Two inbred strains of mice, BALB/c and C57BL, were crossbred to produce Fl hybrids. This breeding scheme ensured a high degree of genetic heterozygosity as exemplified by the fact that the average weight of the Fl hybrids at 10 weeks of age was 10.1 percent greater that that of their contemporaries in the inbred parental strains. The three lines of mice were then challenged with a 0.5 ml intraperitoneal injection of two-percent sheep red blood cells (SRBC). After a 15-day period the mice were bled and their sera were microtitrated for anti-SRBC agglutinin and the titers statistically analyzed. The Fl mice were found to exhibit a highly significant (P < 0.0001) difference in serum antibody titers over both parental strains. Highly significant differences were also shown between the parental strains, the BALB/c mice being superior to the C57BL in antibody production to SRBC. The results of this work indicate a 177.1 percent degree of heterosis in the immune response of the Fl hybrid mice over that of their inbred contemporaries. These findings, coupled with general knowledge of animal genetics and performance, may indicate that the increased immunocompetence of the crossbred mice is directly related to their increased rate of growth.

The objective of this study was to quantitatively document interactions between black bears and backcountry visitors, and to identify the factors affecting those encounters. Fine hundred and ninety-two interactions were observed. The most common responses of visitors to bears were to watch, walk toward, and talk to others and/or point at the bear. Bears responded to humans largely by walking away, watching, traveling around, walking toward, and running away from people. Each behavior for both species was categorized into one of four response classes: (1) fear/avoidance, (2) neutrality, (3) approach, or (4) aggression. Over 65 percent of visitor responses were neutral. People were least likely to react to bears with fear/avoidance behavior. Bears also were most likely to be neutral. Of particular interest is the low occurrence of aggression shown by bears. Less than two percent of all responses fell into this category, most of which were exhibited by two animals. We witnessed no interactions which resulted in injury or even contact between visitors and bears. When ursid aggression did occur, bears appeared to be more aggressive in June, with younger visitors, and at close distances. Both human aggression and fear were correlated with short interactions. Bear behavior was greatly altered by possession of camper foods. Bears were more neutral and walked toward people less after they had begun to eat. They also showed much less fear of visitors at this time. Other correlations of both human and ursid behavior with biotic and abiotic variables ( temporal, spatial, environmental, etc.) are presented and discussed. Recommendations for improved management are also suggested.

Human-elephant conflict (HEC) is complex and a serious elephant conservation concern across Africa and Asia where elephants are found. HEC occurs whenever people and elephants share common interests. For HEC to be ameliorated and elephant conservation to be successful locally and regionally, the distribution and implications of HEC should be understood. The purpose of this study was to determine the spatial distribution of HECs and characterize elephant herds in terms of herd size responsible for crop-raiding in Kasigau. The study was generally guided by two working a priori hypotheses: (1) farms near the bush edge or livestock watering points will experience more crop raiding incidences than those farther away, and (2) given the geographical differences, the total cost of damage to crops sustained in all the farms will be different across the seven villages. For hypothesis 1, the distances of random farms to the bush and to the bush edge were mapped and measured on Google EarthTM. Results of the study showed that there were differences in the distribution of the distances from the bush and from water for farms that experienced damage and a random selection of farms (p < .0001). Additionally, total cost of damage to crops (Kruskal-Wallis; p < 0.0001), average cost of damage to crops per acre per incursion (Kruskal-Wallis ANOVA; p = 0.0255) and mean cost of damage to crops and facilities (Kruskal-Wallis ANOVA; p < 0.0001) were also found to be statistically different across all the villages. Four villages (Bungule,Ngambenyi, Makwasinyi, and Kisimenyi) sustained high total cost of damage to crops and average cost of damage to crops per acre per incursion indicating that these villages had similar elephant pressure. Ngambenyi village sustained the greatest cost of damage to crops while Kiteghe recorded the greatest average cost of damage to crops per acre per incursion. A posteriori hypotheses included: (1) there will be seasonal distribution of elephant attacks on farms. Results showed that the proportion of total crop-raiding incidents was different during wet and dry seasons in my study period (X2 = 5.49, df = 1, p < .019) with the greatest occurrence of attacks taking place in February, which coincided with crop maturity. This indicates that crop raiding incidents were most common during harvesting time. This result coincides with what was reported elsewhere. (2) there will be difference in the number of crop-raiding incidents by single and multiple elephant responsible for crop incursions in Kasigau. Results demonstrated that the number of crop-raiding incidents by single and multiple elephants were significantly different (X2 = 329.1037; df = 1; p < .0001). A total of 163 (72%) farm incursions were caused by elephant herds comprising multiple individuals while single elephants were responsible for 62 crop-raiding incidents, or 28% of total farm incursions. 100% (225 incursion) of crop incursions reported occurred during the night.

Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. The indicator amino acid oxidation (IAAO) method has been successfully used for evaluating amino acid metabolism and requirements in animals and humans. The objective of this research was to use the IAAO method to estimate threonine requirements in mature horses fed two different feed compositions. In the first study, 6 Thoroughbred mares (4 – 16 years old) received each of 6 levels of threonine intake in a high concentrate diet, in a randomly determined order. The experimental diets consisted of concentrate at 0.95% of body weight (BW), and chopped timothy hay at 0.95% of BW, and met or exceeded NRC recommendations for all nutrients. Threonine intakes for the 6 treatments were 45, 56, 67, 79, 90 and 102 mg/kg BW/d and were generated by mixing the two experimental concentrates, containing 2.9 and 14.8 g threonine/kg diet, in different ratios. In the second study, horses received each of 6 levels of threonine intake, 41, 51, 61, 70, 80, and 89 mg/kg BW/d, in a high forage diet, in a randomly determined order. The experimental diet was concentrate at 0.4% of BW, and chopped timothy hay at 1.6% of BW. Study periods for each study were 7-d long and on d 6, blood samples were collected before and 90 min after feeding to measure amino acid concentrations using HPLC. On d 7, horses underwent IAAO procedures, which included a two hour primed, constant intravenous infusion of [13C]sodium bicarbonate to measure total CO2 production and a four hour primed, constant oral administration of [1-13C]phenylalanine to estimate phenylalanine oxidation to CO2. Blood and breath samples were collected to measure blood [13C]phenylalanine, using GC-MS analysis, and breath 13CO2 enrichment, using an infrared isotope analyzer. Experimental data were analyzed using a one-way ANOVA, including orthogonal linear and quadratic contrasts, in the mixed procedures of SAS version 9.3, with treatment as the fixed effect and horse nested in treatment as the random effect. Statistical significance was declared at P0.05). Increasing threonine intake levels in a high forage diet did not affect plasma phenylalanine oxidation by the ANOVA test (P>0.05) but resulted in a linear decrease in phenylalanine oxidation (P=0.04) without a breakpoint by the orthogonal linear contrast. Threonine requirements are still unknown in mature horses fed either high concentrate or high forage diet. The present studies were the first attempt to evaluate threonine requirements in horses by the indicator amino acid oxidation method.

Investigators have shown that elephants exhibit consistent individual differences in behavior by rating elephants using personality adjectives. These adjectives, however, are not based on pre-defined measurements of the behaviors performed. Instead, they are based on the observers’ interpretations of an animal’s behavioral patterns, therefore making them subject to observer bias. Furthermore, elephants have a capacity for learning; thus, they may alter their behavioral patterns over time. This behavioral plasticity in itself might be a way of measuring consistent behavioral differences among individuals. With this in mind, I approached elephant personality as a multivariate problem. I used behavioral observations collected from female elephants in Addo Elephant National Park, South Africa. Instead of grouping behaviors into subjective categories prior to analysis (as is often done in studies of elephant behavior), I used ordination methods to determine which correlations among behaviors were important for defining personality. Ordination methods were performed on matrices of the behavior data set and on subsets of behaviors for each age class. I calculated the angular differences among major axes of covariation from the ordinations of subsets to determine if the behaviors that defined personalities differed by age class. I also defined personalities by centroids (in multidimensional space) for non-metric multidimensional scaling (NMDS) scores of each individual and dispersion of NMDS scores for each individual as a measure of behavioral plasticity. I analyzed the effects of plasticity and age on personality of individual elephants using a non-parametric multivariate analysis of variance. Major axes of covariation were not well defined and therefore not useful in describing differences among groups. The interaction of age and behavioral plasticity did have a significant effect on the personalities of individuals as defined by ordination centroid scores. This suggests that incorporating plasticity may be a helpful measurement in quantifying consistent behavioral differences among individuals.

The role of vitamin K in the blood clotting cascade has been well documented. Vitamin K has recently been implicated in improving bone health. The current studies were conducted to determine the effects of vitamin K in diets with and without mycotoxin contaminated corn on growth performance, bone characteristics, and related blood metabolites in pigs from weaning to market. Menadione sodium bisulfite complex (MSBC, 33% vitamin K) was chosen as the source of supplemental vitamin K because it is the most common form fed to swine. Vitamin K was tested at 0, 0.5, and 2.0 ppm in a corn-soybean meal based diets on two generations of pigs to evaluate any time and dose responses. The first generation of pigs was subjected to mycotoxin contaminated corn in the nursery phase to test for any interactions between the toxins and vitamin K. The addition of 0.5 ppm vitamin K reduced (P < 0.0001) prothrombin time. No additional decrease in prothrombin time was detected when increasing vitamin K inclusion from 0.5 to 2.0 ppm. With regard to growth performance, daily gain, feed intake, and feed efficiency were unaffected (P > 0.10) by supplemental vitamin K. However, pigs fed mycotoxin contaminated corn ate less (P = 0.005) and grew slower (P = 0.015) compared to those receiving good corn. The addition of vitamin K did not alleviate the negative growth effects in response to corn type. Vitamin K did not affect bone characteristics (P > 0.10), blood Ca (P > 0.05) or OC (P > 0.10). Other than blood clotting it does not appear that dietary vitamin K provides any additional benefits at these levels of inclusion and stages of swine production.

