Effect of full feed and early feed restriction on broiler performance, abdominal fat level, cellularity, and fat metabolism in broiler chickens.

Three hundred sixty Peterson x Arbor Acres chicks were fed two feed regimens to compare their effects on adipose cellularity, adipocyte lipolysis, hepatic glucose oxidation, adipocyte lipogenesis, bird performance, and abdominal fat level. Broilers in the first regimen had ad libitum access to feed throughout the 7-wk experiment, whereas broilers in the second regimen consumed feed at will throughout the experiment except that they were subjected to feed restriction (1.49 kcal/g BW2/3 daily) from 7 to 12 d of age (DOA). No differences in mean body weights were observed between the full-fed and restricted males and combined sex broilers at 49 DOA. Feed conversion and abdominal fat levels of female and combined sex were lower (P < .05) for the restricted than full-fed broilers. No differences in adipocyte numbers based either on whole abdominal fat pads at 28 and 42 DOA or per gram fat at 42 DOA were observed between broilers fed the two feed regimens. However, the adipocyte numbers per gram fat at 28 DOA were greater (P < .05) for the restricted broiler than for the broilers that ate freely. Lipolysis based per million adipocytes was not different between the treatments at 28 and 42 DOA; however, lipolysis based on per gram adipose tissue was increased (P < .05) with the addition of isoproterenol and theophylline for the restricted broilers compared to the full-fed broilers at 28 DOA. No difference was observed between the feed regimens at 42 DOA with hormone addition. Lipogenesis of the restricted broilers was lower (P < .05) than that of the full-fed broilers at 14 and 56 DOA. No difference in glucose oxidation was found between chickens fed the two regimens. Reduced abdominal fat in the restricted broilers is attributed to the reduction of adipocyte volume, which may be due to decreased lipogenesis.

Production variables and nutrient retention in single comb White Leghorn laying pullets fed diets supplemented with direct-fed microbials.

Two experiments were carried out for six and seven 28-d periods, respectively, with DeKalb XL Single Comb White Leghorn laying pullets to ascertain the effect of feeding 1,100 mg Lactobacillus (Lacto)/kg diet (ppm) and 2,200 ppm Lacto diets, and the supplementation of these diets with 1 and 3% fat, on layer performance and nitrogen, calcium, and phosphorus retention. The dietary treatments were corn-soybean meal (C-S) control, C-S plus condensed cane molasses solubles (CCMS)-1,100 ppm Lacto (4.4 x 10(7) cfu/mg Lacto), and C-S plus CCMS-2,200 ppm Lacto (8.8 x 10(7) cfu/mg Lacto) without fat (Experiment 1) and without and with 1 and 3% supplemental fat to each Lacto level (Experiment 2). In both experiments, layers fed the 1,100 ppm Lacto diets had better (P < .05) hen-day production, daily feed consumption, egg mass, egg weight, egg size, and feed conversion than layers fed diets without Lacto. Egg mass, interior egg quality, and feed conversion (Experiment 1), mean body weight gains, and nitrogen, calcium, and phosphorus retention (Experiment 2) were further improved (P < .05) with feeding 2,200 ppm Lacto diets. Feeding Lacto diets with 1% fat provided (P < .05) larger eggs and better (P < .05) nitrogen and phosphorus retention, whereas 3% fat decreased (P < .05) feed consumption and nutrient retention and improved (P < .05) feed conversion and body weight gain. Positive correlations between Lacto diets and nitrogen and calcium retentions, daily feed consumption, and egg size were observed. Feeding 1,100 ppm Lacto diets to layers stimulated appetite and improved egg production, egg mass, egg weight, egg size, and feed conversion. Addition of fat to Lacto diets reduced daily feed consumption and provided better feed conversion, egg masses, egg sizes, body weight gains, and nutrient retentions.

Performance of single comb White Leghorn layers fed corn-soybean meal and barley-corn-soybean meal diets supplemented with a direct-fed microbial.

