Observations about declining fertility in a feline breeding colony

Feline breeding colonies are important to the feline industry by preserving traits desirable for a particular breed or in research settings by maintaining medically valuable genetic traits. As breeding females age, their reproductive efficiency declines. The objective of this study was to determine the most common causes of infertility in breeding females that were producing fewer kittens. Knowing the cause and average age of infertility would allow management decisions to be made for the betterment of the colony. The medical records of 70 queens retired from breeding from a single research colony were examined for litter size and number, fertility over their lifespan, and age and reason for removal from breeding stock. Sections of uterus and ovaries were evaluated using gross and histopathological examination for a subset of these queens (46). The data suggests that mature, continuously breeding female cats may show signs of reduced fertility (infertile matings or reduced litter size) as early as 3 years of age and may be a result of undiagnosed Cystic Endometrial Hyperplasia (CEH), endometritis, pyometra and/or ovarian cysts. Evaluation of breeding queens should include periodic ultrasounds to monitor for ovarian cysts and evidence of CEH. Retiring animals from breeding once signs of infertility become apparent is recommended.

Changes in HIV Prevention and Sexual Experiences During the COVID-19 Pandemic: A Mixed-Methods Study

BACKGROUND

STI and HIV services and infection rates were affected during the COVID-19 pandemic, because of changes in access to health care and individual behavior. Understanding how individuals made decisions around prevention and sexual activities during different phases of the pandemic is useful to addressing the rising rates of STIs and HIV.

SETTING

Federally-qualified health center focused on sexual and gender minority health, Chicago IL, 2021.

METHODS

Patients with a history of PrEP use who were contacted by the PrEP retention team as part of standard care were invited to complete an online survey. A subset of survey participants were then contacted to complete one-on-one interviews. Participants were asked about two distinct periods: November 2020 to January 2021 and February to June 2021.

RESULTS

From the 356 survey participants (mostly young, insured, and experienced with PrEP), more than half maintained their number of sex partners during the early pandemic and most also maintained PrEP use; during the later pandemic; most reported more or the same number of sex partners and almost all maintained PrEP use. From interviews, we identified diverse and changing experiences regarding sexual practices throughout the pandemic; whereas many participants changed PrEP use in accordance with sexual practices, many others maintained PrEP use as a habit. COVID-19 prevention was also a factor in sexual activities, particularly prevaccination.

CONCLUSION

Many PrEP users try to align their HIV prevention with their sexual exposures and establish PrEP as a long-term habit. Removing financial and access barriers is important to improve PrEP use and STI testing.

Increased duration of laser environmental enrichment increased broiler physical activity and pen-wide movement without altering tibia measurements

Inactivity and leg disorders negatively impact broiler welfare. Enrichment designed to increase barn complexity may encourage physical exercise. The study aim was to implement a second-generation laser enrichment device, previously shown to increase broiler activity, for extended periods of time and to measure behavior and tibia quality. A total of 1,360 Ross 708 broilers in 40 pens of 34 were assigned to laser enrichment or control (no laser enrichment) for 49 d. Seventy focal birds were randomly selected on d 0 for individual behavior analysis. Laser-enriched birds were exposed to 6-min laser periods 4 times daily. A 3-min novel object test was performed on all pens and tonic immobility was induced on 1 bird/pen on wk 1 and 6. Focal bird time budget and walking distance and pen-wide laser-following behavior and movement were obtained during laser periods d 0 to 8 and 1 d/wk through wk 7. Right tibias were collected from focal birds on d 49 for dual energy x-ray absorptiometry and bone breaking analysis. Time spent active during laser periods was increased on d 3, 6, and 8 and wk 2 to 3 in laser-enriched vs. control focal birds (P = 0.04). Time at the feeder was increased in laser-enriched focal birds on d 0, 3 to 4, and 8 and wk 2 and 4 (P < 0.01). Distance walked during laser periods was increased in laser-enriched focal birds on d 1, 3 to 5, 8, and wk 2 compared to the control (P < 0.01). Pen-wide movement was increased on d 0, 2, 4 to 8, and wk 1 to 5 and 7 in laser-enriched vs. control birds (P < 0.01). More laser-enriched broilers were within 25 cm of the novel object at 1 min 30 s than the control (P = 0.03), and latency to approach the novel object was reduced in both treatments at wk 6 compared to wk 1 (P < 0.01). Tonic immobility duration was increased by 123 s on wk 6 compared to wk 1, regardless of treatment (P < 0.01). Daily laser enrichment for extended periods increased bird activity without inducing fearfulness or altering tibia measures.

Breast muscle white striping and serum corticosterone reduced in broilers exposed to laser environmental enrichment

Genetic selection for breast yields and fewer days to market has inadvertent effects on broiler meat quality. Woody breast (WB) and white striping (WS) are pectoralis major myopathies prevalent in commercial broilers. Effects of voluntary exercise on these disorders, specifically, are unknown. A second-generation laser enrichment device shown to induce activity in Ross 308 and 708 birds was implemented using 1,360 Ross 708 broilers randomly assigned to laser enrichment or control for 49 d. Laser-enriched birds were exposed to 6-min laser periods 4 times daily. Seventy focal birds were gait and contact dermatitis scored weekly. Blood was collected wk 5 to 7 from 56 broilers for serum corticosterone, myoglobin, and troponin. Seventy broilers were sampled for breast muscle width, fillet dimensions, and WB and WS at wk 6 and 7. One and 2-day postmortem, fillet compression force and water-holding capacity were measured. Serum corticosterone was reduced by up to 21% in laser-enriched birds wk 5 to 7 (P < 0.01). Serum myoglobin was increased in laser-enriched broilers by 5% on wk 5 (P < 0.01) but increased in control birds wk 6 to 7 by up to 13% (P < 0.01). Serum troponin was reduced in laser-enriched broilers by 9% at wk 5 (P < 0.01). Laser exposure increased breast width and fillet weight at d 42 by 1.08 cm (P < 0.05) and 30 g (P < 0.05). At d 49, fillet height was increased 0.42 cm in laser-enriched birds (P < 0.05). Laser enrichment reduced severe WS incidence at d 42 by 24% (P < 0.05) and on d 49 by 15% (P < 0.10). Severe WB score was numerically reduced by 11% in laser enrichment on d 42 and 18% on d 49 (P > 0.05). Water-holding capacity was improved in laser-enriched breasts (P < 0.01) and expression of myostatin and insulin-like growth factor 2 were increased on d 49 (P ≤ 0.01. Laser enrichment reduced markers of stress and muscle damage while improving breast muscle quality and is therefore a potential effective enrichment for commercial broilers.

