الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
The present study was carried out at Rabbit Farm Unit, Agricultural Researches and Experiments Station; Faculty of Agriculture, Mansoura University, EL-Mansoura, Egypt, during the period from March to July 2018. A total number of 24 California (CAL) bucks with approximately 5.3-5.5 months of age and 2316-2429 g live body weight were used in this study. Rabbit bucks were disturbed according to body weight into four experimental groups (n=6 in each). Bucks were fed on a commercial diet (CD) without supplements in the first group (Control), CD supplemented with 2% sunflower oil in the 2nd group (2% SFO), CD supplemented with 2% flaxseed oil in the 3rd group (2% FSO), or CD supplemented with 1% SFO+1% FSO in in the 4th group. During the experimental period (16 wk), live body weight (LBW) and daily feed intake (DFI) were weekly recorded, then average daily weight gain (ADG) and feed intake (FI) were calculated at 0-4, 4-8, 8-12, 12-16 and 0-16 weeks of experimental period. Lipid, testosterone and fatty acids profiles were determined in blood serum and seminal plasma. Also, fatty acids profile was determined in Diets and sperm cells. Sixty four California multiparous doe rabbits were naturally mated by five California bucks in each group. Pregnancy diagnosis was performed by abdominally palpation to calculate conception rate. After parturition, kindling rate was calculated. Total litter size at birth and sex ratio were recorded. Results obtained could be summarized as the following: 1) The differences in LBW among experimental groups at each of experimental week were not significant. However, rabbit bucks fed FSO diet tended to be the heaviest at different age weeks as compared to control and other treatments, particularly at 4 week (P<0.07) and 8 week (P<0.06). 2) The effect of dietary oil supplementation on feed intake by rabbit bucks at 4-8, 8-12 and 0-16 week intervals was not significant. However, this effect was significant (P<0.05) at 0-4 and 12-16 week intervals, being the lowest at 0-4 week, and the highest at 12-16 week for rabbits fed SFO+FO diet. These results reflected insignificant differences in feed intake at 0-16 week, although there was a tendency of higher feed intake of rabbits fed the supplemented diets in comparing with those fed control. 3) The effect of dietary treatment on body weight gain of rabbit bucks at 4-8 and 0-16 week intervals was not significant. However, this effect was significant (P<0.05) at 0-4, 8-12 and 12-16 week intervals, being the lowest for SFO+FO diets at 0-4 week, the highest for FSO or SFO+FSO diets at 8-12 week and for FSO diet at 12-16 week, reflecting insignificant differences in weight gain at 0-16 week. Generally, rabbit bucks fed SFO or FSO diet tended to have higher body weight gain than those fed control or SFO+FSO diets. 4) The differences in triglycerides and total lipids concentrations between treatment groups and control one were not significant, but triglycerides level was significantly (P<0.05) higher by FSO than SFO diet. However, phospholipids concentration was significantly (P<0.05) lower in SFO+FSO than in control and other groups. 5) Dietary oil supplementation significantly (P<0.05) increased total cholesterol and LDL concentrations with SFO and with SFO+FSO compared to control, but HDL level was not affected significantly oil supplementation. 6) The differences in activity of AST and ALT in blood serum or seminal plasma as affected by dietary oil supplementation were not significant, but AST and ALT activities were higher in seminal plasma than in blood serum. 7) The differences in testosterone profile in blood serum or seminal plasma as affected by dietary oil supplementation were not significant, and testosterone profile was higher in blood serum than in seminal plasma. 8) Dietary oil supplementation affected total fatty acids concentration and frequency distribution of fatty acids profile, including saturated (SFAs), mono-unsaturated (MUFAs), poly-unsaturated (PUFAs), omega-3 and omega-6 fatty acids as well as omega-3: omega-6 ratio in blood serum of rabbit bucks. 9) Concentration of fatty acids decreased in treatment groups as compared to control one, being the lowest in SFO+FSO group, but the differences was not significant. 10) These results indicated that FSO or in combination with SFO resulted in improving fatty acids profile in seminal plasma of rabbit bucks, in terms of decreasing proportional of SFAs and PUFA, while increased omega-3 fatty acid (C18:3-n3). 11) The SFO diet increased percentage of PUFAs especially PUFAsω6, but did not alter PUFAsω3. The FSO diet decreased percentage most SFAs, while increased MUFAs and PUFAsω6. However, SFO+FSO diet increased most SFAs and PUFAsω6, while decreased PUFAsω3. These results indicated dietary supplementation of FSO on improving fatty acid profile by increasing percentage of omega-3 fatty acids in sperm cells, rather than dietary supplementation of SFO or a combination of SFO+FSO. 12) Results of fertility trail showed insignificant effect on conception and kindling rates of rabbit does mated by bucks fed diets supplemented with different types of oils. On the other hand, litter size was significantly (P<0.05) higher for does mated by rabbit bucks fed FSO or SFO+FSO than SFO or control diets. 13) Effect of rabbit buck treatment was insignificant effect on sex ratio of bunnies born, although there was tendency of increasing female ratio and decreasing male ratio for does mated by bucks fed FSO.