, and testosterone with sexual maturity of the male turkey.

A study was conducted with Large White breeder male turkeys to determine changes in blood constituents and organ weights associated with sexual maturity. Testicular samples from 8- to 32-wk-old turkeys were histologically examined and the changes in the seminiferous tubule epithelium associated with sexual maturity were correlated with changes in blood constituents and organ weights. Spermatozoa were first found in the lumina of the seminiferous tubules at 15 wk, and semen containing mature spermatozoa was first observed in the ductus (d.) deferens at 26 wk. Testes weights increased significantly between 20 and 22 wk and continued to increase until 30 wk of age. Testosterone concentration in the blood was .2 ng/mL at 16 wk, and steadily increased to 1.3 ng/mL at 34 wk. The increase in testosterone paralleled the increase in testes weights. The bursa of Fabricius weight reached a maximum at 16 wk, began to regress at 22 wk, and was completely regressed at 32 wk. Hematocrit values started to increase at 16 wk and reached a plateau at 22 wk. The association of the increase in hematocrit with the functional maturation of the testes suggests that the increase in hematocrit could be used to predict maturation of testicular spermatozoa in the male breeder turkey. However, semen production (semen accumulation in the d. deferens) did not start until 10 wk after mature spermatozoa were found in the testes.

Animals↗
PubMed1991

A retrospective analysis on the epizootiological aspects of outbreaks of Pasteurella anatipestifer infection in turkeys in Minnesota.

The possible risk factors associated with outbreaks of Pasteurella anatipestifer infection in turkeys were analyzed to study the epizootiology of the disease. The data for the study was obtained from flocks affected and unaffected with Pasteurella infection. The results of the analysis suggested that overcrowding, preexisting viral infections, increased activity of wild birds on the farm, and shorter down time were possible factors that initiate the occurrence of the disease in turkey flocks. The statistical models used in the analysis predicted correctly 80% of the unaffected flocks (8 out of 10 flocks), and 95% of the affected flocks (13 out of 14 flocks). The overall correct prediction was 88% (21 out of 24 flocks). Fish meal and meat and bone meal, which are integral components of turkey feed, were analyzed for the possible presence of P. anatipestifer. Its presence in a sample of fish meal was demonstrated.

Animal Feed↗
PubMed1991

Effects of a hydrated sodium calcium aluminosilicate on growing turkey poults during aflatoxicosis.

Effects of adding .5% of a hydrated sodium calcium aluminosilicate (HSCAS) to diets containing 1 or .5 mg aflatoxin (AF)/kg were determined in male turkey poults from 1 day to 3 wk of age. Body weight gains were significantly reduced by 51 and 19% in turkey poults fed 1 and .5 mg AF/kg, respectively; efficiency of feed utilization was not affected. There were no deaths in poults fed .5 mg AF/kg; however, the mortality rate was 88% in poults fed 1 mg AF/kg. The addition of .5% dietary HSCAS resulted in a 68% decrease in mortality to 28% for the 3-wk experimental period. Treatment-related changes in relative organ weights, hematological values, serum biochemical values, and enzyme activities were observed. The HSCAS in the absence of AF did not alter any of the parameters measured. The HSCAS diminished the adverse effects of AF on body weight gains, most relative organ weights, hematological values, serum biochemical values, and enzyme activities associated with .5 mg AF/kg, but not 1 mg AF/kg. These findings indicate that HSCAS may diminish many of the adverse effects of AF in an AF-sensitive species, the turkey.

Aluminum Silicates↗
PubMed1991

Light intensity effects on reproductive performance of turkey breeder hens.

Two trials were conducted to evaluate the reproductive performance of turkey hens to different light intensity during the lay period. In Trial 1 the hens were exposed to 16 h of light (L) and 8 h dark (D) per day (16L:8D) at 54, 108, or 216 lx and in Trial 2 a 2 x 2 factorial arrangement of treatments was used with main treatment factors being intensity level (54 versus 324 lx) and photoperiod (16L:8D versus 14L:10D). Data were collected for time to onset of lay, rate of lay, fertility, hatchability, and egg and poult weight in both trials, and feed intake in Trial 1. In both trials the light intensity treatments were similarly effective in the photoinduction of reproductive performance in Large White turkey hens. This occurred with daily photoperiods of both 14L:10D and 16L:8D in Trial 2 and there was no photoperiod by intensity interaction. There were no significant differences in feed intake or feed efficiency among the 54-, 108-, and 216-lx treatments of Trial 1. It may be concluded that reproductive performance of turkey hens in closed confinement is equivalent within an intensity range of 54 to 324 lx.

Animals↗
PubMed1991

The fate of Pasteurella multocida after intratracheal inoculation into turkeys.

