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Full-Text Articles in Life Sciences

Protected Methionine And Heat-Treated Soybean Meal For High-Producing Dairy Cows, Che-Ming Jimmy Yang Jan 1985

Protected Methionine And Heat-Treated Soybean Meal For High-Producing Dairy Cows, Che-Ming Jimmy Yang

Electronic Theses and Dissertations

The effectiveness of a rumen-protected methionine preparation was studied as an amino acid source for high-producing dairy cows during wk 4 through 16 postpartum. Twenty-four Holstein cows (14 primiparous and 10 multiparous) were fed concentrate containing heat-treated· soybean meal without or with 50 g/cow/day of added ruminally protected methionine product which provided 15 g of added DL-methionine daily. Cows were fed 16% crude protein mixed diets containing 30% of dry matter as corn silage, 15% as alfalfa hay, and 55% as concentrate. Milk production and composition were adjusted for pretreatment values (3 wk postpartum) by analysis of covariance. Adjusted milk …


Comparison Of Two Phosphorus Tests On Calcareous Soils Of Eastern South Dakota, Mohamed Ali Jan 1985

Comparison Of Two Phosphorus Tests On Calcareous Soils Of Eastern South Dakota, Mohamed Ali

Electronic Theses and Dissertations

Phosphorus is an important nutrient in crop production, since many soils in their native state do not contain sufficient available phosphorus to maximize crop yield. Now, more than ever, the importance of an adequate supply of plant nutrients to insure [sic] sufficient crop production is being recognized. Soil scientists and agronomists are continually striving to overcome nutrient deficiencies as well as use improved management practices in order that yields may more nearly approach the genetic limit of crop plants. Phosphorous forms sparingly soluble compounds with divalent and trivalent cations in soils. Therefore, the amount of P in the soil solution …


An Ecological Study Of The Vegetation Of The Grand River/Cedar River, Sioux, And Ashland Districts Of The Custer National Forest, Paul Luther Hansen Jan 1985

An Ecological Study Of The Vegetation Of The Grand River/Cedar River, Sioux, And Ashland Districts Of The Custer National Forest, Paul Luther Hansen

Electronic Theses and Dissertations

A land-classification system based on potential natural vegetation is presented for the Grand River/Cedar River, Sioux, and Ashland Districts of the Custer National Forest. The districts are located in northwestern South Dakota, southwestern North Dakota, and southeastern Montana. The vegetation was characterized according to habitat type based on concepts and methods developed by Daubenmire. A total of 169 stands were intensively sampled over a four-year period. Twenty-six habitat types were described including eight steppe, nine shrub-steppe, four woodland, and five forested habitat types. In addition, two shrub-steppe community types were identified. A diagnostic key is provided for field identification of …


Evaluation Of Urea And Dried Whey In Diets Of Cows During Early Lactation, David Paul Casper Jan 1985

Evaluation Of Urea And Dried Whey In Diets Of Cows During Early Lactation, David Paul Casper

Electronic Theses and Dissertations

Previous research indicated that soluble nitrogen may be utilized more efficiently for rumen microbial production in diets containing dried whey. To further evaluate this, 33 Holstein, cows (30 multiparous and 3 primiparous) were fed one of three concentrate mixes containing all natural proteins (SBM). 1% urea (U), or 1% urea and 30% dried whey (UDW) from wk 3 through 16 postpartum. Urea replaced portions of the soybean meal in the SBM mix while dried whey replaced portions of the corn and soybean meal. Cows were fed total mixed rations consisting of 40% (dry matter basis) corn silage, 10% alfalfa hay, …


The Effects Of Nitrogen And Tillage On Denitrification Rates And The Yield Of Corn, Oats, And Soybeans In Eastern South Dakota, Brian Robert Hilton Jan 1985

The Effects Of Nitrogen And Tillage On Denitrification Rates And The Yield Of Corn, Oats, And Soybeans In Eastern South Dakota, Brian Robert Hilton

Electronic Theses and Dissertations

Two field experiments were established in 1983 to evaluate the effect of nitrogen (N) on corn, oats and soybeans grown under various tillage sytems [sic] in east central South Dakota. A corn-oats rotation was grown under moldboard plow (MP), chisel plow (CH), and no-till (NT) tillage systems in a Poinsett silty clay loam soil (Udic Haplaboroll, fine-silty, mixed). In southeast South Dakota a corn-soybean rotation and a continous [sic] corn rotation were grown under MP NT and till plant (TP) and MP CH and NT systems, respectively on an Egan silty clay loam soil (Udic Haplustoll fine silty mixed). Nitrogen …