An experiment was conducted with Single Comb White Leghorn (SCWL) layers to determine the effect of feeding either corn-soybean meal (C-S) or barley-corn soybean meal (B-C-S) diets with or without condensed cane molasses solubles (CCMS) or with or without CCMS-1,100 mg Lactobacillus (Lacto)/kg (ppm) diet on performance, nutrient retentions, digesta passage rate, and histological changes of the gastrointestinal (GI) tracts. Six dietary treatments were fed for eight 28-d periods and consisted of C-S (control), C-S + CCMS, C-S + CCMS-1,100 ppm Lacto (4.4 x 107 cfu/mg Lacto), B-C-S (control), B-C-S + CCMS, and B-C-S + CCMS-1,100 ppm Lacto. The CCMS served as the carrier for the Lacto, and the CCMS-Lacto premix (55 g Lacto/kg) was incorporated at 2% of the diet. Lactobacillus supplementation in C-S diets improved (P < .05) egg weight, egg mass, egg size, and body weight gains, and in B-C-S diets improved body weight gains. There were no differences in feed consumption, feed conversion, internal egg quality, and egg specific gravity among the dietary treatments. Passage rates of digesta were increased (P < .05) when either C-S or B-C-S layer diets were supplemented with Lacto. Lactobacillus supplementations of the C-S and B-C-S diets increased (P < .05) fat and calcium, and fat, phosphorus, copper, and manganese retentions, respectively. Increased cellularity of Peyer's patches in the ileum indicated a stimulation of the mucosal immune system that responds to antigenic stimuli by secreting immunoglobulin (IgA).

Phytase activity, phosphorus and calcium retention, and performance of single comb White Leghorn layers fed diets containing two levels of available phosphorus and supplemented with direct-fed microbials.

The presence of phytase activities in condensed cane molasses solubles (CCMS) and CCMS-Lactobacillus (Lacto) were determined. Single Comb White Leghorn layers were fed .25 and .45% available P (AP) diets supplemented with CCMS and CCMS-Lacto for nine 28-d periods to determine phytase activities of the gastrointestinal (GI) tract contents and intestine, liver, and pancreatic tissues, the GI tract pH, the P and Ca retention, and layer performance. Six dietary treatments were corn-soybean (C-S) control, C-S+CCMS, and C-S+CCMS-1,100 mg Lacto/kg diet (ppm) [4.4 x 10(7) cfu/mg Lacto] each with .25 and .45% AP. The CCMS were used as a carrier for the Lacto, and the CCMS and CCMS-Lacto premix were incorporated at 2% of the diets. Phytase activity was much higher in CCMS-Lacto premix than in CCMS. Phytase activities of the crop contents were higher with the CCMS-Lacto diets regardless of the AP level. Intestinal phytase activity was higher with the .45% AP CCMS-Lacto diet than the unsupplemented .45% AP diets. Lactobacillus supplementation did not stimulate phytase activities in the intestinal contents or liver and pancreatic tissues. The pH of the crop and intestinal contents were much lower for the Lacto-fed layers than the layers fed unsupplemented diets regardless of dietary AP levels. No differences in Ca retentions were observed with Lacto supplementation regardless of the dietary AP levels. However, higher P retentions were observed with the Lacto supplementation in the .25% AP diet. Layers fed .25 and .45% AP Lacto-supplemented diets had lower hen-day egg production, poorer feed conversion value, consumed slightly more feed, produced less egg mass, and laid larger eggs than the layers fed .25 and .45% AP unsupplemented diets. Lacto supplementation to .25% AP diet produced eggs with higher specific gravity than the unsupplemented .45% AP diet, but not different from unsupplemented .25% AP diet. Layers fed the .25% AP diets had lower BW gains then layers fed the .45% AP diets regardless of lacto supplementation. Phytase activity was present in the lacto source, and the presence of phytase and Lacto supplementation to a .25% AP diet improved P retention in layers.

Dietary pyrrolizidine (Senecio) alkaloids and tissue distribution of copper and vitamin A in broiler chickens.

The effect of feeding a diet containing 5% tansy ragwort (TR) (Senecio jacobaea), a poisonous plant containing pyrrolizidine alkaloids (PA), on the blood and liver levels of copper, zinc, iron and vitamin A in broiler chicks was examined. Serum and liver copper and liver iron concentrations were increased in chicks fed a diet with 5% TR, while serum and liver zinc and vitamin A decreased. When PA were removed from the diet, partial restoration of normal serum vitamin A level occurred, indicating that the ability to mobilize liver vitamin A is not irreversibly inhibited by PA. The decline in serum vitamin A occurred by 8 days of TR feeding with a concurrent decline in growth rate. When chicks were fed a diet high in vitamin A (25,000 IU/kg), followed by a basal diet containing TR, serum vitamin A levels were significantly (P < 0.01) decreased, while liver vitamin A level increased. This indicates that mobilization of previously stored vitamin A from the liver is impaired by PA. Prior feeding of a high vitamin A level resulted in protective effects against PA toxicity, as assessed by histopathology. This study shows that a dietary source of PA modifies metabolism and tissue distribution of minerals and vitamin A.

