Young Turkeys Research Articles

Effects of Feeding Fusarium moniliforme Culture Material, Containing Known Levels of Fumonisin B1, in the Young Turkey Poult

The effects of feeding Fusarium moniliforme culture material, containing known concentrations of fumonisin B1 (FB1), were studied in turkey poults. Day-old poults were allotted randomly to dietary treatments containing 0, 0.41, 0.82, 1.23, 1.64, 2.87, 4.10, 5.33, 6.56, and 7.79% fumonisin culture material (FCM). These levels of FCM supplied 0, 25, 50, 75, 100, 175, 250, 325, 400, and 475 mg FB1/kg of feed. Each dietary treatment was fed to six pen replicates of six poults each for 21 d. Poults fed FCM that supplied 325 to 475 mg FB1/kg diet had lower (P < 0.05) feed intakes and BW gains. Increased (P < 0.05) liver and pancreas weights were observed in poults fed FCM that supplied ≥ 175 mg FB1/kg. Poults fed FCM that supplied 400 and 475 mg FB1/kg diet had increased (P < 0.05) red blood cell counts and increased (P < 0.05) serum concentrations of gamma glutamyl transferase and aspartate aminotransferase. Compared with controls, poults fed FCM that supplied 25, and 75 to 475 mg FB1/kg had increased (P < 0.05) liver sphinganine:sphingosine ratios. Hepatocellular hyperplasia was mild at 75 and 100 mg FB1/kg diet, moderate to severe at 250 mg/kg FB1, and severe at 325 to 475 mg FB1/kg. Multifocal to generalized loss of cross striations and thinning of cardiomyocytes was observed in poults fed FCM that supplied 475 mg FB1/kg diet. Results indicated that diets containing ≥ 1.23% FCM that supplied ≥ 75 mg FB1/kg are toxic to young turkeys.

Body Weight Response of Young Poults and Pre-Market Age Adult Turkeys to Dietary Orabolin (Ethylestrenol)

Abstract Berepubo, N.A., Wekhe, S.N., Iheobi, J. and Jumbo, I. 1996. Body weight response of young poults and pre-market age adult turkeys to dietary orabolin (ethylestrenol). J. Appl. Anim. Res., 9: 181–185. Three separate but related experiments were carried out to test the effect of dietary orabolin or its combination with ampicillin on body weight gain or feed conversion efficiency in pre-market stage adult turkeys and young turkey poults, respectively. The anabolic steroid and steroid I antibiotic combination were administered through feed and water (Groups A and B) while control group C received plain feed and water. Except for linear differences mostly in favour of the treatment groups, there was no significant difference (P>0.05) in respect of feed intake, feed efficiency and body weight gain among the birds of different groups in all the three experiments. It has been concluded that supplementation of diet with orabolin with or without ampicillin at this rate was not beneficial.

A Survey of Sixty Turkey Flocks Exhibiting Hepatic Foci Taken at Time of Processing

Fifty turkey flocks including 24 16-week-old male flocks and 26 20-week-old male flocks were sampled at time of processing. Hepatic foci were cultured for aerobic and anaerobic bacteria. The majority of these did not have any bacteria recovered from the lesions. Of the bacteria that were recovered, most were facultative anaerobes, with Escherichia coli and Salmonella sp. comprising the most common isolates. All of the birds examined (300 total) for parasites were infected with varying levels of Ascaridia dissimilis. The highest average worm burden was found in the 20-week-old flocks. Heterakis gallinarum were found in only a few of the younger turkeys (16 weeks old) and not in any of the older birds. An analysis of the spatial distribution of the hepatic foci performed in an additional 10 turkey flocks (500 birds) revealed that, although present on the surface of all regions of the liver, 56.12% of the lesions were found on the left hepatic lobe and 43.88% were found on the right hepatic lobe.

