6,596 research outputs found
Across-Breed EPD Tables For The Year 2016 Adjusted To Breed Differences For Birth Year Of 2014
Factors to adjust the expected progeny differences (EPD) of each of 18 breeds to the base of Angus EPD are reported in the column labeled 6 of Tables 1-8 for birth weight, weaning weight, yearling weight, maternal milk, marbling score, ribeye area, fat thickness, and carcass weight, respectively. An EPD is adjusted to the Angus base by adding the corresponding acrossbreed adjustment factor in column 6 to the EPD. It is critical that this adjustment be applied only to Spring 2016 EPD. Older or newer EPD may be computed on different bases and, therefore, could produce misleading results. When the base of a breed changes from year to year, its adjustment factor (Column 6) changes in the opposite direction and by about the same amount.
Breed differences change over time as breeds put selection emphasis on different traits and their genetic trends differ accordingly. Therefore, it is necessary to qualify the point in time at which breed differences are represented. Column 5 of Tables 1-8 contains estimates of the differences between the averages of calves from sires of each breed born in year 2014. Any differences (relative to their breed means) in the samples of sires representing those breeds at the U.S. Meat Animal Research Center (USU.S. Meat Animal Research Center) are adjusted out of these breed difference estimates and the across-breed adjustment factors. The breed difference estimates are reported as progeny differences, e.g., they represent the expected difference in progeny performance of calves sired by average bulls (born in 2014) of two different breeds and out of dams of a third, unrelated breed. In other words, they represent half the differences that would be expected between purebreds of the two breeds
Growth curves of crossbred cows sired by Hereford, Angus, Belgian Blue, Brahman, Boran, and Tuli bulls, and the fraction of mature body weight and height at puberty
The objective of this study was to evaluate the growth curves of females to determine if mature size and relative rates of maturation among breeds differed. Body weight and hip height data were fitted to the nonlinear function BW = f(age) = A − Bek×age, where A is an estimate of mature BW and k determines the rate that BW or height moves from B to A. Cows represented progeny from 28 Hereford, 38 Angus, 25 Belgian Blue, 34 Brahman, 8 Boran, and 9 Tuli sires. Bulls from these breeds were mated by AI to Angus, Hereford, and U.S. Meat Animal Research Center III composite (1/4 Angus, ¼ Hereford, 1/4 Red Poll, and 1/4 Pinzgauer) cows to produce calves in 1992, 1993, and 1994. These matings resulted in 516 mature cows whose growth curves were subsequently evaluated. Hereford-sired cows tended to have heavier mature BW, as estimated by parameter A, than Angus- (P = 0.09) and Brahman-sired cows(P = 0.06), and were heavier than the other breeds (P \u3c 0.001). Angus-sired cows were heavier than Boran-(P \u3c 0.001) and Tuli-sired cows (P \u3c 0.001), and tended to be heavier than Belgian Blue-sired cows (P = 0.097). Angus-sired cows did not differ from Brahman- sired cows (P = 0.94). Brahman-sired cows had a heavier mature BW than Boran- (P \u3c 0.001), Tuli- (P \u3c 0.001), and Belgian Blue-sired cows (P \u3c 0.04). Angus-sired cows matured faster (k) than cows sired by Hereford (P = 0.03), Brahman (P \u3c 0.001), Boran (P = 0.03), and Tuli (P \u3c 0.001) sires, but did not differ from Belgian Blue-sired (P = 0.13) cows. Brahmansired cows took longer to mature than Boran- (P = 0.03) or Belgian Blue-sired cows (P = 0.003). Belgian Blue-sired cows were faster maturing than Tuli-sired cows (P = 0.02). Brahman-sired cows had reached a greater proportion of their mature BW at puberty than had Hereford- (P \u3c 0.001), Tuli- (P = 0.003), and Belgian Blue-sired cows (P = 0.001). Boran-sired cows tended to have reached a greater proportion of their mature BW at puberty than had Angus-sired cows (P = 0.09), and had reached a greater proportion of their mature BW at puberty than had Hereford- (P \u3c 0.001), Tuli- (P \u3c 0.001), and Belgian Blue-sired cows (P \u3c 0.001). Within species of cattle, the relative range in proportion of mature BW at puberty (Bos taurus 0.56 through 0.58, and Bos indicus 0.60) was highly conserved, suggesting that proportion of mature BW is a more robust predictor of age at puberty across breeds than is absolute weight or age
Growth curves of crossbred cows sired by Hereford, Angus, Belgian Blue, Brahman, Boran, and Tuli bulls, and the fraction of mature body weight and height at puberty
