Improving the Nutritional Value of Ziziphus Spina-Christi using Degrading Bacteria Isolated from the Rumen

Tannins have many limiting effects on consumption, nutrient digestion, growth and performance, palatability. There are many plants and by-products that are limited in animal feed due to the high content of anti-nutritional compounds such as tannins. The use of methods that can reduce the amount of these compounds will allow their use in animal feed. The aim of the present experiment was to improve the nutritional value of Ziziphus Spina-Christi, which contains tannins and polyphenolic compounds for ruminants.

Ziziphus Spina-Christi leaves were treated with four tannin degrading bacteria including Klebsiella pneumonia, Acinetobacter spp. (isolated from deer rumen), Lactobacillus fermentum (isolated from Najdi goat rumen), and commercial Lactobacillus fermentum. In two stages, chemical composition, digestibility, and fermentation of Ziziphus Spina-Christi leaves were studied alone or in combination in a standard diet of fattening lambs by laboratory methods. Experimental treatments in the first and second stages each consisted of 5 treatments, 1- Ziziphus Spina-Christi leaves or diets containing it without processing (control), 2- to 5- leaves or diets containing it, which were treated separately with each of the four bacteria.

Gas production potential, gas production rate, truly degradable organic matter, microbial biomass production efficiency, ammonia nitrogen concentration, and protozoa population of Ziziphus Spina-Christi leaves treated with tannin-degrading bacteria increased significantly compared to the control (p<0.05). The percentage of dry matter digestibility, NDF, and ADF of the Ziziphus Spina-Christi leaves treated with tannin degrading bacteria also increased compared to the control (p<0.05). In the second phase of the experiment, gas production potential, dry matter, NDF, and ADF digestibility percentage, ammonia nitrogen concentration and protozoa population of fattening lamb diets containing processed Ziziphus Spina-Christi leaves were increased compared to the control (p<0.05). Gas production rate, partitioning factor (PF) coefficient, microbial biomass production, and microbial biomass production efficiency in diets containing processed Ziziphus Spina-Christi leaves increased compared to the control only numerically (p<0.05).

The results of this study showed that considering the positive effects of Ziziphus Spina-Christi leaves processing with tannin-degrading bacteria, it could be said that processing this plant to reduce tannin is a suitable solution for better use of Ziziphus Spina-Christi leaves in the diet.