جستجوی مقالات مرتبط با کلیدواژه « الیاف » در نشریات گروه « علوم دام »

Sheep wool is a very important raw material for the textile industry. Since fiber diameter is one of the most important economic characteristics of sheep wool, identification of genes regulating this characteristic offers an opportunity to increase productivity and improving product quality and variety of product. various researches have been conducted and various genes have been identified in relation to wool production. Each gene may be involved in different biological pathways, and the identification of these biological pathways and the genes that make up them will create a broader view and a more complete understanding of the complex genetic mechanism of the phenotype of productive traits, which can be achieved through the identification of biological biomarkers. For production traits, it is a useful step toward improving breeding. The data used in this research were downloaded from the GEO database with the access number GSE85844 and were analyzed in order to measure quality and uniformity. In order to identify genes with expression differences, a series of thresholds were considered, which include P-value and Fold Change. String software was used for ontology analysis and Cytoscape software with the cytoHubba plugin was used for network analysis. A total of 702 genes with different expressions were identified, which are involved in 37 biological pathways related to the production of wool follicles. The results of the network analysis identified 11 hub genes that affect wool growth and diameter. These results provide valuable resources for increasing the quality and production of sheep wool.

Cashmere is a very fine fiber that is produced by secondary hair follicles in cashmere goat. Based on American test and material association description, cashmere is fine fiber in Asian Indian goat hair follicles with diameter lower than 30 microns. Cashmere is growing as “under coat” in cold season and it shedds during the time from late winter until early spring. It is estimated that 68 goat breeds produce cashmere fibers in the world. Cashmere goats are originated from Asia. The important countries that can produce a large amount of cashmere are China, Mongolia, Iran, Turkey, and India. Total production of cashmere is estimated to be 5mt. During the last decades, due to the economic importance of cashmere, USA, Australia, and NewZealand joined to the cashmere producing countries. Many researchers reported that cold climate is suitable for production of quality cashmere. In this research, effects of nutrition and age on histological characteristics of Raeini Cashmere goat were studied in Tabriz, East Azerbaijan.

For this research, 24 female Raeini cashmere goats were selected. The goats were selected from Baft Raeini cashmere goat breeding and husbandry station. Goats were fed individually   and were treated for 8 months of study based on feeding levels (Maintenance, 0.7 M, 1.4 M, and 1.8M) and age (6 months and 18 months) on fleece growth. The trial was conducted at the khalat-Pushan Research Station, University of Tabriz. The goats allocated to four feeding levels: M (goats fed to maintain live weight, 0.7M (goats fed to lose 3Kg live weight from February to September), 1.4M, and 1.8M (goats fed to gain live weight). Patches of fleece from defined areas were repeatedly shorn at 4 weekly intervals from the right mid side of each goat. For follicle study, in the fist, 120cm2 of left side of animals was marked firstly; then, these region fibers shaved by electrical shaver. Shaving was repeated monthly (for four weeks). Skin biopsy was taken monthly from left mid side of skin of abdomen. samples were fixed in 10% formalin. Paraffinized block were prepared and then, they are sectioned as serial section in 8-micron thickness. Histological sections were stained by sak pic method (reference ????). Results were analyzed by analyses variance and paired t-test.   

This research results, showed that there was no significant effect of feeding level or age on weight of cashmere and hair per area, secondary follicle activity, cashmere length, and yield (P<0.05). Fleece and live weight for young goats were significantly less than that of old goats (P<0.05). Result were appeared that mean cashmere diameters of patch shorn in September of goats fed M, 1.4M and 1.8M were significantly greater than that of goats fed 0.7M (P<0.05). In group feeding more than maintenance requirements, results indicated no increase in cashmere production. Average fiber diameter of cashmere in June was higher than in May. Results of this research indicated that there are not any significant differences between different levels of feeding and age on fiber growth rate (P<0.05). The highest fiber production and the maximum mean of fiber growth rates (1.64 and 1.48 g/120cm2 / 28 days) were observed in June and July. Secondary to primary follicle ratio of all goats was 12.60. Study of secondary follicles ratio showed that different levels of feeding cannot reduce number of secondary follicles. Many researchers reported that increase in feeding levels to over maintenance rate cannot increase cashmere growth rate. This research results confirmed by previous studies. it was reported that feeding limitation can reduce diameter of cashmere, but there is not any increasable effect during over maintenance feeding and an increase in dietary protein. This research indicated that cashmere diameter was more in two-years old goat than one-year old goat cashmere diameter. These   results were similar with reports of Klor et al. (1993), Rafat (1997), and Salehi (1997). Increase in diameter of wool fibers with increasing in the age of animals was reported in sheep and goat. In other studies, it is shown that effect of age on diameter of Norway cashmere goats was significant (P<0.05). Results of our research show that diameter of cashmere in Raeini goats increases at June. Similar results are illustrated in Kerman (with the same age and sex). The weight of produced fibers / body surface was the same in four feeding treatment groups, but diameter of cashmere was different. Numbers of secondary follicles   increased in April. Minimum weight of fibers was observed in April in all of the treatments, which may be because of low activity of follicles in this month. Variation of cashmere diameter and cashmere growth rate can explain differences in total cashmere production. Changes of feeding level from under maintenance to high levels cause increase in cashmere diameter. This study appeared that diameter of cashmere fibers can have reaction to feeding rate. Accordingly, energy has important effect on growth of hair and cashmere. The animals with low energy diet produce low amount of cashmere, Other researchers have opposite idea. According to their statement, there are not any difference in partition for nutrient between primary and secondary follicles. This research result showed that increase feeding cannot increase cashmere production. Jia et al (1995) reported that increase of diet net protein has not any important effect on cashmere goats production in Spain. In other study using unpregnant goat it has been indicated follicular activity and fiber growth is not under influence of pregnancy and milking. However, some researches showed that reproduction condition of animal, as pregnancy and milking, has effect on cashmere fiber growth.  

