The operating costs for farms and ranches in the United States have increased 81 percent between 1970 and 1976. Calf prices over this same period have fluctuated dramatically and have fallen from a high of $58/cwt in 1973 to a low of $2 6/ cwt in 1975. Since 1973, the increasing operating costs have exceeded the returns gene rated by the low calf prices and have left operators in a negative financial position. This case study has shown that the operator has increased both the scale and efficiency of his operation through improved lives tock husbandry and range improvements , yet has been unable to keep up with the increase in operating costs. A res t rot at ion grazing system and associated range improvements were implemented in 1970 on the summer mountain range. The resultant increase in forage prod uction allowed a 45 percent increase in the breeding herd. The meadow hayland and crested wheat grass pastures were also improved to provide winter and spring forage for the increased number of cows. The calf crop weaned and average weaning weights increased from 86 percent and 347 pound s i n 1970 to 93 percent and 363 pounds i n 1976. The total pounds of calf weaned increased 60 percent between 1970 and 1976. The tremendous increase in beef production was offset by the rampant increase in op e rating costs. The net return in 1970 was $2 , lOo but dropped to a loss of - $3,671 i n 1976. However, had the operator not increased the level of production while the operating costs increased, his net loss in 1976 would have been - $24 , 718 . Although the net returns a re negative , the increase in returns over the base level of production is positive. The internal rate of return and net present worth of the grazing system and its associated improvements was 25 percent and $95 ,027 respectively. TI1 e operator has been successful in developing his range and livestock resource and increasing calf production. It is paradoxical that the increase in returns above the base production have rendered the improvements economically profit able yet the combination of increasing operating costs and low livestock prices have produced a negative return from 1974 through 1976.

The objectives of this study were to 1) determine the effects of livestock grazing and periods of rest from grazing on infiltration and erosion rates of unchained woodland; chained, debris-in-place; and chained, debris-windrowed pinyon-juniper sites; and 2) utilize these measurements in developing guidelines for grazing management of pinyonjuniper rangelands that protect or improve the hydrologic condition of the watershed. The study was conducted on sandy loam soils in southeastern Utah during the summers of 1971 and 1972. Runoff and erosion were artificially induced from small plots by simulating rainfall with the Rocky Mountain infiltrometer. Infiltration rates, erosion rates, and selected vegetative and edaphic parameters were measured on each plot. Forage removal by clipping and soil compaction subtreatments were applied to randomly selected plots in an effort to simulate the forage removal and trampling activities of livestock. Analysis of variance techniques were used to determine the effect on infiltration and erosion rates of forage removal and soil compaction subtreatment, grazing and varying periods of rest from grazing, and chaining treatments with similar grazing histories. Multiple regression techniques were used to evaluate the influence of vegetative and edaphic factors on infiltration and erosion. Forage removal and soil compaction subtreatments had no consistent effect on infiltration rates. However, the clipping and compaction subtreatments were an instantaneous application of forage removal and soil pressure and thus may not adequately represent long term, accumulative conditions imposed by actual grazing. Areas rested from livestock grazing since 1967 had significantly higher infiltration rates than grazed areas on unchained woodland and chained, debris-in-place sites. Grazed plots consistently had the lowest infiltration rates although this lower rate was not significantly different from infiltration rates measured on areas protected from grazing since 1969 or 1971. Grazing did not consistently affect infiltration measured on chained, debris-windrowed sites. Infiltration rates increased on all three vegetative conditions as the period of rest from grazing increased. None of the 21 soil and vegetative variables included in this study were identified by multiple regression models as consistently explaining significant amounts of variation in infiltration rates. Results of this study indicate that the primary value of multiple regression models is not to predict changes that will occur in infiltration because one management alternative is selected over another, but to help explain significant differences measured between treatments. Erosion rates were not significantly affected by forage removal subtreatments, but a trend indicates that erosion increases on plots when above ground vegetation is removed by clipping. No consistent relationship between -erosion rates and soil compaction subtreatments was found. A trend toward increased erosion rates on grazed areas was found. No consistent relationship between erosion rates and the various periods of rest from grazing was recorded. Thus, any rest from grazing appears to reduce the erosion potential from pinyonjuniper sites. In summary, pinyon-juniper rangelands can be improved for livestock by chaining and seeding without causing a deterioration in watershed condition. However, to achieve these objectives, the sites to be treated must be carefully evaluated and the appropriate chaining, plant debris disposal, and seeding techniques identified. And following vegetative conversion, the areas must be properly grazed.

