Pharmacotoxicological aspects of nitrate and nitrite in domestic fowls

1. The effects of nitrates and nitrites on growth, erythrocytic count, liver and kidney functions, humoral and cell mediated immune responses in cockerels were investigated. 2. Sodium nitrate (4.2 g/kg diet) and sodium nitrite (1.7 g/kg) retarded growth, caused methaemoglobinaemia and changes in erythrocytic count, serum concentrations of glutamic-pyruvic transaminase, creatinine and urea. 3. Cockerels given nitrate or nitrite in the food had reduced haemagglutination responses after injection of sheep erythrocytes and a reduced delayed hypersensitivity reaction to purified protein derivative tuberculin following sensitisation to Bacille Calmette Guerin. 4. Nitrates and nitrites are environmental pollutants present in food and water and they may contribute to the aetiology of liver and kidney diseases and problems related to failure of immunity in domestic fowls.     

Characterization of the toxicity of the mycotoxins aflatoxin, ochratoxin, and T-2 toxin in game birds. II. Ringneck pheasant.

Ringneck pheasants were fed diets containing 1.25, 2.5, or 5 ppm aflatoxin; 1, 2, or 4 ppm ochratoxin A (OA); or 4, 8, or 16 ppm T-2 toxin. Severe toxin-induced mortality was seen during the first to third weeks with 2.50 and 5.00 ppm aflatoxin (92.5% and 97.5%, respectively), compared with the mortality in control pheasants fed no toxin (0%). Slight mortality (less than or equal to 5%) was seen with OA and T-2 toxin. Body weights were significantly decreased by the lowest level (1.25 ppm) of aflatoxin by 2 weeks of age, by the two highest levels of aflatoxin by 1 week of age, and by 16 ppm T-2 toxin by 1 week of age. The feed-conversion ratio was increased by 2.50 and 5.00 ppm aflatoxin compared with the feed-conversion ratio in controls, although high mortality may have influenced the results. Aflatoxin had no effect on liver weight, but OA increased kidney weight in 3-week-old pheasants. Mouth lesions were seen in some of the pheasants fed T-2 toxin.     

Activities of biotransformation enzymes in pheasant (Phasianus colchicus) and their modulation by in vivo administration of mebendazole and flubendazole

Basal activities of certain pheasant hepatic and intestinal biotransformation enzymes and modulation of their activities by anthelmintics flubendazole (FLBZ) and mebendazole (MBZ) were investigated in subcellular fractions that were prepared from liver and small intestine of control and FLBZ or MBZ treated birds. Several oxidation, reduction and conjugation enzyme activities were assessed. In the liver, treatment of pheasants by FLBZ or MBZ caused very slight or no changes in monooxygenase activities and conjugation enzymes. More significative changes were detected in small intestine. Metyrapone and daunorubicin reductase activities were increased by both substances in the liver. This is the first evidence that certain benzimidazoles modulate reductases of carbonyl group. With respect to the relatively slight extent of the changes caused by FLBZ or MBZ we can assume that repeated administration of therapeutic doses of both FLBZ and MBZ has probably no serious influence on pheasant biotransformation enzyme system.     

The chronic toxicity of inorganic mercury in goats: clinical signs,toxicopathological changes and residual concentrations

Chronic mercury toxicity was induced in goats by administering mercuric chloride at 100 µg/ml in deionized drinking water offered ad libitum for 90 days. Toxic signs of gastrointestinal disturbances and renal dysfunction developed from 43 days onwards without any mortality. The toxicity also induced nephrosis and tubular nephritis; centrilobular necrosis of liver; mild to moderate necrosis in spleen, intestine and lymph node; Zenker's degeneration of cardiac muscles; exudative pneumonia; and pial congestion, oedema and vacuolation in the brain. In addition, hyperaemia, oedema and tissue haemorrhages were evident in most of the organs. The kidneys contained the largest residues of mercury, followed by liver, spleen, intestine, lymph node, skeletal muscles, lungs, heart, brain and the omental fat. The intensity of the cytotoxic changes in the various organs was proportional to the amount of mercury accumulated.     