Abstract P345: Inhibition Of Nuclear Receptor Retinoid-related Orphan Receptor γt Attenuates Interleukin-17A Production And Ameliorates Angiotensin II-induced Neuroinflammation And Hypertension In Rats

Interleukin (IL)-17A, a key inflammatory mediator produced primarily by T helper (Th) 17 cells, has been implicated in the pathogenesis of cardiovascular diseases including hypertension and heart failure. IL-17A can access the brain by disrupting blood-brain barrier (BBB) integrity to induce neuroinflammation. We previously reported that IL-17A contributes to angiotensin (ANG) II-induced hypertension via promoting neuroinflammation and sympathetic excitation. The nuclear receptor retinoid-related orphan receptor γt (RORγt) is a master transcription factor regulating Th17 cell differentiation. Here, we sought to determine whether systemic inhibition of RORγt attenuates IL-17A production and diminishes ANG II-induced neuroinflammation and hypertension. Sprague-Dawley rats received a 2-week subcutaneous (sc) infusion of ANG II (150 ng/kg/min) combined with daily sc injection of a RORγt inhibitor digoxin or vehicle (VEH). Compared with the control animals, blood pressure (162±5* vs 118±3 mmHg, *P<0.05) and sympathetic tone as indicated by blood pressure change in response to ganglionic blockade (55±5* vs 23±3 mmHg) were increased in ANG II+VEH rats, which were reduced (38-41%*) in ANG II+digoxin rats. ANG II+VEH rats also had elevated RORγt mRNA in peripheral blood mononuclear cells (PBMCs: 3.38±0.70* vs 1.12±0.22) and higher IL-17A levels in plasma (23.22±5.85 * vs 4.30±0.66 pg/mL), along with increased IL-17A levels in cerebrospinal fluid (CSF: 11.89±1.91* vs 2.01±0.55 pg/mL), mRNA of IL-17A (3.02±0.48* vs 1.07±0.17), cytokines tumor necrosis factor (TNF)-α (2.78±0.45* vs 1.04±0.12) and IL-1β (2.57±0.53* vs 1.03±0.14) in the hypothalamic paraventricular nucleus (PVN), a key cardiovascular-related center in the brain. Although RORγt mRNA was unchanged in PBMCs, levels of IL-17A in plasma and CSF, mRNA of IL-17A, TNF-α and IL-1β in the PVN was reduced (41-62 %*) in ANG II+digoxin rats. Additionally, mRNA of caveolin-1 (2.26±0.39* vs 1.06±0.17), a marker of the BBB permeability, was increased in the PVN in ANG II+VEH rats and decreased (43%*) in ANG II+digoxin rats. These data suggest that RORγt inhibition improves ANG II-induced hypertension and sympathetic activation probably by reducing IL-17A production and neuroinflammation.

Improving young pig welfare on-farm: The Five Domains Model

Considering welfare through the "neonatal and nursery pig perspective" is an exciting approach, and one that resonates with consumers. Overlaying this with the Five Domains Model, as we suggest in this review, points to practical on-farm improvements that provide each pig the opportunity to experience positive mental states. The Five Domains Model is broken into physical and functional states, that includes Domain 1 Nutrition, Domain 2 Physical Environment, Domain 3 Health and, Domain 4 Behavioral Interaction, and Domain 5 Mental State. The Five Domains Model can build on the breadth and depth of swine welfare science to highlight opportunities to improve welfare on-farm. In Domain 1 management of increasingly large litters is considered, with examples of sow vs. artificial rearing, colostrum quality and quantity, and creep feed management strategies. Efforts can result in positive mental states such as feeling full and content and the ability to experience pleasure of drinking and food tastes/smells. Domain 2 considers space complexity and access to key resources, along with thermal and physical amenities, to promote feelings of physical comfort. Domain 3 considers pig health in three broad, yet inter-linking categories, (a) congenital and hereditary health, (b) environmental pathogen load and, (c) colostrum quality and quantity, and its effect on the microbiome. Improvements can result in a pig that displays vitality and feels healthy. Domain 4 provides the pig opportunities to express its rich behavioral repertoire, specifically positive social interactions, play, and exploration. These efforts can result in pigs feeling calm, safe, comfortable, having companionship, engaged, interested and rewarded. In conclusion, using the Five Domains Model can highlight numerous opportunities to improve current and future housing and management through the "neonatal and nursery pig perspective" with a focus on inducing positive mental states that can result in improved quality of life and welfare state.

Attitudes towards animals and belief in animal mind among first-year veterinary students before and after an introductory animal welfare course

Veterinarians are increasingly looked to for guidance on matters relating to animal welfare, yet little is known about US veterinary students' attitudes and beliefs about animals. In 2019, we surveyed all first-year veterinary students at a major US veterinary college (n = 123) before and after taking a required one-credit introductory animal welfare course. Attitudes were measured using the Pests, Pets and Profit (PPP) scale and belief in animal mind (BAM) was measured using an ad hoc measure adapted from previous work. Pre- and post-course comparisons indicated the introductory animal welfare course had no immediate effect on veterinary students' attitudes or BAM. Veterinary students' attitudes were most positive for animals considered pets, followed by pests and those used for profit. Students believed most species possess a wide variety of mental capacities, including many secondary emotions often considered uniquely human (eg guilt, embarrassment, jealousy). Sociodemographic variables consistently associated with more positive attitudes towards animals were: female gender, vegetarianism and liberal political ideology. Preferring a career involving large or food animal practice was consistently associated with less positive attitudes towards animals. Belief in animal mind explained 3% of the variation in attitude scores, whereas sociodemographic variables explained 49% of variation in attitude scores. Female gender, vegetarianism and preferring small (vs large or food animal practice) were all associated with greater BAM scores. Understanding veterinary student attitudes towards animals and beliefs about the mental capacities of animals is important when evaluating a veterinarian's ability to adhere to their oath.

