Genetics of seam fat in cattle

The document attached has been archived with permission from the World Congress on Genetics Applied to Livestock Production.As far as most consumers are concerned, a good steak is a steak with visibly desirable colour (doneness), a large portion of muscle and a small amount of fat, especially the seam fat located between the muscles. During the intensive growth to commercial slaughter weights in feedlots, there is a distinct change in the composition of the body with the amount of fat increasing and the musculature remaining reasonably constant (Pitchford and Bottema, 2000). Cattle breeds deposit fat at different rates and in different locations (subcutaneous, intermuscular or intramuscular). For example, early maturing Jersey cattle deposit more fat intramuscularly than late maturing Limousin cattle (Pitchford and Bottema, 2000). These differences suggest that there is a genetic basis for fat distribution. The aim of this study was to investigate the genetic variation in seam fat distribution within loin muscles of Jersey and Limousin cross cattle, independent from carcass size and fatness

Wide Angle Polarization Analysis with Neutron Spin Filters

AbstractWe report substantial improvements in a compact wide angle neutron spin filter system that was recently employed on the Multi- Axis Crystal Spectrometer at the Center for Neutron Research at the U.S. National Institute of Standards and Technology. The apparatus consists of a cylindrical 3He polarizer cell and wide-angle 3He analyzer cells, a vertical solenoid to provide a uniform magnetic field, and a shielded radio-frequency solenoid for the polarizer cell. Nuclear magnetic resonance is employed to reverse the polarization in the polarizer cell and monitor the 3He polarization in all cells. The first experiment using this apparatus was carried out with cylindrical analyzer cells with limited angular coverage due to low polarizations in fused quartz cells. We present results for aluminosilicate glass analyzer cells that cover 110 ∘ and have long relaxation times (100h to 400h). Using two 100W diode bars spectrally narrowed with chirped volume Bragg gratings, we have obtained 65% - 80% 3He polarization in these cells. The 3He polarization has been measured by neutron transmission and electron paramagnetic resonance. Additional progress includes an improved holding field solenoid and decreased spin-flip losses

A new algorithm for detecting cloud height using OMPS/LP measurements

The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) ozone product requires the determination of cloud height for each event to establish the lower boundary of the profile for the retrieval algorithm. We have created a revised cloud detection algorithm for LP measurements that uses the spectral dependence of the vertical gradient in radiance between two wavelengths in the visible and near-IR spectral regions. This approach provides better discrimination between clouds and aerosols than results obtained using a single wavelength. Observed LP cloud height values show good agreement with coincident Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) measurements

Factors affecting estimation of marbling in cattle and the relationship between marbling scores and intramuscular fat

The aim of this study was to investigate the relationships between various estimates of marbling in Jersey and Limousin crossbred steers with intramuscular fat percentage (IMF%) as determined by solvent extraction. The correlations between IMF% and various marbling scores ranged from 0.67 to 0.79. AUS-MEAT, MSA or USDA scoring systems were correlated, and ranked animals similarly. However, the best correlation with IMF% was found to be with the AUS-MEAT marbling score. When the range of IMF% was assigned to different scores within each system, the AUS-MEAT and USDA systems were similar whereas MSA scores had a higher concentration of fat per score and a broader range of concentrations. The only factors influencing assessment of marbling were IMF% and breed. Other traits, such as loin temperature, eye muscle area, melting point, fat colour and meat colour were not significant. Jersey cross steers had higher marbling scores (1.9 vs 0.8) and IMF% (6.4 vs 4.4%) than Limousin cross. A breed by sire interaction in marbling was also detected

Are there meat quality differences between cattle breeds in southern Australia?

