Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 3 uppsatser.

Research on the chronic effects of toxic chemicals on individuals, populations, communities, and ecosystems is imperative to regulate pollutants and preserve threatened species and habitats. I designed a two-pronged study to investigate the effects of heavy metal contaminants on small mammal populations, communities and body condition. To compare population and community metrics, I conducted a year-long mark-and-release study from over 5,400 trap nights on a contaminated and reference site within Crab Orchard National Wildlife Refuge, a Superfund site. During the second phase, I compared contaminant residues to body condition in 29 white-footed mice (Peromyscus leucopus) and 21 southern short-tailed shrews (Blarina carolinensis) from the Refuge and from three reference sites. Body weight, age structure, trapping success or species diversity did not differ between sites. Mice from the contaminated site were more abundant with lower reproduction (as number of juveniles per adult female). Cadmium in both livers and kidneys of mice and shrews was significantly greater on the contaminated site. Elevated renal cadmium in mice (96 ± 79 mg/kg dry weight) and shrews (242 ± 166 mg/kg dry weight) from the contaminated site could likely impair physiologic functions with long-term effects. For white-footed mice, increasing renal copper, lead, and nickel were good predictors of low ash, water, and protein but did not correlate significantly with crude lipid content. In shrews, however, metals either showed no relationship or, in the case of renal cadmium and copper were positively related to body condition as increased protein content. Simply comparing animals from reference versus contaminated sites provided few insights into overall community structure or population dynamics of white-footed mice. While metals explained as much as 40% of body condition (ash) in mice, findings in both species are counter-intuitive or refute predictions. Future studies should include manipulative field experiments that pair higher-resolution, biologic responses such as histologic and biomarker assays with population and community dynamics.

North American scoter populations have declined by approximately 60% over the last 30-50 years. Prior studies of other sea duck species suggest that trace elements can have deleterious effects on overall body condition. For surf scoters (Melanitta perspicillatta) and white-winged scoters (Melanitta fusca), this study tested the following hypotheses: (1) Trace element accumulation differs among seasons, locations, and species; (2) Increased trace elements in tissues correlate with declines in body condition; (3) Surf scoters that shift their feeding to a higher trophic level in spring bioaccumulate higher levels of trace elements; and (4) Selenium and mercury co-accumulate in a 1:1 molar ratio. To test these hypotheses, cadmium (Cd), mercury (Hg), and selenium (Se) in livers and kidneys were collected from adult male surf scoters and white-winged scoters in December 2005 and March 2006 from three locations in Puget Sound, Washington. Trace elements in surf scoters differed among locations, and seasons. Se and Cd in liver and kidney explained 21% of the variance in a matrix of body condition factors in surf scoters. In white-winged scoters, body condition differed between March and December, but trace elements in tissues did not, indicating that contaminants did not explain changes in condition. Thus, hypotheses 1 and 2 received partial support while hypothesis 3 did not. Finally, Se and Hg did not covary in either the kidney or liver of either species (hypothesis 4). Compared to other marine birds, scoters in this study contained low contaminant levels. Nonetheless, inorganic contaminants explained substantial variation in body condition of surf scoters, and potentially contribute to their population declines. These findings suggest that inorganic contaminants, particularly Cd, should be considered in assessing habitat quality for sea ducks.

Atualmente, a avaliação do treinamento e da nutrição dos cavalos de esporte, vem sendo amplamente estudada , no intuito de atingir o máximo desempenho dos cavalos de esporte nas competições. A composição corpórea muscular e de deposição de gordura, assim como em humanos, é um dos melhores indicativos deste desempenho. O escore de condição corporal (ECC) é um indicador subjetivo do estado corpóreo em equinos, baseado exclusivamente no depósito de gordura .A ultrassonografia tem demonstrado ser uma ferramenta de grande valor nesta avaliação.Com o objetivo de estudar a relação do escore corporal com medidas de espessura de gordura e músculos obtidas através da ultrassonografia em três raças distintas , utilizou-se 14 equinos Puro Sangue Inglês(PSI), 7 equinos Quarto de Milha(QM) e 10 equinos Puro Sangue Árabe(PSA) , com idade média de 3,5± 0,5 anos e peso médio de 471 quilos. Os animais foram avaliados por ultrassonografia em três regiões paralelas a coluna vertebral: espessura da gordura lombar(EGL), espessura do músculo glúteo(EMG) e espessura da gordura na cauda(EGC).As mensurações foram realizadas a cada 30 dias ,durante 60 dias. Os resultados mostraram um comportamento diferente entre as raças, porém a correlação do escore corporal com a medida de espessura de gordura na base da cauda(EGC),teve uma maior correlação, comparada com as outras variáveis ultrassonográficas. A avaliação ultrassonográfica mostrou-se uma ferramenta confiável e prática de avaliação de condição corpórea nas raças de cavalos de esporte. / Currently, the evaluation of training and nutrition for sport horses, has been widely studied in order to achieve maximum performance of sport horses in competitions. The body composition of muscle and fat deposition, as well as in humans, is one of the best indicators of performance. The body condition score (BCS) is a subjective indicator of body condition in horses, based exclusively on fat deposition. Ultrasonography has proved to be a valuable tool in the evaluation. In order to study the relationship score with measures of body fat and muscle thickness obtained by ultrasonography in three distinct races, we used 14 Thoroughbred horses (PSI), 7 Quarter Horses (QM) and 10 Purebred Arabian horses (PSA) with a mean age of 3.5 ± 0.5 years and average weight of 471 kg. Os animals were evaluated by ultrasonography in three regions parallel to the spine, back fat thickness (EGL ), thickness of gluteal muscle (EMG) and fat thickness in tail (EGC). the measurements were performed every 30 days for 60 days. The results showed a different behavior between the races, but the correlation of scores with a measure of body fat thickness at the head of the tail (EGC), had a higher correlation, compared with the other variables Ultrasonographic evaluation proved to be a reliable and practical tool for assessing body condition of horses in sport horses.

