1,022 research outputs found
Chemical Analysis and Nutrient Loading of Streams Entering Conesus Lake, N.Y with sections on I. Status of Conesus Lake I I. Crayfish as Control Agents of Macrophytes
A program of research was developed at the State University of New York at Brockport\u27s Department of Biological Sciences to investigate the causes of decreasing water transparency and increased salt levels in some streams draining into Conesus Lake and to identify watersheds and sources of. fertilizers that may be polluting the lake and causing increased abundance of weeds . It has been supported by New York State, Livingston County, the Villages of Avon and Geneseo and the Town of Livonia and many private citizens. The thrust of the research has been to gather and synthesize information necessary to determine the physical capabilities of Conesus Lake to maintain its aesthetic character, its use as a water supply, and its ability to continue to serve as the symbol of the region. Phase 1 started in 1985 with the goal to identify the causes of the decrease in water clearness or the increase in turbidity of the Lake water. The higher turbidity was of concern to the New York State Department of Health because turbidity for the first time was exceeding the New York State\u27s Guidelines on Drinking Water. The high turbidity may eventually require the construction of new water treatment plants. Results from this work suggest that the high turbidity was correlated with the accidental introduction of a new fish, the alewife or sawbelly, into the Lake. Detailed information was also gathered concerning the water quality of Conesus Lake to ascertain its status and fragility
Report on Transfer Tax Restructuring
This report is submitted to the Council of the Section of Taxation, American Bar Association as a proposed response to the request of the Treasury Department for suggestions for reform of the Federal transfer taxes (the estate, gift, and generation-skipping transfer taxes). That request was contained in a letter dated November 19, 1985, from Ronald A. Pearlman, the Assistant Secretary (Tax Policy), to Hugh Calkins, then Section Chair.\u27 After receiving individual comment papers on the subject from members of the Section\u27s Committee on Estate and Gift Taxes, Mr. Calkins, on April 14, 1986, created this Task Force and asked it to prepare a more fundamental response
Repeated Calm Handling Can Lead to More Docile Cattle
Changes in temperament in heifers when handled either frequently or infrequently were evaluated subjectively based on their behavior when restrained in (chute score) and exiting from (exit score) a squeeze chute. Chute scores decreased over time–a favorable direction–with more dramatic declines in heifers handled more frequently. Heifers with higher chute scores on the first day of handling had the largest reduction in score. Exit scores changed less over time. Chute score therefore may be more indicative of acclimation to a novel environment than exit score. Both scores appear to offer a fast, easy and inexpensive way to quantify docility in cattle. Heifers became calmer with repeated gentle handling. Producers therefore may benefit from allowing cattle a few days to acclimate to new working facilities before assessing docility
Experience Improves the Reliability of Subjective Measurements of Temperament in Beef Cattle
Reliability of experienced and inexperienced observers when assessing the behavior of cattle when restrained in a squeeze chute (chute score), and when exiting the chute (exit score), was compared. Overall, experienced observers had higher reliability than inexperienced observers. Increasing the number of individuals scoring an animal decreased the degree of agreement. However, within an acceptable tolerance for difference in scores, such disagreement may be beneficial; it allows for subtlety in interpretations of temperament, which when averaged, may better reflect docility. Reliabilities were higher for exit score than chute score. This may reflect the complexity of the trait being evaluated, with fewer behaviors observed when cattle exit as compared to when restrained in a chute. Producers may profitably use chute and exit score to quantify docility in cattle. However, it may be worthwhile to gain experience in using the scoring system before implementing it for selection decisions
Experience Improves the Reliability of Subjective Measurements of Temperament in Beef Cattle
Reliability of experienced and inexperienced observers when assessing the behavior of cattle when restrained in a squeeze chute (chute score), and when exiting the chute (exit score), was compared. Overall, experienced observers had higher reliability than inexperienced observers. Increasing the number of individuals scoring an animal decreased the degree of agreement. However, within an acceptable tolerance for difference in scores, such disagreement may be beneficial; it allows for subtlety in interpretations of temperament, which when averaged, may better reflect docility. Reliabilities were higher for exit score than chute score. This may reflect the complexity of the trait being evaluated, with fewer behaviors observed when cattle exit as compared to when restrained in a chute. Producers may profitably use chute and exit score to quantify docility in cattle. However, it may be worthwhile to gain experience in using the scoring system before implementing it for selection decisions
