PubMed Health⌕ Search

Biomedical subjects

D R Ledoux

Publications and source records attributed to D R Ledoux.

At least 37 records · Page 2Linked to original sources

The individual and combined effects of feeding moniliformin, supplied by Fusarium fujikuroi culture material, and deoxynivalenol in young turkey poults.

The effects of feeding diets containing either 20 mg deoxynivalenol (DON)/kg, 100 mg moniliformin (M)/kg, or a combination of DON and M (20 mg/kg DON and 100 mg M/kg) were evaluated in growing turkey poults, from 1 to 21 d of age. Feed intake and BW gains were decreased (P < 0.05) by dietary treatments containing M. Feed conversion was not affected by any of the dietary treatments, and no interactive effects on performance were evident between M and DON. Absolute weights of hearts and kidneys were increased (P < 0.05) in poults fed diets containing M. Mean cell volume was decreased by the M and DON-M treatments; however, the decrease was much smaller in poults fed the combination DON-M treatment resulting in a significant (P < 0.05) DON by M interaction. Mean cell hemoglobin and mean cell hemoglobin concentrations were not affected by any of the dietary treatments. No histological lesions were seen in control poults or poults fed DON alone. Lesions associated with dietary treatments were only observed in the heart and kidney. Poults fed diets containing M alone or the DON-M combination exhibited an increased incidence of variable sized cardiomyocyte nuclei, with numerous large giant nuclei, and a generalized loss of cardiomyocyte cross striations. Isolated renal tubules in sections of kidney were noted to have mild diffuse mineralization in poults fed M and the combination DON-M treatments. None of the response variables measured were affected by DON alone. No toxic synergy was observed when these toxins were fed simultaneously to turkey poults for 21 d.

Animal Feed↗

Effects of fumonisin B1 on selected immune responses in broiler chicks.

Three experiments were conducted to evaluate immune responses in chicks fed fumonisin B1 (FB1). Day-old male chicks were randomly allotted to dietary treatments: 0, 50, 100, or 200 mg FB1/kg diet. In Experiment 1, chicks were fed diets for 3 wk and were injected intravenously with 4.6x10(6) Escherichia coli on Day 21. Blood samples were collected at 60, 120, and 180 min postinjection, and liver, spleen, and lung were collected after 180 min. Chicks fed 200 mg FB1/kg diet had significantly higher numbers of bacterial colonies in blood, spleen, and liver (P<0.05) than control chicks. In Experiment 2, chicks were placed on the diets for 4 wk and were injected with 0.5 mL inactivated Newcastle Disease virus vaccine on Weeks 2 and 3 of the experiment, and primary and secondary antibody titers were measured 7 d after each injection. The secondary antibody response in chicks fed 200 mg FB1/kg diet was significantly lower (P<0.05) than that of control chicks. In Experiment 3, lymphocyte proliferation in chicks exposed to FB1 in vivo or in vitro was determined. Results of the in vivo study showed that cell proliferation in response to mitogens was lower (P<0.05) in chicks fed 200 mg FB1/kg diet than in control chicks. For the in vitro study, cell proliferation was lower (P<0.05) when cells were exposed to > or = 2.5 microg FB1/mL. Data of the current study suggested that FB1 is immunosuppressive in chicks when present in the ration at 200 mg FB1/kg diet.

Animals↗

Lowering the dietary calcium to total phosphorus ratio increases phosphorus utilization in low-phosphorus corn-soybean meal diets supplemented with microbial phytase for growing-finishing pigs.

