Determination of Antioxidant Properties, Nutritional Value and Rumen-Intestinal Digestion of Pistacia Atlantica Leaf with Nylon Bags Method

This study was carried out to investigate the chemical composition, antioxidant properties and phenolic compounds of Pistacia atlantica leaf at different stages of growth. Intestinal digestibility of determined by nylon bags method.  In order to prepare experimental treatments, Pistacia atlantica leaf (PAL) were collected and dried in three stages (early growing season, mid and end of growing season) from foothills of the around the city of Birjand. The treatments were: 1. PAL in early growing season, 2. PAL in middle of growing season, and 3. PAL at the end of growing season. Neutral detergent fiber and acid detergent fiber was determined. The total amount of phenolic compounds was measured. The total amount of tannins was obtained by calculating the difference between before and after the reaction with polyvinyl pyrrolidone (PVP). Condensed tannin was measured. Antioxidant activity was measured by 2, 2 diphenyl-1-picaril hydrazil (DPPH). To investigate nutritional value of Pistacia atlantica leaf (PAL) by nylon bags method, two Holstein cows fitted with a flexible rumen fistula, fed forage and concentrate in total mixed ration (TMR) at maintenance level twice daily. To determine degradability coefficients, 5 g of DM of PAL sample (ground using 2 mm screen mill) were placed in individual polyester bags and feed samples were incubated for 0, 2, 4, 8, 12, 16, 24, 48, 72, 96 and 120 h. Also, ruminal and post ruminal digestibility were determined with the incubation of samples for 16 hours in the rumen by Daisy system.  The results showed with the advance stage of growth increased, percentage of dry matter, Ash, NDF and ADF. The highest amount of dry matter belonged to the end of the growing season (49.41%) and the lowest was related to the beginning of the growing season (19.51%). The highest amount of crude protein observed at the first stage (early growth) (16.41%) and the lowest at the end of the growing season (P<0.05). With the advancement of the growth stage, the percentage of NDF and ADF was increased (P <0.05). The highest average crude fat was related to the second stage (5.62%) and the lowest average was observed in the first stage (1.82%). The highest average ash was related to the end of growing season (7.27%) and the lowest average was observed in the first stage (5.58%). The highest antioxidant and phenolic compounds was observed in the early stages of growth, this amount decreased in the third stage. The most unsaturated fatty acids of this oil were linolenic acid (26.54%), linoleic acid (10.88%) and oleic acid (12.5%).Also the most saturated fatty acid of this oil was palmitic acid (18.02%). Pistacia leaf oil used in the experiment was contain a 44.85 % saturated fatty acids, 17.83 % unsaturated fatty acid with one double bond, 10.88 % unsaturated fatty acid with two double bonds and 26.54 % unsaturated fatty acids with three double bonds. With increasing incubation time degradability of dry matter and crude protein increased. The rapid part degradation of the dry matter was 28.33% and its effective degradation at the passage rates of 0.04, 0.06 and 0.08 was 48.29, 43.39 and 40.40% respectively. The lowest constant degradation rate (c) was found for crude protein (0.0137). Most effective degradability was observed in 4% pass rate. The effective degradation rate was reduced by increasing the pass rate. Ruminal digestibility of dry matter and crude protein was higher than digestibility of post-ruminal. Overall, the digestibility of dry matter in the total digestive tract was higher than crude protein digestibility. This is due to the high rumen digestibility of dry matter compared with the digestibility of crude protein. Based upon the present research it is concluded that Pistacia atlantica leaf has good degradability. It has high nutritional value and compatible or even is a good alternative to conventional feed ingredients in livestock feed. Also, Pistacia atlantica leaf is rich in phenolic compounds and antioxidant, and it can be used as an alternative to synthetic antioxidants. Due to having about 55.25 percent unsaturated fatty acids, it has a high nutritional value and could be used in livestock diets in order to enrich and enhance oxidative stability of animal products.