Comparative effects of the polychlorinated biphenyl mixture, Aroclor 1242, on porphyrin and xenobiotic metabolism in kidney of Japanese quail and rat.

1. Aroclor 1242 (500 mg/kg, p.o.) produced a marked increase in porphyrin content of quail kidney (1800-fold), and of rat kidney but to a lesser extent (6-fold). 2. delta-Aminolevulinic acid synthetase activity was increased 12-fold in quail kidney but was unchanged in rat kidney following Aroclor 1242 treatment. 3. Uroporphyrinogen decarboxylase activity was significantly inhibited in quail kidney but not in rat kidney. 4. Renal ethoxyresorufin O-deethylase activity was induced in rat and quail whereas renal ethoxycoumarin O-deethylase and glutathione S-transferase activities were induced only in rats by Aroclor 1242.

The broiler chicken as a model for immunotoxicity assessment. 1. Standardization of in vitro immunological assays.

The broiler chicken was developed as an alternative animal model to laboratory rodents for immunotoxicologic assessment. In vivo treatment with 100-200 mg/kg cyclophosphamide (CY) was used as a known immunosuppressive treatment to standardize the assay systems. Protocols for assessing specific immunological functions were developed in specific pathogen-free (SPF) broilers to measure lymphocyte blastogenesis to T-cell (concanavalin A and phytohemagglutinin) and B-cell (Staphylococcus aureus cells) mitogens, delayed-type hypersensitivity (DTH) to tuberculin, natural killer (NK) cell cytotoxicity, plaque-forming cell (PFC) response to sheep red blood cells (SRBC), and serum antibody titers to SRBC. CY was an effective immunosuppressant in the broiler system for assessment of lymphocyte responsiveness to mitogenic stimulation, DTH reactivity, and the antibody response to SRBC as assessed by PFC and serum antibody titers. NK cytotoxicity was not altered on a cellular level following treatment with CY at a dose that produced greater than 75% depletion of spleen cellularity. However, under these conditions, it must be assumed that the capacity of CY-treated birds to mediate NK effector functions would be reduced. These results demonstrate the applicability of the broiler chicken as an animal model for immunotoxicity testing.

Toxicity of excess dicalcium phosphate in the diet of turkey poults.

High mortality in 1-week-old commercial turkey poults was attributed to the accidental substitution of dicalcium phosphate in the diet for corn. At necropsy of the affected birds, lesions were observed in the upper gastrointestinal tract, suggesting acute ingestion of a caustic substance. Mortality and gross and microscopic lesions were reproduced experimentally in turkey poults fed diets similar to the diet fed in the field case. The cause of these lesions was attributed to increased pH due to the phosphoric acid content of the diet.

Reproductive performance of medium white breeder toms fed diets with varying metabolizable energy levels and 7% crude protein.

An experiment was conducted to study the effects of feeding diets composed of triticale (var: Flora) with varying ME levels and 7% CP on fertilizing capacity and semen quality of Medium White breeder toms. Thirty-nine breeder toms were fed ad libitum from 30 to 54 wk of age one of four dietary treatments: 14% CP with 2,892 kcal ME/kg; 7% CP with 2,919 kcal ME/kg; 7% CP with 2,719 kcal ME/kg; and 7% CP with 2,539 kcal ME/kg. Semen volume (SV), packed spermatozoa volume (PSCV), BW, testicular weight (TW), and fertilizing capacity of semen were measured. No differences for SV, PSCV, TW, calculated daily feed, and estimated energy consumption were observed among the dietary energy levels fed. The estimated daily protein intake was higher (P less than .05) for toms fed the 14% 2,892-ME diet than 2,539, 2,719, and 2,919-ME diets containing 7% CP. The 7% 2,919-ME diet reduced (P less than .05) the fertilizing capacity of spermatozoa, whereas the 7% 2,539-ME diet decreased the percentage of fertile eggs hatched. Under the conditions of this experiment, Medium White breeder toms maintained fertilizing capacity and semen quality when provided a diet containing 7% CP with 2,719 kcal ME/kg.

Effects of polychlorinated biphenyls on porphyrin synthesis and cytochrome P-450-dependent monooxygenases in small intestine and liver of Japanese quail.