Crossbred growing-finishing pigs (n = 120) were used to investigate the effect of three dietary Ca:total P (tP) ratios (1.5:1, 1.3:1, or 1.0:1) on P utilization in low-P corn-soybean meal diets supplemented with microbial phytase at 500 phytase units/kg. The basal grower (23 to 54 kg BW) diet contained .39% tP including .07% added inorganic P (iP), and the basal finisher (54 to 123 kg BW) diet contained .32% tP without added iP. An adequate-P positive control diet without phytase supplementation contained .60% Ca and .50% tP during the growing phase and .50% Ca and .40% tP during the finishing phase. Lowering the Ca:tP ratio linearly increased ADG during the growing phase (P < .03) and overall (P < .08), gain:feed ratio during the growing phase (P < .001), and P absorption during the finishing phase (P < .04). Lowering the Ca:tP ratio linearly increased BW at slaughter (P < .02), carcass weight (P < .04), bone breaking strength (P < .04), and bone ash weight (P < .06), whereas dressing percentage and backfat depth remained unchanged. In conclusion, pig performance and P utilization were increased by lowering the Ca:tP ratio from 1.5:1 to 1.0:1 in low-P corn-soybean meal diets supplemented with microbial phytase.

6-Phytase↗

Soaking increases the efficacy of supplemental microbial phytase in a low-phosphorus corn-soybean meal diet for growing pigs.

Sixty-three crossbred barrows averaging 18.7 kg initial BW were used in a 6-wk study of the effects of soaking on the efficacy of supplemental microbial phytase (Natuphos, BASF) in a low-P corn-soybean meal diet. The basal corn-soybean meal diet contained .06% available P, .32% total P, and .55% Ca with no added inorganic P. The basal diet was supplemented with 0, 250, or 500 phytase units (PU)/kg of diet. The diet was fed dry or soaked (2 parts water:1 part diet and mixed for 2 h at 30 degrees C before feeding) in a 3 x 2 factorial arrangement. A positive control diet was supplemented with inorganic P and provided .23% available P, .48% total P, and .60% Ca. Pigs were individually penned and fed their respective diets to appetite in four equal meals daily. There were no soaking x phytase interactions (P > .1 to .6) for growth performance criteria. Daily gain and gain/feed ratio were increased (P < .01) by soaking and increased linearly (P < .01) by phytase. Daily feed intake was increased linearly (P < .01) by phytase. There were soaking x phytase quadratic interactions (P < .01) for apparent P absorption criteria because soaking the 250 PU/kg diet increased P absorption similar to that obtained with the 500 PU/kg diet fed dry. Apparent P absorption criteria were increased by soaking (P < .01) and were increased linearly (P < .001) and quadratically (P < .03) by phytase. Phytase reduced fecal P excretion 37 to 40% with dry feeding (P < .03) and 48 to 49% with soaking (P < .01).

6-Phytase↗

The efficacy of an enzymic cocktail and a fungal mycelium in dephosphorylating corn-soybean meal-based feeds fed to growing turkeys.

A study was conducted to determine the efficacy of phytase, an enzymic cocktail, and a waste Aspergillus niger mycelium to hydrolyze phytate present in corn-soybean meal diets. One hundred turkey poults were assigned to dietary treatments for 2 wk (days 7 to 21). Dietary treatments included: 1) NRC (1994) diet (NRC), with recommended concentration of 0.6% available P (aP) and 1.2% Ca; 2) Phytase diet (PHYT), 1,000 units phytase/kg diet, 0.16% aP, and 0.84% Ca; 3) cocktail diet (COC), 1,000 units of phytase/kg diet plus acid phosphatase (100 units/g of diet), acid protease (42 units/g of diet), pectinase (2.94%), 0.16% aP, and 0.84% Ca; 4) Fungal mycelium diet (MYC), 5% mycelium, 0.16% aP, and 0.84% Ca; and 5) a positive control diet (CTRL+), 0.42% aP, and 0.84% Ca. Turkeys fed the PHYT diet consumed less feed and gained less weight but retained more P than poults fed the CTRL+ or NRC diets. Poults fed the COC diet performed as well as poults fed CTRL+ or NRC diets but retained more P (77%) and Ca (68%). Poults fed the MYC diet retained 79% P, gained the most weight, and were more efficient than poults fed any other dietary treatment. In vitro P release from experimental diets correlated well (R = 0.906) with P retention as observed in the feeding trial. Compared with the diet containing phytase as the sole supplemental enzyme, both the enzymic cocktail and fungal mycelium enhanced performance, bone mineralization, and retention of P and Ca in growing turkeys.

6-Phytase↗

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 > or = to 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 < or = to 1.23% FCM that supplied > or = to 75 mg FB1 /kg are toxic to young turkeys.