The objective of this study was to evaluate the growth curves of females to determine if mature size and relative rates of maturation among breeds differed. Body weight and hip height data were fitted to the nonlinear function BW = f(age) = A − Bek×age, where A is an estimate of mature BW and k determines the rate that BW or height moves from B to A. Cows represented progeny from 28 Hereford, 38 Angus, 25 Belgian Blue, 34 Brahman, 8 Boran, and 9 Tuli sires. Bulls from these breeds were mated by AI to Angus, Hereford, and U.S. Meat Animal Research Center III composite (1/4 Angus, ¼ Hereford, 1/4 Red Poll, and 1/4 Pinzgauer) cows to produce calves in 1992, 1993, and 1994. These matings resulted in 516 mature cows whose growth curves were subsequently evaluated. Hereford-sired cows tended to have heavier mature BW, as estimated by parameter A, than Angus- (P = 0.09) and Brahman-sired cows(P = 0.06), and were heavier than the other breeds (P \u3c 0.001). Angus-sired cows were heavier than Boran-(P \u3c 0.001) and Tuli-sired cows (P \u3c 0.001), and tended to be heavier than Belgian Blue-sired cows (P = 0.097). Angus-sired cows did not differ from Brahman- sired cows (P = 0.94). Brahman-sired cows had a heavier mature BW than Boran- (P \u3c 0.001), Tuli- (P \u3c 0.001), and Belgian Blue-sired cows (P \u3c 0.04). Angus-sired cows matured faster (k) than cows sired by Hereford (P = 0.03), Brahman (P \u3c 0.001), Boran (P = 0.03), and Tuli (P \u3c 0.001) sires, but did not differ from Belgian Blue-sired (P = 0.13) cows. Brahmansired cows took longer to mature than Boran- (P = 0.03) or Belgian Blue-sired cows (P = 0.003). Belgian Blue-sired cows were faster maturing than Tuli-sired cows (P = 0.02). Brahman-sired cows had reached a greater proportion of their mature BW at puberty than had Hereford- (P \u3c 0.001), Tuli- (P = 0.003), and Belgian Blue-sired cows (P = 0.001). Boran-sired cows tended to have reached a greater proportion of their mature BW at puberty than had Angus-sired cows (P = 0.09), and had reached a greater proportion of their mature BW at puberty than had Hereford- (P \u3c 0.001), Tuli- (P \u3c 0.001), and Belgian Blue-sired cows (P \u3c 0.001). Within species of cattle, the relative range in proportion of mature BW at puberty (Bos taurus 0.56 through 0.58, and Bos indicus 0.60) was highly conserved, suggesting that proportion of mature BW is a more robust predictor of age at puberty across breeds than is absolute weight or age
Apparatus for real-time acoustic imaging of Rayleigh-Benard convection
We have designed and built an apparatus for real-time acoustic imaging of
convective flow patterns in optically opaque fluids. This apparatus takes
advantage of recent advances in two-dimensional ultrasound transducer array
technology; it employs a modified version of a commercially available
ultrasound camera, similar to those employed in non-destructive testing of
solids. Images of convection patterns are generated by observing the lateral
variation of the temperature dependent speed of sound via refraction of
acoustic plane waves passing vertically through the fluid layer. The apparatus
has been validated by observing convection rolls in both silicone oil and
ferrofluid.Comment: 20 pages, 11 figures, submitted to the Review of Scientific
Instrument
Postweaning growth and carcass traits in crossbred cattle from Hereford, Angus, Brangus, Beefmaster, Bonsmara, and Romosinuano maternal grandsires
The objective of this study was to characterize breeds representing diverse biological types for postweaning growth and carcass composition traits in terminal crossbred cattle. Postweaning growth and carcass traits were analyzed on 464 steers and 439 heifers obtained by mating F1 cows to Charolais and U.S. Meat Animal Research Center III (1/4 Hereford, 1/4 Angus, 1/4 Pinzgauer, and ¼ Red Poll) sires. The F1 cows were obtained from mating Angus and U.S. Meat Animal Research Center III dams to Hereford, Angus, Beefmaster, Brangus, Bonsmara, and Romosinuano sires. Traits evaluated were postweaning ADG, slaughter weight, HCW, dressing percentage, percentage of carcasses classified as USDA Choice, LM area, marbling score, USDA yield grade, fat thickness, retail product yield (percentage), and retail product weight. Maternal grandsire breed was significant (P \u3c 0.05) for all traits. Animals with Angus grandsires grew faster and had the heaviest carcasses, with the greatest percentage of carcasses classified as USDA Choice and the greatest marbling scores when compared with other grandsire breeds. Animals with Romosinuano and Bonsmara inheritance grew slower, had the lightest weights at slaughter, the lightest carcass weights, the least percentage of carcasses classified as USDA Choice, and the least amount of marbling and fat thickness. Animals with inheritance from these 2 breeds had a more desirable yield grade with the greatest retail product yield. Maternal granddam breed was significant (P \u3c 0.05) for marbling score, USDA yield grade, fat thickness, and retail product yield. Sex class was significant (P \u3c 0.05) for all traits except for retail product yield. Steers grew faster, were heavier, had heavier carcasses, and were leaner than heifers. Heifers had a greater dressing percentage, a greater percentage of carcasses classified as USDA Choice, a greater LM area, and a decreased yield grade when compared with steers. Sire and grandsire breed effects can be optimized by selection and use of appropriate crossbreeding systems
