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11.
Ghavi Hossein-Zadeh N 《Tropical animal health and production》2011,43(6):1111-1115
Calving records from the Animal Breeding Center of Iran collected from January 1987 to December 2007 and comprising 292,875
calving events of Holsteins from 1,413 dairy herds were analyzed using univariate and bivariate linear animal models to estimate
heritabilities and genetic correlations for calving intervals in the first three lactations of Holstein cows. Genetic trends
were obtained by regressing yearly mean estimates of breeding values on calving year. Average calving intervals were from
406 to 414 days and decreased over the parities. Heritability estimates for calving intervals varied from 0.03 to 0.04 across
the parities. Also, estimates of genetic correlations between calving intervals in different parities were high and ranged
from 0.67 to 0.89. The average annual phenotypic trends obtained from fitting linear regression of annual mean calving intervals
at parity 1 and 2 were significant (P < 0.01), but the phenotypic trend of calving interval at parity 3 was not significant over the years. On the other hand,
there was an increasing genetic trend for calving interval at parity 1, and there were decreasing genetic trends for calving
intervals at parity 2 and 3 over the years (P < 0.01). The low estimates of heritability obtained in this study imply that much of the improvement in calving interval
traits could be attained by improvement of production environment rather than genetic selection. 相似文献
12.
The objective of this study was to evaluate the association between cow-specific risk factors and the lactational incidence
risks of retained placenta (RP), metritis (MET) and clinical mastitis (CM) in 57,301 dairy cows on 20 large dairy herds in
Iran between January 2005 and June 2009. A multivariable logistic regression model was used to identify risk factors for MET,
RP and CM and quantify their odds ratio (OR). The lactational incidences of MET, RP and CM were 8%, 5.2% and 18.9%, respectively,
and significant risk factors for MET were dystocia (OR = 4.32), stillbirth (OR = 6.26), RP (OR = 27.74), twin births (OR = 6.57),
primiparity (OR = 1.68), calving during winter season (OR = 2.45) and male calves (OR = 2.41). Significant risk factors for
RP were dystocia (OR = 3.17), stillbirth (OR = 3.18), abortion (OR = 8.46), milk fever (OR = 3.66), twin births (OR = 2.76),
pluriparity (OR = 2.69), calving during winter season (OR = 1.86) and shorter gestation length of dairy cows (OR = 3.82).
Also, significant risk factors for CM were RP (OR = 9.45), milk fever (OR = 12.36), pluriparity (OR = 2.83), calving during
winter season (OR = 1.68) and the first months of lactation (P < 0.001)) and SCC concentrations at previous lactation (OR = 1.82). The current study indicates that differentiation can
be made among cows in the risk of having MET, RP and CM based on a combination of cow factors. These differences among cows
could be useful to aid the better detection of these diseases in the dairy herds. 相似文献
13.
Sara Yavari Saeid Eshghi Enayatollah Tafazoli Najafali Karimian 《Journal of plant nutrition》2013,36(9):1498-1512
Pot experiment was conducted in a greenhouse to compare the effect of four organic substrates [S1: Persian turpentine trees leaf mold (50%) + Soil (50%); S2: Oak leaf mold (50%) + Soil (50%); S3: Cypress leaf mold (50%) + Soil (50%) and S4: liquorice processing wastes (50%) + Soil (50%)] application on strawberry growth, yield, and nutrient concentration, and on some soil properties. Results showed that leaves mold and liquorice wastes application decreased pH, increased soil organic matter, and increased soil concentrations in all mineral elements studied, except for potassium (K). The amount of mineral elements in substrates had also a great influence on the leaf nutrient concentrations. High levels of nitrogen (N), K, iron (Fe), manganese (Mn), and zinc (Zn) were obtained in leaves; while phosphorus (P) concentration was lower than sufficient levels. Although, strawberry fresh and dry weights and leaf chlorophyll content were significantly higher in plants grown in S4 with no added fertilizer, the highest fruit yield was obtained in combination substrates with 50% fertilizer. Our results indicate that use of leaf mold and liquorice wastes in soil mixtures can reduce the amount of fertilizer required for optimum strawberry plant growth and yield. 相似文献
14.
This research was conducted to investigate the effect of natural zeolite on vegetative growth and flower characteristics of tuberose (Polianthes tuberosa L.). The experiment was performed as a completely randomized design with seven treatments (5, 10, 15, 20, 25 and 30 g zeolite/kg soil mixture along with control) and four replicates. Results indicate that zeolite increased the height of flowering stem, diameter of flower, leaf area and chlorophyll content, but decreased the diameter of flowering stem, dry weight of shoots, and roots and bulblets. Overall, zeolite added to the soil mixture had beneficial effects on only some of the parameters of tuberose growth and development. 相似文献
15.
Hesam Amou Posht-e- Masari Abdol Ahad Shadparvar Navid Ghavi Hossein-Zadeh Mohammad Hossein Hadi Tavatori 《Tropical animal health and production》2013,45(5):1259-1263
The objective of this study was to estimate genetic parameters for reproductive traits in Shall sheep. Data included 1,316 records on reproductive performances of 395 Shall ewes from 41 sires and 136 dams which were collected from 2001 to 2007 in Shall breeding station in Qazvin province at the Northwest of Iran. Studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB), and total litter weight at weaning (TLWW). Test of significance to include fixed effects in the statistical model was performed using the general linear model procedure of SAS. The effects of lambing year and ewe age at lambing were significant (P?<?0.05). Genetic parameters were estimated using restricted maximum likelihood procedure, under repeatability animal models. Direct heritability estimates were 0.02, 0.01, 0.47, 0.40, 0.15, and 0.03 for LSB, LSW, LMWLB, LMWLW, TLWB, and TLWW, respectively, and corresponding repeatabilities were 0.02, 0.01, 0.73, 0.41, 0.27, and 0.03. Genetic correlation estimates between traits ranged from ?0.99 for LSW–LMWLW to 0.99 for LSB–TLWB, LSW–TLWB, and LSW–TLWW. Phenotypic correlations ranged from ?0.71 for LSB–LMWLW to 0.98 for LSB–TLWW and environmental correlations ranged from ?0.89 for LSB–LMWLW to 0.99 for LSB–TLWW. Results showed that the highest heritability estimates were for LMWLB and LMWLW suggesting that direct selection based on these traits could be effective. Also, strong positive genetic correlations of LMWLB and LMWLW with other traits may improve meat production efficiency in Shall sheep. 相似文献
16.