Animals↗

An in vitro procedure for studying enzymic dephosphorylation of phytate in maize-soyabean feeds for turkey poults.

An in vitro method was developed to predict inorganic P release from maize-soyabean poultry feeds containing supplemental phytase (EC 3.1.3.8), and to quantify the effect of acid phosphatase (EC 3.1.3.2), fungal protease (EC 3.4.23.6) and Aspergillus niger cellulase (EC 3.2.1.4) on phytate dephosphorylation. Pepsin (EC 3.4.23.1) and pancreatin digestion periods were preceded by a 30 min pre-incubation at pH 5.25 to simulate digestion in the crop of poultry. Pancreatin digestion was carried out in dialysis tubing, with a ratio of about 1:25 (v/v) between the digesta and dialysing medium, to simulate gradient absorption from the duodenum. The feed:water ratio was kept within physiological limits and a constant proportion of feed weight to digestive enzymes was maintained. There was a linear response to increasing dosages of phytase up to 1000 phytase units (FTU)/kg feed, and to increasing phosphate concentration in feeds. In vivo validation was performed with growing turkeys (1-3 weeks) fed on diets containing 12 g Ca/kg and 0, 500 or 1000 FTU phytase/kg in a factorial arrangement with 0, 1, 2 or 3 g supplemental phosphate/kg (from KH2PO4). After a simple transformation (variable/in vitro P = f (in vitro P)), amounts of P hydrolysed from feed samples by in vitro digestions correlated with 3-week body-weight gain (R 0.986, P < 0.0001), toe ash (R 0.952, P < 0.0001), feed intake (R 0.994, P < 0.0001) and feed efficiency (R 0.992, P < 0.0001). The dephosphorylating ability of phytase in vitro was significantly enhanced (P < 0.05) by the addition of acid phosphatase. Fungal acid protease and Aspergillus niger cellulase also enhanced the dephosphorylation process in vitro.

Acid Phosphatase↗

Effects of feeding Fusarium fujikuroi culture material, containing known levels of moniliformin, in young broiler chicks.

An experiment was conducted with 270 male broiler chicks to evaluate the effects of a Fusarium fujikuroi M-1214 culture material containing moniliformin (M) on broiler chicks. Day-old chicks were allotted randomly to dietary treatments containing 0, .24, .48, .72, .96, 1.44, 1.92, 2.40, and 2.88% M culture material (MCM). These levels of MCM supplied 0, 25, 50, 75, 100, 150, 200, 250, or 300 mg M/kg of feed. Each dietary treatment was fed to six pen replicates of five chicks per pen for 21 d. Significant mortality (P < .05) occurred in chicks fed 200 (8 out of 30), 250 (17 out of 30), and 300 (25 out of 30) mg M/kg feed. Chicks fed > 100 mg M/kg had lower (P < .05) feed intakes and smaller BW gains (P < .05) than controls. Increased heart weights (P < .05) were observed in chicks fed > 50 mg M/kg, and increased liver weights (P < .05) in chicks fed > 100 mg M/kg. Gross lesions of M toxicity included generalized cardiomegaly with dilation of the right ventricle. Histopathology revealed a high incidence of large and variably shaped cardiomyocyte nuclei and a generalized loss of cardiomyocyte cross striations in chicks fed > 75 and 200 mg M/kg, respectively. Results indicated that F. fujikuroi culture material containing M is toxic to young broiler chicks.

Animals↗

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 x 2 factorial with treatments of 0 and 75 mg FB1/kg feed and 0 and 200 micrograms 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 micrograms 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.

Aflatoxin B1↗

Fumonisin toxicity in turkey poults.

