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Item Fertility and reproductive health decisions connected to climate change and adaptation in Greenland(Montana State University - Bozeman, The Graduate School, 2024) Peterson, Malory Kaye; Chairperson, Graduate Committee: Elizabeth Rink; This is a manuscript style paper that includes co-authored chapters.The capacity for Kalaallit, the Inuit people of Greenland, to adapt to the effects of climate change will depend on sociodemographic change, population distribution, and existing health inequities in the country. Reproduction in Greenland is influenced by connection to place and access to natural resources, factors that will vary with climate adaptation. Given existing fertility and reproductive health disparities among Kalaallit women, there is a compelling reason to explore how climate change effects and adaptation might influence fertility decisions and population dynamics in Greenland. Rooted in the principles of community based participatory research, this exploratory and comparative study investigated the social, environmental, and economic resources that affect fertility decisions for Kalaallit in Greenland. The research presented contextualizes drivers of fertility decisions within Greenland's climate adaptation policy options and presents strategies to guide health studies in Greenland with principles of community based participatory research. Interviews were conducted with 35 reproductive-aged (18-49 years) men and women and 26 interviews with policymakers and key stakeholders in two communities about climate adaptation, natural resources, economic development, and fertility and reproductive health. Interviews were analyzed using constructivist grounded theory in collaboration with a Kalaallit community research partner. Results indicate that improving community capacity to address existing housing, education, and economic inequities is critical to supporting fertility and reproductive health, irrespective of climate change impacts. Participants observed climate change effects and expressed positive attitudes about Kalaallit ability to adapt and capitalize on benefits of climate change. Evidence from this study indicates that addressing development disparities in Greenland may immediately support fertility and reproductive health for Kalaallit people and facilitate equitable climate adaptation.Item Heifer reproduction strategies: molecular insights into early embryonic development and viability(Montana State University - Bozeman, College of Agriculture, 2022) Manuel, Eden Elizabeth; Chairperson, Graduate Committee: Sarah R. McCoskiCurrent heifer development strategies aim to produce the most fertile female possible. However, in western states heifers commonly transition from high to relatively low nutritional planes following breeding. The effects of maternal nutritive status on the embryonic system are not defined, though this transition is likely contributing to the high rates of early embryonic mortality observed in these animals. This study aimed to decipher the impact of maternal nutrition on day 14 conceptuses collected from beef heifers maintained on ?100% or 70% NRC nutrient requirements. Conceptus RNA was isolated and sequenced to identify differentially expressed genes (DEGs). The DEG set included 771 annotated and 132 novel genes. The biological processes representing the most significant differential expression between conceptuses collected from Low- vs- High groups were hormone metabolic processes (Padj = 0.015), inner ear development (Padj = 0.015), inner ear morphogenesis (Padj = 0.015), hematopoietic progenitor cell differentiation (Padj = 0.015), and tissue morphogenesis (Padj = 0.018). KEGG analysis identified the biological pathways most affected between Low- and High-derived conceptuses. Analysis revealed viral fusion proteins, oocyte meiosis, mineral absorption, and sphingolipid metabolism were significantly affected. Interestingly, the pathways representing the highest number of DEGs were peptidases and inhibitors (n = 22 DEGs), MAPK signaling pathway (n = 17 DEGs), and viral fusion proteins (n = 17). Deeper analysis of the KEGG pathway and gene ontology results linked many of the DEGs to processes related to the cellular differentiation, formation, and function of extraembryonic tissues. While more advanced embryonic patterning and fetal development presented as areas of concern in the literature search, at this time they are not likely factors contributing with the most weight to the high rates of embryonic mortality observed in beef cattle. A majority of the DEGs were related to pathways that control early cell specification events that are necessary for the formation of the trophectoderm and the yolk sac. Data indicates that a decreased plane of maternal nutrition affects the expression of genes associated with critical embryonic events, and likely contributes to increased rates of embryonic mortality by altering the function of extraembryonic tissues.Item Photoperiodic responses of Cannabis sativa: developmental and molecular aspects(Montana State University - Bozeman, College of Agriculture, 2022) Avci, Burak; Chairperson, Graduate Committee: Jennifer A. LachowiecThe timing of reproductive development is influenced by photoperiod (daylength) in many plants, including Cannabis sativa. However, the developmental and molecular details and the variability of photoperiodic responses in C. sativa are not well understood. I evaluated the photoperiod sensitivity of four high-CBD drug-type Cannabis varieties for four stages of reproductive development by comparing the timing of each stage between plants that received different periods of long-day (LD) exposure prior to the short-day (SD) treatment. In addition, I looked at the influence of photoperiod on the duration between different stages of development, and the effect of plant age on photoperiod sensitivity. The timing of each stage, including the induction of solitary flowers and anthesis was accelerated in 'Eden' under SD conditions. 