Effect of passively administered immunoglobulin G on the colonization and clearance of Bordetella avium in turkeys

This study was conducted to detect the effect of parenterally administered immunoglobulin isotype G (IgG) on the colonization and clearance of Bordetella avium at the tracheal surface in young turkeys. In two separate experiments, 3-week-old turkeys were infected with B. avium either after or before IgG administration. Comparisons were made between a control group which received an irrelevant IgG (specific for keyhole limpet hemocyanin [KLH]) and the experimental group which received a B. avium-specific IgG. When given before the bacteria, IgG reduced the numbers of colony-forming units (CFUs) in the trachea. As a supplement to non-specific respiratory defense mechanisms, B. avium-specific IgG also appears to inhibit colonization of the tracheal mucosa. In a second experiment designed to study the role of IgG in bacterial clearance, administration of B. avium-specific IgG after bacterial inoculation significantly reduced the number of CFUs on the tracheal surface. These studies support the role of B. avium-specific IgG in resistance to and recovery from B. avium infection.

Nutritional Value for Growing Turkeys of Corn of Light Test Weight

An experiment was conducted to determine the relationship between test weight of corn and growth, efficiency of feed utilization, nutrient retention, and carcass composition of young turkeys. The MEn values of corn were also measured. Two samples of corn differing substantially in test weight were fed to male turkey poults (Nicholas Large White) from 1 to 20 d of age. The test weights of the light-weight corn and the normal-weight corn were 55 kg/hL (43 lb/bu) and 70 kg/hL (54 lb/bu), respectively. The light-weight corn was lower in crude protein concentration (6.63%) man the normal-weight corn (8.53%). The determined MEn of the corn samples did not differ (3.22 vs 3.25 kcal/g). The light-weight corn diet had modest adverse effects on growth and feed efficiency of poults during the 1 to 7 d after hatching. Poult carcass composition and retention of nitrogen and energy were not affected by the test weight of corn.

Older plasma lipoproteins are more susceptible to oxidation: a linking mechanism for the lipid and oxidation theories of atherosclerotic cardiovascular disease.

Increases in plasma cholesterol are associated with progressive increases in the risk of atherosclerotic cardiovascular disease. In humans plasma cholesterol is contained primarily in apolipoprotein B-based low density lipoprotein (LDL). Cells stop making the high-affinity receptor responsible for LDL removal as they become cholesterol replete; this slows removal of LDL from plasma and elevates plasma LDL. As a result of this delayed uptake, hypercholesterolemic individuals not only have more LDL but have significantly older LDL. Oxidative modification of LDL enhances their atherogenicity. This study sought to determine whether increased time spent in circulation, or aging, by lipoprotein particles altered their susceptibility to oxidative modification. Controlled synchronous production of distinctive apolipoprotein B lipoproteins (yolk-specific very low density lipoproteins; VLDLy) with a single estrogen injection into young turkeys was used to model LDL aging in vivo. VLDLy remained in circulation for at least 10 days. Susceptibility to oxidation in vitro was highly dependent on lipoprotein age in vivo. Oxidation, measured as hexanal release from n-6 fatty acids in VLDLy, increased from 13.3 +/- 5.5 nmol of 2-day-old VLDLy per ml, to 108 +/- 17 nmol of 7-day-old VLDLy per ml. Oxidative instability was not due to tocopherol depletion or conversion to a more unsaturated fatty acid composition. These findings establish mathematically describable linkages between the variables of LDL concentration and LDL oxidation. The proposed mathematical models suggest a unified investigative approach to determine the mechanisms for acceleration of atherosclerotic cardiovascular disease risk as plasma cholesterol rises.

Selective chemisorption and detoxification of aflatoxins by phyllosilicate clay.

Practical and effective strategies for the detoxification of aflatoxins are critically needed. We have shown that a phyllosilicate clay (HSCAS): i) tightly binds aflatoxins in aqueous solutions, including milk; ii) markedly decreases the bioavailability of radiolabeled aflatoxins; iii) greatly diminishes aflatoxicosis in young animals, i.e., rats, chickens, turkeys, lambs, and pigs; and iv) reduces the level of aflatoxin M1 in the milk from lactating dairy cattle and goats. In further studies, ligands with one or more of the functional groups in common with aflatoxin were reacted with HSCAS in vitro in an attempt to elucidate the specificity and mechanism of tight binding (or chemisorption). A chemisorption index (C alpha) was developed, allowing for direct comparison of various clay and zeolitic minerals with HSCAS. Chemisorption indices were determined by HPLC analysis of extracts of the supernatants and sorbed pellets (exhaustively extracted with methanol and chloroform). The beta-dicarbonyl system of aflatoxin was found to be essential for tight binding by HSCAS. Comparison of the chemisorption indices from various classes of compounds with spectral data (DRIFTS) indicated that the molecular mechanism of aflatoxin binding may involve the chelation of metal ions in HSCAS with the beta-dicarbonyl moiety in aflatoxin. Computer modeling was utilized to provide additional information. Preliminary evidence suggests that aflatoxin B1 may react at surfaces and within the interlayers of HSCAS particles. With knowledge of the mechanism involved, it has been possible to further enhance the propensity of HSCAS for aflatoxins.

