Biomedical subjects

M T Kidd

Publications and source records attributed to M T Kidd.

36 records · Page 2Linked to original sources

PubMed2001

Embryo growth and amino acid concentration profiles of broiler breeder eggs, embryos, and chicks after in ovo administration of amino acids.

Two experiments were conducted to evaluate the effect of in ovo amino acid (AA) injections in broiler breeder eggs on AA utilization of embryos. All AA used in these experiments were pure crystalline AA in free-base form. Treatments in Experiment 1 comprised 1) control eggs (no injection), 2) 0.5 mL sterile-distilled water injected eggs, and 3) eggs injected with an AA solution suspended in 0.5 mL sterile-distilled water. Injections were administered into the yolk at Day 7 of incubation. At hatch, chicks were killed and bled, and plasma AA concentration was determined. Plasma AA concentration of hatched chicks decreased (P < 0.05) when water was injected. In addition, all AA from eggs injected with AA, except Glu and Lys, were decreased (P < 0.05) at hatch as compared to control eggs. However, AA pattern was not affected by in ovo water injection, but the AA ratio to Lys was reduced by in ovo AA injection. Experiment 2 was conducted to evaluate whole internal egg AA concentrations over incubation time in the presence or absence of in ovo AA administration. Treatments in Experiment 2 comprised 1) control eggs (no injection), and 2) eggs injected with a AA solution at Day 7 of incubation. The AA contents of embryo, yolk, albumen, and allantoic and amnion fluids were analyzed over time during incubation (Days 0, 7, 14, and 19 of incubation). On Day 14 of incubation, there were no differences in AA contents of all tissues between the control group and the group injected with AA on Day 7 of incubation. On Day 19 of incubation, AA contents of embryo, yolk, albumen, and allantoic and amnion fluids were increased (P < 0.05) as mediated by in ovo administration of AA at Day 7 of incubation. These results suggest that in ovo administration of AA may increase AA concentrations in chicken embryos and other egg contents.

Amino Acids↗

PubMed2001

Growth and immunity of broiler chicks as affected by dietary arginine.

A dietary deficiency of Arg may suppress chick immune system functions; however, research evaluating immune function responsiveness of commercial broilers fed dietary Arg levels near NRC (1994) recommendations is sparse. Therefore, three experiments were conducted to evaluate growth and immunity of broilers fed varying Arg levels near NRC (1994) specifications. Because Arg and Lys are similar in structure and are known to compete in intestinal absorption, dietary Lys treatments [near NRC (1994) recommendations] were evaluated to determine if Arg and Lys interact to affect broiler immunity. There were four dietary treatments in Experiment 1 representing a 2 x 2 factorial design of additional Arg (120% of NRC) or additional Lys (120% of NRC) added to a control diet containing 100% of NRC Arg and Lys (six replications per treatment). Experiment 2 contained the following four treatments: the control diet; the control diet plus L-Arg (0.20% Arg of diet); the control diet plus L-Lys HCl (0.20% Lys of diet); and the control diet plus L-Arg-L-Glu (0.10% Arg of diet). Graduations of Arg were fed from 90 to 120% of NRC in 10% increments in Experiment 3. Also, half of the birds were exposed to vaccinations of Newcastle disease virus and infectious bronchitis virus in Experiment 3 to derive a 2 x 4 factorial design. Experiments 1 and 2 were conducted from Days 1 to 18 and Experiment 3 was conducted from Days 1 to 15 in Petersime battery brooders. No interactions occurred between dietary Lys and Arg in Experiment 1. Increasing dietary Arg, but not Lys, from 100 to 120% of the NRC recommendation increased (P < or = 0.05) Day 18 BW gain. Treatment differences in the cutaneous basophil hypersensitivity assay in Experiment 1 did not occur. In Experiment 2, treatment differences in growth responses, lymphoid organ development, and primary antibody titers to SRBC did not occur. Unvaccinated birds in Experiment 3 fed an Arg-deficient diet had lower (P < or = 0.05) feed conversion in comparison with vaccinated birds fed an Arg-deficient diet. Vaccinated birds had lower (P < or = 0.05) Day 15 BW than unvaccinated birds, but higher (P < or = 0.05) titers to Newcastle disease virus. Increasing dietary Arg in Experiment 3 increased plasma Arg (P < or = 0.05), but did not affect plasma Lys. Although increased dietary Arg improved BW gain in Experiment 1, minimal effects were noted in growth and immune system parameters throughtout this study. A dietary Arg level near the NRC (1994) recommendation should support proper immune system functions in healthy chicks.