'Grape Indica' started developing inflorescences in 6 weeks under LD, but the process was also faster when SD treatment began earlier. The development of 'Auto Pivot', on the other hand, was slightly delayed under SD, but each stage occurred with a consistent number of leaves in all treatments. 'Russian Auto' had a shorter juvenile phase and showed accelerated inflorescence development under SD, but earlier stages were not accelerated even though SD development happened with fewer leaves at each stage. Also, older plants responded to SD slightly earlier, especially compared to plants directly started in SD. These results suggest there are important differences between C. sativa varieties in terms of the timing and the process of reproductive development, even within the day-neutral/auto-flowering varieties. I identified four FLOWERING LOCUS T (FT)-LIKE genes in the Cannabis genome and analyzed their diurnal expression patterns in 'Eden' and 'Auto Pivot' under LD and SD. FTL2 showed a similar expression pattern to FT genes that are known to induce flowering in other SD species, and the expression in photoperiod-sensitive variety, Eden, was different between photo-period treatments, while it was mostly unaffected in the day-neutral variety, Auto Pivot, suggesting FTL2 could be a potential photoperiod-regulated floral promoter in C. sativa.Item The influence of dam age and heifer post-weaning voluntary feed intake on subsequent production, reproduction and lifetime productivity of Angus beef females(Montana State University - Bozeman, College of Agriculture, 2022) Wellnitz, Krista Rose; Chairperson, Graduate Committee: Megan Van Emon and Timothy DelCurto (co-chair); This is a manuscript style paper that includes co-authored chapters.Limited research has been done to evaluate the impacts of dam age or post-weaning voluntary feed intake and its impact on subsequent performance and longevity in the beef herds, specifically female offspring. Therefore, the objectives of this research were to investigate how dam age and post-weaning voluntary feed intake influences lifetime productivity of commercial Angus females. First-calf heifers and mature cows were used to conduct three studies. Results indicate that classification of replacement heifers based on intake as a heifer had little to no impact on subsequent productivity as a mature female, while dam age had a greater influence overall. Productivity as a measure of total pounds of calf weaned through 5 yrs indicated that cows from dams that were 8-yr old or older weaned more total pounds of calf than cows from 3- yr old dams. Results indicated that heifers classified as low intake heifers, had greater mature BW at breeding and greater BCS than cows that were classified as average or high intake as heifers. However, DMI expressed as g/kg of BW displayed no differences with respect to cow age. Milk production was influenced by post-weaning intake for 2 and 5-yr old cows. The dam age study, indicated that dam age will affect future outcomes of replacement heifers. Cow BW at weaning displayed significance for dam age with cows born from 5- and 8-yr old and older dams having greater BW than cows born from 2-yr old. Cow yearling weight was significant for dam age with cows from 5-, 6/7-, and 8-years and older dams having greater yearling weights than cows from 2- and 3-yr old dams. The probability of remaining in the herd at 5-yr old varied across dam age groups with cows from 2-yr old and 5-yr old dams having greater probability to remain in the herd than the other age groups. Therefore, our research suggests that selection of replacement heifers based on post-weaning voluntary feed intake at 45 d post-weaning is not a strong indicator of lifetime productivity. Instead, cow age has a greater impact on lifetime productivity than heifer post-weaning voluntary feed intake.Item Carry-over effects in partially migratory greater sage-grouse, southwest Montana(Montana State University - Bozeman, College of Letters & Science, 2022) Waxe, James Andrew; Chairperson, Graduate Committee: Andrea Litt; This is a manuscript style paper that includes co-authored chapters.Migration is a common natural phenomenon and an important life history strategy for many animal species. Migration allows individuals to accommodate changing environmental conditions, with the potential to increase survival or future reproduction. Many migratory species are subject to carry-over effects, where conditions experienced during one season or life