Seasonal variation in vitamin D status of beef cattle reared in the central United States
The objective was to retrospectively measure seasonal sunlight-associated variation in serum concentrations of 25-hydroxyvitamin D (25OHD) in beef cattle. The concentration of 25OHD was measured in crossbred animals born from March to May in 2011 and 2012. Vitamin D status 2 to 3 mo after birth (period 1) was only available for 2012 calves and was measured in June 2012. Period 1 animals had serum 25OHD concentrations of 26.3 +- 1.5 ng/mL. The 25OHD concentrations for late summer (period 2) were 46.6 +- 1.4 and 51.0 +- 1.5 ng/mL for 2011 and 2012, respectively. Serum concentration of 25OHD in early fall (period 3) were 63.8 +- 1.4 and 55.2 +- 1.5 ng/mL for calves in 2011 and 2012, respectively. Values observed for both late summer and early fall indicated vitamin D sufficiency (P \u3c 0.001) compared with period 1. With diminishing exposure to ultraviolet B and consuming w800 IU or 1800 IU (2011 and 2012, respectively) of supplemental vitamin D, the calves’ midwinter (period 4) 25OHD concentrations fell to 15.2 +- 1.6 and 16.7 +- 1.5 ng/mL for 2011 and 2012, respectively, after 4 to 5 mo on a finishing diet (P \u3c 0.0001). This is considered vitamin D insufficiency in most species. Results indicate that calves are marginally sufficient to insufficient for vitamin D based on serum 25OHD concentrations soon after birth and during winter. Some individual animals would be classified vitamin D deficient. In the absence of sufficient UVB exposure, the dietary vitamin D requirements for rapidly growing beef cattle may need to be increased
Seasonal variation in vitamin D status of beef cattle reared in the central United States
The objective was to retrospectively measure seasonal sunlight-associated variation in serum concentrations of 25-hydroxyvitamin D (25OHD) in beef cattle. The concentration of 25OHD was measured in crossbred animals born from March to May in 2011 and 2012. Vitamin D status 2 to 3 mo after birth (period 1) was only available for 2012 calves and was measured in June 2012. Period 1 animals had serum 25OHD concentrations of 26.3 +- 1.5 ng/mL. The 25OHD concentrations for late summer (period 2) were 46.6 +- 1.4 and 51.0 +- 1.5 ng/mL for 2011 and 2012, respectively. Serum concentration of 25OHD in early fall (period 3) were 63.8 +- 1.4 and 55.2 +- 1.5 ng/mL for calves in 2011 and 2012, respectively. Values observed for both late summer and early fall indicated vitamin D sufficiency (P \u3c 0.001) compared with period 1. With diminishing exposure to ultraviolet B and consuming w800 IU or 1800 IU (2011 and 2012, respectively) of supplemental vitamin D, the calves’ midwinter (period 4) 25OHD concentrations fell to 15.2 +- 1.6 and 16.7 +- 1.5 ng/mL for 2011 and 2012, respectively, after 4 to 5 mo on a finishing diet (P \u3c 0.0001). This is considered vitamin D insufficiency in most species. Results indicate that calves are marginally sufficient to insufficient for vitamin D based on serum 25OHD concentrations soon after birth and during winter. Some individual animals would be classified vitamin D deficient. In the absence of sufficient UVB exposure, the dietary vitamin D requirements for rapidly growing beef cattle may need to be increased
Using pooled data for genomic prediction in a bivariate framework with missing data
Pooling samples to derive group genotypes can enable the economically efficient use of commercial animals within genetic evaluations. To test a multivariate framework for genetic evaluations using pooled data, simulation was used to mimic a beef cattle population including two moderately heritable traits with varying genetic correlations, genotypes and pedigree data. There were 15 generations (n = 32,000; random selection and mating), and the last generation was subjected to genotyping through pooling. Missing records were induced in two ways: (a) sequential culling and (b) random missing records. Gaps in genotyping were also explored whereby genotyping occurred through generation 13 or 14. Pools of 1, 20, 50 and 100 animals were constructed randomly or by minimizing phenotypic variation. The EBV was estimated using a bivariate single-step genomic best