Biochemical and histopathological changes in sheep fed different detoxified karanj (Pongamia glabra) seed cake as partial protein supplements

The study investigated the long-term effect of feeding processed solvent extracted karanj (Pongamia glabra) cake (SKC) on gross pathology and histopathological changes in some vital organs, and on the activities of serum enzymes in Jalauni lambs. Twenty-four male lambs were divided into 4 groups and allotted randomly to a soybean meal (SBM) based control (CON) and 3 treatment groups receiving concentrate mixtures, containing water washed (WW), 2.5% lime (LM) and 0.4% binder (BN) treated SKC replacing 50% nitrogen of SBM to meet the protein requirements. Blood was collected after 150 days from all the lambs and serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were assayed. All lambs were sacrificed after 196 days, and vital organs screened for gross pathological lesions. The representative tissues of liver, intestine, parathyroid gland, testis, and epididymis were sampled, preserved in 10% formalin and processed to examine histopathological changes by staining with haematoxylin and eosin (HE). The serum enzyme activities of AST and ALT were similar in the treatments, but the activity of LDH was higher (P < 0.01) in processed SKC-fed groups than the control. The weight and size of the liver were decreased in BN group, while those of testes were decreased in both LM and BN groups. The histological sections of the testes and epididymis of lambs from LM group showed hypoplastic seminiferous tubules and empty ductules, respectively. The histological sections of the parathyroid gland in the same diet revealed smaller and non-secretory chief cells. The small intestine of lambs from BN group showed infiltration of mononuclear cells (MNC) in lamina propria with mild fibroplasia in intervillous areas. The histological section of liver from this group showed MNC infiltration in portal areas. The inclusion of water washed SKC in the concentrate mixture of lambs did not show gross pathological and histological alterations in the tissues in the vital organs; however, the activity of LDH was significantly (P = 0.001) elevated in processed SKC-fed groups than the control. Thus, feeding of water washed SKC in the concentrate at 225 g/kg for a longer period do not cause any adverse effect in lambs. This is supported by normal activities of serum enzymes and intact histological features in the tissues of liver, intestine, parathyroid gland and testis.