stage influence subsequent life stages. Previous research has largely focused on evaluating the influence of carry-over effects on long-distance migrants, but less is known about these influences on shorter-distance migrants. During research in southwest Montana and southeast Idaho, we used VHF radio collars, red blood cells, stable isotopes, and morphometric information to understand the influence of carry-over effects on Greater Sage-grouse. In this population, some individuals migrate only short distances, while others may not migrate at all. We evaluated the influence of 1) different migration strategies and breeding locations on the body condition of females before breeding and 2) how variation in pre-breeding body condition influenced subsequent reproduction. We found non-migratory individuals were in better pre- breeding body condition than migrants during years with less winter precipitation. Similarly, individuals who experienced less precipitation during the breeding season also had higher pre- breeding body condition. Pre-breeding body condition positively influenced offspring weight early in the breeding season, but this relationship was less apparent later in the season. Our data suggest carry-over effects occur in this population of sage-grouse, but the magnitude of these effects was largely dependent on environmental conditions and timing of breeding. With increasing evidence of carry-over effects in sage-grouse populations, managers should broaden their conservation strategies to account for all life stages. Protecting a variety of winter habitat both near and distant from breeding areas will ensure the persistence and reproductive contribution of individuals with different migration strategies. Furthermore, protecting all known sage-grouse leks provides variation within a single population which allows for flexibility to respond in changing environments. Maintaining or enhancing landscape-level habitat heterogeneity supports variable life-history strategies and is critical for sage-grouse conservation.Item Asynchrony between solitary bee emergence and flower availability reduces flower visitation rate and may affect offspring size(Elsevier, 2021-08) Slominski, Anthony H.; Burkle, Laura A.Climate change can disrupt plant-pollinator interactions when shifts in the timing of pollinator activity and flowering occur unequally (i.e., phenological asynchrony). Phenological asynchrony between spring-emerging solitary bees and spring-flowering plants may cause bees to experience food deprivation that can affect their reproductive success. However, the mechanisms underlying the effects of food deprivation on solitary bee reproduction remain unknown. We investigated 1) whether food deprivation caused by phenological asynchrony affects solitary bee reproduction by influencing female lifespan and/or visitation to flowers, and 2) the relationship between the magnitude of asynchrony and bee responses. We simulated phenological asynchrony by depriving emerged female Osmia cornifrons (a spring-active solitary bee species) of nectar and pollen for 0 to 16 days. Following asynchrony treatments, we used flight cages to monitor 1) post-treatment female lifespan, 2) flower visitation, and 3) reproduction (i.e., total offspring, offspring weight, sex ratio). We found that post-treatment female lifespan was not affected by phenological asynchrony treatments, but that flower visitation rate and offspring weight decreased as the magnitude of asynchrony increased. Due to low offspring production and a lack of female offspring across treatments, we were unable to assess the effects of phenological asynchrony on total offspring produced or sex ratio. Findings suggest that post-emergence food deprivation caused by phenological asynchrony may affect offspring size by influencing nest-provisioning rates. In solitary bees, body size influences wintering survival, fecundity, and mating success. Thus, phenological asynchrony may have consequences for solitary bee populations that stem from reduced flower visitation rates, and these consequences may increase as the magnitude of asynchrony increases. Because many wild flowering plants and crops rely on pollination services provided by bees for reproductive success, bee responses to phenological asynchrony may also affect wild plant biodiversity and crop yields.Item Relating the reproductive performance of westslope cutthroat trout to trait specialization to screen for artificial selection vulnerability in a conservation hatchery(Montana State University - Bozeman, College of Letters & Science, 2022) Preul-Stimetz, Taylor Nicole; Chairperson, Graduate Committee: Christine VerhilleTo mitigate westslope cutthroat trout (WCT; Oncorhynchus clarkii lewisi) declines, Montana Fish, Wildlife, & Parks carries out large scale restorations, including wild-origin stocking efforts from conservation hatcheries. Although hatcheries have made progress in limiting the effects of artificial selection on stocked populations, concerns remain that rearing practices inadvertently reduce the diversity propagated into the wild. The objective of this research was to identify traits of WCT driving poor survival or reproduction in a hatchery, allowing managers to reduce artificial selection by screening