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PubMed1980

Methionine and cystine requirements of growing turkeys.

Sulfur amino acid requirements of starting, growing, finishing male Large White turkeys were investigated in three experiments using 3000 turkeys. Requirements were determined by least squares analyses of response curves obtained by supplementing methionine and cystine deficient basal diets with graded levels of DL-methionine and/or L-cystine. Experiments were conducted from 1 to 4, 8 to 12, and 16 to 20 weeks of age. Diets included starch, soybean meal, faba beans, and field peas. Requirements for total sulfur amino acids (TSAA) determined with diets marginally deficient in cystine were .95 to 1.01, .70 to .71, and .43 to .48% of the diet for starting (1 to 4 weeks), growing (8 to 12 weeks), finishing (16 to 20 weeks) turkeys, respectively, in different experiments. On the basis of dietary metabolizable energy, the respective TSAA requirement values (in %/therm) were .298 to .332, .205 to .221, and .128 to .134. Minimum methionine requirements (determined with excess dietary cystine) were .46, .30, and .19% of the diet for starting, growing, and finishing turkeys, respectively. Cystine replacement values, calculated by dividing the maximum usable levels of cystine (TSAA requirements minus methionine requirements) by TSAA requirements were 55, 58, and 57% of the TSAA requirement for starting, growing, and finishing turkeys, respectively.

Animal Nutritional Physiological Phenomena↗
PubMed1980

Upper lethal environmental temperature in turkeys.

Of a total of 16 turkeys in a temperature controlled chamber with a low air velocity, 14 died during an accidental 16-hr exposure, because of a malfunction of a thermostat, to a temperature of 38.5 C and 80% relative humidity. These turkeys had been previously maintained at a temperature of 20 C for 6 days. Of the 2 surviving turkeys, one alert and one depressed, there were 1) an increased percent erythrocytes in the hematocrit, 2) a decreased ratio of blood mononuclear cells to blood polymorphonuclear cells, 3) a marked increase in plasma corticosterone concentration, and 4) a definite reduction of lymphocytes in the bursal follicles of the alert turkey and a nearly complete depletion in the depressed turkey.

Adrenal Glands↗
PubMed1982

A homologous radioimmunoassay for turkey prolactin: changes during the reproductive and ovulatory cycle.

A rabbit antiserum to turkey prolactin (tPRL) was used in a homologous radioimmunoassay with 125I-tPRL. This assay did not cross-react with turkey luteinizing hormone (tLH), chicken LH (cLH), turkey follicle stimulating hormone (tFSH), or turkey growth hormone (tGH). The within- and between-assay coefficients of variation were 6.2 and 14.0%, respectively, and the useful range of the standard curve extended from .5 to 10.0 ng/tube. In two separate experiments, the plasma concentrations of prolactin were estimated throughout the reproductive cycle of the turkey hen using a heterologous assay previously described and the current homologous assay. The correlation coefficients between the two estimates of prolactin in nonbroody hens were .84 and .83. In both experiments, the plasma concentrations of prolactin were low when egg production was initiated, rose to maximum concentrations 5 to 7 weeks later, and thereafter declined. In the first experiment, the hens were selected because their plasma contained large amounts of immunoreactive PRL during the first 2 weeks after photostimulation in the heterologous tPRL assay. This immunoactivity was not evident when using the homologous assay. Using the heterologous assay, no differences in the plasma prolactin concentrations were detected between broody and nonbroody hens during the reproductive cycle. However, using the homologous assay, a sustained increase in the concentration of prolactin was noted for several weeks after broody behavior was detected. The maximum levels observed in broody hens were equal to those observed when the rate of egg production was maximal. There were no statistically significant changes in the concentrations of prolactin during the ovulatory cycle.

Animals↗
PubMed1982

Incidence of Salmonella in fresh dressed turkeys raised under Salmonella-controlled and uncontrolled environments.

The incidence of salmonella in turkeys from experimental salmonella-controlled and uncontrolled, or normal, flocks processed at three turkey slaughter plants were compared. The results indicate that processing salmonella-controlled turkeys in a plant that routinely kills normal birds may result in the contamination of the salmonella-controlled birds, probably due to salmonella in the plant environment. The salmonella-controlled turkeys studied tended to have a lower incidence of salmonella than normal birds. These observation indicate that salmonella control practices in turkey raising can result in a salmonella reduction in market birds even under existing commercial slaughter, evisceration, and cooling procedures.

Abattoirs↗
PubMed1984

Effect of dietary calcium on blood pressure of turkeys.