The effects of dietary fumonisin B1 were evaluated in young turkey poults. The experimental design consisted of 3 treatments, with 24 female turkey poults allotted randomly per treatment. Day-old poults were fed diets containing 0 mg (feed control), 100 mg, and 200 mg fumonisin B1/kg feed for 21 days. Body weight gains and efficiency of feed conversion decreased linearly with increasing dietary fumonisin. Liver, kidney, and pancreas weights increased linearly with increasing dietary fumonisin, and spleen and heart weights decreased. Serum aspartate aminotransferase levels increased with increasing dietary fumonisin, and serum cholesterol; alkaline phosphatase, mean cell volume, and mean cell hemoglobin all decreased. Biliary hyperplasia, hypertrophy of Kupffer's cells, thymic cortical atrophy, and moderate widening of the proliferating and degenerating hypertrophied zones of tibial physes were present in poults fed diets containing fumonisin B1. Results indicate that fumonisin B1, from Fusarium moniliforme culture material, is toxic in young poults, and the poult appears to be more sensitive to fumonisin than the broiler chick.

Alkaline Phosphatase↗

Effects of a porcine somatotropin implant on tissue mineral status of finishing pigs exposed to a thermoneutral or cold environment.

An experiment was conducted with 24 crossbred (Landrace x Yorkshire x Duroc) finishing pigs (mean BW 85 kg) to study the effects of a single 100-mg recombinant porcine somatotropin (rpST) implant on the tissue mineral status of pigs exposed to either a thermoneutral (TN; 18 to 21 degrees C, 50 to 55% RH) or cold (C; 5 to 15 degrees C, 50 to 70% RH) environment until BW averaged 110 kg. The implants used in this study delivered an average 2.4 to 2.5 mg of rpST/d during the course of the study. Control pigs were implanted with a placebo. All diets were supplemented with minerals at levels that either met or exceeded the requirements of an 85-kg pig. At slaughter (mean BW 110 kg), tissues were collected and analyzed for selected macro- and microminerals. Pigs treated with rpST had higher (P < .05) Ca concentrations and total Ca in liver and kidney and higher (P < .05) Ca concentrations in muscle. Total P, Mg, Na, and K were all higher (P < .05) in the liver and kidneys of rpST-treated pigs. In general, rpST had little influence on Cu, Zn, and Fe in tissues. No consistent trend was evident in the response of tissue minerals to environmental temperature. Results indicated that pigs treated with rpST and supplemented with adequate minerals accumulated more minerals in certain tissues than did pigs not given rpST.

Animals↗

Effects of feeding Fusarium moniliforme culture material, containing known levels of fumonisin B1, on the young broiler chick.

The effects of feeding Fusarium moniliforme culture material, containing known concentrations of fumonisin B1 (FB1), were studied in broiler chicks. Day-old chicks were allotted randomly to dietary treatments containing 0, 1.02, 2.04, 3.06, 4.08, 5.10, 6.12, and 7.14% fumonisin culture material (FCM). These levels of FCM supplied 0, 75, 150, 225, 300, 375, 450, and 525 mg of FB1/kg of feed. Each dietary treatment was fed to four pen replicates of six birds each for 21 days. Chicks fed FCM that supplied 450 and 525 mg FB1/kg diet had lower (P < .05) feed intakes and BW gains; increased (P < .05) liver and kidney weights; and increased (P < .05) mean cell hemoglobin, and mean cell hemoglobin concentrations. Compared with controls, chicks fed FCM had increased (P < .05) free sphinganine levels and sphinganine:sphingosine ratios. Treatment-associated histological lesions were only observed in the liver of chicks fed diets containing FCM that supplied 225 mg FB1/kg or higher. Diets containing FCM that supplied levels as low as 75 mg FB1/kg affected the physiology of chicks by increasing free sphinganine levels and sphinganine:sphingosine ratios. Because inhibition of sphingolipid biosynthesis has been hypothesized as the mechanism of action of FB1, this suggests that diets containing 75 mg FB1/kg FCM may be toxic to young broiler chicks.

Animal Feed↗

Fumonisin toxicity in broiler chicks.