Recently, hunting and associated recreation have become an important business for Texas landowners. Most ranchers want to realize maximum net return from their investments. This study's objectives were to develop white-tailed deer (Odocoileus virginianus) and livestock enterprise budgets and to determine optimal economic combinations and levels of deer and livestock enterprises to maximize net returns. Questionnaires were mailed to landowners in the Edwards Plateau and South Texas Plains who purchased shooting preserve licenses in 1985. Five hundred and twenty-four ranchers responded {23.4%). Respondents were segregated by enterprises (deer, cattle, sheep, and Angora and Spanish goats) and a 5% random sample Has chosen from each group for personal interviews. Forty-two and eighteen ranchers in the Edwards Plateau and South Texas Plains, respectively, provided operational and financial information about their ranch enterprises. Typical ranch enterprise budgets were developed for four types of deer enterprises, three cattle enterprises, one sheep enterprise, two Angora goat enterprises, and one Spanish goat enterprise in the Edwards Plateau. In the South Texas Plains, enterprise budgets were developed for four types of deer enterprises and two cattle enterprises. Available resources, such as hectarage, labor, forage, and capital, were determined for typical ranches in both regions. The year deer enterprise was the most profitable deer enterprise in both regions, followed by the season, short-term/season, and short-term deer enterprises. The nanny-mutton-kid-breeding-mohair Angora goat enterprise was the most profitable livestock enterprise in the Edwards Plateau, while the cow-calf enterprise was the most profitable in the South Texas Plains. Linear programming was used to determine optimal combinations and levels of deer and livestock enterprises on typical Edwards Plateau and South Texas Plains ranches. The most profitable combination (in this case only one activity) in the Edwards Plateau was the nanny-mutton-kid- breeding Angora goat enterprise, which had an extremely high gross income due to high mohair prices and government subsidies. The year deer and cow-calf enterprises were the most profitable combination in the South Texas Plains. The most binding constraints on enterprise combination and level were labor, livestock investment, and spring and summer forage.

The purpose of this thesis is to make an evaluation of the competitive position of the Utah livestock industry based on feed ingredient and transportation costs, This is done by the use of a linear programming model (MPS-360). This is on the basis of the least cost means of production to meet the quantity demanded of the livestock products. This is accomplished by dividing the United States into six regions where Utah is one of these regions to enable careful consideration of Utah's agricultural enterprises. Beef, pork, broilers, turkeys, eggs, and milk are the agricultural products used in the model. The feeds used for production are barley, wheat, corn, oats, milo, hay, and 44 percent soybean meal. Mega calories of metabolizable energy were the energy units used in the model as a medium of exchange between feed inputs and livestock products as outputs.

Magister Scientiae (Biodiversity and Conservation Biology) / Desertification deteriorates the landscape functionality of rangelands, affecting the resilience of biome boundaries which have a cascade effect not only in vegetation composition and characteristics but also in animal communities. The balance between plants and small mammals are essential in maintaining the functionality (i.e. nutrient cycling, soil stability, and water infiltration) of rangeland which includes the arid Steinkopf communal rangeland. However, the landscape functionality of rangelands has not been extensively studied, especially in communal areas where desertification is a serious concern since many people farm with livestock to survive. The aim of this study was to assess landscape functionality along an arid biome boundary and its relationship to small mammal assemblages. This study further aimed to provide a local landscape perspective of the current desertification process and projected expansion of the Desert Biome into more mesic biomes in South Africa. Three replicates for three Desert Biome, ecotone and Succulent Karoo Biome sites (27 sites in total) were selected to assess landscape functionality and survey small mammal assemblages over a one-year period. The change in landscape functionality between the three areas was assessed to determine the resilience of the biome boundary to desertification. For each small mammal survey, 216 live Sherman traps were set up during the summer and winter seasons to account for breeding, mortality, and possible migration. With the data, the body condition index, population density, and diversity were quantified.

