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51.
Rangeland-based animal husbandry has been frequently exposed to the vagaries of weather. While the current rates of climate variability are unprecedented in arid and semiarid regions, climate change is expected to put further pressure on rangelands with medium- and poor-quality forages and increase the vulnerability of households who mainly depend on livestock production. Therefore, it is imperative to ensure that livestock producers increase their resilience to climate variability or change. However, few field-based studies have focused on simultaneous investigation of both vulnerability and adaptation of livestock keepers to climate-related risks. To fill this gap, a field-based research study was conducted in southwest Iran. A survey of 274 herder families, selected using a cluster sampling technique, revealed low, medium and high levels of vulnerability, which were principally distinguished by various degrees of exposure, sensitivity, and adaptive capacity. Further, this study identified the main adaptation strategies employed by the herders of this region (i.e., purchasing fodder; rotational grazing; raising a mixed-herd, on-farm occupation; and postharvest grazing). Results indicated that most herder families applied traditional adaptation strategies in response to climate variability. Findings revealed that herders had to reduce their livestock due to low adaptability. Loan term, purchasing insurance, level of exposure, income, experience, response efficacy, and knowledge were the major determinants of the herders’ adaptation decisions. To increase the resilience of livestock producers against climate change, restructuring traditional livestock production systems, producing participatory knowledge and information for sustainable management of rangelands, and designing or redesigning effective adaptation strategies are required.  相似文献   
52.
1. The aim of the present study was to estimate genetic parameters for average egg weight (EW) and egg number (EN) at different ages in Japanese quail using multi-trait random regression (MTRR) models.

2. A total of 8534 records from 900 quail, hatched between 2014 and 2015, were used in the study. Average weekly egg weights and egg numbers were measured from second until sixth week of egg production.

3. Nine random regression models were compared to identify the best order of the Legendre polynomials (LP). The most optimal model was identified by the Bayesian Information Criterion. A model with second order of LP for fixed effects, second order of LP for additive genetic effects and third order of LP for permanent environmental effects (MTRR23) was found to be the best.

4. According to the MTRR23 model, direct heritability for EW increased from 0.26 in the second week to 0.53 in the sixth week of egg production, whereas the ratio of permanent environment to phenotypic variance decreased from 0.48 to 0.1. Direct heritability for EN was low, whereas the ratio of permanent environment to phenotypic variance decreased from 0.57 to 0.15 during the production period.

5. For each trait, estimated genetic correlations among weeks of egg production were high (from 0.85 to 0.98). Genetic correlations between EW and EN were low and negative for the first two weeks, but they were low and positive for the rest of the egg production period.

6. In conclusion, random regression models can be used effectively for analysing egg production traits in Japanese quail. Response to selection for increased egg weight would be higher at older ages because of its higher heritability and such a breeding program would have no negative genetic impact on egg production.  相似文献   

53.
1. A total of 11 826 records from 2489 quails, hatched between 2012 and 2013, were used to estimate genetic parameters for BW (body weight) of Japanese quail using random regression models. Weekly BW was measured from hatch until 49 d of age. WOMBAT software (University of New England, Australia) was used for estimating genetic and phenotypic parameters.

2. Nineteen models were evaluated to identify the best orders of Legendre polynomials. A model with Legendre polynomial of order 3 for additive genetic effect, order 3 for permanent environmental effects and order 1 for maternal permanent environmental effects was chosen as the best model.

3. According to the best model, phenotypic and genetic variances were higher at the end of the rearing period. Although direct heritability for BW reduced from 0.18 at hatch to 0.12 at 7 d of age, it gradually increased to 0.42 at 49 d of age. It indicates that BW at older ages is more controlled by genetic components in Japanese quail.

4. Phenotypic and genetic correlations between adjacent periods except hatching weight were more closely correlated than remote periods. The present results suggested that BW at earlier ages, especially at hatch, are different traits compared to BW at older ages. Therefore, BW at earlier ages could not be used as a selection criterion for improving BW at slaughter age.  相似文献   

