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排序方式: 共有136条查询结果,搜索用时 15 毫秒
21.
B Grimard B Marquant‐Leguienne D Remy C Richard F Nuttinck P Humblot AA Ponter 《Reproduction in domestic animals》2013,48(2):183-194
The aim of this study was to determine whether postpartum variations of plasma IGF‐1 and IGFBP concentrations, oocyte production and quality were related to parity and subsequent conception rate in Holstein dairy cows. Holstein dairy cows [10 primiparous (PP) and 22 multiparous (MP)] were allotted in six batches and sampled once weekly between calving and oestrous synchronization treatment started at 71.2 ± 2.0 days postpartum. During the 3 weeks before treatment, ovum pick‐up (OPU) was performed twice weekly. Oocytes were scored on a 4‐point scale, and oocytes from OPU1, 3 and 5 were fertilized in vitro. Seventeen cows became pregnant after first and second AI and were considered as fertile (F), while the others were considered to be subfertile (SF). Logistic regression was carried out to investigate the relationships between repeated measurements and fertility including parity and batch effects in the models. Likelihood of fertility significantly increased when plasma urea and IGFBP‐3 concentrations decreased and was higher in PP compared with MP cows. There was a trend for fertility to increase when plasma IGF‐1 concentrations increased (p = 0.07). In vitro cleavage and development rates were similar between SF and F cows (46.4% and 28.3% in SF vs 55.0% and 22.1% in F). Parity had an effect on plasma IGF‐1 concentrations (PP: 61.65 ± 2.67 vs MP: 41.63 ± 5.81 ng/ml, p < 0.001), mean number of follicles aspirated per session (PP: 5.7 ± 1.3 vs MP: 9.5 ± 0.8, p < 0.05) and fertility (PP: 8/10 = 80% vs MP: 9/22 = 41%, p < 0.05) but not on the number of oocytes recovered per session nor their quality. In conclusion, postpartum plasma urea and IGFBP‐3 concentrations, but not oocyte production and quality before breeding, were related to subsequent conception rate in our experimental design. Parity had a significant effect on energy status, follicular growth and fertility and needs to be considered when investigating relationships between nutrition and reproduction. 相似文献
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Objective To determine the prevalence of mastitis pathogens in high‐producing intensive dairy herds in New South Wales. Design Field survey. Procedure Milk samples from the mastitis‐affected quarter were collected from cows on five high‐producing dairy farms in NSW. The 820 samples were cultured using standard microbiological culture techniques. Results Bacteria or fungi were isolated from 83.3% of samples (683/820). More than two colony types were isolated from 16.7% of samples (137/820), two types from 6.6% (54/820), and one type from 52.3% (429/820). No bacteria were isolated from 24.4% (200/820) of the primary cultures, but enrichment cultures of these samples yielded single colony type bacterial isolates from 36.5% (73/200) of samples. Environmental pathogens, including coliforms, environmental Streptococcus and Staphylococcus spp., made up 91% (555/610) of isolates and accounted for 33.6% (205/610), 41.6% (254/610) and 15.7% (96/610), respectively, of isolates. Escherichia coli accounted for 76.1% (156/205) of the coliform isolates, Streptococcus uberis and Streptococcus dysgalactiae accounted for 32.3% (82/254) and 28.0% (71/254), respectively, of the environmental streptococcal isolates. Contagious pathogens were uncommon, comprising only 2.5% (15/610) of the total isolates. Conclusion The incidence and causes of mastitis are largely influenced by farm management. The relatively high prevalence of coliform mastitis in the intensive high‐producing herds in this survey contrasts with the low incidence reported in surveys of pasture‐based herds in Victoria. If the Australian dairy industry continues its current trend of intensification, coliform intra‐mammary infections may emerge as an increasingly important cause of mastitis. 相似文献
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S.K. Salih Kafkas G.D. Selim Cetiner A.N. Ada Nissim-Levi 《The Journal of Horticultural Science and Biotechnology》2013,88(2):242-246
SummaryMarker assisted selection may greatly facilitate pistachio rootstock breeding as well as cultivar improvement, because of the long juvenile period of Pistacia species. Early diagnosis of seedling sex type would assist breeding and nurserymanagement in these dioecious species. We searched for RAPD markers linked to sex in P. atlantica, P. terebinthus and P. eurycarpa, the main wild species in Turkey that are used as rootstocks for P. vera. For this purpose, leaf samples were collected from male and female individual trees from each species and sex-pooled DNA samples were prepared by mixing the DNA of ten male and ten female individuals, to screen for sex associated RAPD bands. A total of 472 primers have been screened so far and two bands, amplified by primers BC156 and BC360, appeared to be sex assocaited in P. eurycarpa. The bands were tested in 30 male and 37 female individuals. Band BC156 (1300) was present in all, except one, female trees and was absent from all the male trees. Band BC360 (500) was amplified in 31 out of 37 females and was absent from all the males. In P. atlantica, one primer, OPAK09, amplified a femaleassociated band (850 bp), that was present in all 46 female individuals tested and absent in all the 38 male trees tested. It is likely that these markers are linked to sex-determining loci. The sex determination mechanism has not been characterized in Pistacia and segregating populations from controlled crosses are required to elucidate such mechanism and also to measure the genetic distance of our markers from the putative sex loci. 相似文献
27.
