Animal & Avian Sciences Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/2741

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Developing a Methodology for the Assessment of Freedom of Movement: The Influence of Spatial Parameters on Movement and Space Use in Mice (Mus musculus)
(2008-11-26) Brooks, Raymond Matthew; Stricklin, William R; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Despite recent progress in developing housing conditions that more effectively meet the needs of managed species, there remains a lack of detailed information regarding the influence of a space on animal health and well-being. If improvements are to be made to current guidelines so that they accurately reflect the needs of the animals, this information and a reliable method for collecting it, is critical. The objective of this project was to systematically examine the effects of spatial parameters on movement and space use of mice (Mus musculus) in open-field arenas. This approach may provide researchers with a means to describe what factors are most important for maintaining an adequate welfare state, and may help address questions regarding why (and how) these factors function as they do. To accomplish this, a standardized method was used across three experiments to test the effects of floor area, arena shape and structural complexity on movement and space use of mice. In each experiment 40 female Swiss Webster mice were observed in four arenas differing in spatial characteristics. In Experiment One, mice were individually observed in four square arenas that differed in floor area (0.5, 1, 2 and 4m2). The results from this experiment demonstrated an effect of both floor area and perimeter length on movement and space use of mice, as measured by track length, area traversed and mean distance to the nearest wall. In Experiment Two, the same variables were used to describe the behavior of mice in four arenas of equal floor area (1.5m2) that differed in shape (circle, square, 2:3 rectangle or 1:3 rectangle). Observation of animals in a circular arena demonstrated the impact of corner space on continuity of movement. In the final experiment, partitions were added in pre-determined configurations to examine the influence of partition location on animals demonstrating thigmotaxis. While the addition of partitions affected the distribution of movements, the specific location of partitions had little impact on movement or space use. With some refinement, this methodology could be used across species to identify specific needs and determine how effective housing systems are at meeting them.
The effect of agonistic encounters on aggressive response in socially isolated Siamese fighting fish, Betta splendens
(2003-12-16) Charles, Debbie; Halperin, Janet R.P.; Estevez, Inmaculada; Animal Sciences
Male Siamese fighting fish were held for 7 to 10 weeks either in visually-social conditions (interact aggressively with a mirror image for 2 min, three times a week) or as visually-isolated fish (no aggression, saw only the back of a mirror). Phase I of this experiment investigated whether visually-isolated fish became hyper-aggressive, compared to visually-social fish. Aggression levels were tested with a series of models and mirrors. Social isolation did not affect duration or frequency of specific agonistic behaviors, nor of pooled behavioral categories (ANOVA, P > 0.05) within aggression tests. Phase II was to determine if aggression levels re-adjusted in visually-isolated fish experiencing live encounters among groups of 4 fish in naturalistic environments. Data was not significant unlike in previous isolation experiments (ANOVA, P > 0.05). However, several behavioral trends were observed that were consistent with previous isolation studies.
Effects of barrier perches and stocking density on the behavior, space use, and leg health of the domestic fowl (Gallus gallus domesticus)
(2009) Ventura, Beth Ann; Estevez, Inmaculada; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The objective of this study was to discern whether providing enrichment in the form of barrier perches across a range of densities might improve leg and foot health and promote behavioral expression and more even use of space in broilers. To investigate this, 2,088 day-old broiler chicks were randomly assigned to one of three barrier treatments at one of three densities. Effects on behavior, space use, foot and hock health, tibia fluctuating asymmetry, fear and production were subsequently assessed. Higher densities appeared to compromise broiler welfare, seen by increased tibia length asymmetry, poorer foot and hock health, suppression of activity, increased disturbances, and decreased use of space. Conversely, barrier perches - particularly simple barriers - appeared to improve footpad quality, promote increased perching and activity, decrease aggression and disturbances, and improve use of the central pen space, all without negatively impacting production traits.
