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PubMed1984

Feed refusal during ochratoxicosis in turkeys.

Previous observations of feed refusal associated with apparent field outbreaks of ochratoxicosis in turkeys but not in chickens suggested that these species differed in response to ochratoxin or that different factors were involved in the field outbreaks. The recent development of laboratory models for the study of feed refusal syndromes in poultry permitted an evaluation of the problem. Pure ochratoxin A reduced the consumption of feed by young turkeys. Refusal of graded concentrations of ochratoxin A in feed was not detected in young chickens. These results, which suggested that feed refusal is a symptom of ochratoxicosis in turkeys but not in chickens, provide additional evidence that the aforementioned outbreaks were caused by ochratoxin and that ochratoxicosis is an emerging problem in the poultry industry.

Animals↗
PubMed1985

Effects of incubation at 4 C on calcium uptake and acrosin activity in turkey spermatozoa.

Turkey semen was diluted 1:1 with a phosphate diluent (Clemson Turkey Semen Diluent) containing radioactively labeled calcium-45 (45Ca) and stored in in vitro at 25 or 4 C to determine the effects of cold-storage on spermatozoa 45Ca permeability. In addition, acrosin activity of semen stored 24 hr at 4 C was compared with that of fresh diluted semen at 25 C. Cold-stored spermatozoa immediately sequestered 45Ca at an exponential rate until the 3 hr disintegrations per min/10(9) spermatozoa equalled that of spermatozoa stored 24 h at 4 C. Washing the spermatozoa after 3 hr incubation reduced the 45Ca of spermatozoa stored at 25 C but not at 4 C. Acrosin activity of spermatozoa diluted 1:1 with CTSD and stored at 4 C for 24 hr was 1.74 times greater than for fresh sperm held 1 hr at 25 C. These results suggest that cooling turkey spermatozoa causes an intracellular influx of calcium ions that may be associated with acrosin formation.

Acrosin↗
PubMed1985

Magnesium, calcium, and phosphorus content of shells from hatching and nonhatching turkey eggs.

Shells of hatching and nonhatching Large White turkey eggs were examined for magnesium, calcium, and phosphorus content. Eggshells containing embryos that hatched contained significantly (P less than .05) more magnesium than shells from nonhatching eggs. No differences were seen in their calcium content. Eggshells from pipped eggs contained significantly (P less than .05) more phosphorus than shells from eggs that were not pipped or those that hatched. Calcium and magnesium in turkey eggshells declined as time in lay increased. Injections of exogenous magnesium both at setting and transfer significantly (P less than .05) depressed hatchability, whereas exogenous calcium injected at transfer significantly (P less than .05) improved hatchability. Injections of exogenous calcium at the time of setting significantly (P less than .05) depressed hatchability. It was concluded that the mineral content of turkey eggshells may influence embryo physiology and hatchability.

Animals↗
PubMed1985

Varying fat and protein in diets of growing large white turkeys.

Two series of three consecutive 4-week experiments with a total of 1,370 Large White turkeys between 8 and 20 weeks of age were conducted to determine the effects of varying levels of dietary fat and protein on body weight gain and feed efficiency. Diets containing 0, 5, and 10% added fat and 18, 20, 22, and 24% protein in a 3 X 4 factorial were each fed to a total of three pens of males and three pens of females. At the end of each 4-week period, the turkeys were rerandomized to form 12 new equivalent groups, and similar diets with 2% less protein were fed. As part of this study, two fats, varying in fatty acid composition, were also compared but found not to affect significantly body weight gain or feed efficiency. Interaction effects of fat and protein on body weight gain, feed consumption, or feed efficiency were not significant. Body weight gain increased .5, .6, and 1.1%, feed consumption decreased 1.1, 1.0, and .9%, and feed efficiency increased 1.7, 1.8, and 2.2% for each 1% added fat during the 8 to 12-, 12 to 16-, and 16 to 20-week periods, respectively. The greater-than-expected increase in feed efficiency from added fat to diets of older turkeys is postulated to be due to stimulated feed consumption and body weight gain rather than to an extra caloric content of fat per se.