The influence of dietary calcium intake on blood pressure of turkeys was studied in 20 male Broad Breasted White turkeys between 45 and 52 weeks of age. The average systolic (P less than .01), diastolic (P less than .01), and mean (P less than .005) blood pressures were significantly lower in turkeys fed high dietary calcium (1.96%) than the turkeys with normal calcium diet (.98%). Concomitantly, the mean total heart weight (P less than .05), left ventricular weight (P less than .025), and heterophil to lymphocyte ratio (P less than .02) were also significantly lower in the high dietary calcium group. These results indicate that high dietary calcium not only attenuates high blood pressure in turkeys but also reduces the development of left ventricular hypertrophy, which is a consequence of arterial hypertension. In addition, high dietary calcium also reduces the heterophil to lymphocyte ratio, which indicates a reduction of stress.

Animals↗
PubMed1985

Effects of aflatoxin on young turkeys and broiler chickens.

The effect of crude aflatoxin (AF) on the growth, performance, and immune response of turkeys and broilers was studied. Crude AF, produced from a natural outbreak of Aspergillus flavus on corn, was ground and mixed in rations to contain either 0, 100, 200, 400, or 800 ppb of aflatoxin B1 (AFB1). Turkeys (Experiment 1) and broilers (Experiment 2) were used in identical experimental designs. In each, 200, 14-day-old birds were divided equally by sex into five groups of 40 and were fed one of five AF diets for 35 days. In Experiment 1, crude AF greater than or equal to 400 ppb was highly toxic to turkeys. These levels produced signs and lesions of aflatoxicosis as well as a significant decrease in weight gain and feed conversion during 5 weeks. In addition, microscopic lesions, indicative of aflatoxicosis, were evident as low as 100 ppb, and significant decreases in cell-mediated immunity were noted in the 200 ppb group birds. Experiment 2 indicated that chickens were less susceptible to crude AF than turkeys. Neither morbidity nor mortality occurred in broilers. Gross lesions consistent with AF toxicity were evident in birds given 800 ppb and microscopic lesions were observed in birds given 100 ppb. Feed conversion was significantly increased in the 800 ppb broilers only. Cell-mediated immunity, measured by a delayed hypersensitive skin test, was significantly decreased in broilers receiving AF at 200 ppb or greater. Neither humoral immunity nor the development of the acquired immunity to Newcastle disease or fowl cholera vaccination were decreased in turkeys or broilers given AF.

Aflatoxins↗
PubMed1986

The influence of prolactin on food intake of turkey hens.

The effect of intracerebroventricular (ICV) injections of turkey prolactin on food intake of turkey hens was studied. Adult, nonlaying medium-weight turkey hens, exposed to 6 hr of light per day, were used in Experiment 1. In Experiments 2 and 3, medium-weight and large-weight turkey hens, respectively, exposed to a long photoperiod and in production, were used. Prolactin was injected into free-feeding hens at doses ranging from 800 to 3200 ng. The ICV injection of prolactin had no significant effect on food intake of hens maintained under 6 hr light per day and not in egg production. In hens exposed to long photoperiods and in egg production, the ICV injection of prolactin caused a significant decrease in food intake. These results suggest that prolactin, acting at the level of the central nervous system, decreases food intake in photostimulated turkey hens.

Animals↗
PubMed1986

Salinomycin toxicity in turkeys.

Five 7-day trials using 336, 24, 24, 40, and 40 Large White male turkeys when 7, 11, 15, 27, and 32 weeks of age, respectively, were conducted to determine the toxic effects of salinomycin. Salinomycin became more toxic as the age of the turkeys increased. When 7-week-old turkeys were fed diets containing 44 or 66 ppm salinomycin, only 1 of 84 died; when turkeys 27 or 32 weeks of age were fed those amounts, 13 of 20 died. Salinomycin at 22 ppm tended to depress rate of growth at young ages and to prevent or decrease growth and to increase mortality at older ages. Caution should be exercised to avoid salinomycin contamination of turkey diets.

Animals↗
PubMed1987

Effect of light intensity, litter source, and litter management on the incidence of leg abnormalities and performance of male turkeys.