A series of on-farm quality assurance schemes for red meat producers across Australia were developed in the late 1990s in response to increasing global demands for greater accountability within the whole food. The Cattlecare and Flockcare schemes were introduced in 1996 and 1998, respectively, to provide mechanisms for producers to demonstrate that their livestock were free of potential chemical residues, and that they had taken measures to prevent injury or stress to livestock. These schemes were independently audited codes of practice. After several years there was some dissatisfaction with the levels of adoption of these schemes, especially Flockcare. By 2001 just over 5% of all cattle producers and just over 1% of all sheep producers had implemented on-farm quality assurance. This covered nearly 16% of all cattle and 2% of all sheep in Australia, indicating that the larger than average producers were implementing quality assurance. Based on previous studies and anecdotal evidence that there were few current benefits for producers, the aims of this study were to identify the reasons for slow uptake and to quantify factors affecting implementation of on-farm quality assurance in the red meat industry. Surveys of "adopters" and "nou-adopters" of these schemes were developed and implemented in 2000 and 2001. Producers were approached initially by phone and given the options of completing the survey over the phone, by mail or by fax. / Three hundred and forty-seven Cattlecare producers (9% of all certified Cattlecare producers) and 142 Flockcare producers (22% of certified Flockcare producers) across Australia were initially approached. A total of 382 adopter surveys were completed. The level of interest from adopters was remarkable, with a 75% completion rate from telephone approaches and only 9 direct refusals. These producers had over 1.3 million cattle and 0.9 million sheep covered by quality assurance schemes. This represented 5% of the total cattle population (27% of certified cattle) and less than 1% of all sheep (26% of certified sheep) in Australia at that time. There was an extremely large variation in the size of properties surveyed, which reflected the structure of the industry. The producers were asked about what motivated them to implement quality assurance, what were the problems, where could it be improved, how much time and money had they invested specifically into implementing quality assurance, what benefits had they gained (financial and other), how it had changed their management or product offered for sale, and their opinion on various issues associated with quality assurance and food safety. In addition 133 non-adopter surveys were also completed to provide a control data set. These producers had over 0.12 million cattle and 0.48 million sheep on their properties. In general, it was much harder to persuade these producers to participate. It was estimated that about 60% of producers approached refused to participate. These producers were asked similar questions; except that they were asked to estimate (if they could) how much time and money it would take to implement quality assurance. Unfortunately, most of these producers were uninterested or knew little about quality assurance and were reluctant to estimate these values, so the data for these producers was very limited. / Analysis of the adopter data indicated the adoption rates between regions and schemes were significantly different. A benefit cost analysis was completed for the adopters based on estimated time and money invested into quality assurance and the tangible benefits gained from selling certified animals. The resulting net benefits were calculated as annual equivalent annuities. Only about 30% of adopters had gained any tangible benefit, and only half of these (15% of the total analysed producers) had a positive net benefit, and these were all cattle producers. Description of time, effort and money spend by adopting producers was most representative using median values due to the extreme data from some producers. Overall, implementation took a median of 13 days in the initial year and 6 days in subsequent years per property, and the median cost was $1,200 in the initial year and $500 in subsequent years. This investment of time and money equated to a median cost of $875 per year. The median net financial loss per year from adopting quality assurance was $660 per property or $2 per 100 DSE of livestock managed. Producers indicated that they were implementing quality assurance to gain financial and market benefits; but, with only 15% of producers gaining a positive net benefit, some producers were disappointed with the schemes. However they did report improvements in product (15% of producers) or management practices (90% had at least one). / Improvements in product included livestock were free from chemical residues, cattle were dehorned and yards had been improved so bruising was reduced. Improvements in management practices included improved record keeping, chemical control and livestock handling. While producers mostly believed it was the right thing to do for the industry, they indicated that they would need to be rewarded for their efforts at some stage. Adopters and non-adopters had different motives for implementing quality assurance. Peer pressure, market advantage and increased returns (27%, 26% and 18% of producers, respectively) were cited as the three major prompts for adopters. All the other categories of reasons for adoption were not business-based, but more emotional. Non-adopters, however, cited increased returns, market advantage and supply chain pressure (44%, 7% and 6%, respectively) as possible prompts to implement quality assurance. Difficulties in adoption actually experienced by adopters were also different to the difficulties anticipated by non-adopters. Paperwork, actually getting to implementing it and the extra time demands (19%, 13% and 12%, respectively) were the major difficulties for adopters, while time, in costs and paperwork (19%, 16% and 12%, respectively) were the anticipated difficulties for non-adopters. / Twenty-four percent of adopters had not had any difficulties, while 16% of non- adopters anticipated no difficulties. Simplification of initial paperwork, increased demand for quality assured livestock and a need to promote the schemes and the associated benefits to producers were the three highest ranking categories of suggested improvements by adopters. Non-adopters indicated similar issues but in a different order - a need to promote the schemes and the associated benefits to producers, simplification of initial paperwork and the process of implementation. Grouping producers based on inputs, attitudes, investment or any combination of these indicators failed to provide a statistically significant prediction of the net benefit or loss for a new adopter. The only way to identify or predict which producers would gain a positive net benefit was to focus on the methods of selling livestock. Selling direct to processors either over the hook, with forward contracts or privately appeared to be the only way to gain financial benefits from implementing quality assurance on-farm.

