Effect of Treated Oily Waste Water of Khartoum Refinery on Nubian Goat Kids

Abstract

One of the very many imposed environmental threats of the petroleum industry internationally is its effluent of treated oily waste water (TOWW), which was reported causing mortalities in small ruminants. This study was carried out to investigate the toxic effects of TOWW of Khartoum Refinery Company (KRC) on Nubian goat kids. Twenty-one goat kids were divided into three groups: Group A (control), arranged in 1x3, and B and C (test groups) arranged in 2x3x3. Each test group was divided into three subgroups; B1, B2 and B3 and C1, C2 and C3. Groups B and C were watered for 6 weeks from KRC oxidation ponds II and III, respectively, diluted at ratios of 1:0, 1:1 and 1:2 with tap water respective to subgroups 1, 2 and 3. The control group was tap watered. All groups were fed on a basal ration of 2.86 Mcal ME/kg and crude protein 20.88% energy concentration meeting goat daily requirements. Clinical signs and mortalities were daily observed. Body weights were recorded fortnightly. Blood and serum samples were collected fortnightly for haematological (RBCs, Hb, PCV, WBCs and their differentials) and serum metabolites (glucose, total protein, albumin and globulin), enzymes (AST and ALP) and electrolytes (Ca, P, Co, Cu, Fe and Mn) examinations. Organs samples for histopathological investigations were collected on post mortem examinations or in extremis slaughter. All test groups significantly (P≤ 0.05) lost weight with variations in the total water consumption and similar average water consumption for all subgroups except C3 (P≤0.05). All test groups showed decreased appetite, diarrhoea, weakness and partial paralysis. The mortality was 100%, 66.6% and 33.3% in subgroups C1, C2 and C3, respectively. The mortality was 66.6% in subgroup B3 and 33.3% in each of B2 or B1. Haematologically, test goats were neither anaemic nor infected with haemodilutions (P≤0.05) in subgroups B3, C2 and C3. All test groups showed congestion or haemorrhage in the intestinal submucosa, with detachment of epithelium or detachment of the villi, in response to the osmotic diarrhoea. All test groups showed no significant (P>0.05) changes in serum metabolites, electrolytes or serum enzymes, but livers were congested, stressed and engorged. Bile and kidney showed shrinkage, necrosis of the glomeruli, congestion and haemorrhage in the cortical and medullary tubules. These signs were indications of intensive mineral excretion. It is concluded that TOWW from KRC has toxic effects on Nubian goat kids judged by the early mortalities and by the clinical signs of diarrhoea and recumbency, metabolic disturbances in the liver with histopathological changes in various body systems. It is recommended that TOWW initial concentration be restored by addition of equivalent water to reduce or abolish its toxic manifestations.