Ontogeny of Pituitary and Serum Growth Hormone in Growing Turkeys as Measured by Radioimmunoassay and Radioreceptor Assay

Some mammalian studies have revealed a wide discrepancy in pituitary and circulating growth hormone (GH) measurements determined by immunological and biological assay methods. Recent studies demonstrating that avian GH exists in numerous isoforms raise concerns that immunological measurement of GH may not accurately reflect the amount of biologically active hormone present. We sampled eight different male turkeys of a commercial strain weekly until 6 wk of age, and then biweekly until 20 wk. Total pituitary GH content and serum GH concentration were measured by avian GH RIA and radioreceptor assay (RRA). The highest mean serum GH concentration occurred at 3 wk, and the ontogeny of serum GH content from 1 to 8 wk was similar whether measured by RIA or RRA. Pituitary GH content was highest at 6 wk, but RIA and RRA estimates differed markedly throughout the study. Pituitary content of biologically active GH, as estimated by RRA, exceeded that of immunologically active GH from 2 to 10 wk, whereas the reverse was true at 14, 18, and 20 wk. We conclude that this avian GH RIA accurately measures bioactive circulating turkey GH, but that the pituitary of the young turkey may contain bioactive GH isoforms that have poor immunological activity in our RIA.

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 MEn 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 μg LPS/mL SAL) at 1, 3, and 5 d of age, respectively. In Experiment 1, two diets were formulated to contain 2,800 kcal MEn/kg. One was a corn-soybean meal based diet (CSBM) and the other contained 8% Solkafloc® (SKF). A third diet (3,100 kcal MEn/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 MEn/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 MEn/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 MEn/kg and 28.5% crude protein did not measurably affect the characteristics of immune function of young turkeys.

A Time-Course Study of the Transfer of Immunoglobulin G from Blood to Tracheal and Lacrimal Secretions in Young Turkeys

Three-week-old turkeys were injected intravenously with Bordetella avium-specific immunoglobulin G (IgG), and absorbance readings were measured in blood, tracheal washings, and lacrimal secretions using an enzyme-linked immunosorbent assay at various time intervals. IgG was detected in tracheal and lacrimal secretions as early as 5 minutes after injection and peaked at 10 minutes after injection. Thereafter, IgG absorbance declined rapidly, reaching background levels by 24 hours. The absorbance readings of IgG in all three sites were comparable at all times from 10 minutes to 24 hours after administration. The results indicated that movement of IgG from blood to mucosal surfaces in turkeys occurs rapidly.

Bordetella avium: An Opportunistic Pathogen in Leghorn Chickens

Experiments were conducted in order to produce bordetellosis in specific-pathogen-free (SPF) leghorn chickens. In the first and second of three experiments, young turkeys and chickens, respectively, were allotted into groups and challenged at 2 weeks of age with one of seven different isolates of Bordetella avium and two isolates of B. avium-like bacteria. Isolates of B. avium with the smooth colony type were pathogenic in turkeys but not in chickens. The B. avium-like bacteria and B. avium isolates with rough colonial morphology were nonpathogenic. In the third experiment, SPF leghorn chicks were vaccinated at 1 day of age with infectious bronchitis virus, Newcastle disease virus, or both and then challenged with B. avium at 7 days of age. Chickens vaccinated and then challenged with B. avium showed clinical signs and lesions similar to bordetellosis in turkeys. No clinical signs were observed in unchallenged chickens. Thus, we conclude that B. avium is an opportunistic pathogen in SPF leghorn chickens.