Ever since 1976, livestock farmers in Fiji have been intrigued about biogas digesters as an animal waste management measure, but the concept has never evolved into one that is sustainable. Renewed interest came in 1997 after a better Chinese Modified Dome (CMD) design was established, with this came government funding, however by 2002, some failure was also observed. This study set out to investigate the reasons why biogas digesters have never been established as a sustainable concept, its effectiveness as an animal waste management tool and what changes if any, can be made to try and influence the further development of the concept in Fiji. In order to achieve the objectives, which were simply obtaining the answers to the questions presented above, several different approaches had to be followed. This study was the first on biogas digesters in Fiji and it was unique in the sense that the major component dealt with the social aspects of farmers in relation to their biogas digesters. Basically the study was carried out in two parts - desktop studies and field studies. Desktop studies were done to better understand the situation while the field studies included semi-structured interviews with the farmers as well as the collection of biophysical data. Twelve outcomes are presented in chapter 7 of this paper. Two in particular are the improvement of construction and maintenance, which can only come about through training. The research questions are also answered in chapter 7, with recommendations put forward on possible directions to take in terms of trying to influence the development of the concept in Fiji / Master of Science (Hons)

This thesis concerns the identification of quantitative trait loci (QTL) for important traits in cattle line crosses. One of these traits is birth weight of calves, which affects both animal production and welfare through correlated effects on parturition and subsequent growth. Birth weight was one of the traits measured in the Davies' Gene Mapping Project. These data form the motivation for the methods presented in this thesis. Multiple QTL models have been previously proposed and are likely to be superior to single QTL models. The multiple QTL models can be loosely divided into two categories : 1 ) model building methods that aim to generate good models that contain only a subset of all the potential QTL ; and 2 ) methods that consider all the observed marker explanatory variables. The first set of methods can be misleading if an incorrect model is chosen. The second set of methods does not have this limitation. However, a full fixed effect analysis is generally not possible as the number of marker explanatory variables is typically large with respect to the number of observations. This can be overcome by using constrained estimation methods or by making the marker effects random. One method of constrained estimation is the least absolute selection and shrinkage operator (LASSO). This method has the appealing ability to produce predictions of effects that are identically zero. The LASSO can also be specified as a random model where the effects follow a double exponential distribution. In this thesis, the LASSO is investigated from a random effects model perspective. Two methods to approximate the marginal likelihood are presented. The first uses the standard form for the double exponential distribution and requires adjustment of the score equations for unbiased estimation. The second is based on an alternative probability model for the double exponential distribution. It was developed late in the candidature and gives similar dispersion parameter estimates to the first approximation, but does so in a more direct manner. The alternative LASSO model suggests some novel types of predictors. Methods for a number of different types of predictors are specified and are compared for statistical efficiency. Initially, inference for the LASSO effects is performed using simulation. Essentially, this treats the random effects as fixed effects and tests the null hypothesis that the effect is zero. In simulation studies, it is shown to be a useful method to identify important effects. However, the effects are random, so such a test is not strictly appropriate. After the specification of the alternative LASSO model, a method for making probability statements about the random effects being above or below zero is developed. This method is based on the predictive distribution of the random effects (posterior in Bayesian terminology). The random LASSO model is not sufficiently flexible to model most QTL mapping data. Typically, these data arise from large experiments and require models containing terms for experimental design. For example, the Davies' Gene Mapping experiment requires fixed effects for different sires, a covariate for birthdate within season and random normal effects for management group. To accommodate these sources of variation a mixed model is employed. The marker effects are included into this model as random LASSO effects. Estimation of the dispersion parameters is based on an approximate restricted likelihood (an extension of the first method of estimation for the simple random effects model). Prediction of the random effects is performed using a generalisation of Henderson's mixed model equations. The performance of the LASSO linear mixed model for QTL identification is assessed via simulation. It performs well against other commonly used methods but it may lack power for lowly heritable traits in small experiments. However, the rate of false positives in such situations is much lower. Also, the LASSO method is more precise in locating the correct marker rather than a marker in its vicinity. Analysis of the Davies' Gene Mapping Data using the methods described in this thesis identified five non-zero marker-within-sire effects ( there were 570 such effects). This analysis clearly shows that most of the genome does not affect the trait of interest. The simulation results and the analysis of the Davies' Gene Mapping Project Data show that the LASSO linear mixed model is a competitive method for QTL identification. It provides a flexible method to model the genetic and experimental effects simultaneously. / Thesis (Ph.D.)--School of Agriculture, Food and Wine, 2006.