Animals↗

PubMed2001

Plasma levels of arginine, ornithine, and urea and growth performance of broilers fed supplemental L-arginine during cool temperature exposure.

Two experiments (Experiment 1 and 2) were conducted to evaluate growth performance, ascites mortality, and concentrations of plasma Arg, urea, and ornithine in male broilers raised in floor pens (2 x 4 factorial experiment, six pens for treatment) and exposed to cool temperatures averaging 16 C after 21 d of age. Broilers were fed low- or high-CP diets in both Experiments. In Experiment 1, Arg treatments consisted of control (no supplemental Arg); 0.15 or 0.3% supplemental Arg in the diet (low- and medium-Arg feed, respectively); and 0.3% supplemental Arg in the drinking water (Arg-water). Arginine levels were increased in Experiment 2 and consisted of the following: control (no supplemental Arg); 0.3 or 0.85% supplemental Arg in the diet (medium- and high-Arg feed, respectively); and 0.6% supplemental Arg in the drinking water (Arg-water). The water treatment followed a 3-d cyclic regimen, with supplemental Arg being provided for 24 h, followed by tap water for 48 h. When the broilers reached 37 d of age and all groups had consumed tap water for the previous 48 h, blood samples were collected from one bird per pen (Time 0, 0700 h); then supplemental Arg was provided in the Arg-water group, and additional blood samples were collected from the control and Arg-water groups at 3, 6, 12, and 36 h after Time 0. Plasma amino acids were analyzed using HPLC. Birds fed the high-CP diet were heavier at 49 d than birds fed the low-CP diet in Experiment 1, but not in Experiment 2. No differences were found in feed conversion or ascites mortality due to CP or Arg treatments in either experiment. In both experiments, plasma Arg was similar for all groups at Time 0, but increased in the Arg-water group at 3, 6, and 12 h after Arg was provided in the water. Within 12 h after returning to tap water, plasma Arg levels of the Arg-water group did not differ from the control group. Plasma urea and ornithine were parallel to plasma Arg concentrations, and the high-CP diets resulted in higher plasma levels of urea and ornithine compared with low-CP diets. These results indicate that kidney arginase was readily activated by Arg provided in the water, resulting in an immediate increase in plasma urea and ornithine. Plasma Arg was increased significantly, but no effects were observed in ascites mortality.

Animals↗

PubMed2001

Male and female broiler responses to low and adequate dietary threonine on nitrogen and energy balance.

This study evaluated nitrogen and energy utilization by male and female broilers that were at 46 and 54 d of age fed diets deficient or adequate in threonine. Birds were reared in floor pens of an open-sided house and were provided diets that met NRC (1994) nutrient recommendations from placement until 6 wk of age. At 42 d, 48 birds (24 per sex) were selected and individually penned in Petersime batteries and were given feeds that were formulated to contain 0.52 or 0.74% total threonine having 18% CP and 3,200 kcal ME/kg. Two 24-h excreta collection periods were conducted on Days 46 and 54 to assess nitrogen and energy recovery. Males receiving adequate threonine had an advantage in retention of nitrogen and recovery of AMEn over males consuming the low threonine diet. Utilization of nitrogen by females was similar at both threonine concentrations, and AMEn corresponded to the concentration recovered by males when threonine was adequate. Inadequate threonine appears to create conditions that reduce recovery of energy by male broilers.

Aging↗

PubMed1999

Effect of amino acid injection in broiler breeder eggs on embryonic growth and hatchability of chicks.

Two experiments were conducted to evaluate the effect of amino acid (AA) injections in ovo in Cobb broiler breeder eggs on hatchability and subsequent chick BW. In Experiment 1, moisture, crude fat (CF), and CP were analyzed over time during incubation (Day 0, 7, 14, and 19 of incubation). Moisture, CP, and CF of the embryo increased, and moisture, CP, and CF of eggs decreased, as incubation time increased (P < 0.05). Combined egg and embryo AA contents, except Gly and Pro, decreased (P < 0.05) as incubation time increased. However, the pattern of AA in the egg did not change as the embryo developed. In Experiment 2, AA were injected into the yolk or air cell at Day 0 and 7 of incubation. Hatchability was reduced (P < 0.05) when AA were injected at Day 0 of incubation. However, when the AA solution was injected into the yolk sac at Day 7 of incubation, hatchability was not affected, and BW of chicks increased relative to egg weight prior to incubation. These results suggest that in ovo administration of AA may be an effective method of increasing chick BW at hatch.