Methemoglobinemia in pigs and the effect of nitrites on the health and growth of piglets

In 357 pigs of ten age categories fed the commercial feed mixtures the highest methemoglobinemia was found in piglets up to three days of age (3.62%) and the lowest in sows and boars (2.25%). In twelve per cent of animals of the whole set the values of methemoglobin (MHb) reached or exceeded 4%, the maximum was 8.1%, without any clinical symptoms. Except the anemic piglets, these values were not observed in sucking piglets older than three days. Testing of the formation and of the subsequent reduction of methemoglobin in vitro by the action of 14.4 micrograms of sodium nitrite in 1 ml of blood proved no increased disposition to methemoglobinemia in new-born piglets. The levels with 29 to 40% of methemoglobin reached their peaks in all age groups within 50 min. The reconversion was the slowest in adult pigs, the quickest in new-born and weaned piglets; after seven hours the reconversion was almost complete. If recalculated to the initial concentration of hemoglobin, its highest transformation to methemoglobin occurred in older and adult pigs, the lowest in the piglets up to the age of six days and at sideropenic anemia. Short-term administration of sodium nitrite to sows prior to delivery resulted in an increased methemoglobin level in new-born piglets, out o of which 12% were still-born. The repeated administration of sodium nitrite to the sucking piglets (33 to 132 mg per day) influenced neither their health condition nor the body weight gains. The effects of nitrates, nitrites and mechanisms of the reconversion of methemoglobin to hemoglobin are discussed.     

Safety,bioavailability and mechanism of action of nitric oxide to control Bovine Respiratory Disease Complex in calves entering a feedlot

Bovine Respiratory Disease Complex (BRDc), a multi-factorial disease, negatively impacts the cattle industry. Nitric oxide (NO), a naturally occurring molecule, may have utility controlling incidence of BRDc. Safety, bioavailability, toxicology and tolerance/stress of administering NO to cattle is evaluated herein. Thirteen, crossbred, multiple-sourced, commingled commercial weaned beef calves were treated multiple times intranasally over a 4 week period with either a nitric oxide releasing solution (treatment) or saline (control). Exhaled NO, methemoglobin percent (MetHg) and serum nitrites demonstrated biological availability as a result of treatment. Cortisol levels, tissue nitrites, behavior and gross and macroscopic pathology of organs were all normal. Moreover, preliminary in vitro studies using Mannheimia haemolytica, Infectious Bovine Rhinotracheitis, Bovine Parainfluenza-3 and Bovine Respiratory Syncytial Virus, suggest a potential explanation for the previously demonstrated efficacy for BRDc. These data confirm the bioavailability, safety and lack of residual of NO treatment to cattle, along with the bactericidal and virucidal effects.     

Effects of herbicides (Gramoxone and Defenuron) on the development and protein levels of quail (Coturix coturix japonica)]

The herbicides Gramoxone (active substance paraquat dichloride) and Defenuron (active principle N-phenyl-N'-methylurea) were studied as influencing the development of the Japanese quail (Coturnix coturnix japonica) and the proteins in their blood serum. The aqueous solution of Gramoxone (500 ppm), applied to the egg surface, reduces the hatchability percentage and delays hatching. Under similar conditions, Defenuron has no inhibitory effect on embryonal development. Gramoxone in drinking water (100 ppm) causes 100% mortality of young quail within a week's time whereas the same amount of Defenuron does not affect the vitality of the birds. Sublethal concentrations of Gramoxone in drinking water (40 ppm) cause great quantitative changes in the proteinogram of the blood serum of the birds. The herbicide Defenuron does not influence the proteinogram even at a concentration of 100 ppm of the active substance in drinking water.     

