The objective of this study was to determine the effect of dietary pistachio by-product (PBP) dietary inclusion on sperm fatty acids profile. Fifteen fertile rams (mean live weight 55.9±1.21 kg, 2.5-3 years old) were randomly allocated to three groups (0 (C), 12.5 (T1) and25 % (T2)) to investigate the effect of different levels of pistachio by-product for 120 days. Semen was collected in breeding season of Iranian sheep at twice a week from August 2, 2014 to December 2, 2014. The semen quality parameters were recorded for semen volume, percentages of motile and progressively motile sperm, normal morphology and sperm viability. The profile of fatty acids in the seminal plasma membrane of the rams was determined by GC. These data were analyzed by one-way ANOVA using SAS software package. The results showed that all fatty acid profiles did not show significant differences between C and T1 groups but at the end of the feeding phase, C17-1, C22-6-n-3, C18-2-Cis and C22-6 n-3 (p<0.05) concentrations decreased with increasing PBP level in T2 group, whereas C18-0 and C18-1-Cis (p<0.05) concentrations increased with the addition of PBP to the diet on T2 group. Other fatty acids were similar between control and treatment groups at this stage. The ratio of unsaturated to saturated fatty acids was significantly differences (P<0.05). These results indicate that adding 12.5% PBP as a cheap by-product could be economically reasonable for extended times in rams.
