Cartilage lesions associated with shaky-leg lameness in turkeys

Shaky-leg lameness is a poorly defined, mild to very severe, painful lameness occurring mainly in 10-to-18-week-old fast-growing male turkeys. Since there are no significant gross or microscopic lesions in early or uncomplicated cases, the cause of the lameness is likely soft-tissue (muscle or tendon) pain. A case history of a flock problem of shaky-leg lameness is described, and it is suggested that stiffness and inactivity secondary to footpad dermatitis in these turkeys was responsible for the severe shaky-leg lameness in the flock. The cartilage lesion described is an avascular lesion and appeared to be the result of inactivity rather than the cause of lameness in these turkeys.     

Ultrastructural alterations in the kidneys of Pekin ducks fed methylmercury.

Ultrastructural alterations in the kidneys of Pekin ducks were studied after subchronic exposure to methylmercury chloride. Twenty-four male and twenty-four female Pekin ducks, 12 weeks of age were fed 0.0 (control), 0.5, 5.0 and 15.0 parts per million of MeHgCl, mixed in a mash diet for 12 weeks. Birds were observed for clinical signs daily. Kidneys were fixed in situ by perfusion with 4% glutaraldehyde in 0.05 M phosphate buffer and routinely processed for electron microscopy. Only minor morphological changes were observed in the renal corpuscle of ducks in the 0.5 ppm group. The component cells of the renal corpuscle in the 5.0 and 15.0 ppm groups showed several ultrastructural alterations, including an increase in number and size of lysosomes and vacuoles in podocytes and mild vacuolation in mesangial cells. The juxtaglomerular cells of afferent arterioles had crystallized granules. No significant changes were observed in glomerular basement membrane thickness and width of podocyte pedicels. The proximal tubules of the 5.0 and 15.0 ppm groups showed some microvillar loss and an increase in the number and size of lipid droplets, vacuoles and lysosomal bodies. The distal tubular changes in the 5.0 and 15 ppm groups included electron lucency and vacuolation of cytoplasm as well as occasional mitochondrial swelling. The collecting ducts of 5.0 ppm and 15.0 ppm groups showed varying degrees of degenerative changes in both mucus secretory as well as absorptive cells. These results suggest that subchronic exposure of Pekin ducks to methylmercury chloride causes subtle ultrastructural changes in renal corpuscle and marked ultrastructural changes in proximal tubules and collecting ducts.     

Fatty haemorrhagic liver syndrome in laying hens on diets supplemented with rapeseed products.

Livers of laying hens of Hy-Line No 934E on low erucic acid rapeseed meals and rapeseed oil were studied. Gross lesions in the livers of hens on experimental diets were moderate to severe fatty degeneration, focal necrosis and moderate to severe haemorrhage. Histological examination revealed oedematous foci and lysis of hepatocytes along with large amounts of lipid droplets in the necrotic lesions. Necrotic lesions were not always associated with large haemorrhages. Connective tissue infiltration of older degenerative and haemorrhagic lesions was not extensive. Abdominal haemorrhage from livers occurred when extensive necrosis in the form of hepatocyte lysis and some vascular changes were present, suggesting hepatocytic degeneration caused by toxic products or their metabolites present in rapeseed by-products.     

Histopathologic and electron microscopic studies on the acute toxicity of ochratoxin A in rats

Ochratoxin A was given by gavage to male rats. Moribund and dead animals were necropsied, and the surviving rats, including the controls, were killed 48 hours after dosing. Many of the principal rats were moribund, or began dying, within 12 to 24 hours after dosing. Lesions suggestive of disseminated intravascular coagulation were seen by light microscopy as early as 12 hours after dosing; fibrin deposits were in the spleen, brain choroid plexus, glomerular capillaries, liver, and heart. Renal tubular nephrosis, hepatic and lymphoid necrosis, and necrotic enteritis with villous atrophy were also seen. Electron microscopy demonstrated fibrin strands mixed with degranulated platelets, necrotic leukocytes, and swollen endothelial cells in glomerular capillaries. Myocardial changes included focal supercontracted sarcomeres adjacent to intercalated disks. Swollen sarcolemma, lysed myofibrils and fragmented Z-bands with interstitial edema, vascular thrombosis, and endothelial damage were also seen. The acute pathologic changes induced by ochratoxin A in the intestine, liver, and lymphoid tissues were more obvious than the tubular nephrosis, and the development of a disseminated intravascular coagulation-like syndrome with myocardial changes was a complicating factor.     