饮水型酸化剂对蛋鸡免疫功能及血清、肝脏和肾脏相关生化指标的影响

试验旨在研究饮水型酸化剂对蛋鸡免疫功能及血清、肝脏和肾脏相关生化指标的影响。将1500只18周龄的蛋鸡随机分为3组,每组5个重复,每个重复100只鸡。对照组全程饮用自来水,试验组A每天自由饮用酸化剂预调水8 h,试验组B隔天自由饮用酸化剂预调水8 h。分别在23、32和43周龄统计各组蛋鸡免疫器官指数,利用试剂盒检测血液、肝脏和肾脏的相关生化指标。结果显示:与相比对照组,①添加饮水型酸化剂能够提升23和32周龄蛋鸡脾脏指数(P<0.05);②添加饮水型酸化剂能够降低23和32周龄蛋鸡血清炎症因子水平(P<0.05);③添加饮水型酸化剂能够降低蛋鸡血清MDA、BUN、LDL-C和TG含量以及GPT和GOT活性,并提升T-AOC活性(P<0.05);④添加饮水型酸化剂能够使蛋鸡肝脏MDA含量下降,T-AOC活性升高(P<0.05),对肝脏SOD、GPT和GOT活性及TG和LDL-C含量变化未产生显著作用(P>0.05);⑤添加饮水型酸化剂对蛋鸡肾脏的MDA、T-AOC和SOD未产生显著影响(P>0.05)。由此可见:添加饮水型酸化剂能够提高蛋鸡机体免疫力,提升血液和肝脏抗氧化能力,缓解蛋鸡肝脏损伤和产蛋前期肾脏损伤,并能够一定程度上降低蛋鸡血清TG和LDL-C水平。     

小麦可溶性非淀粉多糖对大鼠肠道形态与功能的影响

试验采用单因素随机区组设计,研究在玉米淀粉-酪蛋白纯合日粮的基础上梯度添加0%、2%、3%、4%小麦可溶性非淀粉多糖(non-starch polysaccharides,NSP)对大鼠肠道形态与功能的影响。选用48只SD雄性大鼠随机分为4个处理,每处理6个重复,每重复2只大鼠。结果表明,随着日粮中可溶性NSP水平的提高,大鼠小肠各段绒毛高度线性降低(P0.05),大鼠十二指肠、空肠的隐窝深度线性增加(P0.05),大鼠小肠腐胺和精胺的含量线性提高(P0.05),大鼠盲肠乙酸、丙酸、丁酸及总挥发性脂肪酸的含量线性提高(P0.05)。     

Effect of Formic Acid and Plant Extracts on Growth,Nutrient Digestibility,Intestine Mucosa Morphology,and Meat Yield of Broilers

The effect of formic acid and 2 plant extracts on performance traits, apparent ileal digestibility (AID), intestine mucosa morphology, and meat yield of broilers was studied in a 49-d experiment. There were 6 treatments: a negative control diet without additives (control); 10 ppm of avilamycin; 5,000 of formic acid; 10,000 ppm of formic acid; 200 ppm of plant extract based on a blend of oregano, cinnamon, and pepper essential oil; and 5,000 ppm of hydroalcoholic plant extract from sage, thyme, and rosemary leaves. A total of 312 Ross chicks were distributed into 24 groups of 13 in each, comprising 4 replicates per treatment. The performance data revealed significantly better FCR in all the supplemented diets except for the 5,000 ppm of hydroalcoholic plant extract diet. All additives improved AID of nutrients. Both acidifier inclusion levels improved villus height, and the group fed the 10,000 ppm of formic acid diet also had the greatest crypt depth; however, villus surface area was not influenced. Meat yield was not affected. It was concluded that the diets with 5,000 and 10,000 ppm of formic acid, and with 200 ppm of plant extract based on a blend of oregano, cinnamon, and pepper essential oils were similar to avilamycin and were beneficial for improving growth traits and nutrient AID. Furthermore, a positive effect of formic acid on intestine mucosa was observed. This experiment involved a small sample, so the additives that showed beneficial effects should be further studied in commercial farms.     

