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Genetic resistance to diseases is a multigenic trait governed mainly by the immune system and its interactions with many physiologic and environmental factors. In the adaptive immunity, T cell and B cell responses, the specific recognition of antigens and interactions between antigen presenting cells, T cells and B cells are crucial. It occurs through a network of mediator proteins such as the molecules of the major histocompatibility complex (MHC), T cell receptors, immunoglobulins and secreted proteins such as the cytokines and antibodies. The diversity of these proteins that mainly is due to an intrinsic polymorphism of the genes causes phenotypic variation in disease resistance. The well-known linkage of MHC polymorphism and Marek's disease resistance difference represents a classic model revealing immunological factors in resistance differences and diversity of mediator molecules. The molecular bases in any resistance variation to infectious pathogens are vaguely understood. This paper presents a review of the major immune mediators involved in resistance and susceptibility to infectious diseases and their functional mechanisms in the chicken. The genetic interaction of disease resistance with production traits and the environment is mentioned. 相似文献
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Bereket Abraha Abdu Mahmud Habtamu Admassu Habte-Michael Habte-Tsion Fang Yang 《Journal Of Aquatic Food Product Technology》2013,22(10):1048-1062
ABSTRACTMalnutrition in children is a current global burden. A common snack for children is biscuits prepared from cereals. However, these types of biscuits have low protein content. Therefore, producing healthier biscuits enriched with essential amino acids (EAAs) and other micronutrients is of great interest to researchers and manufacturers. In this study, biscuits produced from low gluten wheat flour fortified with sturgeon fillet powder (SFP) in various mixing ratios (100:0, 95:5, 93:7, and 90:10, respectively) were investigated. The results revealed that the nutritional and proximate composition of biscuits were significantly (P ≤ 0.05) improved: moisture (6.77 ± 0.06–7.65 ± 0.06), protein (13.23 ± 0.35–17.12 ± 0.02), fat (15.57 ± 0.18–15.85 ± 0.25), ash (0.84 ± 0.07–0.92 ± 0.06), spread ratio (14.0 ± 0.92–14.33 ± 0.21), and hardness (2,057.90 ± 28.33–3,089.02 ± 51.53). Total amino acids were 6.91, 9.34, 10.32, and 10.58; and EAAs were 2.43, 3.97, 4.48, and 4.22 g/100 g for 0%, 5%, 7%, and 10% SFP, respectively. Leucine was the major amino acid with 5% and 10% SFP, while methionine was the major amino acid with 7% SFP. Fungal counts were not observed, and quality indices were below the maximum acceptable limits in the products. Biscuits supplemented with 7% SFP showed the highest sensory evaluation score. Overall, the inclusion of 7% SFP could produce protein enriched cereal-based fortified biscuits with acceptable sensory and quality attributes and ultimately could insure effective fish utilization and solve malnutrition problems. 相似文献
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Peter R. Gildemacher Wachira Kaguongo Oscar Ortiz Agajie Tesfaye Gebremedhin Woldegiorgis William W. Wagoire Rogers Kakuhenzire Peter M. Kinyae Moses Nyongesa Paul C. Struik Cees Leeuwis 《Potato Research》2009,52(2):173-205
Increased productivity of potatoes can improve the livelihood of smallholder potato farmers in Kenya, Uganda and Ethiopia
and is required to meet the growing demand. This paper investigates the opportunities for potato system improvement that could
result in improved productivity. Through a diagnosis of the potato systems in the three countries on the basis of surveys
and stakeholder workshops, seed potato quality management, bacterial wilt control, late blight control and soil fertility
management were identified as key technical intervention topics. For effective problem solving in these areas, the functioning
of the potato innovation system requires improvement to better deliver the functions of potato marketing as well as knowledge
development and information exchange. With use of a ‘system failure framework’ the shortcomings of the potato innovation system
are identified and discussed and options for improvement are suggested. 相似文献
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Abstract This paper examines the relationship between quality of life, rural development, and several socioeconomic variables. The analysis utilizes data obtained from a survey questionnaire administered to a random sample of more than 2,000 residents in West Virginia, and spatial data obtained by geocoding the survey respondents’ addressees. Quality of life is measured by a three‐point categorical measure of overall satisfaction, and development is measured by a goods and services availability index. A simultaneous ordered probit model is used to examine the relationships. The empirical results are consistent with the theoretical predictions and indicate a simultaneous relationship between quality of life satisfaction and rural development. 相似文献
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A study was carried out to estimate the prevalence, larval burden and risk factors of ovine and caprine oestrosis from December
2007 to May 2008 on 554 heads of randomly selected sheep and goat slaughtered at Ambo town, Western Shoa, Ethiopia. The results
show an overall prevalence of 59.9% with infection rate of 69.8% and 47.3% in sheep and goats respectively. No statistically
