23 research outputs found
Methods of predicting the weight of carcass roast and steak meat from easily obtainable carcass measurements
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A biometrical evaluation of weight of beef cows and performance of their progeny
Data from Experimental Station herds in Alabama, Florida, Georgia, Louisiana, North Carolina, South Carolina and Texas were included in this cooperative Southern Regional Beef Cattle Breeding Project (S-10) study. Records form straightbred Angus, Brahman, Brangus, Herefords and Santa Gertrudis were studied. Analytical methods included the least-squares method of fitting constants and auxiliary methods for estimation of various parameters. Computer programs were written for these methods. Primary objectives of this study were to partition variance in cow weight and to evaluate linear and quadratic relationships between cow weight and progeny preweaning performance. Two measures of cow weight were available: weight after parturition (PCW) and weight at weaning (WCW). Progeny traits were birth weight (BW), weaning weight (WW) and average daily gain from birth to weaning (ADG). Sources of variation evaluated for cow weight included location, breed, sire, year of record, age in years, previous parity and calving month. Paternal half-sib estimates of heritability determined from combined location data were 0.96 for PCW and 0.74 for WCW. Combined location estimates of heritability from the regression of daughter's average record on dam's average record were 0.42 for PCW and 0.44 for WCW. Repeatability estimates indicateed that temporary environmental effects accounted for less than forty percent of the variation in PCW or WCW. The sources of variation evaluated for the progeny traits were location, breed, sire, year, sex, birth month and age, wright and previous parity of dam. Age of calf in days was included in the model for WW. Age and weight of dam tended to account for similar sources of variation in the progeny traits. Dam weight appeared more closely related to variation in BW than did dam age; however, dam age appeared more closely related to variation in ADG and WW than did dam weight. The quadratic relationships between the two weights of dam and the three progeny traits were calculated and plotted for each location. Even though the degree of curvilinearity of the dam weight-progeny trait regression relationship varied considerable across locations, they were generally positive. Sex of calf consistently accounted for an important portion of variation in the progeny traits. Males were heavier at birth and weaning and had higher ADG's than females. Calves raised by dams parous the previous year were lighter at birth and weaning and had lower ADG's. Estimates of heritability for the progeny traits ranged from low to moderate and phenotypic, genetic and environmental correlations among these traits were generally high
The effects of freeze-and-thaw cycles on phosphorus availability in highland soils in Turkey
Ongoing global warming may result in colder soil and thawing cycles and will increase the frequency of soil freezing-and-thawing-treated cycles (FTCs) during winter in the cool-temperate and high-latitude regions. The purpose of this study was to determine the effects of repeated freezethaw cycles on the solubility and adsorption of P in lab and field experiments on Pellustert, Argiustoll, Haplustept, Fluvaquent, and Calciorthid soils, the major soil groups in E Turkey. The results demonstrated that, depending on the soil type, the freezethaw cycle could increase the adsorption and desorption of P within a certain temperature range. Repeated freezing and thawing decreased equilibrium P concentration (EPC) and increased P adsorption. EPC and P adsorption were strongly correlated with the number of FTCs. The highest P adsorption and the lowest P desorption was found in Pellustert followed by Argiustoll, Calciorthid, Haplustept, Fluvaquent when refrozen at 10 degrees C for 15 d, then thawed at +2.5 degrees C for 18 h, and 9 times FTC. However, in the field study, the adsorption value was lower than the value obtained from the laboratory condition. It appears that increasing the frequency of freezethaw processes depending on increase in temperature that leads to decreased plant-available soil P pools, thus requires more P fertilizer in soil solution to supply adequate P during the plant-growth period
The effects of freeze-and-thaw cycles on phosphorus availability in highland soils in Turkey
Genome sequence of Theileria parva, a bovine pathogen that transforms lymphocytes
We report the genome sequence of Theileria parva, an apicomplexan pathogen causing economic losses to smallholder farmers in Africa. The parasite chromosomes exhibit limited conservation of gene synteny with Plasmodium falciparum, and its plastid-like genome represents the first example where all apicoplast genes are encoded on one DNA strand. We tentatively identify proteins that facilitate parasite segregation during host cell cytokinesis and contribute to persistent infection of transformed host cells. Several biosynthetic pathways are incomplete or absent, suggesting substantial metabolic dependence on the host cell. One protein family that may generate parasite antigenic diversity is not telomere-associated.4 page(s