EFFECTS OF MARKS ON AGGRESSION AND STRESS IN THE DOMESTIC FOWL (GALLUS GALLUS DOMESTICUS)
(2004-05-17) Dennis, Rachel; Estevez, Inmaculada; Animal Sciences
Animals are marked for identification in a range of experiments from behavior and wildlife management, to reproduction and pharmacological studies. However, little is known of the impact marks have on animals. The objective of our experiment was to determine the impact of marking on aggression and stress in the domestic fowl. Broilers, in groups of 10 and 50 were housed with 20%, 50% or 100% of the birds marked. Aggressive interactions, given and received, were observed from 3 to 10 wks. Our results revealed that marked birds received significantly more aggression than unmarked birds, and subsequently deliver fewer aggressions to pen mates. Marked birds appear more stressed than their unmarked pen mates, especially in 20% pens. Marked birds in 20% pens also had a lower epinephrine response to manual restraint. Our findings show that marks can impact both the aggressive behavior and stress of the birds bearing them.
FORAGING STRATEGIES, USE OF SPACE AND AGGRESSIVE BEHAVIOR OF DOMESTIC FOWL (Gallus gallus domesticus)
(2004-05-03) Hoerl, Erin Natalie; Estevez, Inma; Animal Sciences
Domestic fowl were tested in three experiments, all investigating the mediating effects of three group sizes of 5, 10, and 20 individuals, on behavioral responses under varying environmental conditions. The first experiment investigated social spacing and aggressive behavior in the presence or absence of cover panels. Smaller group sizes were more affected by cover panels than larger group sizes. In the second and third experiments patchy environments were used to test optimal foraging strategies. In the second experiment, smaller group sizes were more affected by patch locations than larger ones. In the third experiment birds were presented with patches varying in quality. Birds in all group sizes were able to immediately discern patch quality and preferred patches of higher quality. Despite generations of artificial selection pressure domestic fowl continue to forage optimally in patchy environments, and adopt flocking strategies predicted by behavioral ecology theory.
Genetic Variation in Nitrogen and Phosphorus Levels in Broiler Excreta: Opportunity for Improving both Birds and the Environment
(2010) sasikala appukuttan, arun kirshna; Siewerdt, Frank; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The increase in poultry meat consumption has resulted in intensified poultry farming operations with consequent concentration of excreta in major production areas. The nutrient content in the soil surrounding the poultry farms has increased as a result of the high content of nitrogen (N) and phosphorus (P) in the poultry excreta. The current study aimed to propose a strategy to reduce the N and P content in excreta through genetic selection of broilers for efficient nutrient utilization. The traits measured (on a dry matter basis) were the percentage of N in the excreta (PNE) and the percentage of P in the excreta (PPE). Individual 24-hr excreta samples were collected from 6 wk old birds. Excreta samples were collected from a commercial breeding farm at two different time periods from line A and line B birds respectively, and analyzed for PNE and PPE. Analysis of excreta samples collected during the first period (197 bird samples belonging to 15 sire families) and second period (278 birds belonging to 25 sire families) suggested a heritability of 0.08, 0.16 for PNE and 0, 0.20 for PPE, respectively. Phenotypic and genetic correlations between the measured traits from the two lines were very low; however, phenotypic correlation analysis of PNE and PPE with other traits of commercial interest showed some favorable as well as neutral associations. Blood samples collected from the birds were used for an association study of the excreta traits with four candidate genes. The candidate genes were selected based on the results of previous research. Some of the SNPs from the candidate genes were found to have additive and dominance effect on the excreta and production traits and were usually favorably associated with mutations in higher frequency in the populations. The results suggest that genetic selection of birds for PNE and PPE could improve the environment and the market value of the birds.
On-Farm Dry Matter Analysis to Improve Feed Delivery Precision on Dairy Farms
(2011) French, Karin R.; Kohn, Richard A; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Uncertainty in dairy ration content impacts feed efficiency, milk production, expenses, and environmental losses. When measuring silage by weight, unknown changes in dry matter (DM) may change the total mixed ration. The objective of this study was to measure variation in silage DM on selected farms and evaluate an electronic method of on-farm DM analysis. Of 31 Maryland farms surveyed, 63% reported DM analysis by an on-farm method, 83% by any method including laboratory measurement. Eight producers performed DM analysis daily for 21 days using a Farmex 1210 Electronic Silage Tester (on-farm) and they recorded precipitation; matching samples were analyzed for DM in a laboratory after oven drying ("standard" method, 55°C followed by 100°C) and by using a Farmex 1210 (laboratory). The standard deviation of mean silage DM varied from 0.72% to 3.33% DM, depending on farm. The electronic method compared poorly to standard DM analysis for most farms.