Amino Acids↗

PubMed1999

Plasma taurine levels in broilers with pulmonary hypertension syndrome induced by unilateral pulmonary artery occlusion.

Low plasma levels of taurine are associated with losses of cardiac sarcomeric proteins, leading to heart failure in mammals. Recently, it was proposed that cardiac taurine depletion serves to defend the heart against injury caused by regional ischemia in mammals. The role of taurine has not been well documented in broilers, particularly in relation to pulmonary hypertension syndrome (PHS; ascites). Three independent experiments evaluated plasma taurine in male broilers by utilizing the following treatments: unoperated controls (CONTROL; n = 10 in each experiment); sham operated (SHAM; n = 11, 12, and 10); or, unilaterally pulmonary artery clamped (PAC; n = 18, 29, and 24) that did (PAC-ascites) or did not (PAC-normal) develop ascites within 12 d postsurgery. Plasma samples were collected 9 and 11 d postsurgery in Experiments 1 and 2, respectively, and 2 d before and 4, 8, and 12 d after surgery in Experiment 3. Plasma taurine was analyzed by HPLC. Twelve days postsurgery, the birds were euthanatized, and ventricles were weighed for calculating the right:total ventricular weight ratio (RV:TV). The RV:TV of PAC birds (>0.35) consistently was higher (P < 0.01) than that of CONTROL and SHAM birds (<0.27 and 0.25, respectively). In Experiments 1 and 2, plasma taurine was higher (P < 0.05) in PAC-ascites (380 and 370 nmol/mL) than in SHAM broilers (183 and 186 nmol/mL), whereas CONTROL (262 and 278 nmol/mL) and PAC-normal (362 and 300 nmol/mL) broilers tended to have intermediate plasma taurine levels. In Experiment 3, PAC birds had higher (P < 0.05) plasma taurine at 8 and 12 d postsurgery when compared with presurgery levels, whereas plasma taurine was unchanged over time in CONTROL and SHAM birds. These results suggest cardiac taurine may be released into the plasma as a protective mechanism in response to the induction of pulmonary hypertension, hypoxemia, and right-side heart failure, similar to the mechanism reported for protecting cardiac muscle from ischemia in mammals.

Animals↗

PubMed1998

Dietary threonine responses in growing turkey toms.

A study was conducted to evaluate Thr responses in Large White (British United Turkeys) male turkeys during three time periods: 0 to 3, 3 to 6, and 6 to 9 wk of age. The Thr-deficient diets, fed in 3-wk intervals, were composed primarily of corn, peanut meal, poultry meal, and soybean meal as intact protein sources and supplemented with amino acids. Graded levels of L-Thr were added to the Thr-deficient diets. Another group of turkeys received a corn-soybean-poultry meal control diet in each time period. Diets were formulated to meet a minimum of 110% of suggested amino acid specifications (NRC, 1994) for all essential amino acids, except Thr. Feed intake, BW gain, and feed:gain responses were measured. Average environmental temperatures for Weeks 1, 2, and 3 were 29, 27, and 24 C, respectively. From 4 to 9 wk of age, average environmental temperatures varied between 24 and 35 C. Turkeys in each time period responded to Thr in a curvilinear manner with responses at the asymptote being equivalent to turkeys fed the corn-soybean meal control diets. Adequate dietary Thr levels for gain and feed:gain for the 0 to 3 wk period were 0.93% (3.21 g Thr/Mcal ME) and 0.97% (3.34 g Thr/Mcal ME) of diet, respectively. From 3 to 6 wk of age, the level of dietary Thr needed to support adequate BW gain and feed:gain was 0.88% of diet (2.81 g Thr/Mcal ME). The level of dietary Thr needed to support adequate BW gain and feed:gain from 6 to 9 wk of age was 0.77% of diet (2.30 g Thr/Mcal ME). These results indicate that the NRC (1994) estimations of Thr needs up to 9 wk of age are more than adequate.