Experimental enteric infection of gnotobiotic piglets with Chlamydia suis strain S45

Enteric chlamydial infections of pigs with Chlamydia (C.) suis are frequent and often subclinical. The enteric pathogenicity of C. suis strain S45 was investigated in gnotobiotic piglets. Piglets from three litters (n=31) were inoculated with egg-grown chlamydiae at 2-3 days of age (n=17) or used as controls (n=14). They were observed for clinical signs, killed and necropsied sequentially at 2-13 days postinoculation (DPI). Feces were collected daily and investigated with an ELISA for chlamydial antigen. At necropsy, specimens were collected for histopathology and for immunohistochemical, PCR-based, and serological (complement fixation test, ELISA) detection of chlamydiae. Chlamydial replication and associated symptoms and lesions were observed from 2 to 13 DPI and were particularly pronounced within the first week PI. Clinical symptoms consisted of moderate-to-severe diarrhea, slight and transient anorexia, weakness and body weight loss. Immunohistochemistry and ELISA revealed that chlamydial replication was particularly marked at 2-4 DPI and primarily located in the small intestinal villus enterocytes. Further sites of replication included large intestinal enterocytes, the lamina propria and Tunica submucosa, and the mesenteric lymphnodes. Histopathological changes included moderate-to-severe villus atrophy with flattened enterocytes and focal villus tip erosions, and moderate mucosal inflammatory cell infiltrates and lymphangitis in the small intestine. PCR of spleen tissue and blood was mostly negative for chlamydiae, indicating that they did not substantially disseminate into the host up to 13 DPI. All sera were negative for anti-chlamydial antibodies. In conclusion, C. suis strain S45 elicited significant enteric disease and lesions in gnotobiotic piglets indicating its pathogenic potential for swine.     

Fermented wheat in liquid diets: effects on gastrointestinal characteristics in weanling piglets

Effects of adding fermented wheat to liquid diets on gastrointestinal characteristics in weanling piglets were studied. Gastrointestinal characteristics of 40 28-d-old weanling piglets were measured at the day of weaning (d 0) and at d 4 and 8 after weaning. Piglets were group-housed and fed twice daily. Feeding level was based on the average metabolic BW of piglets per group. Groups were fed a liquid diet with either 45% unfermented wheat (FERM_0) or 45% fermented wheat (FERM_45). The other 55% of the diet was identical. To ferment wheat, water at 30 degrees C was added to milled wheat in a 1:2.2 ratio. The pH and contents of lactic acid, acetic acid, propionic acid, and butyric acid were measured in the digesta of the stomach, three parts of the small intestine, cecum, and large intestine. In addition, changes in microbial populations in the digesta were studied during the period after weaning. Moreover, villus height, crypt depth, and villus shape were studied in the small intestine. Piglets fed FERM_45 showed lower gastric pH (P < 0.05) at d 4 and higher gastric lactic acid content (P < 0.001) at both d 4 and 8. Piglets fed FERM_45 showed in the first part of the small intestine higher villus height (P < 0.01) at d 8 and higher villus:crypt ratio (P < 0.001) at both d 4 and 8. Villus shape tended (P < 0.10) to be favorable for piglets fed FERM_45. The present study indicates that feeding a partly fermented liquid diet to weanling piglets may be a concept to prevent undesirable changes in mucosal architecture after weaning.     

Xylanase and beta-glucanase supplementation improve conjugated bile acid fraction in intestinal contents and increase villus size of small intestine wall in broiler chickens fed a rye-based diet

This study was performed with growing chickens (4 to 22 d of age) to evaluate the effects of feeding a rye-based diet supplemented with commercial enzyme preparation containing xylanase and beta-glucanase (Quatrazyme HP, Nutri-Tomen, France) on small intestine wall morphology, bile acid composition, nutrient digestibility, and bird performance compared with unsupplemented rye- or corn-based diets. The rye-based diet decreased (P < or = 0.05) weight gain, feed intake, and feed efficiency and increased water intake compared with the corn-based diet. Moreover, rye consumption reduced crude fat and protein digestibility as well as apparent metabolizable energy (P < or = 0.05). The small intestine wall showed that villus length, width, and surface were decreased in broiler chickens fed the rye-based diet compared with those fed the corn-based diet. However, crypt morphometry parameters were not affected by diet type. The concentration of conjugated bile acids in the small intestine contents of broiler chickens fed the rye-based diet was decreased (P < or = 0.05) compared with those fed the corn-based diet. These findings suggest that feeding a rye-based diet reduces villus capacity for nutrient absorption and bile acid capacity for fat solubilization and emulsification, resulting in decreased bird performance. The addition of xylanase and beta-glucanase to the rye-based diet improved (P < or = 0.05) weight gain, feed intake, and feed efficiency, and decreased water intake. The digestibility of nutrients and apparent metabolizable energy were also increased (P < or = 0.05). Addition of xylanase and beta-glucanase increased (P < or = 0.05) villus size and the villus height-to-crypt depth ratio, as well as the concentration of conjugated bile acids (P < or = 0.05) in the small intestine contents. Exogenous enzymes improved nutrient digestibility and broiler chicken performance, probably by improving the absorption capacity ofthe small intestine through increased villus surface and intestinal concentration of conjugated bile acids.     