Index Selection in Terminal Sires Improves Lamb Performance at Finishing
Lamb meat is often perceived by consumers as fatty, and consumption has decreased in recent decades. A lean growth index was developed in the UK for terminal sire breeds to increase carcass lean content and constrain fat content at a constant age end point. The purposes of this study were 1) to evaluate the effects of index selection of terminal sires on their crossbred offspring at finishing and 2) to evaluate its effectiveness within terminal sire breeds. Approximately 70% of lambs marketed in the UK have been sired by rams of breeds typically thought of as specialized terminal sires. The most widely used are Charollais, Suffolk, and Texel. These breeds participated in sire referencing schemes from the early 1990s by sharing rams among flocks selected on the lean growth index. From 1999 to 2002 approximately 15 “high” and 15 “low” lean growth index score rams were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were commercially reared on 3 farms in the UK. Lambs were finished to an estimated 11% subcutaneous fat by visual evaluation. At finishing, lambs were weighed, ultrasonically scanned, and assessed for condition score and conformation. Records were obtained for 6,356 lambs on finishing BW (FWT), ultrasonic muscle depth (UMD), ultrasonic fat depth, overall condition score (OCS), and conformation of gigot, loin, and shoulder. Ultrasonic fat depth was log transformed (logUFD) to approach normality. High-index-sired lambs were heavier at finishing (1.2 ± 0.2 kg) with thicker UMD (0.7 ± 0.2 mm) and less logUFD (0.08 ± 0.01 mm; P \u3c 0.05). There were no differences in OCS or conformation based on the sire index or breed (P \u3e 0.08). Suffolk-sired lambs were heavier than Charollais (1.0 ± 0.3 kg), which were heavier than Texel (0.9 ± 0.3 kg; P \u3c 0.001). Texel-sired lambs had thicker UMD than Charollais (0.7 ± 0.2 mm; P \u3c 0.001) but were not different than Suffolk. Charollais-sired lambs had greater logUFD than both Texel (0.098 ± 0.016 mm) and Suffolk (0.061 ± 0.017 mm) sired lambs (P \u3c 0.001). Within a breed, high- and low-index-sired lambs differed in performance with the exceptions of FWT and UMD in Suffolks. Index selection produced heavier and leaner lambs at finishing. Producers have flexibility in choosing the terminal sire that best fits their production system
Emissivity Results on High Temperature Coatings for Refractory Composite Materials
The directional emissivity of various refractory composite materials considered for application for reentry and hypersonic vehicles was investigated. The directional emissivity was measured at elevated temperatures of up to 3400 F using a directional spectral radiometric technique during arc-jet test runs. A laboratory-based relative total radiance method was also used to measure total normal emissivity of some of the refractory composite materials. The data from the two techniques are compared. The paper will also compare the historical database of Reinforced Carbon-Carbon emissivity measurements with emissivity values generated recently on the material using the two techniques described in the paper
Index Selection in Terminal Sires Improves Early Lamb Growth
The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection within TS breeds. The most widely used TS breeds in the United Kingdom are Charollais, Suffolk, and Texel. These participated in sire referencing schemes in which they were evaluated on a lean growth index designed to increase carcass lean weight at a given age. From 1999 to 2002, approximately 15 high and 15 low lean growth index rams per breed (93 in total, differing in index on average by 4.6 SD) were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were reared commercially on 3 experimental farms in England, Scotland, and Wales. A total of 6,515 lambs were born between 2000 and 2003. Lambs were weighed at birth (BWT), 5 wk (5WT), and 10 wk (10WT), and their ADG from birth to 10 wk was calculated. Lambs sired by high index rams were on average, across breeds, heavier at all ages (P \u3c 0.01) with 0.07 ± 0.03, 0.3 ± 0.1, and 0.4 ± 0.1 kg greater BWT, 5WT, and 10WT, respectively. Their ADG was 5.1 ± 1.9 g/d greater than low-index-sired lambs (P \u3c 0.01). Suffolk-sired lambs were on average heavier at all ages, with greater ADG, whereas Charollais-sired lambs were lightest with smallest ADG. Overall, there was no significant interaction between sire index and sire breed (P \u3e 0.10). Within Suffolk-sired lambs, there was little difference between high and low index sires for the traits studied (P \u3e 0.3). High and low index Charollais-sired lambs differed in BWT (0.09 ± 0.04 kg) and 5WT (0.3 ± 0.1 kg), and Texel-sired lambs differed in 5WT (0.5 ± 0.1 kg), 10WT (0.9 ± 0.2 kg), and ADG (10.2 ± 3.3 g/d; P \u3c 0.01). Lambs from Scottish Mule dams were heavier, with greater ADG, than lambs born to Welsh Mules (P \u3c 0.01). Lambs reared in Scotland were heavier at all ages (P \u3c 0.01). The results suggest that using index selection in TS can improve the growth of their commercial offspring reared on grass