Abstract P172: Impairment Of Estrogen Protective Effect Contributes To Maternal Gestational Hypertension-induced Sensitization Of Hypertensive Response To Post-weaning High Fat Diet In Female Adult Offspring

Obesity/high fat diet (HFD) is a risk factor for cardiovascular diseases including hypertension. Recent evidence indicates that maternal gestational hypertension (MGHT) induces hypertensive response sensitization (HTRS) elicited by post-weaning HFD in both male and female offspring. However, the increase in blood pressure (BP) in female offspring is less than that in male offspring. In this study, we investigated if estrogen plays a protective role in MGHT-induced HTRS to post-weaning HFD in female offspring, and if estrogen effects are associated with regulation of brain reactivity to pressor agents and altered autonomic function. In post-weaning HFD fed intact female offspring, MGHT induced HFD-elicited HTRS (MAP, offspring of NT dams, 107.9±0.9 to 115.2±0.7 mmHg; offspring of MGHT dams, 107.3±0.8 to 120.7±1.4 mmHg, p<0.05) and enhanced pressor responses to centrally administered angiotensin (ANG) II (Δ13.7±1.1 mmHg, p<0.05 vs NFD offspring) and tumor necrosis factor α (TNF-α) (Δ13.1±0.7 mmHg, p<0.05 vs NFD offspring). Ovariectomy (OVX) significantly enhanced the HFD-induced increase in BP (115.2±0.7 to 127.1±2.2 mmHg, p<0.05) and the pressor response to central ANG II (Δ11.2±0.9 to Δ18.7±2.3 mmHg, p<0.05) or TNF-α (Δ10.0±1.0 to Δ16.5±1.6 mmHg, p<0.05) in HFD offspring of normotensive (NT) dams. However, MGHT-induced HTRS (MAP, 122.5±1.9 mmHg) and pressor responses to ANG II (Δ16.3±1.0 mmHg) or TNF-α (Δ14.9±1.0 mmHg) in HFD-fed intact offspring of MGHT dams were not potentiated further after OVX when compared to HFD-fed OVX offspring of NT dams. The resting BP and elicited pressor responses remained higher than that of NFD fed offspring of both NT and MGHT dams. Moreover, OVX induced an increase in central nervous system sympathetic drive, and HFD feeding potentiated this effect. The results indicate that estrogen normally plays a protective role in antagonizing HFD prohypertensive effects in offspring of NT dams. MGHT compromises this normal protective action of estrogen to induce HTRS elicited by HFD, which is through augmenting brain reactivity and centrally driven sympathetic activity.

Abstract P194: Voluntary Exercise Eliminates Maternal Gestational Hypertension-induced Hypertensive Response Sensitization (htrs) In Post-weaning High Fat Diet Fed Male Adult Offspring

Exercise has profound effects on cardiovascular function and metabolism in both physiological and pathophysiological states. Our previous studies demonstrated that maternal gestational hypertension (MGHT) induces hypertensive response sensitization (HTRS) elicited by post-weaning high fat diet (HFD) in male offspring. The present study tested whether voluntary exercise would protect against MGHT-induced HTRS in HFD fed male offspring. Male offspring from both normotensive (NT) and MGHT dams were given access to either “blocked” (sedentary offspring) or functional running (exercised offspring) wheels for 10 weeks during normal fat diet (NFD) or HFD feeding. HFD feeding significantly increased resting blood pressure (BP) in sedentary offspring of both NT (112.3±0.7 to 119.9±1.2 mmHg, p<0.05) and MGHT (112.5±0.9 to 129.6±1.0 mmHg, p<0.05) dams, but the elevated BP induced by HFD was greater in sedentary offspring of MGHT dams (129.6±1.0 vs. 119.9±1.2 mmHg, p<0.05). The sedentary offspring of MGHT dams also displayed greater sympathetic tone and enhanced pressor responses to centrally administrated angiotensin (ANG) II or leptin. The running distance was comparable in four groups of exercise offspring (9.183±1.183, 9.192±1.677, 7.233±1.080, 8.482±1.455 kilometers/day, p>0.05). Voluntary exercise did not alter BP in NFD fed offspring and HFD fed offspring of NT dams, but it attenuated BP in HFD fed offspring of MGHT dams (129.6±1.0 to 121.1±0.8 mmHg, p<0.05) and body weight and heart rate in all offspring. Moreover, voluntary exercise significantly reduced sympathetic tone (Hexamethonium, ip, MAP Δ-50.6±1.0 to Δ-29.7±2.7 mmHg, p<0.05) and pressor responses to central ANG II and leptin in HFD fed offspring of both NT (ANG II: Δ16.0±0.9 to Δ7.5±1.1 mmHg; leptin: Δ11.8±0.6 to Δ5.4±0.9 mmHg, p<0.05) and MGHT (ANG II: Δ24.3±2.1 to Δ7.6±1.8 mmHg; leptin: Δ16.8±0.9 to Δ5.2±1.0 mmHg, p<0.05) dams and eliminated the differences in these responses between NFD fed offspring and HFD fed offspring. These results indicate that exercise training plays a beneficial role in preventing MGHT-induced HTRS and that this effect is associated with reduced brain reactivity to pressor stimuli and centrally driven sympathetic activity.

