بدری امیری

The aim of this study was to evaluate the effects of different levels of oak Acorn on the biodiversity of rumen epimural bacterial population using PCR-SSCP molecular technique in Merkhoz goats. A total of 24 Markhoz goats with a mean BW of 16.93±1.25 kg and an average age of 4–5 months were tested in a completely randomized design with 4 treatments and 6 replications for 105 days. Experimental treatments included 1) control diet, 2) diet containing 8% oak acorn, 3) diet containing 17% oak acorn and 4) diet containing 25% oak acorn. The results showed that the effect of diet on biodiversity of rumen bacterial epimural community was significant (P <0.001). There was no significant difference between other experimental treatments (P> 0.05), although treatments containing 8% and 17% oak had more variety than treatments containing 25% oak. Sampling site had no effect on biodiversity of rumen bacterial epimural community (P> 0.05). The highest value of Shannon index was related to ventral ruminal site and the lowest was related to reticulum. The interaction effect of diet and sampling position on biodiversity of rumen bacterial epimural community was significant (P> 0.05). The results showed that the use of oak acorn up to 17% in the diet increased the biodiversity of the of rumen bacterial epimural community, while the use of 25% oak in the diet decreased the biodiversity of the rumen bacterial epimural community.

Oak Acorn contains significant amounts of biologically active compounds including tannins. Tannins are plant polyphenolic compounds that affect the rumen microorganism. The effect of tannins depends on the species of microorganism or the source of dietary tannins. Although research has been done on the effect of tannin on the ruminal bacterial population, the effect of oak nutrition on the ruminal bacterial population needs to be investigated. Evaluation of the effects of different levels of oak Acorn on the biodiversity of rumen content bacterial populations was investigated using PCR-SSCP molecular technique in Markhoz goats.

24 Markhz goats (mean weight 16.93 ± 1.25 and mean age 4 to 5 months) were allocated to four diets in a completely randomized design. The duration of feeding with experimental diets was 105 days. Experimental treatments included 1) control diet, 2) diet containing 8% oak acorn, 3) diet containing 17% oak acorn and 4) diet containing 25% oak acorn.

The results obtained from this experiment showed that the use of different levels of oak in the diet of livestock significantly affects the population diversity of rumen microorganisms. The use of oak Acorn in comparison with the control diet increased the diversity of bacterial population containing rumen, but with increasing the level of oak Acorn in the diet, the diversity of bacterial population containing rumen was significantly reduced. The effect of diet on biodiversity of ruminal bacterial population was significant (P <0.001). The lowest value of Shannon index was related to the control treatment which was significantly different from other treatments (P <0.05). The highest value of Shannon index was related to 8% oak treatment which was significantly different from 25% oak treatment and control treatment (P <0.05). Sampling location had a significant effect on biodiversity of ruminal bacterial population (P <0.001). The highest value of Shannon index was related to ventral and ruminal position and the lowest value of Shannon index was related to dorsal ruminal position, which showed a significant difference (P <0.05). No significant difference was observed between other sites (P> 0.05).

The results showed that the use of oak acorn up to 17% in the diet increased the biodiversity of the rumen content bacterial populations, while the use of 25% oak fruit in the diet decreased the biodiversity of the rumen content bacterial populations. Sampling location had a significant effect on biodiversity of ruminal bacterial population. The highest value of Shannon index was related to ventral and ruminal position and the lowest value of Shannon index was related to dorsal ruminal position, which showed a significant difference.