The use of selected plasma enzyme activities for the diagnosis of fatty liver-hemorrhagic syndrome in laying hens

Profiles of plasma enzymes were compared in two strains of single comb white leghorn laying hens, a normal commercial strain and strain UCD-003, which is highly susceptible to fatty liver-hemorrhagic syndrome. Plasma activity of lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) averaged 194 +/- 27, 4.0 +/- 2.8, 146 +/- 20, 1.0 +/- 1.0, and 1041 +/- 268 U/liter, respectively in normal birds. Activities of LDH, GDH, AST, and ALT, but not CK, were significantly higher in UCD-003 than in normal hens. A bimodal distribution of activities of all enzymes was found in the UCD-003 hens, with some birds showing activities comparable with those of the normal hens and others with values that were 2-10 times greater than those found in normal hens. These results are consistent with the extensive hepatic lesions observed in the UCD-003 strain of birds. Average gross hemorrhagic scores from visual inspection (scale of 0-3) were 0.28 +/- 0.45 in normal birds and 1.63 +/- 0.94 in the UCD-003 birds. Even though no clear relationship was found between plasma enzyme activities and the extent of liver hemorrhage in individual birds, the UCD-003 hens consistently had average values significantly higher for plasma enzymes that indicate liver damage. The results suggest that measurement of enzyme activities indicative of liver damage in birds, particularly AST, LDH, and GDH, is a valuable tool in the diagnosis of fatty liver-hemorrhagic syndrome in a flock of layers.     

Reduced erythrocyte deformability as a possible contributing factor to pulmonary hypertension and ascites in broiler chickens.

Deformability of erythrocytes and hematological parameters in white leghorn and broiler chickens were measured at age 7, 14, 21, 28, and 35 days. For deformability testing, a simple vertical apparatus containing a polycarbonate membrane with 5-microns pores was used. This technique assesses erythrocyte deformability by measuring the filtration time of an erythrocyte suspension through the pores. There was a significant difference in filtration time between the leghorns and broilers at all sampling times. These results indicate that reduced erythrocyte deformability in broilers may be one of the predisposing factors that increase resistance to blood flow and alter the rheology of blood in the microcirculation in the lung. Increased resistance to flow may result in pulmonary hypertension, heart failure, and ascites in broiler chickens.