The effects of dietary fumonisin B1 were evaluated in young broiler chicks. The experimental design consisted of 5 treatments each with 9 randomly allotted male broiler chicks. Day-old chicks were fed diets containing 0 (feed control), 100, 200, 300, or 400 mg fumonisin B1/kg feed for 21 days. Response variables measured were chick performance, organ weights, serum biochemistry, and histologic parameters. Body weights and average daily gain dramatically decreased with increasing dietary fumonisin B1, and liver, proventriculus, and gizzard weights increased. Diarrhea, thymic cortical atrophy, multifocal hepatic necrosis, biliary hyperplasia, and rickets were present in chicks fed diets containing fumonisin B1. Serum calcium, cholesterol, and aspartate aminotransferase levels all increased at higher fumonisin dietary levels. Results indicate that fumonisin, from Fusarium moniliforme culture material, is toxic in young chicks.

Animal Feed↗

Estimation of the relative bioavailability of inorganic copper sources for chicks using tissue uptake of copper.

An experiment was conducted with 208 day-old male Cobb feather-sexed chicks to study tissue accumulation of Cu as an estimate of biological availability of inorganic Cu sources for chicks. Chicks were allotted randomly to dietary treatments that included an unsupplemented basal corn-soybean meal diet (11.1 mg/kg Cu, DM basis) or this basal diet supplemented with 150, 300 or 450 mg/kg Cu either as reagent-grade acetate or feed grade oxide, carbonate or sulfate. Chicks were housed in batteries and allowed ad libitum access to feed and tap water for 21 d. Liver Cu was not affected by dietary Cu from the oxide source, but it increased (P less than .001) with increasing dietary Cu from all other sources. Bone Cu was lower (P less than .05) in chicks fed 150 mg/kg Cu compared to other dietary levels of Cu but was not influenced (P greater than .10) by Cu source. Using the slope-ratio technique from regression of log liver Cu on mean daily Cu intake with Cu from acetate set at 100%, the relative biological availability values were estimated to be 88.5 and 54.3% for sulfate and carbonate, respectively, and oxide was essentially unavailable.

Animals↗

Interaction of dietary nutrient concentration and supplemental copper on chick performance and tissue copper concentrations.

An experiment was conducted with 576 female Cobb feather-sexed chicks to study the influence of methionine (MET) and selected nutrient (SN) supplementation on the performance of chicks fed high Cu levels. Day-old chicks were allotted randomly to pens for the 22-day experiment. A 3 X 2 X 2 factorial arrangement of treatments was used which included Cu at 0, 400, and 800 mg/kg, MET at 0 and .4%, and SN at 0 and 20%. A significant (P less than .001) Cu X MET X SN interaction was found for gain. Supplemental MET reversed the growth depression observed in birds fed 400 but not 800 mg/kg Cu. Additions of 400 and 800 mg/kg Cu to the basal diet depressed (P less than .001) feed consumption by 8.6 and 19.4%, respectively. Hepatic Cu concentrations increased linearly (P less than .001) with increasing dietary Cu and were not influenced (P greater than .10) by supplemental MET or SN. Liver weights increased linearly (P less than .001) with increasing dietary Cu and were higher (P less than .05) for chicks on diets supplemented with SN, but lower (P less than .05) for those with diets supplemented with MET. The interaction of MET X SN was significant (P less than .001) for serum Cu; chicks supplemented with SN in conjunction with MET had the lowest (P less than .05) serum Cu concentrations. Serum glutamic-oxaloacetic transaminase (SGOT) activity was not influenced (P greater than .10) by dietary Cu, but SN supplementation resulted in a 10% elevation (P less than .001) in SGOT activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Influence of forage level on passage rate, digestibility and performance of cattle.