linear unbiased prediction model. Pools of 20 animals constructed by minimizing phenotypic variation generally led to accuracies that were not different than using individual progeny data. Gaps in genotyping led to significantly different EBV accuracies (p \u3c .05) for sires and dams born in the generation nearest the pools. Pooling of any size generally led to larger accuracies than no information from generation 15 regardless of the way missing records arose, the percentage of records available or the genetic correlation. Pooling to aid in the use of commercial data in genetic evaluations can be utilized in multivariate cases with varying relationships between the traits and in the presence of systematic and randomly missing phenotypes
Breeding Sustainable Beef Cows: Reducing Weight and Increasing Productivity
Programs for sustainable beef production are established, but the specific role of beef cows in these systems is not well defined. This work characterized cows for two traits related to sustainability, cow weight (CW) and cumulative weight weaned (WtW). Cow weight indicates nutrient requirements and enteric methane emissions. Cumulative weight weaned reflects reproductive performance and avoidance of premature culling for characteristics related to animal health, welfare, and worker safety. Both traits were evaluated with random regression models with records from a crossbred population representing 18 breeds that conduct US national cattle evaluations. The genomic REML analyses included additive and dominance components, with relationships among 22,776 animals constructed from genotypes of 181,286 potentially functional variants imputed from a low-pass sequence. Projected to 8 years of age, the additive heritability estimate for CW was 0.57 and 0.11 for WtW. Dominance heritability was 0.02 for CW and 0.19 for WtW. Many variants with significant associations with CW were within previously described quantitative trait loci (QTL) for growthrelated production, meat, and carcass traits. Significant additive WtW variants were covered by QTL for traits related to reproduction and structural soundness. All breeds contributed to groups of cows with high and low total genetic values (additive + dominance effects) for both traits. The high WtW cows and cows above the WtW mean but below the CW mean had larger heterosis values and fewer bases in runs of homozygosity. The high additive heritability of CW and dominance effects on WtW indicate that breeding to improve beef cow sustainability should involve selection to reduce CW and mate selection to maintain heterosis and reduce runs of homozygosity.
Simple Summary: Improving the sustainability of beef cows involves reducing feed costs and enteric methane emissions and increasing calf production while addressing concerns including animal health and welfare and worker safety. Reducing cow weight can favorably impact feed costs and methane emissions. Cumulative weight weaned observed throughout a cow’s productive life directly addresses calf production and indirectly addresses other concerns—cumulative production is higher for cows who wean healthy calves and avoid culling because of reproductive failure, unsoundness, and dangerous behavior. Using functional variant genotypes imputed from the low-coverage whole genome sequence, this examination of cow weight and cumulative weight weaned in a herd of crossbred cattle resulted in additive heritability estimates of 0.57 for cow weight and 0.11 for weight weaned by 8-year-old cows. Corresponding dominance heritability estimates were 0.02 for cow weight and 0.19 for weight weaned. All breeds were represented by cows projected to have high and low cow weights and weight weaned. Heterosis was higher and genomic inbreeding, measured by runs of homozygosity, was lower among high-weight weaned cows. These results suggest selection should be effective in reducing cow weight. Selection to increase weight weaned will be slow but can be hastened with crossbreeding. Especially when pedigree is not available to estimate heterosis, runs of homozygosity may be a useful indicator of heterosis and a predictor of cumulative productivity. Beef cow sustainability can be improved with appropriate crossbreeding and selection, and may be accelerated by incorporating functional variants associated with sustainability-related traits
HPCC Update and Analysis
Abstract: The last year has seen significant updates in the programming environment and operating systems on the Cray X1E and Cray XT3 as well as the much anticipated release of version 1.0 of HPCC Benchmark. This paper will provide an update and analysis of the HPCC Benchmark Results for Cray XT3 and X1E as well as a comparison against historical results
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