XIII International Congress in Animal Hygiene, June 17-21, 2007, Tartu, Estonia "Animal health, animal welfare and biosecurity" : proceedings. Volume 1

KonverentsikogumikOn behalf of both the Organising Committee and the Scientific Committee, I am pleased to welcome you in Tartu, Estonia, to participate at the XIII International Congress of the International Society for Animal Hygiene (ISAH). The ISAH (www.isah-soc.org) was founded in 1970 and has today members from 48 countries throughout the world. ISAH can be considered as a group of scientists contributing to efficient, sustainable animal farming with healthy animals, providing wholesome food in a sound environment. Veterinarians and non-veterinary academic scientists (animal science, agricultural economics, engineers, microbiologists, public health professionals, epidemiologists etc., etc) and respective professionals in animal husbandry, who work and/or do research and education in the field of animal hygiene, can apply for a membership of ISAH, and are most welcome to attend ISAH congresses. The first ISAH congress was held in Budapest in 1973. The last ISAH main congress took place in Warsaw, Poland in 2005 and the last in-between symposium in Saint-Malo, France in 2004. Starting from Warsaw congress in 2005, the ISAH, considering the need for a more flexible and frequent exchange of scientific and practical knowledge, organizes its congresses every second year. The present, XIII ISAH congress in Tartu, Estonia, in June 17–21, 2007 is organised under the device "Animal health, animal welfare and biosecurity”. The scientific programme, trying to follow the scope of the ISAH and receive the feedback from modern animal husbandry and food production, concentrates with more profoundness on the following subjects: interaction between the environment and health and welfare of individual animal and herds; managing animal health in large dairy units; ensuring animal welfare during transportation and slaughter; economical implications considering animals’ health; possibilities of precision livestock farming in maintaining good health and welfare of animals; measures for prevention the development and spread of diseases and pathogens in animals including those posing risk to human health (zoonoses); food safety relevant infections and contaminations such as residues in food derived from animals; influence of the animal production on the environment and public health. The Proceedings from the XIII ISAH Congress are herewith presented. The papers on lectures from invited speakers, oral and poster presentations from 11 parallel sessions are included in this excellent compilation. In general, the printed contribution to the ISAH-2007 congress illustrates clearly the broad scientific field of the ISAH and related to it activities. I hereby would like to express my most sincere gratitude in the address of ISAH-2007 organising and scientific committees. Special thanks go to Frens Conference Services for their excellent organizational and technical contribution and to AS Triip for their outstanding printing job of these proceedings. We also appreciate different companies and organisations for their considerable financial support which gave us the opportunity to keep the registration fees affordable. Finally, we thank all participants, contributors, chairpersons, organisational and technical assistants for your considerable efforts – you made the ISAH-2007 in Tartu real success. We wish you all interesting and pleasant congress and enjoyable stay in Tartu. A. Aland Editor Chairman of the ISAH-2007 Organising Committe

Evaluation of the performance of dual-purpose cows in European pasture-based systems