Two trials (feedlot and metabolism) were conducted to evaluate the influence of level of chopped tall fescue hay (FH) in high concentrate diets on average daily gain (ADG), liquid and particulate passage rates, digestibility and in situ digestibility of corn. In the feedlot trial, 36 Hereford steers were fed diets containing 15, 30 and 50% FH in combination with 74, 59 and 39% whole shelled corn (WSC) and a soybean meal supplement. Steers offered 15, 30 and 50% FH consumed 9.0, 9.0 and 7.6 kg dry matter (DM) per d; gained 1.19, .89 and .67 kg; and had DM to gain ratios of 7.6, 10.1 and 11.5, respectively. A negative correlation was observed between fecal pH and ADG (r = -.52) and between fecal pH and fecal starch (r = -.40). In a 4 X 4 Latin-square trial, four cannulated steers were fed 4, 8, 16 or 24% FH in combination with 86, 82, 74 or 66% WSC and a soybean meal supplement. After 14 d of adaptation, steers were offered ytterbium (Yb)-labelled WSC and were ruminally pulse-dosed with chromium ethylenediaminetetraacetic acid (Cr-EDTA) on the first day of the collection period. Steers fed 4, 8, 16 or 24% FH had the following particulate passage rates: 2.3, 2.7, 2.7 and 2.9%/h from fecal analyses; 2.3, 1.7, 2.4 and 2.8%/h from ruminal analyses; 6.0, 5.3, 6.3 and 8.1%/h for liquid, respectively. With increasing FH level, liquid passage rate exhibited linear and quadratic effects (P less than .05), while particulate passage rate (rumen sampling) showed linear and cubic effects (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

Chronic effects of moniliformin in broiler and turkeys fed dietary treatments to market age.

Floor pen studies were conducted, with broilers from 1 to 7 wk of age and with turkeys from 1 to 14 wk of age, to evaluate the chronic effects of moniliformin (M). Fusarium fujikuroi (M-1214) culture material was added to typical corn-soybean basal diets to supply 0, 25, or 50 mg M/kg diet (broilers) or 0, 12.5, 25, 37.5, or 50 mg M/kg diet (turkeys). Compared with controls, chicks fed diets containing 50 mg M/kg consumed more feed, had lower body weight gain, were less efficient in converting feed to body weight gain, and had increased relative heart and proventriculus weights. Chicks fed the diet containing 50 mg M/kg also had significantly higher mortality and decreased mean corpuscular volumes compared with controls. Broilers fed 25 and 50 mg M/kg also had increased serum gamma glutamyltransferase activities. Feed intake, body weight gain, and feed conversion of turkeys fed dietary M were not affected. At 6 and 14 wk, turkeys fed 25, 37.5, or 50 mg M/kg diet had increased (P < 0.05) relative heart weights when compared with controls. At week 14, turkeys fed diets containing 37.5 or 50 mg M/kg also had increased (P < 0.05) relative liver weights compared with turkeys fed 0, 12.5, or 25 mg M/kg diet. Lesions, observed only in the hearts of broilers and turkeys fed 50 mg M/kg, were loss of cardiomyocyte cross striations, increased cardiomyocyte nuclear size, and an increased number of cardiomyocyte mitotic figures (turkeys only). Results indicate that > or = 37.5 mg M/kg is hepatoxic and > or = 25 mg M/kg is cardiotoxic to turkeys and 50 mg M/kg diet is toxic to broilers fed to market age.

Animals↗

Effect of ochratoxin A on Escherichia coli-challenged broiler chicks.

A study was conducted to evaluate the effects of ochratoxin A (OA) on Escherichia coli-challenged broiler chickens. Day-old broiler chicks were separated into two groups of 92 chicks each, with one group fed a control mash diet, and the other fed a mash diet containing 2 ppm OA. On day 14, each group was further separated into two groups, with one group inoculated with E. coli O78 (1 x 10(7) colony-forming units/0.5 ml), whereas the other group was not inoculated with E. coli. After E. coli inoculation on day 14, four birds from each group were euthanatized at 1, 2, 3, 5, 7, 10, 14, and 21 days postinoculation. Escherichia coli infection caused dullness, depression, huddling, and diarrhea. Mortality was 14.3% in chicks infected with E. coli but fed no OA. Mortality increased to 35.7% in chicks fed OA and infected with E. coli. Decreased body weight and reduced feed intake were observed in chicks fed OA, and the effects were more pronounced in chicks fed OA and infected with E. coli. Increased serum levels of aspartate aminotransferase, alanine aminotransferase, uric acid, and creatinine and decreased levels of total proteins, albumin, globulins, calcium, and phosphorus were observed in OA-fed birds. Escherichia coli infection did not cause significant alteration in any of the serum biochemical parameters. The presence of OA in poultry rations increased mortality and the severity of an E. coli infection.

Animal Feed↗