Range cattle grazing in semi-arid regions are commonly limited by lack of nutrients from low-quality forage. Due to this, ranchers are faced with the challenge of monitoring diet quality in order to address nutrient limitations. Near infrared spectroscopy (NIRS) of fecal samples is a method used to determine diet quality values like crude protein (CP) and digestible organic matter (DOM) in grazing animals. When combined with a nutritional balance analyzer such as the NUTBAL system, fecal NIRS can be used to monitor diet quality and project animal performance. Our research aimed to test the ability of NUTBAL to project animal performance as represented by body condition score (BCS) in cattle (n=82 Animal Units) grazing on the Santa Rita Experimental Range (SRER) in southern Arizona. Previous work conducted on other Arizona rangelands led to the hypothesis that fecal NIRS coupled with NUTBAL can be used to monitor diet quality and project BCS in a southern Arizona commercial grazing operation. Data collection occurred between June 2016 and June 2017. Standing biomass and botanical composition were measured before each grazing period, and relative utilization was measured following each grazing period. During the midpoint of grazing in each pasture, 30 body condition scores and a fecal composite of 15 samples were collected. Fecal derived diet quality varied between a maximum of 10.75% CP and 61.25% DOM in early August 2016, to a minimum value of 4.00 % CP and 58.40 % DOM in March 2017. This study confirmed the ability of fecal NIRS paired with NUTBAL to project future BCS within 0.5 a score point more than 80% of the time in cattle grazing on the SRER. With this information, cattle managers in southern Arizona can better address animal performance needs and nutrient deficiencies.

The primary objectives of the study were to compare 2 body fat (%, BF) prediction methods for stock-type horses by rump fat thickness (RFT) and D2O dilution with actual tissue fat analysis by near-infrared spectroscopy (NIR) and to identify the relationships among BF, BCS, and physical measurements. Secondary objectives were to determine the fatty acid (FA) composition of mesenteric (MS), cardiac (CD), subcutaneous (SC), intermuscular (IM), and leaf fat (LF) and to identify relationships between of FA composition and BCS in horses. Results indicated that D2O dilution is an accurate predictor of BF, and RFT alone does not accurately predict BF. Additionally, BCS may be useful in predicting BF when used with other physical measurements. The effects of BCS and fat depot on FA composition were independent of each other. The more influential factor in FA composition of adipose tissues was fat depot as opposed to BCS.

Human activities and unpredictable changes to environmental habitats impose a suite of stress and challenges to animal homeostatic function. Stress responses are often controlled by the release of glucocorticoids to mobilize energy, primarily corticosterone in small mammals, to help regulate homeostatic function such as heterothermy and changes to body condition, the latter of which serves as a proxy for energy reserves. Adaptive heterothermy is influenced by daily and seasonal patterns, heat produced from daily activity, and has been shown to increase in small mammals during times of environmental stress to conserve energy budgets. Body condition also changes in response to environmental perturbations, mobilization of energy by corticosterone, seasonal changes, and activity. My study aimed to disentangle the effects of environment and activity on homeostatic responses by pharmacologically manipulating corticosterone in kangaroo rats. Kangaroo rats are ecosystem engineers, heterothermic, and their activity periods are functions of their thermoregulatory patterns as well as environmental conditions thus making the species a great candidate for this form of study. I conducted two in-situ field experiments to assess for the effects of stress responses on thermoregulation, activity, and body condition. In my first experiment, I used body temperature (Tb) as a proxy for activity time and examined how pharmacologically increased corticosterone influenced kangaroo rat heterothermy responses to the moon phases and ambient temperatures. I also examined their fat, lean mass, and water content at the end of the study. Moon phase was a significant predictor of activity period as animals typically waited longer during the waxing moon phase to become active and cooled down below activity earlier in the night during the waning moon phase. As nights shortened, activity decreased despite environmental conditions becoming warmer. Corticosterone also significantly decreased total activity time and thus steadily increased heterothermy across the length of my experiment. These results indicate activity, not environment, are stronger drivers of heterothermy patterns. Total fat content (energy content) at the end of the study was not affected by corticosterone. The lack of change in fat content was presumably because kangaroo rat body condition was measured once at the end of the study and likely not a reflection of changed body condition over time. In my second experiment, I examined body condition across a longer period by measuring lean mass, fat content, and total body water across a 2-month period in the summer by pharmacologically increasing corticosterone to test the relationship between stress and body condition and to dissociate the two from environmental factors. Body condition indices generally increased across the summer, but corticosterone implantation did not significantly affect body any of the indices. The loss of heterothermic control and decrease in activity time across the summer suggests that animals are likely conserving energy budgets leading to preservation of condition. Further, banner-tailed kangaroo rats generally breed in the spring where body condition falls due to stress induced by increased competition and then increases across the summer as late summer monsoons promote the growth of primary resources utilized by animals thereby preserving body condition. This study suggests that body condition is driven more by life-history traits, activity time, and environment rather than stress responses.