Abstract P210: Central Blockade Of Tumor Necrosis Factor-Á-Converting Enzyme (tace) Ameliorates Neuroinflammation, Sympathetic Excitation And Cardiac Dysfunction In Heart Failure Rat

TACE is a key metalloprotease involved in ectodomain shedding of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-α. We previously reported that TACE-mediated production of TNF-α in the hypothalamic paraventricular nucleus (PVN) contributes to the sympathetic excitation in heart failure (HF). Additionally, the upregulated TGF-α in the PVN transactivates the epidermal growth factor receptor (EGFR) to activate extracellular signal-regulated kinase (ERK) 1/2 in HF. Here we sought to determine whether central inhibition of TACE attenuates neuroinflammation and prevents the progress of HF. Male rats underwent coronary artery ligation to induce HF or sham surgery (Sham). These rats were treated with bilateral PVN microinjection of a TACE siRNA or control siRNA while some rats received a 4-week intracerebroventricular (ICV) infusion of TACE inhibitor TAPI-0 or vehicle. Compared with Sham rats, HF rats treated with control siRNA, had higher (*P<0.05) levels of TNF-α (7.88±1.32* vs 2.77±0.98 pg/mL) and TGF-α (28.27±2.76* vs 11.62±2.48 pg/mL) in cerebrospinal fluid, and increased mRNA expression of TACE (2.53±0.30* vs 1.04±0.12), TNF-α (3.43±0.55* vs 1.03±0.11), TNF-α receptor 1 (2.32±0.27* vs 1.07±0.19), cyclooxygenase-2 (2.96±0.31* vs 1.10±0.19) and TGF-α (2.68±0.41* vs 1.06±0.14) in the PVN, but these levels were markedly reduced (39-54%*) in TACE siRNA-treated HF rats. Compared with control HF rats, HF rats treated with TACE siRNA had reduced expression of phosphorylated (p-) NF-κB p65 (1.27±0.14 vs 0.84±0.07*), p-EGFR (0.52±0.05 vs 0.37±0.04*) and p-ERK1/2 (1.06±0.10 vs 0.62±0.09*) in the PVN. Moreover, the elevated plasma norepinephrine levels, lung/body weight, heart/body weight and left ventricular (LV) end-diastolic pressure along with decreased LV dP/dt max in HF rats-treated with control siRNA were significantly attenuated in HF rats treated with TACE siRNA. Treatments with TACE siRNA in the PVN also improved the indicators of cardiac hypertrophy and fibrosis of HF. ICV infusion of TAPI-0 had the similar effects with PVN TACE siRNA on these variables in HF. These data indicate that central interventions suppressing TACE activity ameliorate neuroinflammation, sympathetic activation and cardiac dysfunction in HF.

Abstract P222: Impact Of Adverse Childhood Experiences On Ambulatory Blood Pressure Profiles In Adolescence

Adverse childhood experiences (ACEs) include exposure to abuse (verbal and physical), neglect, and household dysfunction during childhood. ACEs have long-lasting health impacts including increased risk for cardiovascular disease (CVD) and hypertension in adulthood. However, it is not clear how ACE exposure impacts CVD risk earlier in the life course, particularly in adolescence. To address this gap in knowledge, in this study we hypothesized that ACE exposure is associated with abnormal ambulatory blood pressure (ABP) profiles in adolescents, with an increased incidence of ambulatory hypertension phenotypes that have normal casual clinic BP [e.g., masked hypertension (MH) or blunted nocturnal dipping (BND)]. We utilized 24-h ambulatory BP monitoring (ABPM; Spacelabs) and casual clinic BP to construct a profile of adolescents with and without ACEs. Abnormal ABP profiles included the following categories: ambulatory hypertension (AH, elevated ABP and casual clinic BP ≥95 th percentile for age, sex, and height), white-coat hypertension (WCH, elevated casual clinic BP with normal ABP), MH (normal casual clinic BP with elevated ABP), or BND (drop in ABP < 10% during sleep). This study included 78 male and female adolescents (median age=16) recruited from Children’s of Alabama Pediatric Clinics. Exclusion criteria included known CVD and antihypertensive medication. Participants recorded wake and sleep times in a diary. Based on the ACE questionnaire, 51 (65%) of adolescents experienced at least 1 ACE. The prevalence of abnormal ABP profiles was similar between the group with ACE exposures vs. the group without ACE exposures (34% vs. 36%; P =0.87). In participants with ACE exposure (n=51), 9% had AH, 6% had MH, 19% had WCH, 43.1% had systolic BND and 22% had diastolic BND. In participants without ACEs (n=27), 4% had AH, 4% had MH, 29% had WCH, 37% had systolic BND and 15% had diastolic BND. Further analysis with covariates are necessary. These results suggest that adolescents with ACEs have similar prevalence of abnormal ABP overall, but higher prevalence of individual ABP phenotypes such as AH, MH, and BND compared to adolescents without ACEs.

Abstract P136: Effects Of Sex Hormones On The Hemodynamic And Sympathetic Responses To Centrally Administered Tumor Necrosis Factor-α In Rats

Inflammation plays an important role in the pathophysiology of cardiovascular dysfunction and neurohumoral excitation in heart failure and hypertension. Growing evidence has demonstrated significant sex differences in the inflammatory response and immune processes, with estrogen exerting an anti-inflammatory effects and testosterone potentially having pro-inflammatory influence. We previously reported that central administration of tumor necrosis factor-α (TNF-α) elicited different effects on blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA) in male and female rats. Whether the sex steroids estrogen and testosterone contribute to the observed differences in TNF-α-induced hemodynamic and sympathetic responses remains unknown. We hypothesized that estrogen protects against TNF-α-induced sympathetic excitation and pressor responses while testosterone enhances these excitatory outcomes in response to TNF-α. Female or male Sprague Dawley rats (10-12 weeks) anesthetized with ketamine plus xylazine underwent bilateral ovariectomy or castration, respectively, 2 weeks prior to study. Sham-operated (Sham) female or male animals served as controls. TNF-α (100 ng) was administered intracerebroventricularly (ICV). BP (mmHg), HR (bpm) and RSNA (% change) were recorded in urethane anesthetized rats. In ovariectomized female rats (n=6), ICV TNF-α induced significantly (*p<0.05 vs. Sham) larger increases in BP (19.3 ± 1.4* vs. 12.8 ± 1.2 ), HR (76.3 ± 4.8* vs. 51.5 ± 4.3) and RSNA (104.8 ± 6.9* vs. 72.4 ± 5.1), compared with Sham-female rats, that began within 20-30 mins and peaked at 90-120 mins after ICV injection. In castrated male rats (n=6), ICV TNF-α-elicited significantly smaller increases in BP (15.2 ± 1.3* vs. 21.8 ± 1.6), HR (57.7 ± 4.2* vs. 82.6 ± 4.1) and RSNA (72.6 ± 4.3* vs. 110.3 ± 4.7), compared with Sham-male animals. These data indicate a distinct role of sex hormones estrogen and testosterone in central inflammation-driven cardiovascular and sympathetic activation and suggest a protective effect of estrogen and a harmful effect of testosterone in the development of hypertension and heart failure.