Two trials were conducted to evaluate the performance of male turkeys reared in either a low or high intensity lighting regimen. Turkeys were also subjected to the following four litter treatments: hardwood shavings intensively managed; hardwood shavings unmanaged; rice hulls intensively managed; and rice hulls unmanaged. Male turkeys reared in high intensity light (20 lx) had significantly heavier body weights, poorer feed to gain ratios, shorter tarsometatarsal bones, earlier growth plate closure, heavier testes, and were less active during the times of behavioral observations than male turkeys reared in low intensity light (2.5 lx). The width of the tarsometatarsal bone, mortality, and the incidence of leg abnormalities and tibial dyschondroplasia were unaffected by lighting. Poor litter conditions or type of litter (hardwood shavings vs. rice hulls) had no effect on the performance of male turkeys.(u3)

Animals↗
PubMed1988

Response of growing turkeys to dietary fat.

Growth, feed efficiency, and carcass fat were evaluated in turkeys fed diets in which added fat varied, holding energy or the calories:protein ratio constant. In the 1 to 3-wk-old turkey, growth and feed efficiency increased with dietary energy, but did not change significantly when fat was added isocalorically. The 12 to 14-wk-old turkey responded with improved growth and feed efficiency when dietary fat was added either isocalorically or with increasing energy density. However, the response to the isocaloric fat addition was smaller in magnitude than the response when fat was added without calorie adjustment. No difference could be detected in 12 to 15-wk-old turkeys in the performance response to tallow and soybean oil. Carcass fat deposition generally increased with dietary fat supplementation, regardless of the caloric change. The results suggest that in the midterm of development of the growing turkey, dietary fat per se affects growth, feed efficiency, and carcass fat. Growth and feed efficiency responses to nutrient density occur in both young and older birds.

Adipose Tissue↗
PubMed1991

Effect of diet and population density on male turkeys under various environmental conditions. 2. Body composition and meat yield.

Large White Nicholas male turkeys were reared at two stocking densities (.21 or .46 m2 per bird) and fed one of four diets: 1) control corn and soybean (mash) with 1% fat (CSM); 2) as Diet 1, pelleted (CSP); 3) as Diet 1 with supplemental fat increasing from 1 through 8% with age (CSF); and 4) as Diet 1 with barley at 0, 20, 35, 50, and 65% during successive 4-wk periods (CSB). The turkeys were reared in four environments: (A) intermittent light schedule [4(2 h light (L):4 h dark D))] with temperature at 7 or 21 C during light and dark photoperiod, respectively; (B) and (D) with intermittent light (2L:4D) with a constant 21 and 7 C temperatures, respectively; (C) continuous light cycle (18L:6D) with temperatures as in Environment A. At 20 wk of age, two turkeys per replicate pen, were killed for determination of body composition and meat yield. Compared with turkeys fed CSM diet, those on CSF and CSP diet had increased percentage carcass fat. Meat yield per bird and percentage carcass fat were greater for turkeys reared at .46 m2 per bird compared with rearing at .21 m2 per bird. Pelleting and fat supplementation resulted in significantly increased amounts of breast meat and leg compared with CSM. Breast meat yield (percentage) and amount were greater at 7 C (Environment D) than at 21 C (Environment B) and the cycling regimen (Environment A). Percentage abdominal fat was greatest at 7 C. Interactions of environment and diet were detected for breast meat yield percentage (P less than .023) and weight (P less than .036). Diet type had no effect on percentage breast meat or weight in Environment C. An increased amount of breast meat was obtained by feeding CSP in Environments A, B, and D, and dietary fat supplementation increased breast meat yield in Environments A and D over CSM treatment.

Adipose Tissue↗
PubMed1991

Genetics of growth and reproduction in the turkey. 12. Results of long-term selection for increased 180-day egg production.

A line of turkeys selected 28 generations for increased 180-day egg production (E) was compared through regression analysis with the randombred control population (RBC1) from which it originated. The only curvilinear trends observed for RBC1 were for egg weight and 8-wk (both sexes) and 16-wk (males) BW. Linear declines in egg production and rate of lay through 84 and 180 days of lay, the number of clutches during the 180-day production period, effective days of egg production, and 16-wk (females) and 20-wk (both sexes) BW were observed for RBC1. The RBC1 turkeys had linear increases in the percentage of broody hens during the first 84 and 180 days of production, the average length of the broody period, and the total number of days lost to broodiness during the 180-day period. When expressed as a deviation from RBC1, positive quadratic curvilinear changes were observed for E turkeys for number of clutches and broody periods, and days lost to broodiness during the first 180 days of production. Percentage hatch of fertile eggs at 8 and 12 wk of production also exhibited a positive quadratic change with generation. Linear increases in egg production, rate of lay, clutch length (average and maximum), number of effective days of production, and percentage hatch of fertile eggs 12 wk into production were observed for E turkeys. There were linear declines in number of days from photostimulation to the production of first egg, number of clutches, and number, average length, and days lost to broodiness for E line turkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Myosin isoform expression in skeletal muscles of turkeys at various ages.

