مجله کشاورزی دانشگاه تهران
سال نهم شماره 2 (پیاپی 15، پاییز 1386)

The follicle arrangement and secondary to primary follicle ratio (S/P) were studied in the ‎skin of nine male and nine female Markhoz goats breed from one week to 16 weeks of age. The ‎skin samples were taken from mid-side area of each animal in nine stages every other week. The ‎follicles were arranged in groups, predominantly including three primary and several ‎secondary follicles. Each primary follicle associated with sudoiferous gland, bilobed sebaceous ‎gland and erector pili muscle and each secondary follicle associated with only monolobed (and ‎some bilobed) sebaceous gland. The mean of S/P ratio was significantly different in different ‎stages (except stages six and seven) (P? 0.05). The maximum S/P ratio was observed at 16 ‎weeks after birth. Effect of sex and interaction of sex and age on S/P ratio was not significant ‎(P > 0.05).‎

Isolates of A. flavus obtained from different feeds such as corn, barley, wheat, cotton ‎seed, bread waste, soybean, alfalfa, wheat bran, barley meal, canola meal, corn silage and beet ‎pulp from nine dairy farms in Tehran province during 2004. Ability of sclerotiom production by ‎isolates was tested. Results showed 62.9 percent of isolates produced sclerotiom on CzA medium ‎and 68.5 percent of these isolated were aflatoxigenic. From pollution of feed by A. flavus point of ‎view in dairy farms were between 20.37 - 3.7 percent. 16.67 percent of isolates obtained from ‎beet pulp as the most contaminated feed. Alfalfa, canola meal and corn meal with‏ ‏medium 1.8 ‎percent were of the least in every contaminated feeds. Analysis of milk samples by HPLC ‎showed that the rate of AFM1 in samples varied and ranged from 0.0009 to 0.5269 ppb. ‎Calibration regression coefficients determined 0.99 to 0.997 for these experiments and ‎determined recovery was between 70.31 to 1.4.93 percent in these experiments. ‎

In this study traits of body weight in different ages and effect of selection on breeding value ‎at 42 days were investigated in three strains of Japanese quail for two generation. In the first ‎generation 51 male and 51 female of each strain were randomly selected from the base ‎population and one male with one female were located in‏ ‏each cage. Body weight‏ ‏‎(BW) of the ‎progeny was measured at 14, 28, 42 and 49 days of age. For the second generation in White, ‎Canadian Wild and Brown strains a number of 30, 40 and 35 pairs of male and female birds ‎that have the highest BV were selected. Mean differential of breeding value in two generations ‎for male and female in White strain were 10.7 and 10.2 gr, in Canadian wild strain were 8.6 and ‎five gr and in Brown strain were four and 9.1 gr, respectively. Heritability of BW at 14, 28 and ‎‎42 days for White strain was 0.37, 0.26, 0.74, Canadian wild strain was 0.21, 0.17 and 0.44 and ‎for Brown strain were 0.39, 0.45 and 0.52, respectively. ‎

An experiment conducted to evaluate the level of molybdenum, sulphur and iron ‎supplement on the copper status and clinical deficiency in Iranian sheep and goat. Eight of one ‎year -old Sanjabi sheep and Markhoz goats housed in individual crates in animal house of Razi ‎University. Animals fed with the same basal diet which was supplemented with different levels of ‎minerals of Mo, S and Fe during five months experiment. Blood samples were collected in EDTA ‎containing tubes to measure plasma copper and thiomolybdate. Wool and Mohair samples were ‎collected by taking patch samples (10 × 10 cm2) from the mid-side area of the animals every ‎three weeks to measure copper content and quality parameters. Supplementing the diet with 30 ‎mg molybdenum, 400 mg iron and 2.5 g sulfur /kg DM produced sub clinical copper deficiency ‎with minor dipigmentation of fleeces and mohair and poorer crimp being observed. The ‎response to high levels of molybdenum, iron, and sulfur in sheep and Markhoz goat was ‎different. The fiber diameter significantly reduced after four months of experiment especially in ‎goat mohair.‎

This research was based on survey strategy with the aim to study factors influencing research ‎function of agricultural faculty members. The population of this research consisted of all faculty ‎members of public agricultural faculties and colleges of Ministry of Scientific, Research and ‎Technology (N = 1260). Using multi-phase sampling method, 172 faculty members were selected and ‎studied. Validity of questionnaire as data gathering instrument, confirmed by selected faculty ‎members and researchers, and Coronbach Alpha coefficient (equal to. 74) used to confirm its ‎reliability. The results of priority setting of research functions based on coefficient of variation shows ‎that agricultural faculty members, mostly engaged in postgraduate research and their participation ‎in research outreach and international research collaboration is so partial and limited. Calculated ‎Pearson coefficients of correlation indicated significant relationship between a number of personal ‎and professional variables of faculty members (participation in training workshop and ‎courses, ‎professional‏ ‏internet usage, research project, etc) and their research function. Stepwise regression ‎analysis led to a linear equation including several personal and professional variables and R2Ad ‎coefficient indicated that this linear equation, explained 70 percent of variance of research function of ‎faculty members as dependent variable.‎

Mechanical weeding is one of the non-chemical methods to control weeds. In this paper a ‎new mechanism has been presented for mechanical cultivation. The machine works based on ‎the manual tools operation, which farmers still use in small scale for weeding and consists of a ‎number of four-bar linkage mechanisms. Each mechanism consists of a blade which moves ‎forward (active course) and backward (passive course). The three precise position methods ‎were applied to design the mechanism. The Matlab software was used for solving the equations ‎and drawing the path of motion. Considering the parameters and solving the equations, a four-‎bar linkage (crank-rocker) was proposed.‎

The effect of four concentrations (0.5, 1, 2.5, and 5 mg/lit) of two insect growth regulators ‎‎(IGRs) of Buprofezin and pyriproxifen on 1 and 4-day eggs, different nymphal instars, and ‎pupae of Trialeurodes vaporariorum (Homoptera: Aleyrodidae), was studied at 26 ± 2 °C, 80 ± ‎‎5% RH, and 16: 8 (L: D) on Lantana camara in the greenhouse. The effect of both IGRs was ‎positively related to increasing of concentrations. The susceptibility of one-day eggs of T. ‎vaporariorum to the insecticides was more than four-day ones, and also early nymphal instars ‎‎(1st and 2nd) than 3rd, 4th, and pupa. The mean percentage of adult eclusion from first to fourth ‎nymphal instars and pupa in 2.5 mg/liter of pyriproxifen was 0, 0, 0, 61.32 ± 11.06, and ‎95.73 ± 3.66, in 5 mg/liter of it was 0, 0, 0, 54.16 ± 10.55, and 98.09 ± 1.14, in 2.5 mg/liter of ‎buprofezin was 19.88 ± 7.67, 48.35 ± 12.05, 60.28 ± 11.34, 85.84 ± 7.18, and 91.85 ± 6.55, and in 5 ‎mg/liter of it was 12.15 ± 4.60, 34.72 ± 8.96, 45.92 ± 7.87, 79.27 ± 8.95, and 92.28 ± 7.13 percent, ‎respectively. ‎