Comparative Nutritive Value Of Soybean Meal, Sunflower Meal, And Meat And Bone Meal For Egg Production, Smart M. Oruseibio Jan 1985

Comparative Nutritive Value Of Soybean Meal, Sunflower Meal, And Meat And Bone Meal For Egg Production, Smart M. Oruseibio

Electronic Theses and Dissertations

Two experiments were conducted over a period of two years to evaluate the comparative nutritive value of soybean meal, sunflower meal, and meat and bone meal. Experiment 1 consisted of 864 Babcock--3OO pullets randomly distributed into twelve diet treatments. Each treatment was replicated six-times with twelve birds per unit. Layers diets were formulated at 16, 14, and 12% protein levels with and without amino acid supplementation. The 12% amino acid supplemented level served as the control in the experiment. Soybean meal, sum-lower meal, and eat_ and bone meal were utilized as major sources of protein supplement in yellow-corn based diets. …


Studies On Perennial Weed Control In South Dakota, Steven Robert Gylling Jan 1985

Studies On Perennial Weed Control In South Dakota, Steven Robert Gylling

Electronic Theses and Dissertations

Studies were conducted to measure efficacy and economics of selected herbicide treatments for leafy spurge control in pasture, and to characterize the interaction of ammonium sulfate and glyphosate for quackgrass control. Several treatments resulted in leafy spurge control exceeding 90% in the tested pasture. Mean herbage dry-weight yield in treated plots was 2340 kg/ha, a 67% increase over untreated plots. Forage yields did not significantly differ among treatments controlling 90% or more leafy spurge. Marginal net return over marginal cost from herbicide treatments ranged from $35 to loss of $63/ha. Treatments providing satisfactory leafy spurge control with minimum economic risk …


Response Of Five Spring Wheat Cultivars To Drought, Gregory Keith Hess Jan 1985

Response Of Five Spring Wheat Cultivars To Drought, Gregory Keith Hess

Electronic Theses and Dissertations

Response of plants to water stress are numerous and interrelated. Morphological traits and growth patterns have been studied and reviewed extensively. Root growth patterns, leaf area and thickness, presence of cuticle hair and waxes, leaf movement, and wilting are only a few traits studied. Metabolic functions and how water stress affects these processes through stomatal behavior, transpiration rates and carbon dioxide exchange rates have also been reviewed. Plant breeders are continually searching for traits which aid in selecting for high yielding genotypes in any one environment. Moisture is often limiting in South Dakota's environment, leading to relatively low grain yields …


Effects Of Partial Homogenization Of Milk On Yield And Quality Of Cheddar Cheese, Anand Rao Jan 1985

Effects Of Partial Homogenization Of Milk On Yield And Quality Of Cheddar Cheese, Anand Rao

Electronic Theses and Dissertations

In the past decade, the cheese industry in the United States (US) has grown rapidly, with cheese sales increasing by 33% (36). The cheese industry, in 1983, utilized 29.2% of total US milkfat supply as compared to 20.3% utilization in 1973 (36). Compared to the total cheese production of 2,059,2Z8 kg (4,539,822 lb) in 1982, 2,185,611 kg (4,818,449 lb) of cheese were manufactured in 1983 in the .US (36). The increased production of cheese was made possible by modifications in the cheese making process and advent of modern equipment; and it was fostered by increased demand .and higher prices. One …


Evaluation Of Yield And Quality Of Cheddar Cheese Manufactured From Milk With Added Whey Protein Concentrate, Kirk Alan Baldwin Jan 1985

Evaluation Of Yield And Quality Of Cheddar Cheese Manufactured From Milk With Added Whey Protein Concentrate, Kirk Alan Baldwin

Electronic Theses and Dissertations

Large quantities of whey are produced as a by-product from the manufacture of cheese or casein. The United States has an annual cheese production of about 2.2 billion kg. The cheese industry has also experienced a steady increase in cheese production of about 6% a year (44). In the process, nearly 18.1 billion kg of whey are produced. Whey was once a discarded product of little value to the cheese producers. With the advent of laws and regulations governing the disposal of whey, whey became a problem that had few solutions. Even today, with the high cost of disposal and …