for fish requiring alternative rearing. In Chapter 1, I repeatedly measured 18 behavior, morphology, and health traits from hatchery intake (July 2019) to spawn (June 2021). I identified traits with low within- relative to between-individual variation as traits likely to be indicative of specialization. As specialists tend to maximize performance under a narrow range of conditions, they may be vulnerable to artificial selection within hatcheries. In Chapter 2, I tested whether the specialized traits identified in Chapter 1, growth rate, or age at hatchery intake of individual WCT could predict survival or reproduction. In Chapter 1, I identified nine specialized (relative condition, weighted health index, health index, body shape, energetic reserves, latency, and upper jaw, lower jaw, and anal fin residual length) traits. I hypothesized these traits would predict later survival or reproductive performance. In Chapter 2, I identified October 2019 daily growth rate in weight and every replicate length measurement after October 2019 to strongly predict total ovulated eggs and total number of hatch embryos produced by females. However, among individual variation in the median percent hatch embryos was not explained by maternal size. Male gamete quality and fertilization success was consistently high, and I found no biologically significant predictors of reproductive performance for males. I also found no predictors of survival for males or females. Despite high total ovulated eggs and total hatch embryo success for females, variable female median percent hatch embryos suggests that quality of ovulated eggs is driving current limitations to WCT hatchery reproduction. I recommend further investigation into impacts of rearing stressors and post-ovulatory aging on female WCT and their reproductive performance.Item Reproductive biology and phenology of western pearlshell mussels in Montana(Montana State University - Bozeman, College of Letters & Science, 2022) Cook, Kristen Ann; Chairperson, Graduate Committee: Alexander V. ZaleThe Western Pearlshell mussel is the only native freshwater mussel inhabiting trout streams of western Montana; it has been designated a state Species of Concern because of declines in abundance and distribution. Conservation of Western Pearlshells in Montana will require fundamental information on their reproduction and life-history traits that is currently lacking. We therefore estimated the age and length at sexual maturity and incidence of hermaphroditism in mussels using histology. We determined the timing of reproductive events (spawning, brooding, embryogenesis, larval release, and larval infestation of hosts) and their relationship to temperature by collecting gonadal and marsupial biopsies to identify gamete presence and embryo developmental stages, visually identifying brooding mussels, and examining captured fish for the presence of mussel larvae. We identified the hosts of Western Pearlshells in nature by quantifying the probability of infestation and infestation intensities among salmonid species. Mussels reached sexual maturity at an estimated 34 mm in length and 11.5 years of age. Of 31 mature mussels examined histologically, all but one were gonadal hermaphrodites. The reproductive phenology of Montana Western Pearlshells differed among populations and years. Mussel populations brooded for about 24 to 39 days in May and June. Embryogenesis was synchronous among individuals in all populations except one and was about two to three weeks in duration. The larval infestation period generally occurred in June and July and was 47 to 71 days in duration. Some larvae grew > 400% in length before leaving the host. Gonadal recrudescence was rapid whereby mussels possessed mature or nearly mature gametes by early autumn. Both photoperiod and temperature appear to influence the timing of reproductive events. Native Westslope Cutthroat Trout and nonnative Brook Trout were the most susceptible fish species to infestation of Western Pearlshell larvae. Nonnative Brown Trout were moderately susceptible to infestation in the Flint-Rock watershed. Nonnative Rainbow Trout and native Mountain Whitefish were least likely to be infested with mussel larvae. Our findings will inform future conservation and propagation efforts of Western Pearlshells in Montana.Item Reproductive and juvenile ecology of mountain whitefish in the upper Green River, Wyoming(Montana State University - Bozeman, College of Letters & Science, 2022) Brown, Colter Davis; Chairperson, Graduate Committee: Christopher S. GuyMountain Whitefish Prosopium williamsoni are a salmonid native to the northern Rocky Mountains that has experienced declines in population abundance in rivers throughout Idaho, Colorado, Wyoming, and Montana. Problems with recruitment are suspected, but often the specific mechanisms causing population declines are unknown. Our approach to better understand the mechanisms that influence Mountain Whitefish population dynamics was to compare population characteristics between the Green River, Wyoming and the Madison River, Montana populations. Boyer et al. (2017a) conducted an extensive study on the movement and reproductive ecology of Mountain Whitefish in the Madison River, and we used this study as a template to make