Generally, results of this study showed Raeini cashmere goats in East – Azarbayjan climate did not show any fundamental changes in diameter and length of cashmere in comparison with Raeini cashmere goats which reared in Kerman province.

Inorder to evaluate the effects of four sources of fiber (soy hulls, barley hull, rice husk and corn husks) each with two particle size (with 1 and 2- mm of geometric mean) on performance, nutrient digestibility, some blood parameters, small intestine morphology and secum bacteria in broiler chicken, 540 Ross308 broiler male chicks from 1 to 42 days were used in a completely randomized design with a factorial arrangement 2×4, with nine treatments (one control treatment), four replications and 15 broilers in each replicate.Weight gain in the starter and finisher periods, feed intake during the finisher and the whole period, and feed conversion ratio in the growr, finisher and the whole period of breeding were affected the entire fiber source. The treatment with coarse barley hull had more weight gain, lower feed intake, and less conversion ratio (P<0.05). The most unfavorable feed conversion ratio observed in treatment containing rice husk. Crude protein (P<0.0493) and ether extract (P<0.0004) digestibility in corn husks fed diets was higher than other treatments. In duodenum, jejunum and ileum, the highest and lowest villus height were observed in barley hull treatment and control group, respectively (P <0.05). The depth of crypt was affected only in the jejunum and crypt diameter in all three parts of the intestine (P<0.05). The number of intestinal Lactobacilos in the chiks fed diets containing corn and barley hulls was significantly more than those fed with diets containing soya and rice hull. The fibers particle size had significant effect on E.Coli and coliform bacteria (P<0/007). However, with adding a fiber source such as barley or corn hull, to broiler diets would have beneficial effects in yield, health and welfare of the bird.

This experiment was conducted to determine chemical composition, and fermentation and digestion characteristics of black mulberry leaves, or diets content 0, 25, 50, 75 and 100% of it, by whole rumen microorganisms or rumen fungi. Dry matter, crude protein, NDF, ADF, Ash and tannin of the black mulberry leaves was 96.5, 19.30, 36.82, 15.90, 9.31 and 0.30%, respectively. Partitioning factor, truly organic matter degradability, microbial biomass and microbial biomass efficiency in the black mulberry leaves were more than alfalfa hay (P

This research was conducted to compare fiber and follicle characteristics of Chios, ArkhaMerino×Moghani, and Suffolk×Moghani sheep. forty non-lactating ewes (16 heads of Chios, 12 head ArkhaMerino×Moghani, and 12 heads of Suffolk×Moghani) at the age of 22 months were randomly selected and kept for a period of 50 days. At the end of the experimental period, 50 grams of wool was collected from left midside of a sheep to assess the fiber characteristics. A skin sample from right midside of all the sheep was taken to evaluate the follicle characteristics. Results indicated that efficiency, staple length and percentage of medullated fibers in Suffolk×Moghani sheep were significantly (P<0.01) higher than those in Chios and ArkhaMerino×Moghani. Fiber diameter in ArkhaMerino×Moghani sheep was significantly (P<0.01) less than that in Chios and Suffolk×Moghani. Diameter coefficient variation in Chios sheep was significantly (P<0.01) higher than that in Suffolk×Moghani and ArkhaMerino×Moghani. Percentage of true wool fibers in ArkhaMerino×Moghani sheep was significantly (P<0.01) higher than those in Chios and Suffolk×Moghani. Percentage of kemp fibers in Chios sheep was significantly (P<0.01) higher than those in Suffolk×Moghani and ArkhaMerino×Moghani. There were no significant differences observed in primary follicle density, secondary to primary follicles ratio and percent of inactive follicles among the sheep. Total and secondary follicle densities in ArkhaMerino×Moghani sheep were significantly (P<0.01) higher than those in Chios and Suffolk×Moghani.