Fertigation of humic substances improves yield and quality of broccoli and nutrient retention in a sandy soil 总被引:1,自引:0,他引:1
There is lack of information available concerning the effect of humic substances (HS) applied via fertigation on plant growth in sandy soils. Therefore, a field experiment was carried out at El‐Saff district (20 km southwest of Cairo), Egypt, to investigate the role of HS fertigation on water retention of a sandy soil, yield and quality of broccoli (Broccoli oleracea L.) as well as on soil nutrient concentration retained after harvest. The experiment consisted of six fertigation treatments (50%, 75%, and 100% of the recommended NPK‐fertilizer rate for broccoli combined with and without HS application at 120 L ha–1) in a complete randomized block design with three replicates. Humic substances affected spatial water distribution and improved water retention in the root zone. Furthermore, application of HS increased total marketable yield and head diameter of broccoli as well as quality parameters (i.e., total soluble solids, protein, and vitamin C). Higher nutrient concentrations were found in the broccoli heads and concentrations of plant‐available nutrients in soil after harvesting were also higher, indicating an improvement in soil fertility. In conclusion, HS fertigation can be judged as an interesting option to improve soil water and nutrient status leading to better plant growth. 相似文献
28.
A Shirazi M Derakhshan‐Horeh AA Pilvarian E Ahmadi H Nazari B Heidari 《Reproduction in domestic animals》2011,46(1):87-94
The objective of this study was to determine the effects of various methods of sperm pre‐treatment on male pronuclear (MPN) formation and subsequent development of ovine embryos derived from in vitro‐matured oocytes and intracytoplasmic sperm injection (ICSI). The effect of treatment of injected oocytes with dithiothreitol (DTT) on embryo development was also assessed. In Exp. 1, the injected oocytes with non‐treated sperm were activated with three different procedures. The cleavage and blastocyst rates in those activated with DTT was lower (p < 0.05) than those activated with either ionomycin (Io) + 6‐dimethylaminopurine (6‐DMAP) or DTT + I + 6‐DMAP. In Exp. 2, the effects of sperm pre‐incubated with DTT, sodium dodecyl sulphate (SDS) or DTT + SDS as well as two‐time frozen/thawed sperm (without cryoprotectant) on MPN formation and oocyte activation were examined. The non‐treated sperm served as controls. The MPN formation in DTT + SDS group was higher (p < 0.05) than other groups except for freeze–thaw group. No difference in the rate of activated ICSI oocytes was observed among groups. In Exp. 3, the effect of pre‐treatment of sperm on subsequent development of ICSI embryos and blastocyst cell numbers were examined. The rates of cleavage and blastocyst formation as well as the blastocyst cell numbers were similar among the pre‐treated and control groups. In conclusion, pre‐treatment of sperm with DTT + SDS positively affected MPN formation, although the subsequent development capacity of the resulting embryos remained limited. Moreover, DTT was not effective on oocyte activation compared with Io + 6‐DMAP after ICSI. 相似文献
29.
Abdel-Moneim Abdel-Moneim Eid Selim Dina A. Basuony Hamdy A. Sabic Essam M. Saleh Ahmed A. Ebeid Tarek A. 《Tropical animal health and production》2020,52(2):671-680
Tropical Animal Health and Production - The present trial investigated the feeding effect of B. subtilis spores on growth performance, blood metabolites, antioxidative status, and digestive enzyme... 相似文献
30.
TF JUBB DC MAIN† AA MITCHELL† RG SHIVAS† KW DE WITTE‡ 《Australian veterinary journal》1996,73(2):49-51
A new, fatal mycotoxicosis of cattle has been recognised in north-western Australia. A feeding trial confirmed the toxicity of a previously unknown species of Corallocytostroma that grows on Mitchell grass (Astrebla spp). The disease has been colloquially named ‘black soil blindness’ because its most prominent features are its confinement to pastures on black soil, and blindness and death of affected animals. Over 500 cattle have died and considerable subclinical disease is present. Above average wet season rainfall and extended growing seasons may explain the emergence of the fungus. The disease is important because cattle production in large areas of Australia utilise Mitchell grass pastures. 相似文献