The demand for organic products in Europe is growing, especially organic products of animal origin. Organic dairy milk production requires grazing of cows, which results in a feed ration that is pasture-based. The breed that is kept by far the most for dairy production in Europe is the Holstein Friesian cow, a high-yielding dairy cow. This cattle breed has been developed in North America and was selected for its high milk yield. The disadvantages of this one-sided selection for production manifest in the health, fertility and longevity of the cow. More important, the high milk yield of the Holstein Friesian is only achieved when the cows are fed a diet of high quality and especially concentrates, which is not always possible in a pasture-based system. In this study the alternative for the Holstein Friesian breed is considered, namely the dual-purpose cow. Most countries feature indigenous cow breeds which were traditionally kept for both milk and meat. Because of the popularity of the Holstein Friesian breed these local breeds are less used in dairy production systems. An extensive literature study was carried out to compare the popular Holstein Friesian breed to the local dual-purpose cattle breeds. This showed that local dual-purpose breeds display in many traits such as health, fertility, meat quality and longevity an advantage over the Holstein Friesian. Additionally, dual-purpose cows are better able to cope with a harsh environment and a diet of low quality. Furthermore, the grazing behaviour of one of the Dutch dual-purpose breeds, the Dutch Friesian, was compared in the current study to the Holstein Friesian. For this purpose the monitoring system SensOor (AGIS) was used. SensOor registers the four main conducts of the cows, namely eating, ruminating, resting and other activity (such as walking, standing, etc.). The system expresses the time the cows spend on these conducts in percentages per hour or per day. In this study the SensOor system was validated under grazing conditions for the first time. Before, the SensOor system was only validated indoors or in a dirt pen. The validation under grazing conditions was done by observing the behaviour of the cows on the pasture, and comparing these observations with the SensOor output. The observation of the activity ‘grazing’ corresponded very well with the detection of the activity ‘eating’ (R² = 0.97). As the validation of SensOor under grazing conditions was successful, the output of the system was used to compare the behaviour of the two cattle breeds. In the current study no significant differences in behaviour were found, which can be explained by the differences in size of the cows (HF: 650 kg, DF: 575 kg) which have therefore different energy requirements. Another explanation could be that the high quality of the grassland on the studied farm concealed the ability of dual-purpose cows to cope with low-quality roughages. Besides the study of the behaviour of the cows, the herbage production on two farms was estimated. This was done by the placement of grass cages on the pastures. The herbage growth under the cages was mown, weighed and analysed. In conclusion, the monitoring system SensOor is very suitable to monitor the grazing time of cows. The literature study showed that dual-purpose cows have advantages over the Holstein Friesian (especially in milk composition, meat quality, health and longevity). Concerning their grazing behaviour, dual-purpose cows might spend more time on grazing and constitute more grass in their diet. This difference in behaviour was not shown by the output of SensOor. The absence of this difference might be explained by the excellent environment of the Friesian pastures. It is expected that the advantage concerning grass and feed intake of dual-purpose cows are better demonstrated in a harsh environment with pastures of low quality

Forbidden Substructures in Graphs and Trigraphs, and Related Coloring Problems

Given a graph G, χ(G) denotes the chromatic number of G, and ω(G) denotes the clique number of G (i.e. the maximum number of pairwise adjacent vertices in G). A graph G is perfect provided that for every induced subgraph H of G, χ(H) = ω(H). This thesis addresses several problems from the theory of perfect graphs and generalizations of perfect graphs. The bull is a five-vertex graph consisting of a triangle and two vertex-disjoint pendant edges; a graph is said to be bull-free provided that no induced subgraph of it is a bull. The first result of this thesis is a structure theorem for bull-free perfect graphs. This is joint work with Chudnovsky, and it first appeared in [12]. The second result of this thesis is a decomposition theorem for bull-free perfect graphs, which we then use to give a polynomial time combinatorial coloring algorithm for bull-free perfect graphs. We remark that de Figueiredo and Maffray [33] previously solved this same problem, however, the algorithm presented in this thesis is faster than the algorithm from [33]. We note that a decomposition theorem that is very similar (but slightly weaker) than the one from this thesis was originally proven in [52], however, the proof in this thesis is significantly different from the one in [52]. The algorithm from this thesis is very similar to the one from [52]. A class G of graphs is said to be χ-bounded provided that there exists a function f such that for all G in G, and all induced subgraphs H of G, we have that χ(H) ≤ f(ω(H)). χ-bounded classes were introduced by Gyarfas [41] as a generalization of the class of perfect graphs (clearly, the class of perfect graphs is χ-bounded by the identity function). Given a graph H, we denote by Forb*(H) the class of all graphs that do not contain any subdivision of H as an induced subgraph. In [57], Scott proved that Forb*(T) is χ-bounded for every tree T, and he conjectured that Forb*(H) is χ-bounded for every graph H. Recently, a group of authors constructed a counterexample to Scott's conjecture [51]. This raises the following question: for which graphs H is Scott's conjecture true? In this thesis, we present the proof of Scott's conjecture for the cases when H is the paw (i.e. a four-vertex graph consisting of a triangle and a pendant edge), the bull, and a necklace (i.e. a graph obtained from a path by choosing a matching such that no edge of the matching is incident with an endpoint of the path, and for each edge of the matching, adding a vertex adjacent to the ends of this edge). This is joint work with Chudnovsky, Scott, and Trotignon, and it originally appeared in [13]. Finally, we consider several operations (namely, "substitution," "gluing along a clique," and "gluing along a bounded number of vertices"), and we show that the closure of a χ-bounded class under any one of them, as well as under certain combinations of these three operations (in particular, the combination of substitution and gluing along a clique, as well as the combination of gluing along a clique and gluing along a bounded number of vertices) is again χ-bounded. This is joint work with Chudnovsky, Scott, and Trotignon, and it originally appeared in [14]

