This experiment carried out in order to determine the ruminal disappearance rate of ten feedstuffs used in ruminant diet and to determine the best ruminal digestive model using mobile nylon bag technique. Feedstuffs were corn grain, barley grain, corn silage, alfalfa hay, whole barley hay, cotton seed meal, soybean meal, meat meal, fish meal and wheat bran. The nylon bags containing each feedstuff were in duplicate for 0,2,4,8,12,24,48 and 96 h in three steers fitted with rumen fistula. In order to determine the disappearance rates in 0 h , samples were washed by cold water. Disappearance rates of dry matter and crude protein determined by calculating of rate of their weight loss. Using completely randomized design the statistical comparing of disappearance rates of dry matter and crude protein of feedstuffs in three studied groups (energy, protein and forage sources) carried out. Disappearance rates of dry matter and crude protein in 0 h in each of the three sources had significantly differences(p<0.05) and disappearance rate of dry matter and crude protein of feedstuffs in 96 h in each of protein and forage sources had significantly differences but in energy sources had not significantly differences. The best ruminal model for determining disappearance rate constants of dry matter and crudeprotein of feedstuffs was: IR (t) =Di. exp(-kd.t)+ I0 which IR (t),Di, kd,t and I0 were insoluble residue at any time t ,potentially digestible fraction at any time disappearance rate constant, time and indigestible residue respectively. Dry matter fractional rate constant of digestion (kd) in ruminal digestive models for corn grain, barley grain, corn silage, alfalfa hay, barley hay, cottonseed meal, meat meal, fish meal, wheat bran and soybean meal were :4, 15,6,9,15,26,32, 10,4 and 5.9 % / h respectively, and indigestible fraction (residue) of dry matter were: 25, 183, 364, 401, 6/341, 633, 608, 208.3, 450 and 133 g.kg-1 respectively. Crude protein fractional rate constants of digestion (kd) in ruminal digestive models for corn grain, barley grain, corn silage, alfalfa hay, barley hay, cottonseed meal, meat meal, fish meal , wheat bran and soybean meal were: 0.2, 17,0.4, 14, 18,24,35, 14,69 and 2.8 % / h respectively, and indigestible fraction (residue) of crude protein were: 0,30.02,0,69.6, 13.2,266.5, 435,37.92, 103.15 and 69.72 mg, respectively.    

Ruminal disappearance and intestinal protein digestibility of various feeds including forages (alfalfa hay and silage, corn and whole barely silages, and wheat straw), grains (barley and corn), by-products (sugar beet pulp and wheat bran), protein sources (soybean, cottonseed and fish meals) and whole soybean (Sahar and Williams varieties) were evaluated using the in situ mobile nylon bag technique (MNB) and three-step (38T) in situ/ in vitro enzyme procedure. Total tract protein disappearance of wheat straw was significantly less than the other forages (P<0.05). Intestinal protein digestibility of barely grain determined by MNB and 38T (0.74 and 0.83, respectively) was significantly (P<0.05) higher than corn grain (0.63 and 0.75, respectively). Mean total tract protein digestibility of soybean meal determined by MNB and 38T (0.87 and 0.92, respectively) was significantly (P<0.05) higher than cottonseed meal (0.78 and 0.77, respectively) and fish meal (0.80 and 0.81, respectively). Intestinal and total tract protein digestibility of roasted whole soybeans were significantly (P<0.05) higher than non-rosasted seads. The coefficient of determination (r2) for the relationship of intestinal protein digestibility between the mobile nylon bag technique and three-step procedure was 0.94.

The disappearance of dry matter (DM), crude protein (CP) and amino acid in steers after rumen incubation and intestinal passage of the feedstuffs used in ruminant diet was measured in six steers, using mobile nylon-bag technique. Disappearance of dry matter (DM) after rumen incubation varied between feedstuffs from 310 (meat meal and cottonseed meal) to 500 (soybean meal) gr.kg of feed DM, disappearance of DM after intestine incubation varied between feedstuffs from 240 (cottonseed meal) to 890 (fish meal) gr.kg of rumen residue dry matter and disappearance of dry matter in total tract was from 470 (cottonseed meal) to 930 (fish meal) gr.kg of feed dry matter. Disappearance of CP after rumen incubation varied between feedstuffs from 320 (meat meal and fish meal) to 650 (cottonseed meal) gr.kg of feed CP, after intestine incubation varied between feedstuffs from 660 (meat meal) to 930 (fish meal) gr.kg of rumen residue CP and in total tract was from 770 (meat meal) to 950 (fish meal) gr/kg feed CP. Disappearance of total amino acids (AA) after rumen incubation varied between feedstuffs from 200 (soybean meal) to 440 (meat meal) gr/kg of feed amino acids, disappearance of AA after intestine incubation varied between feedstuffs from 580 (meat meal) to 910 (fish meal) gr/kg of rumen residue amino acids and disappearance of AA in total tract was from 770 ( meat meal) to 960 (fish meal) gr/kg feed amino acids. It was concluded that nutrients that escape rumen degradation were disappeared in the intestine.