Aging↗
PubMed1985

Infection and immunity with a virus isolate from turkeys.

Avian pox virus was isolated from cutaneous pox lesions removed from turkey breeders that had been vaccinated three times with a commercial fowl pox vaccine. In three cross-immunization experiments with turkeys and two with chickens, the turkey pox isolate, designated NC5271, proved immunologically different from fowl, pigeon, and quail pox viruses. Significant protection against NC5271 virus infection and inducement of pox lesions was only attained when the homologous isolate was used as a vaccine. The potential need in the field for such a vaccine was discussed.

Animals↗
PubMed1985

Supplemental thyroid hormones and hatchability of turkey eggs.

Fertile turkey eggs were injected with thyroid hormones to test the effects of exogenous hormones on hatchability. Physiological doses of thyroxine (T4) and triiodothyronine (T3) of 50 and 25 ng, respectively, injected at setting, depressed hatchability. Conversely, injections of T4 and T3 at 25 days of incubation significantly (P less than .05) improved hatchability. Injections with thyroid-stimulating hormone (TSH) or tyrosine had no significant effect on hatchability when injected at setting or at 25 days of incubation. Injections of thyroid-releasing hormone (TRH) had no effect on hatchability when injected at setting but significantly (P less than .05) improved hatchability when injected at 25 days of incubation. Because T4 and T3 significantly (P less than .05) depressed hatchability when injected whereas TSH and TRH had no effect on hatchability when injected at setting, these data suggest classic negative feedback mechanisms function very early in the embryonic turkey. The improvement in hatchability observed when thyroid hormones were injected at 25 days of incubation offers further evidence that hypothyroidism may be a cause of poor hatchability among turkey eggs.

Animals↗
PubMed1986

An on-farm method for determination of sulfonamide drug residues in turkeys. 1. An agar-diffusion analysis for sulfadimethoxine in whole blood.

A simple and inexpensive sulfonamide-screening test was evaluated using turkeys. An agar-diffusion procedure was developed to estimate the levels of sulfonamides in the edible tissues of turkeys by determining the drug level in whole blood. The analysis was adapted for use on whole blood that was easily collected from live birds on the farm with minimal equipment and skill. This Whole Blood Sulfa Test (WBST) was quantified by the use of a standard curve and was successfully applied to on-farm use in the Pacific Northwest. Agar plates were prepared using fortified Mueller-Hinton medium. Bacillus megaterium spores were applied to the agar to form confluent growth, and paper discs (10 mm) were laid onto the agar. Whole blood was collected from commercial turkeys prior to marketing, and the blood was immediately applied to the test paper discs. After incubation, blood that contained sulfa inhibited bacterial growth around the disc, and the clear zones of inhibition were measured. The WBST was consistently accurate to 1.22 ppm, and sulfa levels were detected as low as .04 ppm. Results were attained in 12 hr and were relatively inexpensive at $3.00/test/flock.

Animals↗
PubMed1986

Semen quality and fat accumulation in prepuberal and postpuberal male turkeys as affected by restricted feeding.

Growth, semen production, and carcass fat distribution were examined in adult male turkeys subjected to feed restriction from 10 to 46 weeks of age. Turkeys were randomly assigned to one of three feeding treatments: control (ad libitum) or restricted-fed to maintain body weight at 80% (80R) or 60% (60R) of the control toms. Feed consumption for the 80R and 60R males was decreased significantly by 27.3 and 50.9%, respectively, when compared with the control males during the 10 to 46-week production period. Feed restriction resulted in a 2-week delay in semen production as evidenced by reduced testis weights and reduced semen volume at 34 weeks of age. Semen production was not affected by feed restriction at 36 or 42 weeks of age. A major change in fat accumulation was found after exposure to a stimulatory lighting regimen. The change was from a uniform weight distribution among the fat stored in the abdominal, clavicular, and back at 28 weeks to a major increase in the clavicular fat depot at 34 weeks of age. Total fat accumulation was decreased significantly by feed restriction of turkey males.

Adipose Tissue↗
PubMed1987

Field rickets in turkeys: relationship to vitamin D.