Abstract 17: Early Life Stress Sensitizes The Angiotensin II-elicited Hypertensive Response

Separation of neonatal rodent pups from their mothers has been used as a model to study the effects of early life stress (ELS) on behavioral and physiological responses in adults. Using an Induction-Delay-Expression experimental paradigm, our previous studies demonstrate that a wide range of stressors administered during an induction period produces hypertensive response sensitization (HTRS) in response to a subsequent pro-hypertensive stimulus. HTRS is accompanied by activation of the brain renin-angiotensin system (RAS) and CNS inflammation. The present study investigated whether ELS induces HTRS and changes in brain-related underlying mechanisms. Rat neonates from Sprague-Dawley breeders were subjected to ELS by separating them each morning from their mothers for 3 h on postnatal days 2 to 14. Pups from non-handled litters formed control groups. At 10 weeks of age, male rats were used to evaluate blood pressure and autonomic function using telemetric probes and pharmacological methods. In addition, in separate control and ELS groups, the lamina terminalis (LT) structures and the hypothalamic paraventricular nucleus (PVN) were analyzed for mRNA expression of RAS components and proinflammatory cytokines. Adult ELS rats as compared to non-separated controls exhibited 1) HTRS during expression testing using 2 week ANG II infusions (120 ng/kg/min s.c.; ELS animals, Δ45.5±4.5 mmHg vs. controls, Δ22.4±3.1 mmHg); 2) a greater reduction in mean arterial pressure following ganglionic blockade (hexamethonium, 30 mg/kg, ip), 3) increased sympathetic drive to the heart (atenolol, 8 mg/kg, ip), 4) decreased vagal tone (atropine, 8 mg/kg, ip), and 5) increased mRNA expression of several components of the brain RAS and proinflammatory cytokines in the LT and PVN. These results suggest that maternal ELS may predispose individuals to hypertension that is mediated by upregulation of the brain RAS and proinflammatory cytokines and increased sympathetic drive to the cardiovascular system.

Abstract P219: Mice Exposed To Early Life Stress Have Impaired Autonomic Activity At Baseline And In Response To Acute Stress In Adulthood

Early life stress (ELS) is an independent risk factor for the development of cardiovascular disease in adulthood in both humans and rodent models. Maternal separation and early weaning (MSEW), a model of ELS, produces mice with an increased risk of cardiovascular dysfunction in adulthood, despite resting blood pressures (BP), heart rates (HR), and body weights comparable to normally reared controls. Autonomic regulation of HR and BP is an important component of the homeostatic response to stress but has not been investigated in MSEW mice. We hypothesized that exposure to MSEW impairs autonomic function at baseline and in response to an acute psychosocial stressor in adult male mice. C57Bl/6J litters were randomly assigned to MSEW or normally reared control conditions. MSEW litters were separated from dams for 4 h on postnatal days (PDs) 2-5, 8 h on PDs 6-16, and weaned at PD 17. Control litters were undisturbed until weaning at PD 21. At 9 weeks old, telemeters were implanted in MSEW (n=16) and control mice (n=12). During cage switch stress (CSS), mice were moved to a soiled, unfamiliar cage for 4 h. HR, systolic BP (SBP), diastolic BP (DBP), and activity (monitored by telemetry) were similar between control and MSEW mice at baseline and during CSS (p>0.05, 2-way ANOVA). Spectral analysis of HR, SBP, and DBP indicated that HR variability (HRV) total power was lower in MSEW mice during the 12 h inactive period compared to controls (18.9±1.1 ms 2 vs. 27.5±3.1 ms 2 ; p=0.0033, 2-way ANOVA) at baseline. HRV low frequency (LF) power was also lower during the 12 h inactive period in MSEW mice (4.2±0.4 ms 2 vs.6.6±0.9 ms 2 ; p=0.009). At baseline, 12 h and 24 h DBP variability LF/high frequency (HF) ratio, normalized LF, and normalized HF power were lower in the MSEW group (p<0.05, all comparisons). During the final 90 minutes of CSS, MSEW mice had lower HRV total, LF, and HF power compared to controls (p<0.05); although HR, SBP, DBP, and activity remained similar between groups. These data suggest that MSEW mice have impaired autonomic control of HR and DBP and lack the ability to robustly respond and recover from an acute stressor. Reduced responsiveness of the autonomic nervous system may contribute to the increased risk of cardiovascular disease development in adult mice exposed to MSEW.

Reciprocal interactions between sodium appetite and need-free sugar intake

Behavioral sensitization occurs during sodium appetite (expressed as sodium intake to compensate for depleted sodium) and need-free sodium intake (expressed as daily overnight sodium intake in excess of dietary sodium need). Previously, we found that a slow-onset sodium appetite protocol cross-sensitized need-free sucrose intake in sucrose-naïve adult rats. That is, a history of sodium depletion elevated later sucrose intake. The objective of the present work was, first, to investigate whether a protocol that evokes a rapid-onset (within 2 h) sodium appetite using furosemide along with a low dose captopril (Furo/Cap), also cross-sensitizes sucrose intake. Then, we investigated whether 1) sensitization of need-free 0.3 M NaCl intake interacts with need-free sucrose intake, and 2) MK-801, a glutamate NMDA receptor antagonist, inhibits cross-sensitization of sucrose intake. Groups received 3-4 Furo/Cap or vehicle treatments with 48/72-h intervals. We investigated sucrose intake in hydrated and fed conditions for 2 h/day for 5 days, starting 6-10 days after the last Furo/Cap treatment. Episodes of Furo/Cap sensitized need-free sodium intake, as expected. Similar to our prior work, the rapid-onset Furo/Cap protocol cross-sensitized sucrose intake in sucrose-naïve rats and had no persistent effect on blood biochemistry. MK-801 treatment along with Furo/Cap injections appeared to prevent cross-sensitization of sucrose consumption. Sucrose intake tests unexpectedly reduced sensitized need-free sodium intake. However, MK-801 treatment allowed a rebound in need-free sodium intake subsequent to the last sucrose intake test. The results suggest that plasticity in glutamatergic mechanisms mediate inverse and reciprocal interactions between the production of sodium appetite and sucrose intake.