This experiment was conducted to determine chemical composition and degradability of dry matter (DM) of whole Safflower seed using nylon bags in Ghezel rams. Values of DM, CP, OM, EE, CF, ADF and NDF of whole Safflower seed, were 96.25, 17.63, 94.12, 30.32, 26.13, 40.8 and 63.8 percent, respectively. Water soluble fraction (a), slowly degradability fraction (b), potential degradability (a+b) and rate constant (c), respectively were 8.3, 39.6, 47.83 percent and 0.216 for the DM. Effective degradability (r) 0.02 for DM was calculated. According to these results, whole Safflower seed can be used as a good source of dietary nutrition in ruminants.

A ruminal in situ experiment using three ruminally fistulated multiparous non-lactating dairy cows was conducted to determine dry matter (DM) and crude protein (CP) degradation of soybean meal and xylose-treated soybean meal. Samples were suspended in the rumen of cows for 0, 2, 4, 8, 16, 24 and 48 h. Xylose-treated soybean meal had higher soluble digestible fraction (a) of DM than soybean meal (21% vs. 27%). Soluble digestible fraction (a) CP of xylose-treated soybean meal was considerably lower than that of soybean meal (3% vs. 20%). Xylose-treated soybean meal showed higher slowly digestible fraction (b) CP than soybean meal (84% vs. 78%). Effective degradability of CP at outflow rates of k=0.05 and k=0.08 h-1 was significantly lower for xylose-treated soybean meal than soybean meal (27 and 20% vs. 62 and 53%). Results from this study showed that xylose-treated soybean meal had lower available protein for rumen microorganisms compared with soybean meal.

Regarding to problems of digestible protein, metabolizable protein (MP) is offered. This system is based on microbial protein and undegraded protein in the rumen that is digestible in the small intestine. In order to determine of degradable protein in the rumen, ruminal undegradable protein and metabolizable protein of fish meal and cottonseed meal using crude protein degradability coefficients by in situ and ADIN data based on AFRC equation this experiment was designed. Three castrated sheep (49±2.6 kg) was used.the equation of P=a+b (1-e-ct) was used for estimating of CP degradabilities coefficients. The MP of fish meal and cottonseed meal was achieved 39.67 and 23.21 g/kgDM.

To compare the decomposition rate of leaves and stems Prangos ferulaceae species during a year, this research was carried out at training and research station Hossein Abad of Fars. The litter bag technique with size of 20×20 cm and 2 mm pores was used in this research. Each bag was filled with 5 gr dried plant specimens. Totally 54 bags with leaf, stem, composition of leaf and stem treatments with three replications were placement in the field. Bags were taken at intervals of 60 days (6 times in a year). The amount of nutrients N, C, K, P and C/N in leaves, stems and the composition of leaves and stems were measured after each sampling. The results showed that more nitrogen and lower hemi cellulose in the leaves rather than stems was caused tendency of microorganisms (especially bacteria) in this organ. As a result faster decomposition and increase the mineralization rate of its nutrient happens. Generally, the plants decomposition rate depends on the ratio of carbon to nitrogen. As this ratio is lower; the resistance of plant against the decomposer factors will be lower.

Aims The use of intrauterine devices (IUDs) has been one of the most effective, the safest and cost-effective methods for preventing pregnancy, for a long time. However, some complications have been reported for IUDs. The complications may be reduced by using a specific technique for placement of IUD. The objective of this study was to introduce the rotating withdrawal technique for the first time, which was investigated to reduce the complications of IUD insertion. Materials & Methods This historical cohort study was conducted on 1199 females who referred to Sarem Medical Center for IUD insertion from 1984 to 1995. After primary examinations, IUD was inserted by rotating withdrawal technique. The subjects were followed up for 2 years. Findings Displacement was observed just in 20 cases (1. 67%). All of them were seen in the first month after placement. For these cases, IUD insertion was done again. After the second replacement, displacement was observed in 4 cases (0. 035%) after one month. Therefore, it was recommended to them to use another preventive method. There was no pregnancy or displacement in the other cases during 2 years. Conclusion The rotating withdrawal technique can minimize the pregnancy rate when IUD is used. In addition to the type and quality of IUD, insertion method of IUD can increase its effectiveness.