Kidney structure and responses of two commercial single comb White Leghorn strains to saline in the drinking water.

1. Growing pullets from two commercial strains were provided with saline (10 g sodium chloride) drinking water for three days to assess in vivo the urinary concentrating capacity of their kidneys. 2. Most of the pullets from strain A continued to gain body mass while drinking saline, indicating their kidneys conserved free water by forming a concentrated urine. Most pullets from strain B lost body mass while drinking saline, indicating their kidneys were unable to concentrate the urine sufficiently to obtain free water from the saline. 3. High proportions of large (0.23 to 0.42 mm circumference) glomeruli were found in the kidneys of pullets that gained body mass while drinking saline, whereas high proportions of small (0.07 to 0.18 mm circumference) glomeruli were found in the kidneys of pullets that lost body mass while drinking saline. 4. Glomerular sizes did not differ significantly when male birds of the two strains were compared. Urine from males of strain A had significantly (P less than 0.05) lower concentrations of hydrogen ions than urine from males of strain B, but no further differences were detected in comparisons of urine flow rates, glomerular filtration rates, renal plasma flow rates, urine osmolality, free water clearance, or sodium or potassium excretion rates.     

Artificial rearing influences the morphology,permeability and redox state of the gastrointestinal tract of low and normal birth weight piglets

Background: In this study the physiological implications of artificial rearing were investigated. Low(LBW) and normal birth weight(NBW) piglets were compared as they might react differently to stressors caused by artificial rearing. In total, 42 pairs of LBW and NBW piglets from 16 litters suckled the sow until d19 of age or were artificially reared starting at d3 until d19 of age. Blood and tissue samples that were collected after euthanasia at 0, 3, 5, 8 and 19 d of age. Histology, ELISA, and Ussing chamber analysis were used to study proximal and distal small intestine histomorphology, proliferation, apoptosis, tight junction protein expression, and permeability. Furthermore, small intestine,liver and systemic redox parameters(GSH, GSSG, GSH-Px and MDA) were investigated using HPLC.Results: LBW and NBW artificially reared piglets weighed respectively 40 and 33% more than LBW and NBW sowreared piglets at d19(P 0.01). Transferring piglets to a nursery at d3 resulted in villus atrophy, increased intestinal FD-4 and HRP permeability and elevated GSSG/GSH ratio in the distal small intestine at d5(P 0.05). GSH concentrations in the proximal small intestine remained stable, while they decreased in the liver(P 0.05). From d5 until d19, villus width and crypt depth increased, whereas PCNA, caspase-3, occludin and claudin-3 protein expressions were reduced. GSH,GSSG and permeability recovered in artificially reared piglets(P 0.05).Conclusion: The results suggest that artificial rearing altered the morphology, permeability and redox state without compromising piglet performance. The observed effects were not depending on birth weight.     

Intestinal permeability in pigs during rotavirus infection.

Macromolecular permeability of the small intestine was tested in four 3-week-old gnotobiotic pigs inoculated with porcine rotavirus strain RV277 (group A). Pigs were administered 125I-labeled polyvinylpyrrolidone (molecular weight [mol wt], 40,000) orally 1 day before and 2 and 24 hours after virus inoculation, and blood samples were obtained every 6 hours. Eight hours after rotavirus inoculation, pigs had watery diarrhea. Increased permeation of 125I-labeled polyvinylpyrrolidone was not observed after clinical signs of infection had developed. Serum total protein and urea nitrogen concentrations increased slightly at the end of the study, probably as a consequence of dehydration. Differences in blood glucose concentration were not seen. At 48 hours after viral inoculation, macromolecular permeability was tested morphologically by injecting horseradish peroxidase (mol wt, 40,000) into the jejunal lumen just distally to the ligamentum colicoduodenale. After an incubation period of 20 minutes, small segments of jejunum were obtained for stereomicroscopic, histologic, and ultrastructural investigations. Moderate hyperregenerative villus atrophy was found. Ultrastructural changes of the villus epithelium were minor, and increased macromolecular permeation was not observed.     