Comparative study of hepatic VLDL secretion in vivo in the growing turkey ( Meleagris gallopavo) and chicken ( Gallus domesticus)

Hepatic secretion of VLDL was compared in young turkeys and chickens (8 and 4 weeks of age, respectively) and older birds (11 and 8 weeks of age, respectively) reared together under the same nutritional conditions. VLDL, VLDL-TG and total TG secretion rates were higher in chickens than in turkeys. The cholesteryl ester content of turkey VLDL was higher than that of chicken. Differences in the fatty acid composition of the VLDL lipids were observed between the species: the proportion of linoleic acid was greater in turkeys, whereas monounsaturated fatty acids were more abundant in chickens. These results are consistent with the hypothesis of a positive relationship between hepatic lipogenesis, delta-9-desaturation, VLDL secretion and fattening in turkeys and chickens.

Trichothecene mycotoxins depress the mononuclear-phagocytic system of young turkeys.

Macrophage cells isolated from the abdominal cavity of 21-day-old turkeys after a single injection of Sephadex suspension were used to quantitate the effects of direct in vitro exposure to deoxynivalenol (DON), 3-acetyldeoxynivalenol (3ac-DON), scirpentriol (STO), or 15-acetylscirpenol (15-MAS). Macrophage monolayers were established on glass surfaces and cells were exposed to graded levels of individual mycotoxins for 1 hour: DON, 20-640 micrograms/microliters of culture; 3ac-DON, STO, 15-MAS, 20-1280 micrograms/microliters of culture. All four mycotoxins caused dose-related effects. A concentration of 50 micrograms/microliter DON caused a significant decrease in macrophage adherence, phagocytosis of opsonized SRBC, and number of opsonized SRBC per macrophage; at 200 micrograms/microliter, phagocytosis of unopsonized SRBC was decreased. There were also increasing percentages of damaged macrophages with increasing DON doses as indicated by morphological alterations. Linear decreases in macrophage viability on exposure to 3-acDON and STO were observed. Moreover, STO and 15-MAS decreased macrophage adherence to glass and 3-acDON, STO, and 15-MAS induced macrophage morphological alterations. This study suggests that trichothecene mycotoxins may be immunosuppressive by affecting viability, adherence and phagocytic potential of mononuclear phagocytic cells of young turkeys.

Influence of Supplemental Dietary Fat on Changes in Vitamin E Concentration in Livers of Poults

An experiment was conducted to determine the influence of supplemental dietary fat on α-tocopherol (TOC) stored in the livers of young turkeys during the first 21 d after hatching. The four dietary treatments were obtained by supplementing a corn-soybean meal diet with 8% sucrose (SUC), 8% animal-vegetable fat (AVF), 8% tallow (TAL), or 8% coconut oil (COC). All diets were supplemented with 12 IU of dl-α-tocopheryl acetate (vitamin E)/kg of diet. Body weight at 21 d of age was not affected by dietary fat, whereas feed efficiency was improved (P < .05) by added fat, irrespective of source. Liver TOC (micrograms per gram of liver and micrograms per total liver weight) decreased markedly between 1 to 14 d of age, irrespective of fat source. Average TOC concentration in liver was 78.9 μg/g at 1 d, but was only .5 μg/g at 14 d. Between 14 and 21 d of age, total liver TOC increased slightly in all treatment groups. No diet effect was observed on the liver TOC concentration until 21 d of age. At this time, poults fed TAL had less (P < .05) TOC in liver than those fed COC and AVF. The data show that neither the presence of supplemental dietary fat nor fat source changed the pattern of marked decrease in liver TOC during the first 14 d after hatching.