Identification Of Volatile Compounds Produced By Brevibacterium Linens That Inhibit Molds, Samuel E. Beattie Jan 1985

Identification Of Volatile Compounds Produced By Brevibacterium Linens That Inhibit Molds, Samuel E. Beattie

Electronic Theses and Dissertations

Mold contamination of processed food and its raw ingredients is a major concern in agriculture. Although at one time mold contamination of cheese and other foods was considered to be of little conse9uence, discovery of carcinogenic and/or teratogenic toxins (73) produced by molds commonly associated with food has changed this innocuous and frequent inconvenience into a serious health consideration. The presence of mold on or in cheese is a common occurrence, indeed, many cheeses depend upon molds to provide characteristic cheese flavor and texture. Cheeses such as blue, Roquefort, Camembert, and Brie are ripened under controlled conditions by species of …


Characterization Of Kpni Interspersed, Repetitive Dna Sequence Families And Their Association With The Nuclear Matrix, Joseph A. Chimera Dec 1984

Characterization Of Kpni Interspersed, Repetitive Dna Sequence Families And Their Association With The Nuclear Matrix, Joseph A. Chimera

Electronic Theses and Dissertations

The KpnI, 1.2 and 1.5 kb families of interspersed repetitive DNAs from the African green monkey genome were isolated and characterized. Each family contains three populations of segments based on their sequence lengths and susceptibility to cleavage by the restriction enzymes KpnI and RsaI. The first population contains the smallest segments which are susceptible to both KpnI and RsaI cleavage and have fragment lengths of 1.2 kb (1.2 kb family) and 1.5 kb (1.5 kb family) respectively. The members in this population are referred to as KpnI-sensitive segments. The second population contains longer segments (> 2 kb) which represent fusions …


The Manufacture Of Cheddar Cheese Using Vacuum Concentrated Milks, Charles A. Bemis Jan 1984

The Manufacture Of Cheddar Cheese Using Vacuum Concentrated Milks, Charles A. Bemis

Electronic Theses and Dissertations

The United States (US) cheese industry has grown rapidly in the past decade. From 1971 to 1981, milk fat utilization for cheese manufacture increased from 17.7 to 27.6% of the total US milk fat supply, accompanied by a 49% increase in sales of cheese per capita (34). Offsetting substantial increases in sales and prices for cheeses, there have been marked increases in the cost of labor, energy, waste treatment, raw materials, and equipment. Hence, the manufacturers are realizing narrower profit margins. As a survival mechanism, cheesemakers have sought to maximize cheese yields per unit of milk, since increases in cheese …


Environmental, Nutritional, And Physiological Factors Associated With Hoof Growth And Wear In Holstein Cows, Lisa Hartson Bemis Jan 1984

Environmental, Nutritional, And Physiological Factors Associated With Hoof Growth And Wear In Holstein Cows, Lisa Hartson Bemis

Electronic Theses and Dissertations

Environmental, nutritional, and physiological parameters associated with hoof growth and wear were evaluated using data from 140 Holstein cows in five herds. Growth and wear of the dorsal and lateral regions of the front and rear outside claws were measured at approximately 2 mo intervals over a 14 mo period. Housing facilities varied from continuous confinement on concrete to confinement in dirt lots and included loafing sheds, free stall barns, and one comfort stall facility with rubber mats. Lateral hoof regions grew 24% faster than dorsal regions in the front and 20% faster in the rear hooves. Rear hooves grew …


Ultrastructure Of Wheat (Triticum Aestivum) Leaf Cells Infected With Leaf Rust (Puccinia Recondita), And Wheat Streak Mosaic Virus, Saleh H. Shrief Jan 1984

Ultrastructure Of Wheat (Triticum Aestivum) Leaf Cells Infected With Leaf Rust (Puccinia Recondita), And Wheat Streak Mosaic Virus, Saleh H. Shrief