Animal Feed↗

PubMed1998

Dietary arginine and lysine ratios in Large White toms. 2. Lack of interaction between arginine:lysine ratios and electrolyte balance.

The effect of dietary Arg:Lys ratios and dietary electrolyte balance (DEB) on growth and carcass parameters of Large White toms was evaluated in one experiment from 8 to 20 wk of age. Growth, feed conversion, and carcass composition were measured. All toms received a common basal diet from 0 to 8 wk of age. At 8 wk of age, 600 toms were randomly placed into 40 pens (15 toms per pen). The corn-soybean meal-based experimental diets were fed from 8 to 12, 12 to 16, and 16 to 20 wk of age and evaluated two Arg:Lys ratios (0.98 vs 1.22) and two DEB levels (148 vs 202 mEq/kg of diet) in a complete factorial arrangement. All experimental diets were pelleted. Composite samples of protein-contributing ingredients and complete experimental diets were analyzed for all amino acids, CP, DM, Cl, Na, and K. High and low average house temperature for the 8 to 20 wk period were 19 and 15 C, respectively. No interactions occurred between Arg:Lys ratios and DEB for any parameter measured except litter moisture. Increasing the Arg:Lys ratio improved 20-wk BW (P < or = 0.027) and 8 to 20 wk gain (P < or = 0.023). Feed:gain from 0 to 20 wk of age was decreased by increasing the Arg:Lys ratio (3.01 vs 2.94; P < or = 0.026) and by increasing the DEB (3.01 vs 2.95; P < or = 0.045). Dietary treatments did not affect mortality. Increasing DEB decreased cold carcass yield (P < or = 0.020). Total breast meat yield was increased (P < or = 0.076) by 1% in toms fed the diets containing the 1.22 Arg:Lys ratio vs toms fed diets containing the 0.98 Arg:Lys ratio. Toms responded favorably to increasing the Arg:Lys ratio for growth, feed conversion, and breast meat yield independent of DEB level.

Animal Feed↗

PubMed1998

An evaluation of threonine requirements of young turkeys.

Two experiments were conducted to evaluate the Thr requirements of male Large White turkeys from 3 to 6 and 6 to 9 wk of age. One group of turkeys was fed to 3 wk using nutritionally adequate diets and fed test diets from 3 to 6 wk; another group of turkeys was fed to 6 wk using nutritionally adequate diets and fed test diets from 6 to 9 wk. Test diets were composed of peanut meal, soybean meal, corn, and grain sorghum as intact protein sources and were supplemented with amino acids. Peak performance of turkeys fed the test diets was equivalent to that of turkeys fed conventional corn-soybean meal diets formulated to meet NRC (1994) standards. Estimates of Thr requirements for weight gain were 0.92 and 0.86% for 3 to 6 and 6 to 9 wk, respectively. For feed conversion, estimates of Thr requirements were 0.87% and 0.84% for 3 to 6 and 6 to 9 wk, respectively. The results of the two experiments reported herein would suggest that the Thr requirements suggested by NRC (1994) for turkeys up to 9 wk of age are safe estimates; they may slightly overestimate the requirements but not by a large margin.

Animal Feed↗

PubMed1998

Dietary arginine and lysine in Large White toms. 1. Increasing arginine:lysine ratios does not improve performance when lysine levels are adequate.

A study was conducted utilizing two strains of male Large White turkeys (BUT Big 6 and Nicholas 700) to determine the effects of increasing Arg:Lys ratios on live performance and carcass composition. Diets were formulated to provide 100, 110, and 120% of NRC (1994) Lys levels, adjusted for dietary energy level, with Arg:Lys ratios of 1.0:1, 1.1:1, 1.2:1, and 1.3:1 in a 3 x 4 factorial arrangement. Eight pens of 15 poults (four pens of each strain) were fed each of the 12 test diets for an 18-wk period. Diets were changed at 3-wk intervals rather than the 4-wk interval suggested by NRC. The results of this study suggest that the Arg and Lys levels suggested by the NRC (1994) are not sufficient when diets are fed on 3-wk intervals, rather than the 4-wk intervals suggested by NRC. This conclusion is in agreement with the studies of Waldroup et al. (1997b). Increasing Arg:Lys ratios improved performance of turkeys only when the diets contained insufficient amounts of Arg in association with low levels of Lys. Increasing Arg:Lys ratios when diets contained sufficient amounts of these two amino acids was without benefit, in contrast to the report of Brake et al. (1994). Turkeys of the BUT Big 6 strain appeared to be more sensitive to marginal deficiencies of Lys and Arg than did turkeys of Nicholas 700 strain.