The appearance of myosin isoforms in skeletal muscles of turkey embryos, poults, and toms was studied, using monoclonal antibodies raised against myosin isoforms in chicken fast-twitch muscle (Pectoralis). The myosin extract was prepared by repeated salt extraction-precipitation. The reactivity of monoclonal antibodies with turkey myosin isoforms was tested by an enzyme linked immunosorbent assay using alkaline phosphatase-conjugated antibody and detection by color development with p-nitrophenyl phosphate. Detection was also effected by protein slot blotting using peroxidase-conjugated antibody and color development with 3,3'-diaminobenzidine tetrahydrochloride. The monoclonal antibody AB8 was found to be specific for the adult myosin isoform, present in Pectoralis muscle of 14-day-old and adult turkeys and adult chickens. Subsequent peptide mapping also indicated that the adult myosin isoform of turkey Pectoralis muscle was nearly identical to the adult isoform from chickens. The monoclonal antibody 2E9 reacted with the myosin extract only from poults at ages of 7 days and 14 days posthatch, indicating that 2E9 is specific for the neonatal myosin isoform. The reactivity of 2E9 was noted with the muscle of the mixed fiber type (the thigh muscle group) as well as with the fast-twitch muscle (Pectoralis). Monoclonal antibodies EB 165 and AG6 were found to react with the myosin extract from all ages tested. Based on the reactivity with monoclonal antibodies, it was concluded that myosin in turkey muscles existed as at least three discrete isoforms that were expressed sequentially in the course of muscle development.

Age Factors↗
PubMed1991

Cloning and sequence analysis of the common alpha-subunit complementary deoxyribonucleic acid of turkey pituitary glycoprotein hormones.

Two cDNA clones of nearly full length that encode the turkey pituitary common alpha-subunit glycoprotein hormone have been isolated from a pituitary cDNA library and their nucleotide sequences have been determined. The longer alpha-subunit clone was 777 bp in length. It contained 88 bp of the 5'-untranslated region (UTR), an open reading frame of 360 bp (that encodes the turkey alpha-subunit 24 amino acid leader polypeptide fragment and 96 amino acid apoprotein), and a 312-bp 3'-UTR followed by a 17-bp poly A tract. When the nucleotide sequence of the turkey alpha-subunit was compared with the sequence of the chicken alpha-subunit clone, the coding region was greater than 98% homologous, but was only 69 to 76% homologous when compared with mammalian alpha-subunit sequences. Northern blot analysis showed an approximate 800 bp processed transcript that hybridized to the labeled turkey alpha-subunit cDNA. There was a greater than fourfold up-regulation of the steady-state levels of turkey alpha-subunit transcription when intact cultured pituitaries were treated with chicken gonadotropin-releasing hormone I.

Amino Acid Sequence↗
PubMed1992

The effects of cooling large white turkey embryos on growth and white blood cell development.

In each of two experiments, trays containing 15 developing turkey eggs were cooled for 1 h at 18 C on a specific day of incubation or left within the incubator (controls). Ten embryos from each treatment were bled on Day 23 of incubation, at which time all embryos were killed with CO2 gas, weighed, and sexed. Packed cell volumes and differential white blood cell (WBC) counts were performed on all blood samples. A single, brief cooling episode during incubation did not significantly (P greater than .05) affect BW or hematocrit values in 23-day-old turkey embryos. Based on a differential classification of WBC in the blood smears of these turkey embryos, there were 82, 10, 8, less than 1, and less than 1% of heterophils, lymphocytes, basophils, eosinophils, and monocytes, respectively. Circulating heterophils, the most numerous WBC in turkey embryos, were significantly (P less than or equal to .05) reduced in all embryos cooled during the latter half of incubation. This effect was mirrored in the total WBC numbers counted. The effect of cooling on the other classes of turkey embryonic WBC, which represent about 20% of the circulating WBC, were more variable.

Animals↗
PubMed1992

Effects of androgen (testosterone, 5 alpha-dihydrotestosterone, 19-nortestosterone) administration on growth in turkeys.