direct comparisons between the populations. Our primary research questions were 1) what is the age and length at first maturity, spawning periodicity, fecundity, and age structure of Mountain Whitefish, 2) what is the spatial and temporal distribution of Mountain Whitefish through their spawning period, and what influence do abiotic factors have on spawning and movement, and 3) what is the spatial distribution and habitat use of age-0 Mountain Whitefish? We collected otoliths and gonadal samples from 127 Mountain Whitefish in the Green River, implanted 100 fish with radio transmitters and tracked them from September 1 to early November in 2019 and 2020, determined spawning period and locations using egg mats, kick netting, and angling, and sampled age-0 Mountain Whitefish using a beach seine in slow-water habitats. The geographic separation and difference in hydrogeomorphic conditions between the systems allowed us to form generalizations about Mountain Whitefish in the Intermountain West. We found Mountain Whitefish in both systems mature between ages 2 and 4, primarily spawn annually, have a similar relative fecundity, spawning movements vary, males begin movement prior to females, and age-0 fish drift downstream of spawning locations and use slow-water silt-laden habitats after hatching. The main disparities between systems were that in the Green River water temperature was more suitable for embryo development, and age structure was more uniform and older. This research enhanced our understanding of Mountain Whitefish reproductive and juvenile ecology and provided evidence for factors that may influence recruitment of Mountain Whitefish.Item The influence of heifer post-weaning residual feed intake on subsequent production, reproduction, grazing behavior, supplement intake behavior, dry matter intake and milk production of Black Angus beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) Parsons, Cory Todd; Chairperson, Graduate Committee: Timothy DelCurto; Julia Dafoe, Samuel Wyffels, Tim DelCurto, Darrin Boss and Megan Van Emon were co-authors of the article, 'Impacts of heifer post-weaning residual feed intake classification on reproductive and performance measurements of first, second and third parity Angus beef' in the journal 'Translational animal science' which is contained within this dissertation.; Julia Dafoe was a co-author of the article, 'The influence of residual feed intake and cow age on body weight and body condition change, supplement intake, resource use, and grazing behavior of beef cattle winter grazing mixed-grass rangelands' in the journal 'Animals' which is contained within this dissertation.; Julia Dafoe, Samuel Wyffels, Tim DelCurto and Darrin Boss were co-authors of the article, 'The influence of residual feed intake and cow age on dry matter intake post-weaning and peak lactation of Black Angus cows' in the journal 'Animals' which is contained within this dissertation.Residual feed intake (RFI) is a recognized measure of biological efficiency in beef cattle. However, RFI determination is expensive, time consuming and not well studied in beef cattle fed forage-based diets, nor how post-weaning RFI influences grazing behavior, supplement intake behavior or dry matter intake at different ages and physiological stages of production. Thus, the objectives of this research were to investigate how post-weaning RFI influences reproductive and productive performance, grazing behavior, supplement intake behavior as well as dry matter intake at different ages and physiological stages of production. A commercial herd of black Angus cows were utilized to conduct three experimental studies. Results indicate that classification of RFI for replacement heifers had little to no effect on subsequent beef cattle production and reproductive efficiency through the weaning of the 3rd calf. Subtle differences were denoted for cow Julian birth dates based on RFI classification and conception of 1st calf-heifers categorized as low RFI. However, heifer post-weaning RFI had little effect on subsequent cow performance (BW or BCS), grazing behavior, supplement intake behavior, and resource use. In addition, cow age significantly influenced cow performance, grazing behavior, supplement intake behavior, and resource use. We also observed high individual variability in grazing site selection, suggesting that individual-level factors may be driving grazing resource use and grazing behavior. Heifer post-weaning RFI did not influence mature cow dry matter intake, and this was consistent for both lactating and non-lactating beef cows. In contrast, cow age did correspond to quadratic increases of DMI and intake rates of mature cows. However, when DMI was expressed as g x kg body weight-1 no differences were observed with respect to cow age in lactating and non-lactating cows. Milk production was influenced by heifer post-weaning RFI for 2/3 and 5/6-yr old cows. Therefore, our studies suggests that selection for low RFI females would not impact overall herd productivity of cattle on foraged-based production systems, and that cow age has more of an impact on resource use, supplement intake, and grazing behavior, as well as DMI than heifer post-weaning RFI while grazing dormant-season mixed-grass prairie rangelands.