Young adult turkeys were intratracheally inoculated with the P-1059 strain of Pasteurella multocida, and the fate of the organism was studied by quantifying the organism in various respiratory and systemic tissues at various times after the inoculation. The results showed that, in the first 2 h, on the order of 10(8) to 10(9) organisms deposited at the upper trachea multiplied in situ to gradually spread downwards to the lower respiratory tract. In the majority of turkeys, by 6 h postinoculation the organism invaded the circulatory system and multiplied vigorously in the liver and spleen. In some birds, however, the organism appeared to have reached the liver from the trachea instantaneously by an unidentified mechanism. Vaccination with inactivated vaccines protected turkeys from intratracheal challenge exposure, as well as from intramuscular inoculation.

Animals↗
PubMed1991

Iodine toxicity in large white turkey breeder hens.

Iodine was fed to turkey breeder hens during a 20-wk laying cycle to determine the appropriate dietary level to support reproduction and avoid toxicity. A basal diet that contained by analysis. 7 ppm iodine supported good hatchability of Large White turkey eggs. Supplementing 35 or 350 ppm iodine to the basal diet resulted in toxic effects (P less than or equal to .05) on hatchability. Feeding 350 ppm also depressed (P less than or equal to .05) egg weights, egg production, and eggshell water vapor conductance. Embryonic mortality data indicated that toxic effects of iodine on embryos occur principally during the 1st wk of incubation and immediately prior to and during pipping. It was concluded that iodine toxicity may occur in Large White turkey breeder hens when 350 ppm are fed in the diet.

Animals↗
PubMed1991

Characterization of growth and development of male British United turkeys.

Body weight and the size of various organs (tibia, pectoral muscle, leg muscle, liver, spleen, and testes) were monitored in growing male turkeys (British United Turkeys) in an effort to characterize their growth pattern. The results were fitted with either a single- or a double-component Gompertz equation, describing single and diphasic growth patterns, respectively, using an iterative nonlinear estimation algorithm. The diphasic model with an early and a late growth component provided a better description of the body weight function than the single-phase model. The start of sexual maturation, evidenced by testicular development, marked the transition age between the early and the late phases of growth. A single-component Gompertz equation was sufficient to describe growth of various individual organs. Growth of bone and liver appeared to follow the early growth component, whereas the path of muscle development appeared to be closer to the later growth component. The results suggest that the diphasic growth behavior of male turkeys is caused by a differential growth rate of various organs, rather than by a periodicity in the overall growth rate.

Animals↗
PubMed1991

Effect of overcooked soybean meal on turkey performance.

Three turkey growth experiments were conducted to evaluate the effect of overcooked soybean meal (SBM) on BW gain and gain:feed ratio (FE). On two occasions soybean meals were custom prepared by changing the temperature and the retention time (RT) of the desolventizer-toaster unit at a commercial soybean processing plant. Three different meals were produced for each occasion mainly by altering RT from normal to approximately 1.35 and 2.43 times normal operating conditions (designated SBM1 to 3 on the first occasion and SBM4 to 6 on the second occasion). For SBM1 to 6, urease activities were .06, .00, .20, .01 and .00 delta pH, protein solubilities in .1 M borate at 40 C were 44, 45, 16, 44, 32, and 24%, and protein solubilities in .2% KOH were 86, 84, 76, 90, 85, and 85%, respectively. In two sequential long-term experiments, SBM1 to 3 were fed to turkeys from 0 to 8 wk, then a control (normal processing conditions, SBMF), was fed to the all treatment groups from 8 to 12 wk of age. The SBM4 to 6 were fed from 12 to 18 wk of age after rerandomizing treatment allocation of replicate pens. In the first trial, poults fed SBM3 showed significantly reduced BW gain from 3 wk on and a lower FE shown at 9 wk. No difference in BW gain and FE was observed in the trial from 12 to 18 wk. In a 15-day, short-term experiment starting with 3-day-old poults and feeding diets containing SBM2 to 6, BW gain and FE did not differ among treatment groups. It is concluded that SBM did not show a detrimental effect on turkey growth until it was overcooked by 2.4 times the normal conditions. The usual operating conditions in a commercial processing plant are well within the range for producing adequate SBM for poultry feed.

Animal Feed↗
PubMed1992

The effect of light source and intensity on turkey egg production.

The effect of light source and intensity on egg production, fertility, hatchability, egg weight, and shell quality in turkey hens was investigated. Turkey hens were exposed to either incandescent, high-pressure sodium vapor (HPSV), or daylight fluorescent (FL) lights at an intensity of 21.6 1x during the growth phase (after 8 wk). During the breeder phase, hens were assigned to the same light sources at light intensities of either 53.8 or 166.4 1x in a 3 x 3 x 2 factorial arrangement of treatments. Light source during the growth phase had no significant effect on subsequent egg production, egg weight, fertility, or hatchability. Egg production, shell quality, fertility, and hatchability were also unaffected by light source or intensity during the breeder phase. Egg weight was significantly increased in hens exposed to HPSV compared with incandescent lights during the breeder phase. The HPSV and FL lights can be used effectively for turkey breeder hens both during the prebreeder and breeder periods. Furthermore, light intensities of 53.8 and 166.4 1x appear to be equally effective in stimulating production.