0977 Risk Factors For Developing Sleep Disorders In Children

Introduction

Unidentified sleep disorders can affect emotional, cognitive and social development in children. Screening for sleep disorders within the pediatric population is not common practice during medical visits. The objective of this study is to identify specific questions related to behavioral and physiological factors having potential to screen and detect those at risk for sleep disorders in a general pediatric clinic.

Methods

A retrospective archive from electronic medical records was analyzed from 1,361 children patients, 0-18 years old, that visited a pediatric clinic from March-November of 2019. Children or their parents reported on the presence of eight objective behavioral and physiological factors on the Kids Sleep Screener Questionnaire (KSSQ), which were used as potential risk factors for sleep disorders. Propensity of daytime sleepiness was measured through the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD). Scores higher than 11 were considered a positive indicator of potential sleep disorders because of excessive daytime sleepiness. Positive scores from the ESS-CHAD were used for comparison with the KSSQ factors using chi-square test of SAS software.

Results

Among the eight factors, snoring was the strongest risk factor and increased sleep duration was the weakest risk factor associated with a positive ESS-CHAD. Relationships among risk factors and the increased likelihood for developing sleep disorders were statistically significant (p&lt;0.05-p&lt;0.0001) and identified as following: snoring by 2.46 times, restless sleeper by 2.03 times, behavioral or learning difficulties by 1.43 times, nocturnal awakenings by 1.16 times, excessive sleepiness during the day by 1.10 times. Sleep onset latency and increased sleep duration were weak indicators due to a likeliness of less than one time (p&lt;0.05) to be associated with a positive ESS-CHAD. Abnormal sleep behavior was not a statistically significant risk factor (p≥0.05) for potential sleep disorders in children.

Conclusion

There were associations between seven behavioral and physiological risk factors with overall sleep propensity in children. These results exhibit that the KSSQ is an important tool to identify potential sleep disorders in children and the need for follow up with a sleep specialist. The KSSQ is under validation for becoming a standard sleep screener in pediatrics.

Support

N/A

A novel environmental enrichment device improved broiler performance without sacrificing bird physiological or environmental quality measures

Modern commercial broilers have been genetically selected for fast growth and heavy breast muscling, contributing to a top-heavy phenotype and increased leg lameness. A quick-growing phenotype coupled with poor leg health fosters inactivity. The objective of this study was to stimulate broiler movement using novel environmental enrichment and determine the impact of movement on production, leg health, and environmental parameters. A total of 1,200 Ross 308 broilers were housed in 40 pens with 30 birds/pen for 6 wk in 2 separate rooms (laser enrichment or control). Each enrichment device was mounted above 2 adjoining pens, projected 2 independent, randomly moving laser beams at the floor to stimulate innate predatory behavior, and was active 4 times daily in 4-min periods. Performance outcomes were calculated by pen and averaged per bird for each performance period and overall days 0 to 42. A total of 70 randomly selected focal birds were examined for breast blisters and footpad dermatitis each week and euthanized on day 42 for tibia quality measures. Air quality and litter moisture were sampled by week. Laser-enriched pens had greater average bird feed intake in starter (P < 0.001), grower (P = 0.004), finisher periods (P = 0.004), and overall days 0 to 42 (0.19 kg/bird; P = 0.0003). Average bird weight gain was also increased in enriched pens in each performance period: starter (P = 0.043), grower (P = 0.001), finisher (P < 0.001), and overall days 0 to 42 (0.24 kg/bird; P < 0.001). Enriched pens had improved feed conversion ratio (FCR) vs. control with a decrease of 3 FCR points in the grower (P = 0.031), 18 points in the finisher (P < 0.001), and 7 points overall (P < 0.001). Enriched pens had higher ADG during starter (P = 0.048), finisher (P < 0.001), and overall (5.7 g/bird/d; P < 0.001). No differences were found in breast blister, footpad dermatitis, tibia, air, or litter quality measures (P > 0.05). In summary, a novel enrichment device based on bird visual feeding and predatory instincts positively affected performance through decreased FCR and increased ADG without sacrificing external animal-based measures, tibia quality, or air or litter quality.

Abstract P1116: Early Life Stress Induces HDAC-Dependent Expression of Pro-Oxidant Genes in the Aorta

Childhood adversity or early life stress (ELS) is an understudied risk factor for cardiovascular disease (CVD). The mouse ELS model, maternal separation with early weaning (MSEW), generates robust effects on anxiety as well as immunological consequences in adulthood. Previous studies from our laboratory showed that MSEW induces a pro-oxidant vascular phenotype in adulthood. Early in life or during development, epigenetic mechanisms such as the cellular balance of histone acetylation and deacetylation (HDACs) critically influences gene expression. We hypothesized that MSEW induces HDAC-dependent expression of pro-oxidant genes in the vasculature. Thoracic aortae were isolated from male adult (12 wk) normally-reared (NR) or MSEW mice. Histone 3 lysine acetylation (H3K27) status was found to be significantly decreased in aorta from MSEW compared to NR mice, indicating MSEW induced increased HDAC activity. The MSEW-induced increased in aortic NADPH oxidase (NOX) 2, NOX4, and toll-like receptor (TLR) 4 expression and was significantly blunted with ex vivo trichostatin A (TSA) treatment with no changes in NR mice (relative mRNA; NOX2: MSEW+VEH 1.55±0.12 vs MSEW+TSA 1.24±0.16, NOX4: MSEW+VEH 1.68±0.14 vs MSEW+TSA 1.25±0.07, TLR4: MSEW+VEH 1.65±0.16 vs MSEW+TSA 0.79±0.09, N=4-8, p<0.05). Further, MSEW-induced endothelial dysfunction was reversed with ex vivo TSA treatment with no changes observed in NR mice (E max NR+VEH 86.3±3.5, NR+TSA 82.8±6.3, MSEW+VEH 64.1±8.2 vs MSEW+TSA 85.9±1.7, N=8-12, p<0.05). Reports show that HDAC9 is associated with increased risk for vascular diseases. Aorta from MSEW mice had a significant increase in HDAC9 abundance compared to NR mice (rel. mRNA; NR: 1.02±0.1 vs MSEW: 1.67±0.2, N=6, p<0.05). To determine whether HDAC9 directly induces NOX2, NOX4, and/or TLR4 expression, we utilized HDAC9 over-expressing (HDAC9-OE) mice. Aortic tissue from HDAC9-OE mice revealed a 10-fold NOX4 and 13-fold TLR4 increase, with no change in NOX2 expression. Our results indicate that HDACs, especially HDAC9, are ELS-sensitive mediator(s) of pro-oxidant gene expression. We conclude, that activation of HDAC-dependent pro-oxidant genes, specifically NOX4 and TLR4 pathways, contribute to increased CVD risk following ELS.