Thirty-two outbreaks of leg disorders in turkeys were investigated during 1981-1985. Among them, 22 were characterized by a low percentage of bone ash and were considered as field rickets. Most of the field rickets cases exhibited reduced plasma calcium and inorganic phosphorus. Plasma 25-hydroxyvitamin D3 and intestinal calcium-binding protein were lower in the rachitic than in normal turkeys. These symptoms are typical of rickets resulting from vitamin D deficiency. The vitamin D3 equivalence of a diet that had been fed during field rickets outbreaks was assayed biologically and found to be 111 micrograms/kg diet, about eight times the minimal requirement. In two other cases no symptoms of rickets were observed in turkeys fed diets that had been previously consumed during field rickets outbreaks. The results indicate that in some cases of field rickets there was no involvement of dietary factors and confirm a previous suggestion that field rickets may result from defects in metabolism of vitamin D3, or in its expression.

Animals↗
PubMed1987

Pineal gland and ocular influences on turkey breeder hens. 1. Reproductive performance.

The influence of the pineal gland and the eyes on reproductive performance of turkey hens was examined. Photosensitive, yearling Large White turkey breeder hens underwent pinealectomy (PX) or bilateral ocular enucleation (EX) or both while held on 8 hr of light per day (8L:16D) and were then photoinduced into a typical 20-week egg laying period by exposing the birds to 16 hr of light per day (16L:8D). Data were obtained for the time to first egg (sexual maturation), rate of egg laying, percent fertility, percent hatchability, weight of poults at hatching, and plasma melatonin levels. A significant interaction between PX and EX treatments occurred in the sexual maturation data only. Pinealectomy significantly delayed (P less than .05) the onset of egg laying (by 4.1 to 7.4 days) compared with the other treatment groups. No other significant differences in onset of lay occurred. Pinealectomy significantly depressed egg production during weeks 11 to 20 of lay and this resulted in fewer eggs per PX hen over the 20-week study (85.4 vs. 93.3 eggs in the PX and pineal intact groups, respectively). Enucleation did not significantly affect egg production. Neither the PX nor the EX treatment significantly affected fertility or hatchability determined at 4-week intervals over the 20-week study. However, poult weights were significantly greater as a result of either PX (P less than .01) or EX (P less than .05) treatment. Nocturnal elevation of plasma melatonin was significantly reduced by PX but not by EX. It was concluded that an extraretinal, extrapineal photoreceptive mechanism is operative in turkey breeder hens but both the pineal gland and the eyes can influence certain reproductive parameters.

Animals↗
PubMed1987

Comparison of bone and muscle growth in turkey lines selected for increased body weight and increased shank width.

A subline (FL) of a long-term growth-selected line (F) of turkeys was established by mass selecting solely for increased shank width at the narrowest point (dew claw). A comparison was made of bone and muscle growth in Line FL (fourth generation of selection), Line F (17th generation of selection), and a randombred control (RBC2, the base population of F) at 8, 16, and 20 wk of age. Also, a sample of the tibiotarsal and femur bones was studied histologically for evidence of pathological conditions. No significant pathological changes were observed in bones from turkeys of the different lines at the ages examined. Samples for histological study were taken at Day 1, 27, 56, 84, 112, and 140 posthatching. Genetic increases in body weight (F and FL lines) resulted in a significant decline in the relative amount of leg muscles from 16 to 20 wk of age while in Line RBC2 the relative amount of leg muscles increased slightly from 16 to 20 wk of age. This resulted in a significant line x age interaction. No significant differences in the amount of leg muscles were detected between turkeys of Lines F and FL. Amount of breast muscles increased consistently with age in all lines. Amount of breast muscles (absolute and as a percentage of body weight) was larger in Line F than in the FL and RBC2 lines. The actual weight of the breast muscles was larger in Line FL than in the RBC2 line but as a percentage of body weight there was no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Protein, methionine, and lysine requirements of growing hen turkeys under various environmental temperatures.