Electronic Theses and Dissertations

Puccinia recondita ultrastructure resembles that of other rust species. The urediospore infection was characterized by the formation of a specialized structure, the haustorium, within the leaf cells. The haustorium contains organelles such as nuclei, mitochondria, microbodies, ribosomes, lipid bodies, and vacuoles. A haustorial neck connects the haustorium with the haustorial mother cell, and contains a neck band made up of darkly stained material. The neck band was located at the last one third of its length toward the haustorium. The haustorial mother cell was situated intercellularly, and closely adhering to the cell wall, but contained few organelles, and the nucleus …


Factors In Ultrafiltration And Thermal Concentration Of Whey Affecting Commercial Lactose Crystallization, Howard Henry Bonnemann Jan 1984

Factors In Ultrafiltration And Thermal Concentration Of Whey Affecting Commercial Lactose Crystallization, Howard Henry Bonnemann

Electronic Theses and Dissertations

The source for lactose production in the United States is almost exclusively sweet (low acid) whey which is the byproduct of cheese manufacture. Its extraction from the whey is motivated largely by pressures to utilize whey components to advantage. The ability to recover lactose efficiently is important to the manufacturers because they are in business ·to make a profit. At current market prices this profit margin will be difficult to realize unless an operation is fairly large a11d quite efficient. However, when considering the alternative of disposing of whey or its components, including lactose, as waste instead of attempting to …


The Effects Of Calcium Hydroxide Treatment Of Sunflower Seeds On Ration Digestibility And Rumen Parameters In Holstein Steers, Ann C. Spearow Jan 1984

The Effects Of Calcium Hydroxide Treatment Of Sunflower Seeds On Ration Digestibility And Rumen Parameters In Holstein Steers, Ann C. Spearow

Electronic Theses and Dissertations

Digestibilities of rations containing 10% (dry matter basis) oil-type, rolled sunflower seeds treated with three levels- of calcium hydroxide were compared using .a randomized complete block design. Forty-eight Holstein steers were fed one of six completely mixed rations consisting of (DM basis) 44% corn silage, 10% chopped alfalfa hay, and 46% concentrate mix. Concentrate mixes contained: CSM = control; SCS =control+ 22% sunflower seeds; SCL = SCS + 3.5% additional limestone; SCH2, SCH4, and SCH8 = SCS + 2, 4, and 8% calcium hydroxide (% sunflower seed DM), respectively. Total rations were isonitrogeneous at approximately 16% crude protein and isocaloric …


The Use Of Whole-Rolled Sunflower Seeds With Or Without Additional Limestone In Lactating Dairy Cattle Rations, Anne M. Finn Jan 1983

The Use Of Whole-Rolled Sunflower Seeds With Or Without Additional Limestone In Lactating Dairy Cattle Rations, Anne M. Finn

Electronic Theses and Dissertations

Thirty Holstein cows were utilized in a lactation trial evaluating diets containing whole-rolled sunflower seeds. Cows were randomly assigned to treatments, grouped according to previous milk production and lactation number. The cows were fed one of three diets: 1) the control was a com-soybean meal mix (CSM), 2) com-soybean meal mix plus 22% whole-rolled sunflower seeds, and 3) a corn-soybean meal mix with 22% whole-rolled sunflower seeds with an additional 3.5% limestone over SCS (SCL). Additional limestone was added in an attempt to form fatty acid insoluble soaps. Rations were formulated to be isonitrogenous at 16% crude protein, fed as …


Digestibility Of Sunflower Hulls Treated With Sodium, Ammonium, And Potassium Hydroxides, Bal Krishna Sharma Jan 1983

Digestibility Of Sunflower Hulls Treated With Sodium, Ammonium, And Potassium Hydroxides, Bal Krishna Sharma

Electronic Theses and Dissertations

In vitro dry matter digestibility (IVDMD) of sunflower hulls (SFH) treated with sodium hydroxide (NaOH), ammonium hydroxide (NH4OH), and potassium hydroxide (KOH) at increasing levels were studied. Tested concentrations of each alkali as percent dry matter (DM) on SFH were 1.63, 2.45, 3.26, and 4. 08. In vitro dry matter digestibility of sunflower hulls increased with higher concentrations of NaOH and KOH. Percent IVDMD for control (un-treated SFH) was 18.0. Percent IVDMD for SFH treated at 1.63, 2.45, 3.26, and 4.08% of DM were: 18.9, 21.4, 22.2, and 22.9 for NaOH; 18.3, 18.0, 18.3, and 18.5 for NH …


