The response of perennial ryegrass/white clover mini-swards to elevated atmospheric CO₂ concentrations: effects on yield and fodder quality   总被引：1，自引：0，他引：1  

U. Schenk  H.-J. Jäger  & H.-J. Weigel 《Grass and Forage Science》1997,52(3):232-241

In order to assess the effects of future elevated atmospheric CO₂ concentrations on yield, mineral content and the nutritive value of mixed swards of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), both species were grown as monocultures and as different mixtures and were exposed season-long to ambient (380 p.p.m.) and elevated (670 p.p.m.) CO₂ concentrations in open-top chambers. Mini-swards were cut four times at about monthly intervals at a height of 5 cm, dry-matter yields were determined and content of macroelements (N, P, K, S, Mg, Ca, Na) and crude fibre, crude protein and ash content were measured. The CO₂-related increase in seasonal yield amounted to 16–38% for white clover monocultures, 12–29% for mixed swards and 5–9% for ryegrass monocultures. The white clover content of all swards was significantly enhanced by elevated CO₂. The K and Na content of total yield was decreased by high CO₂ but did not fall below the minimum requirements for ruminants. As the Ca content of total yield was increased by elevated CO₂ and the P content was not changed, the Ca/P ratio of total yield was increased and exceeded values required for animal nutrition. The crude protein content of total yield was reduced by high CO₂ at the beginning of the growing season only and was increased by elevated CO₂ in the course of the experiment, whereas crude fibre content was decreased throughout the season, sometimes falling below the minimum requirement for ruminants. Removal of N, P, S, Mg and Ca by cutting was significantly enhanced because of CO₂ enrichment. The results show that, besides the positive effect of rising atmospheric CO₂ on dry-matter yield of white clover/ryegrass swards, impacts on the nutritive value should be expected. Possible changes in species composition and implications for grassland management are briefly discussed.  相似文献   

Matrilin-1 expression is increased in the vertebral column of Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis> L.) individuals displaying spinal fusions     

Pedersen ME  Takle H  Ytteborg E  Veiseth-Kent E  Enersen G  Færgestad E  Baeverfjord G  Hannesson KO 《Fish physiology and biochemistry》2011,37(4):821-831

We have previously characterized the development of vertebral fusions induced by elevated water temperature in Atlantic salmon. Molecular markers of bone and cartilage development together with histology were used to understand the complex pathology and mechanism in the development of this spinal malformation. In this study, we wanted to use proteomics, a non-hypothetical approach to screen for possible new markers involved in the fusion process. Proteins extracted from non-deformed and fused vertebrae of Atlantic salmon were therefore compared by two-dimensional electrophoresis (2DE) and MALDI-TOF analysis. Data analysis of protein spots in the 2DE gels demonstrated matrilin-1, also named cartilage matrix protein, to be the most highly up-regulated protein in fused compared with non-deformed vertebrae. Furthermore, real-time PCR analysis showed strong up-regulation of matrilin-1 mRNA in fused vertebrae. Immunohistochemistry demonstrated induced matrilin-1 expression in trans-differentiating cells undergoing a metaplastic shift toward chondrocytes in fusing vertebrae, whereas abundant expression was demonstrated in cartilaginous tissue and chordocytes of both non-deformed and fused vertebrae. These results identifies matrilin-1 as a new interesting candidate in the fusion process, and ratify the use of proteomic as a valuable technique to screen for markers involved in vertebral pathogenesis.  相似文献   

Use of threshold serum and milk ketone concentrations to identify risk for ketosis and endometritis in high-yielding dairy cows   总被引：2，自引：0，他引：2  

Reist M  Erdin DK  von Euw D  Tschümperlin KM  Leuenberger H  Hammon HM  Künzi N  Blum JW 《American journal of veterinary research》2003,64(2):188-194

OBJECTIVE: To use threshold concentrations of acetone and beta-hydroxybutyrate in milk and serum, respectively; identify risk for ketosis and endometritis; and assess analyses of blood and milk samples as predictors of risk for ketosis in high-yielding dairy cows. ANIMALS: 90 multiparous Holstein cows. PROCEDURE: At intervals before and after parturition, blood samples were obtained for determination of glucose, nonesterified fatty acids, leptin, insulin, insulin-like growth factor-1, and beta-hydroxybutyrate concentrations. Samples of milk were obtained at similar intervals after parturition for determination of fat content and concentrations of acetone, protein, and lactose. Reproductive examination of each cow was performed weekly. RESULTS: For each cow, threshold concentrations of acetone and beta-hydroxybutyrate were calculated as 75th and 90th percentiles of maximum postpartum concentrations of acetone in milk (0.40 and 0.87 mmol/L) and beta-hydroxybutyrate in serum (2.30 and 3.51 mmol/L). Significant decrease in milk production (442 to 654 kg of energy-corrected milk/305-day period per cow) was associated with acetone or beta-hydroxybutyrate in excess of threshold values. Milk acetone concentrations > 0.40 mmol/L were associated with 3.2 times higher risk for endometritis. Low plasma glucose, high serum beta-hydroxybutyrate, and high milk acetone concentrations during week 1 after parturition were indicators of increased risk for ketosis later during lactation. CONCLUSIONS AND CLINICAL RELEVANCE: Determination of milk acetone concentration during the week after parturition may identify cows at risk for ketosis and endometritis; with appropriate interventions, development of disease and production losses may be reduced.  相似文献