Effect of Infection with Hemorrhagic Enteritis Virus on Susceptibility of Turkeys to Escherichia coli

The present study was designed to investigate hemorrhagic enteritis virus (HEV) as a predisposing factor influencing the susceptibility of young turkeys to Escherichia coli infections. In addition, the pathologic changes caused by administration of E. coli by various routes were compared. Following oral infection with HEV, groups of turkeys were inoculated with various doses of pathogenic E. coli by intravenous (IV), intra-air sac (IA), or intratracheal (IT) routes. A synergistic effect was observed in birds that were exposed to a combined HEV-E. coli challenge, resulting in higher mortality than that caused by either pathogen alone. This synergy was more evident when the bacteria were administered by the IT route than when it was administered by the two other routes. Turkeys infected with HEV and then inoculated IT with E. coli O78 had higher mortality (61%) and higher occurrence of gross body lesions (74%) than birds given E. coli alone (0% mortality and 16% gross lesions). After E. coli inoculation by the IA and IT routes, lesions observed were mainly pericarditis, perihepatitis, lung and air-sac lesions, splenic enlargement, and occasional arthritis. The incidence of lesions was affected by HEV exposure. In contrast, IV inoculation with E. coli O78 usually resulted in arthritis, and its incidence was independent of previous HEV exposure. The synergistic effect between HEV and E. coli administered IT can be used as a challenge model for testing E. coli vaccines.

Individual and Combined Effects of Feeding Fusarium moniliforme Culture Material, Containing Known Levels of Fumonisin B1 and Aflatoxin B1 in the Young Turkey Poult

The individual and combined effects of fumonisin B1 (FB1) and aflatoxin B1 (AF) were evaluated using a 2 × 2 factorial with treatments of 0 and 75 mg FB1/kg feed and 0 and 200 μg AF/kg feed. Each of the four diets was fed to eight pen replicates of six poults from Day 1 to 21. Body weight gain was reduced (P < .05) by AF and the FB1-AF combination. Poults fed AF or the FB1-AF combination were less efficient (P < .05) in converting feed to gain. Fumonisin B1 increased (P < .05) liver weights whereas AF and the FB1-AF combination increased (P < .05) spleen weights. The AF and the FB1-AF combination decreased (P < .05) serum concentrations of albumin, total protein, and cholesterol. Fumonisin B1 and the FB1-AF combination increased (P < .05) serum sphinganine:sphingosine (SA:SO) ratios. Treatment-associated lesions were observed only in the liver. Hepatocellular hyperplasia and biliary hyperplasia were seen in poults fed 75 mg FB1/kg and 200 μg AF/kg, respectively. The combination of FB1 and AF caused an increased primary immune response to sheep red blood cells. However, the phytohemagglutinin delayed hypersensitivity response was not affected by dietary treatment. These data indicate that FB1 and AF, alone and in combination, can adversely affect poult performance and health at these dietary concentrations.

Dietary zinc-methionine enhances mononuclear-phagocytic function in young turkeys. Zinc-methionine, immunity, and Salmonella.

The ability of dietary zinc-methionine (Zn-Met) to enhance mononuclear-phagocytic function against Salmonella arizona and enteritidis was investigated in young turkeys. Feed/gain and body wt gain at 21 d of age were not affected by Zn-Met. The addition of 30 or 45 ppm Zn from Zn-Met to a Zn adequate diet significantly increased cutaneous basophil hypersensitivity to phytohemagglutinin-P. The clearance of intravenously administered S. enteritidis from blood was not affected by 30 ppm of supplemental Zn from Zn-Met. However, 30 ppm Zn from Zn-Met increased the reduction of intravenously administered S. arizona from spleen. Percentages of myeloid and mononuclear-phagocytic cells before and after S. enteritidis infection were not affected by supplemental Zn-Met. Turkeys supplemented with Zn-Met showed enhanced in vitro phagocytosis of S. enteritidis by Sephadex-elicited abdominal exudate cells. The phagocytosis of S. arizona was unaffected by Zn-Met.

Blood Clearance of Escherichia coli and Evaluation of Mononuclear-Phagocytic System as Influenced by Supplemental Dietary Zinc Methionine in Young Turkeys