The effects of acute exposure to polychlorinated biphenyls (PCBs) on porphyrin synthesis and cytochrome P-450-dependent monooxygenases in the small intestine and liver were studied in male Japanese quail. The birds were dosed orally with the PCB mixture, Aroclor 1242, or the individual PCB isomers, 2,4,2',4'-tetrachlorobiphenyl (2-TCB) and 3,4,3',4'-tetrachlorobiphenyl (3-TCB), and were killed 48 h later. All the PCB compounds caused a significant increase in porphyrin content and delta-aminolevulinic acid synthetase (ALA-S) activity in the small intestine and liver. Increases in porphyrins were greater in the small intestine than in liver. However, a smaller increase in ALA-S activity occurred in the small intestine than in liver, suggesting that ALA-S induction is not a major mechanism for the increased porphyrin content of small intestine. All the test compounds significantly increased the cytochrome P-450 content of liver. In the small intestine, cytochrome P-450 content was increased by Aroclor 1242 and 2-TCB but not by 3-TCB. The activity of 7-ethoxyresorufin O-deethylase, however, was increased by all test compounds in both liver and small intestine. In contrast, there was a striking difference between small intestine and liver in the induction of 7-ethoxycoumarin O-deethylase (ECOD) activity by Aroclor 1242. In the liver, ECOD activity was unchanged or decreased, but in the small intestine, ECOD activity increased linearly with dose. No tissue difference in ECOD activity was observed after treatment with 2-TCB or 3-TCB. These findings suggest that acute exposure to a given PCB results in marked differences between small intestine and liver in porphyrin metabolism and in the induction of cytochrome P-450 isozymes and associated monooxygenases.

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

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

Accumulation rate in the whole blood of market turkeys fed prophylactic and therapeutic levels of sulfadimethoxine.

A study was conducted to determine the accumulation of sulfadimethoxine (SDM) in the blood of market turkeys. Fifty-two 12-week-old female turkeys were fed SDM at either prophylactic or therapeutic levels, .00625 and .03125% (w/w), respectively, for 24 days. A semiqualitative test, the Whole Blood Sulfa Test (WBST), was used to determine sulfa levels in the whole blood. Blood samples were obtained at 0, 3, 6, 12, and 24 hr for the first day for both groups after the incorporation of SDM in the feed. Blood sampling was continued at 2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 days in the prophylactic treatment and at 2, 3, 12, and 24 days in the therapeutic treatment. Six birds were chosen at random from each drug level for the sampling period. The blood concentration of SDM reached a plateau of about 1 ppm after 15 days of feeding with the highest level of about 1.2 ppm attained at 14 days in the prophylactic treatment. In the therapeutic treatment, the level of SDM in the whole blood leveled at 24 hr at approximately 4 ppm, and the highest levels of 30 ppm were attained at 11 days on the drug.

Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens' volcanic ash dust.

Fourteen hundred broilers were exposed to Mt. St. Helens' volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day).

Effects of chlorobenzenes on hepatic porphyrin and drug metabolism in chick embryo and day-old chick.

Administration of monochlorobenzene (MCB), p-dichlorobenzene (DCB), or 1,2,4-trichlorobenzene (TCB) at single doses of 800 mg/kg produced an increase in the total porphyrin content of liver of day-old chicks. Porphyrinogenic activity was higher in DCB- and TCB-treated chicks than in MCB-treated chicks. Administration of any of these compounds to chick embryos (40 mg/egg) failed to produce an induction of liver porphyrins. TCB enhanced the excretion of porphyrin in bile of chicks but not of chick embryos. In day-old chicks TCB increased hepatic cytochrome P-450 levels and the activity of 7-ethoxyresorufin deethylase. However, 7-ethoxycoumarin deethylase activity was decreased while cytosolic glutathione S-transferase activity was unchanged. These results point out the differential response of chick embryos and day-old chicks to chlorobenzene-induced changes in porphyrin metabolism as well as the differential induction of microsomal monooxygenases in chicks by TCB.

Differential induction of hepatic drug metabolizing enzymes in Japanese quail by 1,2,4-trichlorobenzene.