significant difference in the prevalence was noted with regard to the assumed risk factors like sex, nose color, face color,
horned versus polled, origin, and months (p > 0.05). Sheep were nearly twice more likely to be infected as compared to goats (p = 0.0001, odds ratio (OR) = 1.975). Age of the animals was found to be protective (OR = 0.579; 95% confidence interval = 0.393,
0.853; p = 0.006). As compared to very fat animals, poor (p = 0.040, OR = 4.834), medium (p = 0.049, OR = 4.198), and fat (p = 0.022, OR = 5.795) body condition animals are more likely to be infected by Oestrus ovis larvae. Nasal and sinus cavity pathology is positively correlated with the total larval count (r = 0.56, p < 0.0001). Out of a total of 3,770 larvae collected, 57.5% were L1, 30.8% L2, and 11.7% L3 larvae. All the three larval instars
were seen throughout the study months. It is concluded that oestrosis is a common problem in the study area and more prevalent
in sheep than goats, in adult than young, and in animals with poor body condition. 相似文献
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Abdu Mahmud Bereket Abraha Mogos Ghirmatsion Fang Yang 《Journal Of Aquatic Food Product Technology》2013,22(9):910-921
ABSTRACTThe aim of the present study was to evaluate the quality of wheat flour noodles supplemented with 0%, 10%, 20% and 30% grass carp protein concentrate (GCPC). Proximate composition, color analyses, cooking properties (cooking time, cooking loss, swelling index and water absorption index), texture profile analyses (TPA), and sensory evaluations were performed. Significant (p ≤ 0.05) increases in the crude protein (18.94–35.19%), crude fat (0.88–1.06%), and ash (0.89–1.02%) were recorded for GCPC supplemented cooked noodles. Brightness (L*), redness (a*) and yellowness (b*) of GCPC 10–30% fortified cooked noodles was recorded as 77.00–69.97, 1.50–2.81 and 19.08–22.25, respectively. Cooking loss (CL) and optimal cooking time were significantly (p ≤ 0.05) increased with increased level of GCPC from 0%-30%, with readings of 6.13% ?8.90% and 7.53–11.77 min, respectively. Swelling and water absorption indices showed a decreasing trend at 2.33–1.77 and 102.6–78.49%, respectively. A significant (p ≤ 0.05) decreasing trend in hardness (24.50–19.03N) was observed for cooked noodles with increased level of GCPC, while the remaining TPA parameters were significantly different at p> .05. Sensory analyses showed higher preference for control noodles and noodles fortified with 10% GCPC. 相似文献
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Hiwet Gebremedhin Girmay Gebresamual Nigussie Abadi Kassa Teka Shimbahri Mesfin 《Arid Land Research and Management》2018,32(2):236-252
With rapid population growth and absence of agricultural intensification, smallholders need more land to grow crops. This resulted in communal grazing land conversion to cultivated land. This study, therefore, aimed at exploring the magnitude of communal grazing land conversion and its influence on soil properties and vegetation cover change. Ecological time line approach was used to measure the magnitude of change. Plants and soil samples were taken from open grazing land, seasonal grazing land, 6 years old cultivated land, 16 years old cultivated land and 20 years old cultivated land. Moreover, 95 respondents were selected to assess their perception on the subject. Data were analyzed using statistical analysis system software. Results showed that grazing land declined by 41.88%, while cultivated land increased by 56.80% in the years between 1992 and 2012. Plant attributes showed significant (P?P?相似文献
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Kassaye Aragaw Berhanu Sibhat Gelagay Ayelet Eystein Skjerve Endrias Z. Gebremedhin Kassahun Asmare 《Tropical animal health and production》2018,50(8):1821-1827
This work was conducted to estimate the seroprevalence, to identify potential factors that influence seroprevalence of bovine viral diarrhea virus (BVDV), and to investigate the association between BVDV serostatus and occurrence of reproductive disorders in dairy cattle in three milksheds in Ethiopia. A total of 1379 serum samples were obtained from cattle randomly selected from 149 herds from three milksheds representing central, southern, and western Ethiopia. Sera samples were examined for bovine viral diarrhea virus (BVDV) antibodies using commercial competitive enzyme-linked immunosorbent assay (ELISA) kit. Logistic regression analysis was employed to investigate associations between risk factors and the risk of BVDV seroprevalence, and BVDV serostatus and reproductive disorders. Seroreaction to BVDV antigens was detected in 32.6% of the 1379 cattle and 69.8% of the 149 herds sampled. Factors associated with BVDV seroplevalence were age, breed, and herd size (P?<?0.05). Adult cattle ≥?18 months old had 2.1 (95% CI 1.5, 3.1) times the odds of BVDV seroreaction than younger cattle. Holstein-Friesian (HF) local crosses (OR?=?2.1, 95% CI 1.3, 3.4) and HFs (OR?=?1.3, 95% CI 0.9, 1.9) were more likely to be seropositive than Jersey and the odds of seropositivity in cattle in large herds with 11 or more animals were higher (OR?=?1.8, 95% CI 1.3, 2.5) than the odds of BVDV seropositivity in smaller herds. Seroprevalence was not associated with geographical region (P?>?0.05). Risk of reproductive disorders was not affected by BVDV serostatus, except for repeat breeding (P?>?0.05). The present study demonstrated that BVDV has wide distribution in the country being detected in all the 15 conurbations and 69.8% of herds involved in the study. 相似文献