The pyrrolizidine alkaloids (PAs) and ergot alkaloids are known natural toxicants found in livestock forage. These alkaloids contribute to large economic losses in livestock throughout the world. An understanding of the mechanisms of toxicity and development of better diagnostic tools for better management practices was investigated. Variability exists in the toxicity of PAs in ruminants where cattle are more susceptible and sheep are more resistant. The mechanism of PA resistance in sheep has been attributed to hepatic metabolism or rumen microbial degradation of PAs to non-toxic moieties. The hepatic metabolism of the PA senecionine was investigated in cattle and sheep liver microsomes. The level of a toxic pyrrole metabolite 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine pyrrole (DHP) formed in cattle and sheep were similar. However, the level of a non-toxic N-oxide metabolite was greater in sheep than in cattle. Cytochrome P450 and flavin monooxygenases (FMOs) responsible for PA oxidative metabolism were similar in both ruminant species. Therefore, hepatic metabolism of PAs is not solely responsible for resistance observed in sheep versus cattle. Ergot alkaloids present in endophyte-infected plants also cause toxicity in livestock. HPLC is the typical method used to quantify ergot alkaloid content; however, it is costly and time-consuming. An enzyme-linked immunosorbent assay (ELISA) developed with lysergol as the hapten was evaluated to ascertain its feasibility as an analytical tool for the ergot alkaloids found in forage plants. The ELISA detected the presence of lysergic acid but was not a reliable assay for the ergopeptine alkaloids such as ergovaline. The genetic divergence in mice previously selected into ergot alkaloid susceptible and resistant lines was studied after ten generations of relaxed selection. Physiologically no difference was seen between the susceptible and resistant line for average daily weight gain. However, hepatic metabolism of the ergot alkaloid ergotamine showed differences between genders and between animals on diets containing no ergot alkaloids or a high concentration of ergot alkaloids. Four major biotransformation products were identified as hydroxylated ergotamine isomers based on mass spectroscopic analysis. / Graduation date: 2003

Livestock odour has been an obstacle for the development of livestock industry. Air dispersion models have been applied to predict odour concentrations downwind from the livestock operations. However, most of the air dispersion models were designed for industry pollutants and can only predict hourly average concentrations of pollutants. Currently, a livestock odour dispersion model that can consider the difference between livestock odour and traditional air pollutants and can account for the short time fluctuations is not available. Therefore, the objective of this research was to develop a dispersion model that is designed specifically for livestock odour and is able to consider the short time odour concentration fluctuations. A livestock odour dispersion model (LODM) was developed based on Gaussian fluctuating plume theory to account for odour instantaneous fluctuations. The model has the capability to predict mean odour concentration, instantaneous odour concentration, peak odour concentration and the frequency of odour concentration that is equal to or above a certain level with the input of hourly routine meteorological data.<p> LODM predicts odour frequency by a weighted odour exceeding half width method. A simple and effective method is created to estimate the odour frequency from multiple sources. Both Pasquill-Gifford and Hogstr¨¯m dispersion coefficients are applied in this model. The atmospheric condition is characterized by some derived parameters including friction velocity, sensible heat flux, M-O length, and mixing height. An advanced method adapted from AERMOD model is applied to derive these parameters. An easy to use procedure is generated and utilized to deal with the typical meteorological data input as ISC met file. LODM accepts and only requires routine meteorological data. It has the ability to process individual or multiple sources which could be elevated point sources, ground level sources, livestock buildings, manure storages, and manure land applications. It can also deal with constant and varied emission rates. Moreover, the model considers the relationships between odour intensity and odour concentrations in the model. Finally, the model is very easy to use with a friendly interface.<p> Model evaluations and validations against field plume measurement data and ISCST3 and CALPUFF models indicate that LODM can achieve fairly good odour concentration and odour frequency predictions. The sensitivity analyses demonstrate a medium sensitivity of LODM to the controllable odour source parameters, such as stack height, diameter, exit velocity, exit temperature, and emission rate. This shows that the model has a great potential for application on resolving odour issues from livestock operations. From that perspective, the most effective way to reduce odour problems from livestock buildings is to lessen the odour emission rate (e.g. biofiltration of exhaust air, diet changes).