An Examination Of Prostaglandins As Causative Agents In Pine Needle (Pinus Ponderosa) Abortion, Daniel P. Shue Jan 1983

An Examination Of Prostaglandins As Causative Agents In Pine Needle (Pinus Ponderosa) Abortion, Daniel P. Shue

Electronic Theses and Dissertations

Cow and calf losses due to pine needle abortion in cattle grazing foothill ranges of ponderosa pine (Pinus ponderosa) continue to cause managerial and economic problems for ranchers in South Dakota, Colorado, Idaho, California, Montana and many areas throughout Canada. Because of its overall economic significance, investigators have been attempting to isolate and characterize causative agents of pine needle abortion. To date, a large number of pine needle constituents have been shown to possess abortifacient capabilities. In addition to actual pine needles, it appears that several other undefined factors may be associated with, and (or) predispose animals to, pine needle …


Effects And Interactions Of Nitrogen And Soil Moisture Status Under A High Yield Irrigated Corn Environment, Dwayne L. Beck Jan 1983

Effects And Interactions Of Nitrogen And Soil Moisture Status Under A High Yield Irrigated Corn Environment, Dwayne L. Beck

Electronic Theses and Dissertations

A two-part study was conducted during the 1979 and 1980 growing seasons on irrigated lands adjoining the Missouri River in central South Dakota. Empirical [sic] models were developed to describe the response of irrigated corn (Zea mays L.) to soil water status and nitrogen fertilization at a location recently developed for sprinkler irrigation. Nitrogen fertilizer rates of 0, 100, 200, and 400 kg of N/ha were used under water treatments consisting of a 2.5 cm irrigation when soil water matric potential at a depth of 40 cm decreased to -35, -50, and -75 kPa. Yield differences due to soil water …


Ultrafiltration Of Skim Milk Prior To Cottage Cheese Making, Izhar H. Athar Jan 1983

Ultrafiltration Of Skim Milk Prior To Cottage Cheese Making, Izhar H. Athar

Electronic Theses and Dissertations

Cottage cheese has the largest sales volume potential of all cultured dairy products in the United States today. Moreover, it can be a highly profitable product if proper control is exercised during its manufacturing (46). Commercial production of cottage cheese utilizes a significant portion of the total fluid milk produced in the U. S.A. After the 1955's, yearly per capita consumption of cottage cheese increased from 1. 7 7 kg (3.9 lb) to a high of 2. 45 kg (5.4 lb) in 1972 (67) . Consumer demand for lower fat dairy products gradually increased, which put more pricing emphasis on …


Influence Of Cultural Practices On The Sunflower Seed Weevil In South Dakota, Joe V. Gednalske Jan 1983

Influence Of Cultural Practices On The Sunflower Seed Weevil In South Dakota, Joe V. Gednalske

Electronic Theses and Dissertations

The purpose of this study was to evaluate cultural methods for sunflower seed weevil control. Procedures examined included the influences of tillage methods, crop rotation, date of planting, hybrid maturity, and degree-day units in emerging seed weevil populations. Tillage practices done as both fall and spring treatments including discing, chisel plowing, nobel blading, and moldboard plowing were examined for their effect on larval position in the soil, time of adult weevil emergence, and the number of adults emerging from the soil. Crop rotations were investigated for possible influence on weevil mortality and time of adult emergence. Sunflower planting date and …


Rumen Microbial Protein Synthesis In Cows Fed Dried Whey, Paul M. Windschitl Jan 1983

Rumen Microbial Protein Synthesis In Cows Fed Dried Whey, Paul M. Windschitl

Electronic Theses and Dissertations

Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid …


Generation, Isolation And Assay Methods For Human Lymphocyte Mitogenic Factor, Thomas E. Seay Dec 1982

Generation, Isolation And Assay Methods For Human Lymphocyte Mitogenic Factor, Thomas E. Seay

Electronic Theses and Dissertations

Activated lymphocytes secrete many products including the lymphokine human lymphocyte mitogenic factor (HLMF). In preliminary experiments lymphocytes from peripheral blood and palatine tonsils were evaluated as possible sources of HLMF by evaluating their level of activation through screening their spontaneous and concanavalin A (con A)-induced blastogenic responses. Tonsil lymphocytes (TL) were found to have high spontaneous proliferation as compared to peripheral blood lymphocytes (PBL). Cells from both sources responded to con A by undergoing a typical blastogenic response. Because TL must be obtained septically, they are frequently cultured in the presence of the antimycotic agent, Amphotericin B (Am B). Since …