Animals↗

PubMed1997

Performance and carcass composition of large white toms as affected by dietary crude protein and threonine supplements.

This experiment evaluates the effect of decreasing dietary CP, in addition to the effects of dietary supplements of L-Thr to low CP diets, in Large White Nicholas toms from 0 to 18 wk of age. Toms were fed dietary treatments consisting of four levels of dietary CP as a percentage of NRC (1994) recommendations (100, 92, 84, and 76% of NRC recommendations). Additional treatments consisted of supplements of L-Thr (0.1 and 0.2% of diet) added to the 92 and 84% NRC CP treatments. All eight dietary treatments were formulated to meet a minimum of 105% of NRC (1994) recommendations for Met, TSAA, Lys, Thr, and Trp. Body weight, feed conversion, mortality, and carcass composition responses were measured. Decreasing CP to 84% of NRC resulted in 18-wk BW lower than that (P < or = 0.001) of toms fed diets containing 100 or 92% of NRC CP; however, toms fed 84% of NRC CP diet supplemented with 0.1% L-Thr had 18-wk BW equal to (P < or = 0.001) that of the 100 and 92% NRC CP treatments. Toms fed diets containing 76% of NRC CP had depressed BW and feed:gain in comparison to all other treatments. No adverse effects in cumulative feed:gain (0 to 18 wk) were noted by decreasing CP from 100 to 84% of the NRC recommendations. Mortality did not differ among treatments. Treatments had no effect on carcass fat expressed as a percentage of hot carcass weight. Breast meat yield (deboned Pectoralis major and Pectoralis minor) was highest (P < or = 0.001) in toms fed the 100 and 92% NRC CP treatments. The 84 and 76% NRC CP treatments resulted in decreased breast meat yield regardless of L-Thr supplements. These results indicate that diets containing Met, TSAA, Lys, Thr, and Trp at a minimum of 105% NRC recommendations may support favorable breast meat yield when CP is decreased to 92% of the NRC (1994) recommendation. If growth and feed conversion are the desirable traits, rather than breast meat yield, CP levels below 92% of the NRC (1994) recommendation may support favorable responses.

Animals↗

PubMed1997

T-2 tetraol is cytotoxic to a chicken macrophage cell line.

Cytotoxic effects of T-2 tetraol, a T-2 toxin derivative, on the MQ-NCSU chicken macrophage cell line were quantified by direct in vitro exposure. Macrophage cultures were exposed to 1, 10, 20, 40, 80, 160, and 320 micrograms/mL of T-2 tetraol for 1 h. Macrophage viability after exposure to T-2 tetraol. Macrophage viability was reduced by increasing concentrations of T-2 tetraol (linear effect, P < or = 0.001; quadratic effect, P < or = 0.025). The ability of macrophages to adhere to glass surfaces was impaired by increasing concentrations of T-2 tetraol (linear effect, P < or = 0.003). This experiment demonstrates that T-2 tetraol is cytotoxic to chicken macrophages in vitro.

Animals↗

PubMed1997

Dietary interactions between lysine and threonine in broilers.