Animal Husbandry↗
PubMed1993

Effect of maternal dietary triiodothyronine on embryonic physiology of turkeys.

The objective of the present experiment was to feed triiodothyronine (T3) to lines of turkey breeders selected for egg production and growth, and an unselected control line. The data were collected to determine a genetic basis for thyroid-mediated maternal effects on embryonic physiology and livability. At 30 wk of age, turkeys of the three lines were photostimulated and half of each line was fed a diet containing .5 ppm T3. Maternal dietary T3 increased egg weight, reduced yolk solids and eggshell conductance constants, and increased albumen solids and water in eggs in all lines compared with control eggs. Hatchability in all lines was not affected by the dietary treatment (Control = 72.2%; T3 treatment = 70.7%), but there was a significant interaction between dietary T3 and line of turkey for the time of embryonic mortality, time of hatching, and carbohydrate metabolism of the embryo. The T3 increased mortality of the Egg line and unselected line during pipping, increased mortality of the Growth line in the plateau stage, but decreased its mortality during internal pipping. Reduced glycogen in liver as well as a reduced gluconeogenesis were evident in embryos of the two selected lines fed T3. It is concluded that genetic lines may have different metabolic patterns based on their genetic constitution in order to compensate for variations in egg solids and eggshell conductance constants. The metabolic patterns are reflected in different levels of embryonic blood plasma glucose, glycogen, and gluconeogenesis.

Animals↗
PubMed1994

The effect of protein level fed during the prebreeder period on performance of large white turkey breeder hens after an induced molt.

An experiment was conducted to examine the effects of prebreeder protein levels on reproductive performance Large White turkey breeder hens after an induced molt. One hundred and sixty-eight, Nicholas Large White turkey breeder hens were fed either 8, 12, or 16% CP diets (2,904 kcal ME/kg) during the prebreeder period from 56 to 64 wk of age. All hens were photostimulated with 15.5 h of light/d and fed a standard 16% CP breeder ration from 64 to 87 wk of age. Feed intake, plasma triglyceride concentration, reproductive performance, and body weight were regressed on age and prebreeder dietary protein intake using a general linear model. Prebreeder protein intake increased linearly as dietary CP increased. Treatments did not affect prebreeder feed consumption or subsequent egg production. Egg weight and breeder feed consumption were greatest for hens fed 12% CP during the prebreeder period. Plasma triglyceride and body weight increased as prebreeder dietary CP increased. Body weight increased from 56 to 87 wk in a cubic response as the hens aged. Feed consumption increased during the prebreeder period and decreased during the breeder period. Plasma triglyceride content was not affected by turkey hen age or stage of production.

Animal Feed↗
PubMed1994

Effects of the maternal thyroid status on embryo physiology and hatchability of commercial turkey eggs.

Fertile turkey eggs produced by commercial hens fed iodine or triiodothyronine were compared with those from hens fed a control diet to observe the effects of the maternal thyroid status on the energy budget of turkey eggs. Dietary iodine improved hatchability, decreased the number of dead pips, and maintained blood glucose concentrations during pipping and hatching with less reliance on hepatic gluconeogenesis (as assessed by glucose-6-phosphatase activity) compared with controls. Hatchability of eggs from hens fed triiodothyronine was not different from that of control hens but was less than those of iodine-fed hens. The data suggest that the maternal thyroid function of commercial breeder hens can influence hatchability of their eggs and that dietary iodine may be a means to improve hatchability of commercial turkey eggs.

Animals↗
PubMed1994

Age-related changes in the incidence of tibial dyschondroplasia in turkeys.

Age-related changes in the incidence and severity of tibial dyschondroplasia (TD) and its relationship to body weight and other bone pathologies were studied in turkeys from ages 2 through 15 wk. A steady increase in the incidence and severity of TD was observed from 11 wk onwards. Whereas there was no correlation between the body weight and TD in early ages, during Weeks 14 and 15 the turkeys with severe TD had significantly higher body weight relative to those without or with mild lesions. Starting from Week 13, hemorrhage was evident in the base of TD-affected growth plates of many turkeys, which increased linearly during the following weeks. Histological examination of these areas revealed mild necrosis with erosion in TD tissues accompanied by occasional bone formations, fibrosis, and the presence of multinucleate chondroclasts and large number of erythrocytes adjacent to lesions. Sporadic rod-like bacterial colonies were discernible in TD tissues and cartilage canals. These studies show 1) whereas the onset of TD may have an independent etiology, the severity of the disease may be influenced by a higher body weight; and 2) subepiphyseal hemorrhages possibly facilitate a healing-type response that leads to replacement of TD tissue by way of resorption, bone formation, and fibrosis, but simultaneously makes the tissue accessible to bacteria.

Age Factors↗