Our objective was to know how the hepatic transcriptome expression of growing beef (Angus-cross) heifers (0.5 kg gain/day) was affected by the feeding of different sources of dietary (3 mg/day) Se supplements: inorganic Se (ISe, sodium selenite), organic (OSe, Sel-Plex®), or a blend (1.5 mg:1.5 mg) of ISe:OSe (Mix), compared to the adequate but non-Se supplemented “Control”. The biopsied hepatic tissues of these four groups heifers collected at day 168 (when liver Se assimilation had stabilized) after supplements of Se, was subjected to the microarray analysis to assess Se treatment effects. The results suggest that there were clear differences in the hepatic gene expression profile of the four Se treatment groups. 139 significantly treatment-induced differentially expressed transcripts were selected. Among them: 1) the gene expression profiles of Control and OSe appeared to be more similar than Control and ISe, 2) eight distinct gene expression patterns among treatments were identified and each of them indicates affected biofunctions and networks, 3) they were grouped as the expression profile relative to Control, there were solely and commonly affected transcripts for four Se treatments and they indicated different biofunctions, 4) of them, three microRNAs were identified and their predicated mRNA targets showed different biofunctions.

Equine pituitary pars intermedia dysfunction (PPID) typically occurs in horses older than 15 years of age and is characterized by hair coat abnormalities, muscle atrophy and decreased insulin sensitivity. The first objective of this research was to compare the rate of whole body protein metabolism and relative abundance of key factors in the signaling pathways associated with muscle protein synthesis and protein breakdown in response to feeding in Control and PPID horses. No differences (P > 0.05) were seen between the PPID and Control groups in whole-body protein metabolism or post-prandial activation of the muscle signaling pathways regulating skeletal muscle protein synthesis and breakdown. The second objective of this research was to determine if aged horses with PPID had reduced insulin sensitivity and alterations in the insulin-mediated signaling pathways in the skeletal muscle when compared to non-PPID, aged Control horses. Measures of insulin sensitivity and the activation of factors associated with protein synthesis and breakdown were similar between the PPID and Control groups (P > 0.05). Overall, insulin sensitivity and protein metabolism are similar between the PPID and Control groups. The studies suggest that abnormalities may exist as a function of advanced age rather than PPID status directly.

Three experiments were conducted to assess the efficacy of including selected feed additives in the diet of weaning and grow-finish pigs. Experiment 1 utilized 24 crossbred grow-finish pigs and measured the effect of added EHY on DM, N, and energy digestibility. There were no differences in DM, Energy, and N digestibility between diets 1 through 4. Experiment 2 utilized a total of 36 crossbred pigs [18 barrows, 18 gilts] in order to determine if preference would be shown when presented with naturally-contaminated corn. There were three dietary comparisons, Control vs Diet 2 (Comparison 1), Control vs Diet 4 (Comparison 2), and Diet 2 vs Diet 4 (Comparison 3). A preference was shown for the control diet over Diet 2, as well as for the control diet over Diet 4. Experiment 3 utilized a total of 24 crossbred pigs [12 barrows, 12 gilts] in order to measure the effect of contaminated corn on performance and DM, energy, and N digestibility. DM, energy, and N digestibility were affected by corn quality.

The current study describes the composition and activity of the snake community of the Pa-hay-okee wetlands of Everglades National Park. The study was conducted from January 1987 to January 1989. Sixteen species were observed, with Thamnophis sauritus, Thamnophis sirtalis, Nerodia fasciata pictiventris, and Agkistrodon piscivorus representing 90.2% of the total sample. The seasonal distribution and activity of the snakes were closely related to fluctuations in the water table. Most activity occurred in the winter months as snakes migrated west following the drying water edge of Shark River Slough. Seventy percent of all snakes observed during this study were either injured or dead on the road. Over 50% of annual mortality occurred during migration. The impact that road mortality is having on the local snake community cannot be ignored. Management options are provided to minimize loss. A comparison is made to the snake community of the Long Pine Key Region of Everglades National Park.