The Southern Crossbreeding Project was designed to examine a range of Bos taurus cattle breeds for production and beef quality traits. Jersey, Wagyu, Angus, Hereford, South Devon, Limousin and Belgian Blue sires were mated to Hereford cows with calves born over four years (1994-97). By testing two cohorts (1995-drop steers and 1996-drop heifers) representing 50 sires, it was concluded that there were no breed differences in tenderness or pH but there were differences in juiciness. Breeds high in intramuscular fat (Jersey and Wagyu) and the double-muscled Belgian Blue had less cooking loss than the other breed combinations

Differences in Delta(9) desaturase activity between Jersey- and Limousin-sired cattle

The original publication can be found at www.springerlink.comAn experiment examined Δ⁹ desaturase activity and FA composition in subcutaneous adipose tissue in two differing breeds of cattle. Jersey-sired cattle had significantly higher rates of desaturase activity than Limousin-sired cattle (1.55 vs. 0.75 nmol/mg protein/min). This difference was also demonstrated by a lower concentration of individual (e.g. 18∶0) and total saturated FA (38.3 vs. 45.1 wt%), and a higher concentration of individual (e.g., 16∶1) and total monounsaturated FA (58.2 vs. 52.7 wt%) in the Jersey animals. Other indices of desaturation calculated from the FA composition showed this same difference. The slip point of adipose tissue of Jersey cattle (36.8°C) was significantly lower than that of Limousin cattle (39.2°C), but Jersey adipose tissue had a greater content of β-carotene. The positive relationship between adipose tissue β-carotene and desaturation opposes the negative relationship between dietary β-carotene and desaturation determined elsewhere. These results, however, lead to the hypothesis that some cattle have a reduced capacity to metabolize β-carotene to various forms of vitamin A, a compound that can reduce Δ⁹ desaturase enzyme activity. In addition, the higher level of intramuscular fat in Jersey cattle (6.97 vs. 3.82%) is possibly related to a lack of inhibition of the adipocyte differentiation genes by vitamin A.B.D. Siebert, W.S. Pitchford, Z.A. Kruka, H. Kuchela, M.P.B. Deland, and C.D.K. Bottem

Validation of ozone profile retrievals derived from the OMPS LP version 2.5 algorithm against correlative satellite measurements

The Limb Profiler (LP) is a part of the Ozone Mapping and Profiler Suite launched on board of the Suomi NPP satellite in October 2011. The LP measures solar radiation scattered from the atmospheric limb in ultraviolet and visible spectral ranges between the surface and 80 km. These measurements of scattered solar radiances allow for the retrieval of ozone profiles from cloud tops up to 55 km. The LP started operational observations in April 2012. In this study we evaluate more than 5.5 years of ozone profile measurements from the OMPS LP processed with the new NASA GSFC version 2.5 retrieval algorithm. We provide a brief description of the key changes that had been implemented in this new algorithm, including a pointing correction, new cloud height detection, explicit aerosol correction and a reduction of the number of wavelengths used in the retrievals. The OMPS LP ozone retrievals have been compared with independent satellite profile measurements obtained from the Aura Microwave Limb Sounder (MLS), Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) and Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). We document observed biases and seasonal differences and evaluate the stability of the version 2.5 ozone record over 5.5 years. Our analysis indicates that the mean differences between LP and correlative measurements are well within required ±10 % between 18 and 42 km. In the upper stratosphere and lower mesosphere (> 43 km) LP tends to have a negative bias. We find larger biases in the lower stratosphere and upper troposphere, but LP ozone retrievals have significantly improved in version 2.5 compared to version 2 due to the implemented aerosol correction. In the northern high latitudes we observe larger biases between 20 and 32 km due to the remaining thermal sensitivity issue. Our analysis shows that LP ozone retrievals agree well with the correlative satellite observations in characterizing vertical, spatial and temporal ozone distribution associated with natural processes, like the seasonal cycle and quasi-biennial oscillations. We found a small positive drift ∼ 0.5 % yr−1 in the LP ozone record against MLS and OSIRIS that is more pronounced at altitudes above 35 km. This pattern in the relative drift is consistent with a possible 100 m drift in the LP sensor pointing detected by one of our altitude-resolving methods