The present studies examined the effect of three androgens, testosterone, a reduced form 5 alpha-dihydrotestosterone (5 alpha-DHT), and the readily aromatizable anabolic androgen, 19-nortestosterone, on growth in male and female turkeys. Growth (body weight, average daily gain, and right breast muscle weight) was increased by testosterone (females), 5 alpha-DHT (males and females), and 19-nortestosterone (males and females). Moreover, both feed:gain ratio and the weight of abdominal adipose tissue was reduced in turkeys treated with testosterone (females), 5 alpha-DHT (males and females), and 19-nortestosterone (females and males). Bursa of Fabricius weights were reduced in androgen-treated male or female turkeys with the decrease following 19-nortestosterone being greater than those observed with either testosterone or 5 alpha-DHT. Androgen treatment had no effect on skeletal growth (as indicated by shank-toe length) or weights of the liver, spleen, or testes. In female turkeys, plasma concentrations of hormones were determined following androgen treatment. No effects were observed on plasma concentrations of insulin-like growth factor-I or luteinizing hormone after any androgen treatment. Testosterone administration was followed by a physiological increase in the plasma concentrations of testosterone. Plasma concentrations of growth hormone were unaffected by either 5 alpha-DHT or 19-nortestosterone but reduced by the high dose of testosterone. The effect of castration on growth in the presence or absence of 19-nortestosterone was also examined. Castration did not depress growth compared with sham-operated controls, but increased adiposity. 19-Nortestosterone increased growth of castrated turkeys, increased muscle weight, and reduced abdominal adipose tissue weight.

Adipose Tissue↗
PubMed1993

The turkey major histocompatibility complex: characterization by mixed lymphocyte, graft-versus-host splenomegaly, and skin graft reactions.

A turkey subline at the Ohio Agricultural Research and Development Center was developed by DNA typing of the MHC using a chicken MHC Class II probe, and it segregated for specific MHC genotypes. Histocompatibility was examined between turkeys of known MHC genotype using skin graft procedures, mixed lymphocyte reactions (MLR), and graft-versus-host reactions (GVHR). Skin grafts were exchanged among 3-wk-old turkeys and it was found that when birds shared DNA patterns (genotypes), the skin grafts were usually accepted. In contrast, skin grafts were always rejected when birds did not share the identical DNA pattern. Similarly, MLR only occurred when the lymphocytes were derived from birds that did not share the same DNA pattern. Lastly, GVHR were examined in embryos injected with either sire or dam blood. The GVHR in embryos was dependent on the parental MHC genotype. Four MHC haplotypes were identified in the turkey subline. The turkey MHC has been designated MhcMega-B, and each of the haplotypes, Mega-B(1) through Mega-B(4).

Analysis of Variance↗
PubMed1995

Effects of early immune stress and changes in dietary metabolizable energy on the development of newly hatched turkeys. 2. Selected characteristics of immune function.

Two 21-d experiments were conducted to document the effects of an early immunologic stress and changes in dietary ME(n) on selected characteristics of immune function of newly hatched turkeys. Eight treatments were included in each experiment. Treatments were the result of complete factorial arrangements of two types of injection and four isonitrogenous diets. Turkeys in both experiments were injected i.p. with .5, .5, and .2 mL of saline (SAL) or .5, .5, and .2 mL of a solution of Escherichia coli lipopolysaccharide (LPS) (100 micrograms LPS/mL SAL) at 1, 3, and 5 d of age, respectively. In Experiment 1, two diets were formulated to contain 2,800 kcal ME(n)/kg. One was a corn-soybean meal based diet (CSBM) and the other contained 8% Solkafloc (SKF). A third diet (3,100 kcal ME(n)/kg) was formulated by substituting 8% sucrose (SUC) for the 8% SKF. The fourth diet (HE) included in Experiment 1 was formulated to contain 3,700 kcal ME(n)/kg. The CSBM and SUC diets and two additional diets were tested in Experiment 2. The latter were the CSBM diet containing 74.5 mg ibuprofen/kg (IBU) and a corn-soybean meal diet formulated to contain 3,100 kcal ME(n)/kg (CS31). Concentrations of plasma IgG and jejunal IgG and IgA were not affected by injection or diet. Age-related changes in Ig concentrations were consistently observed in Experiments 1 and 2. Injection with LPS reduced the number or responses of blood leukocytes to mitogens at 8 d of age (P < .01), as compared with samples from turkeys injected with SAL. Leukocytes in whole blood samples from turkeys fed the HE diet responded less to LPS stimulation than those fed the SUC diet (P < .01). Injection with LPS did not markedly affect the characteristics of immune function studied, and feeding a diet with 3,100 kcal ME(n)/kg and 28.5% crude protein did not measurably affect the characteristics of immune function of young turkeys.

Animal Feed↗