Two experiments were conducted to study the protein and amino acid requirements of growing Large White female turkeys at temperatures of 7, 14, 21, and 28 C. In Experiment 1, five dietary treatment series (A, B, C, D and E) which ranged in protein content from 24.3 to 16.9, 20.4 to 14.2 and 17.8 to 11.9%, were fed during 8 to 11, 11 to 14, and 14 to 17 wk of age, respectively. The D diet series was also supplemented with methionine or lysine or both to equal the levels in the B series forming the D, DM, DL, and DML treatments. In Experiment 2, B and C protein levels were fed between 11 and 14 wk of age. Between 14 and 17 wk of age, the B, C, D, and E protein levels were fed to each group forming a 2 X 4 factorial arrangement. In Experiment 1, during 8 to 11 wk of age, body weight gain decreased when birds were fed diets containing less than 22.5% protein. From 11 to 14 wk of age, at 7 and 14 C, the C diet supported maximum gains but at 21 and 28 C, the B and A diets, respectively, resulted in heavier turkeys. With the D diet, methionine supplementation significantly (P less than .05) improved body weight of birds during 8 to 11 and 11 to 14 wk of age: lysine supplementation had no effect during 8 to 11 wk and inconsistent effects on gain during 11 to 14 and 14 to 17 wk of age. Results from 14 to 17 wk of age show that the protein requirement of female turkeys during this age was overestimated by the National Research Council in 1984.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Water balance in incubating turkey eggs.

The eggshell water vapor conductance capable of maintaining constant water content in incubating turkey eggs was determined for three different egg weight classifications. Metabolism of the developing turkey embryos was altered by increasing or decreasing eggshell permeability. Eggshell permeability accommodated metabolic water in large eggs very well. Both relative poult weights and relative water content of embryos in large eggs at the plateau stage in oxygen consumption decreased or increased allometrically to the permeability treatment. However, among small and medium eggs, if eggshell permeability was increased, relative poult weights at hatching were much less than expected. This occurred despite the fact that relative water content of the eggs at 25 days of incubation was not similarly affected. The data suggest a biological asynchrony for egg size, metabolism, and water content of turkey eggs.

Animals↗
PubMed1988

Comparison of commercial diluents for holding turkey semen 24 hours at 5 C.

The ability was examined of three commercial turkey semen diluents, Beltsville Poultry Semen Extender II (BPSE), Instruments for Veterinary Medicine (IMV), and Minnesota Turkey Growers Association (MTGA) and two diluents containing antibiotics, BPSE + tobramycin (T) and MTGA + gentamicin (G), to maintain the fertilizing capacity of turkey semen held for 24 h at 5 C. Hens were inseminated weekly with 200 million viable spermatozoa for 15 wk. Fertility of unstored, diluted (1:1) semen in MTGA + G (90%) was significantly lower than semen diluted in BPSE (95%) or IMV (95%). Fertilizing capacity of spermatozoa diluted in BPSE + T (94%) and MTGA (91%) was not different from that of semen diluted in the other diluents. Fertility of semen stored for 24 h was highest stored in BPSE (77%) followed by values for storage in BPSE + T (64%), MTGA + G (60%), MTGA (41%), and IMV (38%). Fertility was affected by a significant interaction between semen diluent and storage time. When compared with effects of storage in both Beltsville extenders, spermatozoa stored in the other diluents were less motile. Spermatozoa stored in all extenders except BPSE had a high rate of lysis.

Animals↗
PubMed1988

Improved hatchability of turkey eggs at high altitudes due to added oxygen and increased incubation temperature.

Turkey egg hatchability at high altitudes was examined at two different oxygen tensions and two incubation temperatures. Incubating turkey eggs in a 149-torr oxygen environment at 37.7 C gave significantly better hatchability than a 109-torr oxygen environment at 37.5 C. Embryonic mortality data indicated that the higher incubation temperature in combination with increased oxygen tension decreased embryonic mortality during the 3rd and 4th wk of incubation and resulted in higher hatchability. The data suggest that hatchery managers at high altitudes should supplement with oxygen and incubate turkey eggs at higher temperatures than employed at lower altitudes.