The effects of single oral administration of 1,2,4-trichlorobenzene (TCB), 200, 400, 800 or 1600 mg/kg, and of daily oral administration of TCB, 400 mg/kg, for 3 consecutive days, on components of the microsomal monooxygenase system, glutathione, and the activities of cytosolic glutathione S-transferase and microsomal epoxide hydrolase in Japanese quail liver were studied. Cytochromes P-450 and b5 contents of liver microsomes and the activities of 7-ethoxyresorufin deethylase (7-ERD) and glutathione S-transferase were significantly increased 1 day after administration of single doses of TCB. Liver GSH and 7-ethoxycoumarin deethylase (7-ECD) activity were unchanged. Microsomal epoxide hydrolase activity was significantly decreased at TCB doses above 400 mg/kg. Increases in cytochromes and activities of 7-ERD and glutathione S-transferase were also seen following the 3-day administration of TCB, 400 mg/kg. In addition, liver GSH and the activity of NADPH-cytochrome c reductase were significantly increased whereas 7-ECD was significantly decreased by the 3-day treatment. These findings indicate that in Japanese quail, TCB is an inducer of 7-ERD and glutathione S-transferase but not of 7-ECD and epoxide hydrolase.

Studies on the porphyrinogenic action of 1,2,4-trichlorobenzene in birds.

The porphyrinogenic action of 1,2,4-trichlorobenzene (TCB) was examined in 17-day-old embryos, day-old chicks, 18-day-old chickens and adult Japanese quail. The quail was found to be the most sensitive species towards TCB induced porphyria whereas the chick embryo was totally non-responsive. The liver porphyrins of Japanese quail were increased in a dose-dependent manner 1 day after TCB. Elevation in porphyrin levels in quail was associated with comparable increases in delta-aminolevulinic acid synthetase (ALA-S) activity 1 day after TCB treatment. In contrast, ferrochelatase activity was found to be unchanged 1 day after TCB. Multiple administration of TCB produced only a slight increase in liver porphyrin levels and ALA-S activity in quail. However, there was a marked induction in ferrochelatase activity suggesting increased porphyrin turnover. Liver glutathione and glutathione S-transferase activity were also significantly increased following repeated administration of TCB in quail, which could indicate an enhancement of detoxication of reactive metabolites of TCB. Thus, it is suggested that the inability of low multiple doses of TCB to cause porphyria in Japanese quail may be related to the low responsiveness of ALA-S but high inducibility of ferrochelatase liver GSH and glutathione S-transferase.

Anticoccidial drugs and duckling performance to four weeks of age.

Frequently, publications pertaining to waterfowl state that medicated feeds should not be fed to ducklings and goslings. In some localities, producers and hobbyists who raise a small number of ducklings and goslings can purchase only medicated chick, turkey, or gamebird starter and grower feeds. Because of the lack of documented information on this subject and the numerous requests for advice on this matter, anticoccidial drugs, zoalene, sulfaquinoxaline, and amprolium, were mixed in mash feed and fed to Khaki Campbell male ducklings to 4 weeks of age. No significant differences in mean body weight, mortality, and anatomical development were observed among the treatments. Medicated commercial crumble turkey and chick starter feeds produced significantly better feed conversion than the mash medicated or nonmedicated feeds. These differences can be attributed to greater feed spillage with the mash feed. Some ducklings in all treatments showed unsteadiness of gait and shaky legs. These conditions disappeared when the ducklings were moved from the battery brooder to an outside pen. Zoalene, sulfaquinoxaline, and amprolium used at the recommended levels for chickens and turkeys did not cause any leg or anatomical problems in ducklings.

Distribution of inorganic elements of poultry house dust.

Distribution of inorganic elements was measured in poultry house dust from five types of poultry houses during either winter, spring, or summer. With varied environmental conditions at the time of sampling, the levels of calcium, sodium, iron, zinc, magnesium, and aluminum were higher than the other elements found in dust samples from the five types of poultry houses. The most abundant element in poultry house dust was calcium. The level of this element samples from the mechanically ventilated house used for research purposes corresponded closely to the level found in the feed fed at sampling time. High zinc levels in layer houses may be attributed to either the abrasive actions of feathers and feet of layers against the galvanized wire cages on the high zinc content in feathers. The ash content of dust from the five types of poultry houses ranged from .31 to 3.54%. Air particulate counts for particles ranging in size from .5 to 10 micro meter were much higher in the layer house used for commercial purposes (ranged from 34.9 to 66.3 X 10(6) /m3) than in the layer houses used for research purposes (ranged from 5.8 to 9.8 X 10(6)/m3) than the level during summer (66.3 X 10(6)/m3). The commercial broiler house was dustier than the commercial layer house during the summer.