The influence of diets containing Zn-Met on in vitro and in vivo uptake of Escherichia coli by the mononuclear-phagocytic system was evaluated. Female Nicholas turkeys reared in battery brooders were supplemented with 40 μg Zn/g as Zn-Met in a corn soybean meal diet from 1 to 3 wk of age. Chemical analysis of the basal diets indicated that the basal diets contained 130 μg Zn/g and the Zn-Met diets contained 165 μg Zn/g. Each diet was fed to three replicate pens of 8 birds in Experiment 1 and three pens of 16 birds in Experiment 2. Body weight gain, feed conversion (FC), and clearance of injected E. coli from blood were determined in Experiments 1 and 2. Abdominal exudate cells (AEC) were recruited by intra-abdominal Sephadex injection. Substrate adherence potential and incidence of macrophages in AEC, phagocytosis of E. coli in vitro in terms of percentage phagocytic macrophages, and number of internalized E. coli per phagocytic macrophage, were quantified in Experiment 1. Plasma Zn concentrations and plasma alkaline phosphatase activity (ALKP) were determined in Experiment 2.Supplemental Zn-Met improved 3-wk BW gain (P ≤ .003) only in Experiment 2. Dietary Zn-Met increased mean adherence of cells by 69% (P ≤ .001). The number of phagocytized E. coli per macrophage did not differ significantly between treatments; however, E. coli clearance from blood was significantly improved in poults receiving Zn-Met in Experiment 2. Plasma Zn was higher in poults supplemented with Zn-Met prior to and after E. coli administration (P ≤ .02). Plasma ALKP activity was marginally suppressed in plasma from poults supplemented with Zn-Met.

Endocrine and metabolic responses of intact and hypophysectomized turkey poults given a daily injection of chicken growth hormone

Female turkey poults were hypophysectomized at 4-5 weeks of age. Beginning at 6 weeks of age, 20 hypophysectomized and 20 intact birds received a daily intramuscular injection of natural chicken growth hormone (cGH, 100 micrograms/kg body weight) or vehicle for 12 days. Blood samples were taken from each bird just before injection and 4 hr post-injection at 6 and 12 days of treatment. Hypophysectomy reduced the growth rate of turkey poults to 75% of that of intact controls, significantly reduced carcass protein and ash percentages, and significantly lower plasma concentrations of GH, insulin-like growth factor-I, triiodothyronine, thyroxine, insulin, glucose, triglycerides, and non-esterified fatty acids. Hypophysectomy was without effect on liver GH receptor binding activity, but increased liver 5'-monodeiodinase activity. Daily cGH injection had no effect on the average daily gain of either hypophysectomized or intact poults when compared to vehicle-injected controls over 12 days of treatment. Daily cGH administration increased plasma insulin-like growth factor-I levels in intact and hypophysectomized turkeys, and increased plasma triiodothyronine, insulin, glucose, and triglyceride concentrations in hypophysectomized birds, but not in intact birds. Responses of young turkeys to hypophysectomy and GH replacement were consistent with the known metabolic role of GH in other species, but the influence of GH on growth appears to be of less importance in poultry than in mammals.

Effects of Glucagon Infusion, Alone or in Combination with Somatostatin, on Plasma Growth Hormone and Metabolite Levels in Young Female Turkeys Under Different Feeding Regimens

The lipolytic effect of glucagon alone or in combination with somatostatin-14 (SRIF-14) was studied in 9- to 11-wk-old female turkeys that either consumed feed ad libitum or were deprived of feed (FD) for 20 h. During the infusion of various doses of glucagon (.005 to 1.5 μg glucagon/min), blood samples were serially collected every 10 min for determination of plasma concentrations of growth hormone (GH) and energy-related metabolites [nonesterified fatty acids (NEFA), glucose, and triacylglycerol (TG)]. Glucagon infusion resulted in decreases (P < .05) in plasma GH in both groups of turkeys. During glucagon infusion, dose-dependent increases in both glucose and NEFA occurred, with greater relative increases in the ad libitum turkeys. In contrast, plasma TG was decreased by glucagon infusion in the ad libitum turkeys but unchanged in the FD turkeys. The effect of simultaneous infusion of SRIF-14 and glucagon on GH and NEFA concentrations varied depending on the previous hormonal treatment. Plasma glucose was not affected by SRIF-14 in either group of turkeys. The present studies show that: 1) glucagon is an important agent for directing carbohydrate and lipid metabolism in growing female turkeys; 2) SRIF-14 has little effect on carbohydrate metabolism, but does affect lipolysis in a complex manner with glucagon; and 3) in vivo, glucagon depresses plasma GH.