Genetic structure and admixture in sheep from terminal breeds in the United States
Selection for performance in diverse production settings has resulted in variation across sheep breeds worldwide. Although sheep are an important species to the United States, the current genetic relationship among many terminal sire breeds is not well characterized. Suffolk, Hampshire, Shropshire and Oxford (terminal) and Rambouillet (dual purpose) sheep (n = 248) sampled from different flocks were genotyped using the Applied Biosystems Axiom Ovine Genotyping Array (50K), and additional Shropshire sheep (n = 26) using the Illumina Ovine SNP50 BeadChip. Relationships were investigated by calculating observed heterozygosity, inbreeding coefficients, eigenvalues, pairwise Wright’s FST estimates and an identity by state matrix. The mean observed heterozygosity for each breed ranged from 0.30 to 0.35 and was consistent with data reported in other US and Australian sheep. Suffolk from two different regions of the United States (Midwest and West) clustered separately in eigenvalue plots and the rectangular cladogram. Further, divergence was detected between Suffolk from different regions with Wright’s FST estimate. Shropshire animals showed the greatest divergence from other terminal breeds in this study. Admixture between breeds was examined using ADMIXTURE, and based on cross-validation estimates, the best fit number of populations (clusters) was K = 6. The greatest admixture was observed within Hampshire, Suffolk, and Shropshire breeds. When plotting eigenvalues, US terminal breeds clustered separately in comparison with sheep from other locations of the world. Understanding the genetic relationships between terminal sire breeds in sheep will inform us about the potential applicability of markers derived in one breed to other breeds based on relatedness
Assessment of genetic diversity and population structure of U.S. Polypay sheep from breed origins to future genomic selection
Knowledge of past and present genetic diversity within a breed is critical for the design and optimization of breeding programs as well as the development of strategies for the conservation of genetic resources. The Polypay sheep breed was developed at the U.S. Sheep Experiment Station (USSES) in 1968 with the goal of improving productivity in Western U.S. range flocks. It has since flourished in the more intensively managed production systems throughout the U.S. The genetic diversity of the breed has yet to be documented. Therefore, the primary objective of this study was to perform a comprehensive evaluation of the genetic diversity and population structure of U.S. Polypay sheep using both pedigree- and genomic-based methods. Pedigree data from 193 Polypay flocks participating in the National Sheep Improvement Program (NSIP) were combined with pedigree records from USSES (n = 162,997), tracing back to the breed’s origin. A subset of these pedigreed sheep from 32 flocks born from 2011 to 2023 were genotyped with the GGP Ovine 50K BeadChip containing 51,867 single nucleotide polymorphisms (SNPs). Four subgroups were used for the pedigree-based analyses: 1) the current generation of animals born in 2020–2022 (n = 20,701), 2) the current generation with a minimum of four generations of known ancestors (n = 12,685), 3) only genotyped animals (n = 1,856), and 4) the sires of the current generation (n = 509). Pedigree-based inbreeding for the full population was 2.2%, with a rate of inbreeding of 0.22% per generation. Pedigree-based inbreeding, Wright’s inbreeding, and genomic inbreeding based on runs of homozygosity were 2.9%, 1.3%, and 5.1%, respectively, for the genotyped population. The effective population size ranged from 41 to 249 for the pedigree-based methods and 118 for the genomic-based estimate. Expected and observed heterozygosity levels were 0.409 and 0.403, respectively. Population substructure was evident based on the fixation index (FST), principal component analysis, and model-based population structure. These analyses provided evidence of differentiation from the foundation flock (USSES). Overall, the Polypay breed exhibited substantial genetic diversity and the presence of a population substructure that provides a basis for the implementation of genomic selection in the breed
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