Abstract P341: Melanocortin Receptor 4 Activation Mediates Leptin-Induced Sensitization of the Angiotensin II-Elicited Hypertensive Response in Mice

Obesity has been shown to promote the renin-angiotensin system (RAS) activity and inflammation in the hypothalamus that increase BP and sympathetic activity. Our previous studies using an Induction-Delay-Expression (IND-DEL-EXP) experimental design demonstrated that in the rats high-fat diet (HFD) or central leptin pretreatment resulted in an enhanced hypertensive response to subsequent treatment with angiotensin (ANG) II. The present study tested whether the leptin sensitization of ANG II-induced hypertension is mediated by activation of brain melanocortin receptor 4 (MC4R) in mice. The animals pretreated with either 3-week HFD or systemic leptin during IND responded with enhanced hypertension to ANG II (1000 ng/kg/min, sc.; HFD, Δ44.0±2.1 mmHg vs. Δ29.4±3.2 mmHg; leptin, Δ43.0±1.7 mmHg vs. Δ29.4±2.0 mmHg). This sensitized ANG II hypertensive response produced by systemic leptin given during IND was blocked by co-administration of icv SHU9119, a MCR4 antagonist (Δ24.0±2.9 mmHg). Moreover, a similar sensitization of the ANG II-induced hypertensive response was produced by icv pretreatment with MT II, a MC4R agonist (Δ39.6±2.1 mmHg). The results indicate that leptin-induced sensitization of ANG II-elicited hypertension is mediated by activation of brain MC4R.

Aging affects isoproterenol-induced water drinking, astrocyte density, and central neuronal activation in female Brown Norway rats

Age-dependent impairments in the central control of compensatory responses to body fluid challenges have received scant experimental attention, especially in females. In the present study, we found that water drinking in response to β-adrenergic activation with isoproterenol (30 μg/kg, s.c.) was reduced by more than half in aged (25 mo) vs. young (5 mo) ovariectomized female Brown Norway rats. To determine whether this age-related decrease in water intake was accompanied by changes in central nervous system areas associated with fluid balance, we assessed astrocyte density and neuronal activation in the SFO, OVLT, SON, AP and NTS of these rats using immunohistochemical labeling for GFAP and c-fos, respectively. GFAP labeling intensity was increased in the SFO, AP, and NTS of aged females independent of treatment, and was increased in the OVLT of isoproterenol-treated rats independent of age. Fos immunolabeling in response to isoproterenol was reduced in both the SFO and the OVLT of aged females compared to young females, but was increased in the SON of female rats of both ages. Finally, fos labeling in the AP and caudal NTS of aged rats was elevated after vehicle control treatment and did not increase in response to isoproterenol as it did in young females. Thus, age-related declines in water drinking are accompanied by site-specific, age-related changes in astrocyte density and neuronal activation. We suggest that astrocyte density may alter the detection and/or processing of signals related to isoproterenol treatment, and thereby alter neuronal activation in areas associated with fluid balance.

Differential effects of long-term slow-pressor and subpressor angiotensin II on contractile and relaxant reactivity of resistance versus conductance arteries

Vascular reactivity was evaluated in three separate arteries isolated from rats after angiotensin II (Ang II) was infused chronically in two separate experiments, one using a 14-day high, slow-pressor dose known to produce hypertension and the other using a 7-day low, subpressor but hypertensive-sensitizing dose. There were three new findings. First, there was no evidence of altered vascular reactivity in resistance arteries that might otherwise explain the hypertension due to the high Ang II or the hypertensive-sensitizing effect of the low Ang II dose. Second, the high Ang II dose exerted a novel differential effect on arterial contractile responsiveness to the sympathetic neurotransmitter, norepinephrine, depending on the level of sympathetic innervation. It clearly enhanced that responsiveness in the sparsely innervated aorta but not in small mesenteric resistance arteries or the proximal (conductance) portion of the caudal artery, both of which are densely innervated. This suggests that the increased expression of alpha adrenergic receptors after long-term exposure to Ang II as previously reported for aortic smooth muscle, is prevented in densely innervated arteries, likely due to long-term Ang II-mediated increase in sympathetic neural traffic to those vessels. Third, the same high dose of Ang II impaired aortic relaxation in response to the nitric oxide (NO) donor nitroprusside without impairing aortic endothelium-dependent relaxation. NO is the main relaxing substance released by aortic endothelium. Accordingly, it is possible that this dose of Ang II is also associated with enhanced release of and/or enhanced smooth muscle responsiveness to other endothelial relaxing substances in a compensatory capacity.

Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.

Abstract P389: Post-traumatic Stress-induced Sensitization of Angiotensin II Hypertension is Reversed by Blockade of Angiotensin-converting Enzyme or Tumor Necrosis Factor-alpha

Using an Induction-Delay-Expression experimental paradigm, our previous studies demonstrated that post-traumatic stress disorder (PTSD) sensitizes angiotensin (ANG) II-elicited hypertension, which was associated with upregulation of central renin-angiotensin system (RAS) components and proinflammatory cytokines (PICs). The present study investigated whether inhibition of angiotensin-converting enzyme (ACE) or tumor necrosis factor-α (TNF-α) prior to PTSD blocks sensitization of ANG II-elicited hypertensive response. The resident-intruder paradigm was used to model PTSD. Each intruder rat (male Sprague-Dawley) was pretreated with ACE inhibitor (captopril, 0.5 mg/Ml) or with TNF-α inhibitor (pentoxifylline, PTX, 100 mg/kg/day) in the drinking water for two weeks and then exposed to a different resident (male Long-Evans) for 2 hours on three days with each session separated by 1 day. Beginning 3 days after the last exposure, the intruder (PTSD) rats and unstressed control rats received a subcutaneous infusion of ANG II (120 ng/kg/min) for 2 weeks. The PTSD rats had a significantly enhanced hypertensive response to the ANG II infusion and an upregulation of mRNA expression of RAS and PIC components and of a microglial marker in the lamina terminalis (LT) when compared to control rats. Both the sensitized hypertensive response and enhanced gene expression were blocked by pre-treatment with either ACE inhibitor or TNF-α antagonist. These results suggest

that upregulation of the brain RAS and PICs produced by a severe stress contribute to PTSD-induced sensitization of the hypertensive response to ANG II.