Zara Ahmed Lydia C. Powell Navid Matin Andrew Mearns-Spragg Catherine A. Thornton Ilyas M. Khan Lewis W. Francis 《Marine drugs》2021,19(8)
Osteoarthritis (OA) is a multifactorial disease leading to degeneration of articular cartilage, causing morbidity in approximately 8.5 million of the UK population. As the dense extracellular matrix of articular cartilage is primarily composed of collagen, cartilage repair strategies have exploited the biocompatibility and mechanical strength of bovine and porcine collagen to produce robust scaffolds for procedures such as matrix-induced chondrocyte implantation (MACI). However, mammalian sourced collagens pose safety risks such as bovine spongiform encephalopathy, transmissible spongiform encephalopathy and possible transmission of viral vectors. This study characterised a non-mammalian jellyfish (Rhizostoma pulmo) collagen as an alternative, safer source in scaffold production for clinical use. Jellyfish collagen demonstrated comparable scaffold structural properties and stability when compared to mammalian collagen. Jellyfish collagen also displayed comparable immunogenic responses (platelet and leukocyte activation/cell death) and cytokine release profile in comparison to mammalian collagen in vitro. Further histological analysis of jellyfish collagen revealed bovine chondroprogenitor cell invasion and proliferation in the scaffold structures, where the scaffold supported enhanced chondrogenesis in the presence of TGFβ1. This study highlights the potential of jellyfish collagen as a safe and biocompatible biomaterial for both OA repair and further regenerative medicine applications. 相似文献
17.
Mass culture of fairy shrimp Branchinecta orientalis (G. O. Sars 1901) (Crustacea: Anostraca) using effluent of rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds 
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下载免费PDF全文 Navid Pormehr Yabandeh Lynda Beladjal Naser Agh Behrooz Atashbar Gilbert Van Stappen 《Aquaculture Research》2017,48(11):5455-5462
The variable quality and high price of Artemia (Leach 1819) cyst products, used worldwide as live food, motivate aquaculturists to find an appropriate alternative, especially for fresh/brackish water organisms. In this study, Branchinecta orientalis (G. O. Sars 1901), a common fairy shrimp in north‐western Iran, was reared for 15 days using effluent from trout ponds enriched with effluent filtrate as sole feed, or co‐fed with microalgae (Scenedesmus sp.). The effluent filtrate was replaced by algae at different ratios (25% and 50%), and feeding experiments were designed at densities of 100, 200 and 400 individuals/L in 3‐L containers and at 100 individuals/L in 20‐L containers. The results indicated that, at a certain density, the final length and survival were not significantly affected by different feeding regimes (p > .05). In 3‐L containers, the highest length and survival were observed at the lowest density. B. orientalis contained the highest amounts of proteins, carbohydrates and lipids, though, when co‐fed algae, although the differences with the treatment fed solely effluent filtrate were often limited. Inclusion of algae in the diet also resulted in higher levels of a number of PUFAs. Our study proves that B. orientalis can be mass‐cultured successfully using trout effluent as culture medium without additional microalgae. Fish pond effluent is massively available as a cheap food source. Recycling aquaculture effluent for this type of live food production contributes to lowering the use of natural resources and to less discharge of nutrient loads into natural water bodies. 相似文献
18.
Crisp Jason A. Partridge Gavin J. D’Souza Frances M. L. Tweedley James R. Moheimani Navid R. 《International Aquatic Research》2017,9(1):1-10
International Aquatic Research - The effects of temperature and salinity on the survival and development of larval Metapenaeus dalli were investigated in two experiments. First, the effects of four... 相似文献
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20.
Estimation of genetic and phenotypic relationships between age at first calving and productive performance in Iranian Holsteins 总被引：1，自引：0，他引：1
Ghavi Hossein-Zadeh N 《Tropical animal health and production》2011,43(5):967-973
Calving records from the Animal Breeding Center of Iran collected from January 1990 to December 2007 and comprising 207,106
first calving events of Holsteins from 2,506 herds were analysed using univariate and bivariate linear sire models to estimate
heritabilities and genetic correlations between age at first calving (AFC) and productive performance. Average AFC was 26.48 months
in this study. The peak in the frequency distribution of AFC clearly exists coinciding with cows calving for the first time
at approximately 25 months of age. Heritability estimate for AFC was 0.34 which was greater than the corresponding values
for productive traits. The heritability estimates were low to medium for productive traits which ranged from 0.17 to 0.26
for cows in their first calvings. Except for fat and protein percentages of milk, phenotypic and genetic correlations between
AFC and productive performance traits were low to moderately negative. Range of genetic correlations between productive traits
was −0.53 to 0.99. Reduction of age at first calving appeared to have a negative effect on first lactation protein and fat
percentages; however, it had positive effects on milk yield, fat yield, protein yield and their mature equivalents. It seems
that reducing age at first calving to 24–25 months is probably more profitable than reducing age at first calving to an earlier
time in Iranian conditions. 相似文献