Altitude↗
PubMed1988

Estimates of genetic parameters in turkeys. 2. Body weight and carcass characteristics.

Data were taken from 1,088 individuals--504 females (F) and 584 males (M)--produced by 34 sires and 168 dams from a randombred control line (RBC2) of turkeys maintained at the Ohio Agricultural Research and Development Center, Wooster, OH. Turkeys were used to estimate genetic and phenotypic parameters among 16-wk body weight and a number of body composition characteristics. Heritabilities (h2) were estimated from sire components of variance for 16-wk weights of muscles of breast (BM: F = .08, M = .35); thigh (TM: F = .12, M = .17); and drum (DM: F = .30, M = .44); weights of leaf fat (LF: F = .13, M = .51) and total abdominal fat (AF: F = .21, M = .55); and total percentage carcass fat (%F:F = .06, M = .24), percentage protein (F = .07, M = .20), and percent moisture (F = nonestimable, M = .11). The h2 of percentage carcass ash was nonestimable from both data sets due to negative estimates of the sire variance components. Due to the non-normal distributions of some of the fat measures, the fat measure data were converted to natural logarithms. Genetic estimates from the transformed data were similar to those from the nontransformed data. Genetic correlation (rG) estimates indicated a positive genetic association between body weight (BW) and all the fat characteristics measured. The BW was highly correlated with BM (F = .48, M = .86), TM (F = .81, M = 1.01), and DM (F = 1.04, M = .70). However, BW was correlated to a lesser degree with LF (F = .02, M = .27), AF (F = .25, M = .32), and %F (F = .93, M = .50). The BM was only moderately correlated with TM (F = .43, M = .28) and DM (F = .73, M = .27). The TM and DM were highly correlated (F = 1.02, M = .84). The existence of these correlations, which are less than unity, indicate that selection for BW alone will lead to increasing levels of fat in commercial turkeys, and to disproportionate increases in breast vs. leg muscles.

Adipose Tissue↗
PubMed1988

Early protein undernutrition and subsequent realimentation in turkeys. 2. Effect on weights and proportions of organs and tissues.

Male and female Large White Nicholas turkeys were fed corn and soybean meal diets for 24 and 20 wk, respectively. The same series was fed with a low protein modification (75% of control in protein and 66% of control in methionine and lysine per Mcal ME) during 0 to 6 wk of age. For the study of organ and tissue growth, six male turkeys per treatment were sampled at 2, 4, 6, 8, 12, 16, 20, and 24 wk of age. Six females per treatment were also sampled at 2, 4, 6, 8, 11, 14, 17, and 20 wk of age. Weights of eviscerated carcass, breast, thigh, drumstick, wing, back, neck, feathers, liver, heart, pancreas, alimentary tract less gizzard, and gizzard were depressed by early protein undernutrition to 6 wk of age. Compared with values for controls, undernutrition increased proportions of the liver, alimentary tract less gizzard, gizzard, and heart at 6 wk of age; proportions of the back, neck, feathers, and pancreas were not affected, but breast and thigh proportions were reduced. Compensatory growth during realimentation eliminated all differences between undernourished and control turkeys in weight and proportions of organs and tissues by 20 wk of age.

Animals↗
PubMed1988

5-azacytidine-induced increase in plasma prolactin levels of immature turkeys.

Immature female turkeys (7 wk old) were treated with 5-azacytidine, a cytidine analog that has been shown to inhibit cytosine methylation in eukaryotic DNA. Such methylation has been repeatedly implicated in the control of specific gene expression in higher vertebrates. Turkeys administered 5-azacytidine (5 mg/kg) by intravenous injection daily for 5 days exhibited elevated (P less than .05) circulating prolactin (Prl) levels, whereas hens treated with saline, cytidine, or 6-azathymine did not show altered circulating Prl levels. Absence of response upon treatment with the normal nucleoside cytidine or the 6-aza analog of thymine reasonably eliminates nonspecific drug-induced stress as the cause of Prl level elevation. Based on these findings, DNA methylation is implicated in the control of circulating Prl levels in the young turkey.

Animals↗