Secretion of dopamine and norepinephrine in hypophyseal portal blood and prolactin in peripheral blood of Holstein cattle

The objective was to test the hypothesis that dopamine regulates prolactin (PRL) secretion by determining acute changes in catecholamine concentrations in hypophyseal portal blood of cattle, and their relation to peripheral blood concentration of PRL in hypophyseal stalk-transected (HST) and sham-operated controls (SOC). Holstein heifers (606 +/- 21 kg BW; mean +/- SE) were subjected to neurosurgery for 8 h to collect hypophyseal portal blood with a stainless steel cannula designed with a cuff placed under the pituitary stalk and peripheral blood via a jugular vein catheter. PRL plasma concentration was measured by radioimmunoassay, and dopamine and norepinephrine in portal plasma by radioenzymatic assay. During anesthesia before HST or SOC, PRL plasma concentration ranged from 20-40 ng/ml throughout 255 min. PRL abruptly increased and remained above 90 ng/ml after HST compared with a steady decrease to <20 ng/ml in SOC heifers throughout 440 min. Within 5 min after severing the hypophyseal stalk, dopamine in portal blood (>8 ng/ml) was significantly increased (P < 0.05) compared with peripheral blood (<2 ng/ml). Norepinephrine concentration in portal blood was significantly greater (P < 0.05) than in peripheral blood during the first 60 min. The sustained high PRL level in peripheral plasma after severing the hypophyseal stalk stimulated hypothalamic dopamine secretion from hypophyseal portal vessels during the prolonged period of blood collection. Norepinephrine concentration in these cattle was greater in hypophyseal portal than in peripheral blood, implicating both an important hypothalamic source of the catecholamine as well as an adrenal gland contribution during anesthesia.     

Moisture-dependent physical properties of jatropha fruit

The physical properties of fruit are important in designing and fabricating equipment and structures for handling, transporting, processing and storage, and also for assessing quality. The study was conducted to investigate some physical properties of jatropha fruit at various moisture levels. The average length, width, thickness and 1000 mass were 29.31 mm, 22.18 mm, 21.36 mm and 1522.10 g, respectively, at moisture content of 7.97% d.b. The geometric mean diameter increased from 24.03 to 24.70 mm and the sphericity varied between 0.82 and 0.83 as moisture content increased from 7.97% to 23.33% d.b., respectively. In the same moisture range, the bulk and true densities decreased from 278 to 253 and 546 to 435 kg m^?3, respectively, whereas the corresponding porosity also decreased from 49.08% to 41.84%. As the moisture content increased from 7.97% to 23.33% d.b., crushing strength was decreased from 275 to 79 N, whereas the angle of repose and surface areas were found to increase from 36.41° to 41.72° and 1815.73 to 1917.59 mm², respectively. The static coefficient of friction of jatropha fruit increased linearly against the surfaces of three structural materials, namely plywood (47.81%), mild steel (62.88%) and aluminium (34.82%) as the moisture content increased from 7.97% to 23.33% d.b.     

Moisture-dependent physical properties of jatropha seed (Jatropha curcas L.)

The study was conducted to investigate some moisture-dependent physical properties of jatropha seed namely, seed dimension, 1000 seed mass, surface area, sphericity, bulk density, true density, angle of repose and static coefficient of friction against different materials. The physical properties of jatropha seed were evaluated as a function of moisture content in the range of 4.75–19.57% d.w. The average length, width, thickness and 1000 seed mass were 18.65 mm, 11.34 mm, 8.91 mm and 741.1 g, respectively at moisture content of 4.75% d.w. The geometric mean diameter and sphericity increased from 12.32 to 12.89 mm and 0.66 to 0.67 as moisture content increased from 4.75 to 19.57% d.w., respectively. In the same moisture range, densities of the rewetted jatropha seed decreased from 492 to 419 kg m⁻³, true density increased from 679 to 767 kg m⁻³, and the corresponding porosity increased from 27.54 to 45.37%. As the moisture content increased from 4.75 to 19.57% d.w., the angle of repose and surface area were found to increase from 28.15° to 39.95° and 476.78 to 521.99 mm², respectively. The static coefficient of friction of jatropha seed increased linearly against the surfaces of three structural materials, namely plywood (44.12%), mild steel sheet (64.15%) and aluminum (68.63%) as the moisture content increased from 4.75 to 19.57% d.w.     

Induction of resistance against downy mildew pathogen in pearl millet by a synthetic jasmonate analogon

The synthetic 1-oxo-indanoyl-l-isoleucine methyl ester (Ind-Ile-Me) represents a highly active mimic of octadecanoic phytohormones, which are involved in plant defenses against pathogens and pests. Seed treatments and foliar spray with Ind-Ile-Me were tested for induced resistance against downy mildew disease caused by the phytopathogenic oomycete Sclerospora graminicola in pearl millet (Pennisetum glaucum) under greenhouse and field conditions. Under greenhouse conditions, a 50% protection level was achieved after seed treatment. Seed treatment in combination with foliar spray resulted in 60% protection. The induction of resistance was correlated with the enhanced activities of defense-related proteins such as phenylalanine-ammonia-lyase, peroxidase, and enhanced level of hydroxyproline-rich glycoproteins. Under field conditions, a maximum protection of 62% was recorded upon seed treatment along with foliar spray. Hence, it infers that Ind-Ile-Me can be used as a valuable protection compound at least in downy mildew disease management.