فهرست مطالب homayun farhangfar

This research was undertaken to evaluate the effects of roasting and extruding heat processes on chemical composition, nitrogenous fractions, urease activity, metabolic protein, properties of degradability, and the ruminal- intestinal digestibility of dry matter and crude protein of raw and processed soybeans.

This study was carried out at the Research Farm, Faculty of Agriculture, University of Birjand, Iran. During the extrusion process, soybeans were affected for 20-30 seconds at 150-160°C in the extruder by heat and pressure and finally were dried and cooled. In the process of roasting, the soybean for 15 minutes at temperature of 145°C was heated and for 45 minutes holding tank for heat storage remained. Seeds were dried and cooled by air flow, dry and cold. Approximate analysis of samples including dry matter, crude protein, crude fat and ash was determined by AOAC. The urease activity of raw and processed soybean was determined based on ISO-3896. Degradability parameters of the samples were measured after incubation for 0, 2, 4, 8, 16, 24 and 48 hours in the rumen of two fistulated Brown Swiss cows. Also, ruminal and post ruminal digestibility were determined with the incubation of samples for 12 hours in the rumen by Daisy system. The DM and CP degradation data were fitted by exponential equation: P=a+b (1-e–ct). Effective degradability (ED) were calculated using of equation ED = a + {(cb)/(c + k)} and taking into consideration passing rate (k) 0.04, 0.06 and 0.08 per hour.

The findings of the present research revealed that roasting and extruding heat processes lead to increase of dry matter through decreasing water content and that it had no significant effect on other chemical composition. The findings showed that the process of roasting and extruding caused the amount of actual protein of the soybean to increase and was not effective on the amount of insoluble nitrogen in neutral detergent of the soybean. The non-protein nitrogen and nitrogen dissolved in the buffer soybean under the influence of roasting and extruding decreased. The amount of acid detergent insoluble nitrogen soybean decreased which might be due to the removal of some of the shells in the processing soybean has taken place or influence of roasting and extruding decreased. The urease inhibitor of the soybean became inactive by the process of roasting and extruding. Consequently, it caused intestinal protein digestibility to increase and affected by thermal process, the amount of metabolic protein of the soybean increased significantly, too. The process of roasting and extruding reduced the rapid part degradation of dry matter of the soybean (6.27 and 4.57 percent, respectively). Also, process of roasting and extruding caused the slow part of degradation to increase (of 63.75 to 74.73 and 63.25 to 85.82 percent, respectively). In addition, the rate constants degradation of dry matter of the soybean in rumen decreased (of 6.66 to 4.21 and 6.09 to 4.74 percent) under the influence of roasting and extruding. The process of roasting and extruding reduced the rapid part degradation of crude protein (38.4 and 68.4 percent, respectively) and the slow part of degradation to increase (17.3 and 26.1 percent, respectively), the rate constants degradation of crude protein of the soybean decreased (ranged from 7.61 to 3.79). Also, thermal processes reduced effective degradability of dry matter and crude protein of the soybean. Roasting and extruded with the reduction of the amount of ruminal disappearance and the increase of the post ruminal digestibility of dry matter and crude protein of soybean cased the degradability process of the soybean to be improved so that it transferred the place of the digestion of protein from the rumen to the small intestines and cased the amount of digestible of dry matter and crude protein in the intestine to increases. The increase of digestibility in the total digestive system shows that the reduction of ruminal digestion of soybean affected by the processes of roasting and extruding has been compensated by the increase of post ruminal digestibility.

The experiment results indicated that thermal processes of roasting and extrusion were an appropriate strategy for reduction the ruminal degradability of the soybean and the supply of passing protein needed by high milk producing dairy cows.

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.

The objective of this study was to estimate genetic parameters coupled with genetic and phonotypic trends for age at first calving (AFC) and first and second calving interval (CI1 and CI2) in Iranian Holstein cows. Records of reproduction from 1983 to 2007 for AFC, CI1 and CI2 were 261116, 163234 and 92661, respectively. Single and two trait animal model was used to estimate genetic parameters by restricted maximum likelihood procedures using Average Information algorithm in ASREML software. Estimates of heritability were 0.19±0.005 for AFC, 0.04±0.003 for CI1, and 0.04±0.004 for CI2. Genetic trends for AFC, CI1 and CI2 were - 0.75±0.11, 0.004±0.02, - 0.02±0.01day per year and phonotypic trends were -2.35±0.38, - 1.13±0.39, - 0.28±0.23 day per year, for AFC, CI1 and CI2, respectively. The genetic, phonotypic and environmental correlations were – 0.049, 0, 0.002 for AFC and CL1; 0.014, - 0.004, -0.004 for AFC and CL2; and 0.877, 0.081, 0.043 for CL1 and CL2, respectively.