Proteomic Profiling and Label-Free Quantification of Bovine Milk Proteins during Experimentally Induced Escherichia coli Mastitis
(2009) Boehmer, Jamie Layne; Peters, Robert R; Bannerman, Douglas D; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Coliform mastitis has been a primary focus of dairy cattle disease research due to staggering affiliated losses, severe systemic complications arising from host inflammatory response to lipopolysaccharide, and the poor response of coliform pathogens to antimicrobials. Reliable biomarkers are needed to evaluate the efficacy of adjunctive therapies for the treatment of inflammation associated with coliform mastitis, and to aid in the approval of new veterinary drugs. The aims of the current analyses were to utilize proteomic methodologies to evaluate protein expression in whey from cows with experimentally induced coliform mastitis, and to employ label-free quantification strategies to estimate changes in relative abundance of proteins identified in milk over the course of clinical infection. Two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI- TOF) mass spectrometry (MS) resulted in the identification of complement factors, antimicrobial proteins, and acute phase proteins in mastitic milk. Analysis using liquid chromatography (LC) inline with electrospray ionization - quadrupole TOF tandem mass spectrometry (MS/MS) resulted primarily in the identification of abundant whey and casein proteins, and the transient detection of proteins related to host response. Nano-LC- nanospray-MS/MS using a linear ion trap, however, led to the robust discovery of over fifty inflammatory proteins in whey from mastitic milk, including the novel markers kininogen-2 and inter-alpha trypsin inhibitor heavy chain-4. Normalized spectral counts were compared to enzyme-linked immunosorbant assay (ELISA) for select proteins to assess the accuracy of the spectral count data. Similar expression patterns were detected using spectral counts and ELISA. Results indicate that proteomic methodologies can detect biomarkers of coliform mastitis in bovine milk during clinical infections, and that spectral counts are a viable means of evaluating relative changes in protein biomarkers of mastitis, including those for which no antibody currently exists.
Separating the Effects of Group Size, Density, and Enclosure Size on Movement and Use of Space in Domestic Fowl (Gallus gallus domesticus)
(2008-04-24) Leone, Erin Hoerl; Estevez, Inmaculada; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This project was designed to separate the confounded effects of group size, density, and enclosure size, and to examine the role of enclosure design and its related parameters in shaping movement patterns and use of space in the domestic fowl. While previous research has suggested that group size, density, and enclosure size are highly relevant to broiler (meat-type chicken) welfare, confounding between variables makes their individual contribution difficult to distinguish. My novel treatment structure with 10, 20, and 30 birds in small (1.5 m2), medium (3.0 m2), and large (4.5 m2) enclosures enabled me to determine the impact of enclosure size while systematically controlling for group size and density. Three enclosure designs: rectangular, square, and square with partitions to maintain a constant perimeter to area ratio, were employed in order to determine the impact of enclosure parameters such as length to width and perimeter to area ratio. Enclosure size and design were the most relevant factors for space use, which was immune to the influence of group size and density. Birds consistently had larger home ranges in larger enclosures. The design of the enclosure had a strong effect of movement, altering the response of birds to the treatment combinations. Movement appeared to be greatest in rectangular enclosures, where the largest straight-line distance is available and the perimeter to area ratio declines at a relatively slow rate with increasing enclosure size. While enclosure size played a significant role in determining nearest neighbor distances and net displacement, these parameters appeared to be limited by density. The presence of partitions designed to increase interior perimeter space appeared to reduce movement and increase inactivity. Movement patterns did not appear to be restricted by social interactions for any group size. Rather, the physical presence of group mates at even a relatively low density of 6.7 birds/ m2 appeared to act as a barrier to group dispersal and movement. Group size had little effect on young domestic fowl. Overall, this project has shown that for young domestic fowl the most relevant factors to overall space use are the amount of space available and enclosure design.