The aim of this diploma thesis is to evaluate the data about holstein dairy cow body condition at calving and to review its effect on ketones blood level and its relation to incidence of ketosis. The monitoring took place in a selected dairy farm from October 2017 to February 2019. Body condition of 280 cows was evaluated on the day of calving by assessing the body condition score (BCS) and later on 10 days in milk the blood level of B-hydroxybutyrate was measured. Furthermore, parity, body weight in calving day, body weight on 10 days in milk, content of milk fat and protein on 10 days in milk and milk yield on 10 days in milk were monitored. Average BCS of the herd was 3,7, the maximum measured BCS value was 5, the minimum was 2. Total incidence of ketosis on herd level was 21,07 % considering ketosis if BHB 1,0 mmol.l-1. 62,7 % of that was a subclinical form of ketosis while the remaining 37,3 % was the clinical form of ketosis. Correlation analysis of the relation between parity and level of BHB in blood showed positive correlation (r=0,15, p=0,00), when cows on higher lactation had higher level of blood BHB. Positive correlation between fat/protein ratio in milk and level of BHB in blood was evaluated by correlation analysis (r=0,31 , p=0,00). The BCS at calving and BHB level on 10 days in milk showed positive correlation (r=0,14 , p=0,02). As far as negative energy balance is taken into account, the positive correlation between BCS at calving and body weight loss was confirmed (r=0,17 , p=0,00). The fact that heavier cows and cows with higher BCS mobilise more body fat reserves was confirmed by positive correlation between the body weight at calving and the body weight loss (r=0,47, p=0,00) and between the body weight at calving and the fat/protein ratio in milk (r=0,27, p=0,00). Body weight at calving had provable positive impact on the milk yield (r=0,19, p=0,00).

Agricultural practices have intensified over the last 50 years, increasing crop production and altering the Canadian Prairie landscape by removing non-cropped habitats and wetlands. The productivity, trophic structure and diversity have changed through increased agrochemical inputs and reductions in yearly rotation and diversification of crop types. Most intensive agricultural practices have negative effects on invertebrate communities that can indirectly affect higher trophic organisms, such as birds. Many populations of aerial insectivorous bird species have been experiencing rapid declines in the last 30–40 years. Dependency on high abundances of aerial insects for reproduction and survival is a common link among all species of this guild. My thesis examined aerial insect abundance as a potential link between agricultural land use and the reproductive ecology, nestling body condition, and diet of an aerial insectivore species, the tree swallow (Tachycineta bicolor). My broad goal was to determine whether agriculture has deleterious effects on timing of breeding, reproductive investment and success, and nestling quality, as mediated by food supply and differences in diet. Aerial insect abundance and biomass estimates obtained from passive insect traps which capture primarily aquatic dipterans were similar between agricultural and reference sites during all stages of breeding. However, estimates derived from sweep-net sampling in terrestrial habitats in 2013 indicated higher abundances of aquatic and terrestrial Diptera at a reference site relative to agricultural sites. Multiple measures of tree swallow productivity were not related to agriculture land use but nestling body condition was significantly lower on agricultural sites. Using stable isotope analysis (delta 13C and delta 15N), I found site and age specific differences in swallow diets and isotopic niche widths but variation was not consistently related to agricultural land use. Aquatic insect prey (Diptera and Odonata) made up the majority of the diet of swallows but nestlings had a larger proportion of terrestrial Diptera which resulted in larger isotopic niche widths compared to adults. The assimilated isotopic diet of nestling and adult swallows were not strong predictors of body size, mass or condition, suggesting that site differences in the diet do not appreciably affect condition. Nestlings raised on agricultural sites had lower body condition that was not directly linked to their diet alone. This suggests other unmeasured factors related to agricultural land use may affect nestling tree swallows. This study tested responses in an aerial insectivore species to land use and potential shifts in the insect community, which may provide important information for conservation and management decisions for many species within the aerial insectivore guild.