54.
Iraq is an agricultural country with a large population of animals: sheep, goats, cattle, water buffaloes, horses, donkeys, mules, and camels. In the 1980s, the successful poultry industry managed to produce enough table eggs and meat to satisfy the needs of the entire population; at one time, the thriving fish industry produced different types of fish for Iraqis' yearly fish consumption. There are four veterinary colleges in Iraq, which have been destroyed along with the veterinary services infrastructure. Understandably, improvements to the quality of veterinary education and services in Iraq will be reflected in a healthy and productive animal industry, better food quality and quantity, fewer zoonotic diseases, and more income-generating activities in rural areas. Thus, if undergraduate, graduate, and continuing education programs are improved, the veterinary medical profession will attract more competent students. This will satisfy the country's increased demand for competent veterinarians in both public and private sectors. Although Iraq has an estimated 5,000-7,000 veterinarians, there is a need for quality veterinary services and for more veterinarians. In addition, there is a need for the improvement of veterinary diagnostic facilities, as zoonotic diseases are always highly probable in this region. This article provides insight into the status of veterinary medical education and veterinary services in Iraq before and after the 1991 Gulf War and gives suggestions for improvement and implementation of new programs. Suggestions are also offered for improving veterinary diagnostic facilities and the quality of veterinary services. Improving diagnostic facilities and the quality of veterinary services will enhance animal health and production in Iraq and will also decrease the likelihood of disease transmission to and from Iraq. Threats of disease transmission and introduction into the country have been observed and reported by several international organizations.  相似文献   
55.
Triploid fish are increasingly used in aquaculture because they are generally unable to reproduce successfully. Energy is channeled into somatic growth rather than gonadal development, and in the event of escape, the animals are unlikely to breed successfully among themselves or with wild conspecifics. This study tested the ability of recently matured triploid African catfish (Clarias gariepinus) to produce and fertilize eggs with and without ovaprim treatment. Triploid females did not show the increase in ovary size observed in diploid members of the same cohort between 8 and 9 months of age, or the coincident decrease in visceral fat deposits, and this was unaffected by up to 5 weekly i.m. injections of 0.5 ml kg−1 Ovaprim. However, we observed advanced vitellogenin (Vtg) sequestration in oocytes of triploid females, albeit to a lesser degree and with lesser cortical alveoli, compared to oocytes from diploid cohort members. Histological sections revealed a positive trend of oocyte development up to the third weekly ovaprim injection followed by a negative gonadal development in weeks four and five. Milt from triploid males injected 9–12 h earlier with 0.25 ml kg−1 ovaprim i.m. fertilized more diploid eggs than milt from untreated triploid males (30 vs. 20%), but none of the developing embryos of triploid paternity survived to hatch. In contrast, milt of diploid males fertilized 49% of eggs, and 20% of the developing embryos hatched successfully. These rates were improved in ovaprim-injected diploid males to 70% fertilization and 33% hatch. This study demonstrates potential of overcoming non-viability of eggs from triploid female African catfish, and enhancing the ability of triploid milt to fertilize eggs.  相似文献   
56.
In this study, various biodegradable organic acids with varying numbers of carboxylic acid groups were incorporated into the ink formulation both in the presence and absence of sodium hypophosphite (SHP) to investigate the colour yield and antibacterial properties. Ink-jet prints on cotton fabric, which were either pretreated (industry standard practice) or non-pretreated, were analyzed to determine if there is a significant difference in their properties. Antibacterial activities and dye fixation of printed cotton fabrics were also tested. The results indicated that at optimum pH, the non-pre-treated samples printed with ink formulations containing more carboxylic acid groups in their structure (BTCA) in the absence of SHP, demonstrated higher levels of reactive dye fixation and antibacterial properties than pre-treated samples containing no biodegradable organic acid in the ink formulation. The printed cotton fabrics with ink formulation that contained BTCA without dye were characterized by ATR-FTIR and thermogravimetric analysis (TGA) and their morphology was investigated through the use of SEM to determine if cross-linking had taken place.  相似文献   
57.

Background

Attempts for early detection of gastric cancer have recently focused on host''s genetic susceptibility factors and gene-environment interactions. We have, herein, studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection, smoking, age and gender on the risk of gastric cancer among an Iranian population.

Methods

Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI).

Results

The interactions of MTHFR genotype with H. pylori infection (P = 0.03), age (P = 0.049) and gender (P = 0.007) were statistically significant. Accordingly, MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1.8, 95% CI = 1.0-2.9) significant excess risk of non-cardia gastric cancer. Furthermore, subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1.4, 95% CI = 1.0-2.0) and 100 (OR = 2.0, 95% CI = 1.2-3.2) percent increased risk of gastric cancer, respectively.

Conclusion

MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection, age and gender. Key Words: Helicobacter pylori, Smoking, Gender identity, Age group, Methylenetetrahydrofolate reductase  相似文献   
58.
Unfilled polypropylene and polyropylene/ZnO nanocomposite fibers were produced using a melt spinning apparatus; then the fibers were exposed to UV irradiation. The structure and properties of the fibers were examined using scanning electron microscopy, tensile measurements, wide angle X-ray diffraction (WAXD), Fourier transform infrared (FTIR) spectroscopy, birefringence measurements and differential scanning calorimetry (DSC). Following 150 hours of exposure to UV irradiation, some transverse cracks on the surface of unfilled polypropylene fibers were observed. It was observed that both carbonyl and hydroperoxide indexes, which are the criteria for the detection of UV degradation of the fibers, were increased due to the increase in the UV irradiation exposure time and the increase in these indexes was smaller for nanocomposite fibers than those of unfilled Polypropylene fibers. It was also observed that crystallinity, crystallite size and total molecular orientation of UV irradiated nanocomposite fibers were increased in comparison with non-irradiated nanocomposite fibers. It was also found that the extent of increase in molecular orientation of the fibers was higher comparing to that for the nanocomposite fibers due to the UV irradiation exposure for the unfilled polypropylene fibers. Tensile properties of both unfilled and nanocomposite fibers were decreased after UV irradiation; this reduction correlated with the extent of the increase in molecular degradation of the fibers, as determined by measuring carbonyl and hydroperoxide indexes.  相似文献   
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