Two experiments were conducted to evaluate the effects of two dietary levels of lysine and four dietary levels of threonine in a factorial arrangement on broiler growth, carcass traits, and immunity. In both experiments, 120 broilers were allocated to each of 56 floor pens (6,720 total broilers). In Experiment 1, two levels of lysine (1.10 and 1.20% of diet) and four levels of threonine (0.68, 0.74, 0.80, and 0.86% of diet) were fed to broilers from 1 to 18 d of age in a sorghum-peanut meal diet. Body weight gain, feed:gain, mortality, and cellular and humoral immunity were measured. In Experiment 2, all broilers received a common basal diet up to 18 d of age. Experimental diets were fed from 18 to 34, 34 to 44, and 44 to 54 d of age. Two levels of lysine [100 and 105% of NRC (1994) recommendations] and four levels of threonine [83, 92, 100, and 108% of NRC (1994) recommendations] were included in the experimental diets for each age group (seven replications per treatment). The diets consisted of wheat (soft), corn gluten meal, soybean meal, and meat and bone meal Weight gain, feed:gain, mortality, and carcass traits were measured at 54 d of age. In Experiment 1, increasing dietary lysine from 1.10 to 1.20% from 1 to 18 d in broilers improved (P < 0.001) BW gain (453 vs 488 g) and feed:gain (1.39 vs 1.33). No interactions between lysine and threonine were observed in Experiment 1. Differences in immune parameters or mortality were not observed. In Experiment 2, an interaction in 18 to 54 d weight gain occurred with the highest gain in broilers receiving dietary lysine and threonine levels equivalent to 100 and 83%, respectively, of NRC (1994) or lysine and threonine at levels of 105% and 100% of NRC (1994), respectively (P < or = 0.05). Supplemental lysine (105% of the 1994 NRC) improved (P < or = 0.01) 18 to 54 d feed:gain (2.30 vs 2.26). No differences in mortality occurred. Supplemental lysine increased preslaughter weight (P < or = 0.05), but differences in carcass yield were not observed. Breast fillet yields were the highest (P < or = 0.03) in broilers receiving 100% of NRC lysine and 83 or 92% of NRC threonine or 105% of NRC lysine and 100 or 108% of NRC threonine. In conclusion, additional lysine improved feed:gain independent of threonine from 1 to 54 d of age. However, lysine and threonine interact to increase weight gain and breast fillet yields.

Aging↗

PubMed1996

Dietary Spirulina platensis enhances humoral and cell-mediated immune functions in chickens.

Cornell K-strain White Leghorns and broiler chicks were raised to 7 wks and 3 wks of age respectively, with diets containing various levels (0, 10, 100, 1,000 and 10,000 ppm) of Spirulina platensis from day of hatch. Chicks in all treatment groups had comparable body weights. While bursal and splenic weights did not change, the K-strain chicks had larger thymuses (P < or = .05) over the controls (0 ppm group). No differences were observed in anti-sheep red blood cells antibodies during primary response. However, during secondary response, K-strain chicks in all Spirulina-dietary groups had higher total anti-SRBC titers with 10,000 ppm group being the highest (6.8 Log2) versus the 0 ppm (5.5 Log2) group. In broiler chicks, a one Log increase in IgG (P < or = .05) was observed in 10,000 ppm group over the controls. Similarly, chicks in 10,000 ppm Spirulina group had a higher PHA-P-mediated lymphoproliferative response over the 0 ppm controls. Macrophages isolated from both K-strain (10,000 ppm group) and broilers from all Spirulina groups had higher phagocytic potential than the 0 ppm groups. Spirulina supplementation at 10,000 ppm level also increased NK-cell activity by two fold over the controls. These studies show that Spirulina supplementation increases several immunological functions implying that a dietary inclusion of Spirulina at a level of 10,000 ppm may enhance disease resistance potential in chickens.

Adjuvants, Immunologic↗

PubMed1995

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.

Animals↗

PubMed1994

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.

Alkaline Phosphatase↗

PubMed1994

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 micrograms 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 micrograms Zn/g and the Zn-Met diets contained 165 micrograms 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 < or = .003) only in Experiment 2. Dietary Zn-Met increased mean adherence of cells by 69% (P < or = .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 < or = .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗

PubMed1992

Progeny performance when dams and chicks are fed supplemental zinc.

Three consecutive trials involving approximately 700 to 800 broilers (0 to 28 days) were conducted to examine effects on growth and immunity of chicks after supplementing dams with inorganic Zn versus organic Zn. Offspring from hens fed a basal diet (72 mg Zn/kg) or diets with 152 mg Zn/kg supplemented with ZnO or organic Zn-Met were randomized across four battery brooders. Chicks were fed a starter diet without supplemental Zn containing 100 mg Zn/kg or diets supplemented with 40 mg/kg Zn from ZnO and DL-Met or Zn-Met containing 140 mg Zn/kg. No differences among treatments (P greater than .05) were found in feed conversion or average BW. Supplemental Zn-Met in hen diet increased (P less than .06) cellular immune response in progeny. Embryonic bone weights were higher (P less than .05) in progeny when dams were fed Zn-Met. Zinc as Zn-Met in diets of dams and progeny enhanced primary antibody titers to Salmonella pullorum antigen.

Animals↗