Soil Studies Educational Unit And Soil Reconnaissance Survey Of Piney Woods Conservation Center, Consuelo Garcia Campos Klotz Dec 1982

Soil Studies Educational Unit And Soil Reconnaissance Survey Of Piney Woods Conservation Center, Consuelo Garcia Campos Klotz

Electronic Theses and Dissertations

A soil reconnaissance survey was conducted on 2,500 acres adjacent to Sam Rayburn Reservoir, in the Angelina National Forest, San Augustine County, the future site of the proposed Piney woods Conservation Center. Data from the soil reconnaissance survey was interpreted and organized into a soil studies educational unit to be used to familiarize teachers with a variety of soils and their properties. Five of the eight soils were integrated into the study unit which is a portion of the total outdoor education and conservation program to be developed for the Piney Woods Conservation Center.


Drought-Tolerance Comparison Of Aleppo Pine And Brutia Pine Seedlings, Mohammad S. Abido May 1982

Drought-Tolerance Comparison Of Aleppo Pine And Brutia Pine Seedlings, Mohammad S. Abido

Electronic Theses and Dissertations

Seedlings of Pinus halepensis and P. brutia were grown from seeds in a greenhouse. When 6 months old, randomly sampled seedlings were subjected to water stress by withholding irrigation. During this period, foliage and root characteristics of seedlings not under moisture stress were recorded. Pinus halepensis showed the greater ability to endure moisture stress and to maintain a higher level of needle-moisture content during the dry-down period. Meanwhile, P. brutia showed important anatomical and morphological adaptations which enable the species to conserve moisture.


Tonsil Cell Products Which Modify In Vitro Proliferation Of Blood Lymphocytes, Thomas W. Hodge May 1982

Tonsil Cell Products Which Modify In Vitro Proliferation Of Blood Lymphocytes, Thomas W. Hodge

Electronic Theses and Dissertations

Human palatine tonsil lymphocytes, when compared to peripheral blood lymphocytes (PBL), were in an activated state even though there was no in vitro stimulation. When these tonsil lymphocytes were cultured in the absence of serum and polyclonal mitogens or antigens, the supernatant fluid often inhibited the proliferative response of target PBL to con A. The extent of this suppression ranged from 22% to 84%, and target cell viability was 90% or greater. There was no evidence for the presence of immunoglobulins or (alpha)2-macroglobulin in whole supernatant fluids. The suppressor was partially denatured at 80(DEGREES)C and was rendered completely inactive upon …


Assessment Of The Impact Of The European Corn Borer At Three Locations In South Dakota, David R. Raemisch Jan 1982

Assessment Of The Impact Of The European Corn Borer At Three Locations In South Dakota, David R. Raemisch

Electronic Theses and Dissertations

The European corn borer (Lepidoptera: Pyralidae) varies as an

economically significant pest in South Dakota from south to north. In

the northern part of the state the European corn borer (ECB) is limited

to one generation per year. In contrast, there are localized sites

along the Missouri River in southern South Dakota which usually

experience a substantial second brood population. Infestation by

either first or second brood ECB occurs at different stages in the

developmental sequence of the corn plant. As such, each brood must be

considered separately when assessing relationships between yield loss

and ECB larval cavities within the …


Genetic Correlations Among Sex-Limited Traits, Michael D. Macneil Jan 1982

Genetic Correlations Among Sex-Limited Traits, Michael D. Macneil

Electronic Theses and Dissertations

Monte Carlo simulation techniques were used to assess the merits of three methods for calculation of the genetic correlation when traits have been measured on half-sibs of each sex. The restricted maximum likelihood, path coefficient and covariance component estimators did not differ significantly in their accuracy. Path coefficient and covariance component methodologies gave nearly unbiased estimators for traits of high heritability. Across both levels of heritability, the restricted maximum likelihood methodology resulted in genetic correlations being estimated with significantly smaller sampling variance than the other methods. Genetic correlations were estimated for age of puberty, weight at puberty, conceptions per service, …