Dynamics of a Socially and Spatially Structured Giraffe Population in a Human-Natural Landscape

Sociality involves a constant trade-off between fitness benefits and costs of living in groups, and this trade-off can be influenced by the social and ecological environment in which individuals live. In this PhD I explored socioecological factors underlying the social and spatial population structure and dynamics of a large tropical herbivore with a highly fission-fusion social system, the giraffe (Giraffa camelopardalis). Using a dataset of more than 3,000 uniquely identified individuals collected over a period of 8 years in the coupled human-natural Tarangire Ecosystem of northern Tanzania, I (1) investigated natural and anthropogenic factors as mechanisms of giraffe grouping dynamics, social structure, space use, and vital rates; (2) quantified fitness consequences of social behaviours of adult female giraffes in relation to the influence of their physical environment; and (3) compared social versus spatial dispersal of subadult female and male giraffes. I used capture-mark-recapture techniques to estimate survival rates while accounting for imperfect detection, and social network analysis to derive network- and individual-level social metrics and to delineate discrete communities of socially associated adult female giraffes within a larger contiguous metapopulation. Natural and anthropogenic factors included vegetation types and preferred plant forage species, natural predation, and distance to traditional (bomas) and modern human settlements (towns). I found that grouping patterns of giraffes were influenced by food availability, predation risk, and presence of humans, with particular requirements for mothers with calves (chapter 1). I parsed the metapopulation into 14 distinct, modular yet overlapping communities of socially associated adult female giraffes, with 11 communities large enough to test hypotheses explaining variation in social structure (chapter 2). Adult females in communities closer to bomas had weaker relationship strengths among all members of the community and more exclusive relationships with fewer other females, suggesting that the presence of humans disrupted their social structure. In an examination of social versus ecological drivers of variation in reproduction and survival among 10 of the communities, I showed demographic rates were correlated with vegetation and proximity to humans, as communities with more dense bushlands had lower calf survival while those closer to human settlements had higher reproductive rates (chapter 3). Adult female survival did not differ among communities (chapter 3), but more gregarious females (being in larger groups) and females with higher betweenness (associated with more groups) had higher survival (chapter 4). Survival of adult females is improved by being well-integrated into their larger social community through having weaker bonds with many others rather than by forming stronger and highly stable bonds with just a few individuals. This suggests that the disruption of social structure close to bomas as evidenced in chapter 2 could have demographic consequences, although proximity to bomas did not influence adult female survival as much as their level of sociability (chapter 4). In chapter 5, I investigated patterns of natal dispersal, and found that while most young males dispersed into new social communities far from where they were first detected as calves, many shifted into new communities that were close to their natal areas. In contrast, few young females dispersed, but those that did disperse rarely shifted into a new social community. Instead females moved spatially while remaining within their natal community, further demonstrating the importance of maintaining social ties, from calf to adulthood, across their community of associates. Human presence influenced space use of adults, as adult females living closer to densely populated towns had significantly larger home ranges, but no such relationship was evident with bomas, indicating a difference in anthropogenic impact on movements of giraffes between traditional versus modern human lifestyles (chapter 6). My research indicates that social associations among individuals in addition to ecological conditions are likely to be important for population persistence, and should be considered when developing and implementing conservation measures for giraffes such as land-use plans and translocations