Changes in intestinal villi, cell area and intracellular autophagic vacuoles related to intestinal function in chickens

1. Morphological changes in the intestinal villi, cell area and cell mitosis number in the duodenal epithelial cells were compared in cockerels fasted for 1, 2 and 3 d, and also when refed for 1 and 2 d after 3 d of fasting, to demonstrate whether these morphological changes are related to intestinal function. Alterations in the fine structure of vacuoles in epithelial cells were also examined in each group to investigate whether the vacuolar changes are associated with these morphological changes, and to obtain an index for judging the nutritional condition of the chicken intestine. 2. Fasting induced decreases in villus height, cell area and cell mitosis number, which recovered rapidly after refeeding, suggesting that these parameters are related to changes in intestinal function and may be useful for assessing intestinal function. 3. At 1 d of fasting, small electron-dense bodies appeared in the absorptive epithelial cells, some of them fusing with each other. As the fasting period increased, these small bodies developed to moderate-sized nascent autophagic vacuoles containing various kinds of electron-dense contents and finally became large autophagic vacuoles with electron-lucent contents. Some vacuoles showed positive acid phosphatase reactions, which indicated that they were lysosomal autophagic vacuoles containing hydrolytic enzymes. 4. After 1 d of refeeding the large autophagic vacuoles seen after 3 d fasting rapidly decreased to the small electron-dense bodies seen after 1 d of fasting. 5. These findings suggest that intestinal epithelial cells have the ability to digest their own cell components to supply nutrients during fasting by means of lysosomal active autophagic transport mechanisms: after refeeding, the epithelial cells return to the absorption of nutrients. 6.The present results demonstrate that the autophagic vacuolar changes are correlated with changes in intestinal villus height, cell area and cell mitosis number induced by fasting and refeeding; this indicates that autophagic vacuoles are a useful index of the nutritional condition of chicken intestine. The greater the number of electron-lucent vacuoles there are in the duodenal absorptive cells, the lower the nutritional condition of the chicken intestine.     

Notes on some coccidia of peafowl,pheasants and chickens

The coccidium Isospora mayuri was isolated from sick peafowl on a farm in Essex (Great Britain). This is the first British record. The oocyst morphology and an unsuccesful attempt to infect chickens are described. The degree of pathogenicity is uncertain. Oocyst production might be controlled by sulphaquinoxaline and diaveridine in the drinking water but further studies are necessary.The coccidia Eimeria phasiani, E. duodenalis and E. colchici were isolated from pheasants on an Essex estate over two years. Coccidiosis due to E. colchici in intensively raised pheasants was controlled by sulphaquinoxaline and diaveridine in the drinking water.Two attempts were made to infect pheasants with the chicken coccidium E. tenella using birds raised coccidia-free in cages. The pheasants showed no signs of infection, which contradicts the conclusions of previous authors based only on field studies.     

吉林白鹅小肠形态学发育规律

应用组织切片技术对11～53日龄吉林白鹅小肠绒毛高度、绒毛宽度、隐窝深度和肌层厚度进行测定。结果显示,小肠各段绒毛高度及宽度随日龄增加整体上呈增长趋势,空肠绒毛最长,回肠绒毛高度、宽度在39日龄达到峰值,早于空肠和十二指肠。回肠隐窝深度11～53日龄随日龄增加而增加,十二指肠和空肠隐窝深度在39日龄达到峰值,39～53日龄变浅。小肠各段肌层厚度与日龄呈正相关,回肠的肌层厚度在46日龄达到高峰,十二指肠和空肠的肌层厚度在53日龄达到高峰。小肠各段绒毛高度/隐窝深度的比值随日龄增加而增加,53日龄时空肠的绒毛高度/隐窝深度的比值最高。