Isolation and Molecular Characterization of Dromedary Lipoproteins and Screening their levels at Different Feeding Status

Abstract

Butana and Darfurian at the age of (18-24 month) and average body weight at (225.5±35 kg) were purchased from a local livestock market, used in a feeding trial for 120 days. At the start of the experiment (Camel Research Centre, Tumbool) the camels were divided into two groups as zero browsing and free browsing groups. The animals were fed complete ration composed of traditional ingredients of crushed sorghum grains as the main source of energy and groundnut cake as the major source of protein, so as to reduce the cost of feeding, sugar cane molasses and urea were incorporated as major sources of energy and nitrogen, respectively. Wheat bran was added to the diets to adjust their total metabolizable energy (ME) and crude protein contents. In addition, Dura husk (semema) was added to the concentrate diet as roughage to study the effects of fattening on dry matter intake (DMI), feed conversion ratio (FCR), feed intake , body weight gain and some blood parameters which include total protein, albumin, globulin, urea, uric acid, creatinine, glucose, total cholesterol, HDL, LDL, VLDL, triglycerides, Na, P, the activity of ALT and AST, also on the various fractions of camel lipoproteins by using polyacrylamide gel electrophoresis and the exepression of apolipoprotein B mRNA using Agarose gel electrophoresis The animals were individually weighed weekly , blood samples and tissue samples were taken weekly. Blood metabolites were measured using standard methods. The data was analysed using student (t test). The results revealed a significant increase (P< 0.05) in mean body weight and average growth rate in zero browsing groups as compared to free browsing groups. The average total gain was almost double in zero browsing groups than free browsing group. Furthermore, the study showed no significant (P<0.05) differences in the average daily gain (ADG), feed intake and Feed conversion ratio (FCR) among the types groups. The results obtained showed that the feedlot performance had significant effects on some blood metabolites and minerals concentrations. The results revealed a significant increase (P<0.05) in the concentration of plasma glucose, triglycerides, serum urea , creatinine, cholesterol, HDL- cholesterol, sodium and glutamate oxaloacetate transaminase concentrations in zero browsing group than the free browsing camels. Also there was neither apparent change in quantitative nor qualitative protein pattern distribution between zero browsing and free browsing in the LDL-rich fraction. While, there was a noticed increase in expression of protein in the HDL fraction as observed by wide protein bands at 27 KD when compared with free browsing group. Liver homogenate of lipoprotein in zero grazing group showed dense clear banding at low molecular weight in the range of 10 KD. This dense band not clearly proved to appear in the free browsing group. The specific band at 125 bp indicates the presence of the cDNA corresponds to ApoB gene in our samples with higher rate of expression in the hepatic tissue as compared to other tissues (muscles and adipose tissue). Availability of feed could induce significant physiological and biochemical changes in the camel and therefore, it is beneficial to provide concentrate feed to export camels.