Winthrop University Undergraduate Scholarship & Creative Activity 2018

University College and Winthrop University proudly present Undergraduate Scholarship and Creative Activity 2018. This seventh annual University-wide compilation of undergraduate work chronicles the accomplishments of students and faculty mentors from at least 32 academic departments and programs, spanning all five colleges of the university: College of Arts and Sciences (CAS), College of Business Administration (CBA), College of Education (COE), College of Visual and Performing Arts (CVPA) and University College (UC).https://digitalcommons.winthrop.edu/undergradresearch_abstractbooks/1016/thumbnail.jp

Prediction of cow fertility based on productivity traits in dairy cattle under different production systems

A study to examine factors that influence dairy cattle fertility was conducted in the United Kingdom (UK) and Malawi. Productivity data from the UK comprising 56,014 records from 574 Holstein cows were retrieved from a database at Scotland’s Rural College Dairy Research Centre in Dumfries. The cows were of either high (select) or average (control) genetic merit and fed total mixed rations with high or low forage. These formed four production systems - high forage select (HFS), low forage select (LFS), high forage control (HFC) and low forage control (LFC). Data from Malawi were obtained through a baseline survey in 67 smallholder farms and monitoring of 28 and 62 dairy cows from smallholder farms and a commercial farm, respectively. The breeds were Holstein-Friesians and Holstein-Friesian x Malawi Zebu crosses predominantly fed forages supplemented with concentrates. Some cows were fitted with accelerometers to enable monitoring of cow activity which was then related to cow fertility and energy balance. The data were analysed using descriptive statistics, mixed models and logistic regression models using SAS 9.3. The UK data showed that production system significantly (p<0.05) influenced milk yield, body energy content (BEC) and fertility. BEC is a trait that indicates absolute level of energy in the body per day regardless of energy use and intake the previous day. Daily milk yield of LFS cows was 35±0.1 (mean±SEM) litres which was significantly (p<0.05) higher than that of LFC (30.4±0.1 litres), HFS (27.5±0.1 litres) and HFC (24.3±0.1 litres) cows. LFS cows also had the highest milk yield acceleration to peak milk yield (0.51 litres/day/day) than (LFC 0.47±0.02 litres/day/day), HFC (0.47±0.03 litres/day/day) and HFS (0.46±0.03 litres/day/day) cows. The interval from calving to nadir BEC was 68±5, 83±6, 88±5 and 106±6 days for LFC, LFS, HFC and HFS cows, respectively. Days to first high luteal activity (DFHLA) and days to successful service (DSS) were significantly different with production system and genetic merit, respectively. LFC cows had DFHLA of 27±2 days (mean±SEM) which were significantly lower (p<0.05) than those of HFC (30±3 days), HFS (30±2 days) and LFS (35±3 days) cows. Average genetic merit cows had significantly lower (p<0.05) DSS (119±5 days, mean±SEM) than high genetic merit cows (132±5 days). Results from data collected in Malawi showed variations that reflected differences in management and other environmental factors. Average daily milk yield per lactation in Malawi was 13.3±4.9 (mean±SD) litres. Fertility traits in the UK herd were better than those in Malawi herds. The average DFHLA in Malawi was 79±29 days while in the UK it was 31±18 days. Cow activity in both the UK and Malawi farms varied with the feeding system, genetic merit and BEC. Select cows on home grown feeding system were more active (motion index =6250±40), stood longer (13.4±0.04 hours/day) and spent more time eating (5.6±0.32 hours/day, mean±SEM) than select cows on by products feeding system that had motion index, standing and eating time of 5166±37, 11.9±0.04 hours/day and 4.6±0.16 hours/day, respectively. Genetic merit, lactation number, days to first observed oestrus, calving BEC, service BEC and service milk yield were significant predictors of pregnancy to first insemination (p<0.05) while genetic merit, milk yield, percentage BEC between calving and service, service milk yield and service BEC were significant predictors (p<0.05) of pregnancy to the first three inseminations. Validation of models derived showed C-statistics of the receiver operating characteristic (ROC) curve of 0.66 (95% confidence interval (CI): 0.57 to 0.75) and 0.65 (CI: 0.55-0.75), respectively. It is concluded that genetic merit, feeding system, parity, energy status and stage of lactation are the major factors that determine the likelihood of achieving pregnancy following insemination. Models developed have a potential to predict the probability of pregnancy to an insemination at an acceptable level of accuracy