Abstract P306: Maternal High Fat Diet Acts on the Brain to Induce Baroreflex Dysfunction and Sensitization of Angiotensin II-induced Hypertension in Adult Offspring

Accumulating evidence indicates that maternal high fat diet (HFD) is associated with metabolic syndrome and cardiovascular disease in adult offspring. The present study tested the hypothesis that maternal HFD modulates the brain renin-angiotensin system (RAS), oxidative stress and proinflammatory cytokines that alters angiotensin II and tumor necrosis factor-α (TNF-α) actions to sensitize the angiotensin II-elicited hypertensive response in adult offspring. All offspring were cross-fostered by dams on the same or opposite diet to yield 4 groups: offspring from normal fat control diet (CD)-fed dams suckled by CD-fed dams (OCC) or by HFD-fed dams (OCH) and offspring from HFD-fed dams fed HFD suckled by CD-fed dams (OHC) or by HFD-fed dams (OHH). RT-PCR analyses of the lamina terminalis (LT) and paraventricular nucleus (PVN) indicated upregulation of mRNA expression of several RAS components, NADPH oxidase and proinflammatory cytokines in 10-week old male offspring of dams fed HFD during either pregnancy, lactation or both (OHC, OCH and OHH). These offspring also showed decreased baroreflex sensitivity and increased pressor responses to intracerebroventricular microinjection of either angiotensin II or TNF-α. Furthermore, chronic systemic infusion of angiotensin II resulted in enhanced upregulation of mRNA expression of RAS components, NADPH oxidase and proinflammatory cytokines in the LT and PVN and an augmented hypertensive response in the OHC, OCH and OHH groups when compared to the OCC. The results suggest that maternal HFD blunts baroreflex function and enhances pressor responses to angiotensin II or proinflammaroty cytokines through upregulation of the brain RAS, oxidative stress and inflammation.

Brain Transforming Growth Factor-β Resists Hypertension Via Regulating Microglial Activation

BACKGROUND AND PURPOSE

Hypertension is the major risk factor for stroke. Recent work unveiled that hypertension is associated with chronic neuroinflammation; microglia are the major players in neuroinflammation, and the activated microglia elevate sympathetic nerve activity and blood pressure. This study is to understand how brain homeostasis is kept from hypertensive disturbance and microglial activation at the onset of hypertension.

METHODS

Hypertension was induced by subcutaneous delivery of angiotensin II, and blood pressure was monitored in conscious animals. Microglial activity was analyzed by flow cytometry and immunohistochemistry. Antibody, pharmacological chemical, and recombinant cytokine were administered to the brain through intracerebroventricular infusion. Microglial depletion was performed by intracerebroventricular delivering diphtheria toxin to CD11b-diphtheria toxin receptor mice. Gene expression profile in sympathetic controlling nucleus was analyzed by customized qRT-PCR array.

RESULTS

Transforming growth factor-β (TGF-β) is constitutively expressed in the brains of normotensive mice. Removal of TGF-β or blocking its signaling before hypertension induction accelerated hypertension progression, whereas supplementation of TGF-β1 substantially suppressed neuroinflammation, kidney norepinephrine level, and blood pressure. By means of microglial depletion and adoptive transfer, we showed that the effects of TGF-β on hypertension are mediated through microglia. In contrast to the activated microglia in established hypertension, the resting microglia are immunosuppressive and important in maintaining neural homeostasis at the onset of hypertension. Further, we profiled the signature molecules of neuroinflammation and neuroplasticity associated with hypertension and TGF-β by qRT-PCR array.

CONCLUSIONS

Our results identify that TGF-β-modulated microglia are critical to keeping brain homeostasis responding to hypertensive disturbance.

Goosefish Lophius americanus fecundity and spawning frequency, with implications for population reproductive potential

To improve knowledge of goosefish Lophius americanus' reproductive biology, females were collected during 2009-2012 from the Mid-Atlantic Bight shelf region of the U.S. east coast. Batch fecundity increased with total length (L_T ), from 229 100 to 2 243 300 mature oocytes per female (L_T range: 55·5-112 cm; n = 54). This estimate of fecundity at L_T is lower than one derived from a sample collected during 1982-1985. Examination of whole oocyte diameters in different months indicated that L. americanus is a serial spawner, releasing more than one egg veil per spawning season, as suspected or observed for other Lophius species. Seasonality of spawning was evident from whole oocytes and gonad histology, and from larval fish surveys spanning the U.S. north-east shelf, and confirmed a protracted (c. 6 months) spawning period. Peak spawning activity progressed northward from spring to autumn. The population-level implications of these results were explored by estimating population reproductive potential (P_RP ), which considered the value of both current and future per capita reproduction using decade-specific age structure and fecundity at length. P_RP is now more than 50% lower compared with the historical period (1982-1985), a result of the lower proportions of large females and reduced fecundity across all sizes. Mechanisms that could explain this loss of stock productivity are fishing-induced size-age truncation or regime shifts in egg production caused by changes in energy density of common forage species.

Measuring the efficacy of flunixin meglumine and meloxicam for lame sows using a GAITFour pressure mat and an embedded microcomputer-based force plate system

Pain associated with lameness on farm is a negative affective state and has a detrimental impact on individual farm animal welfare. Animal pain can be managed utilizing husbandry tools and through pharmacological approaches. Nonsteroidal anti-inflammatory drugs including meloxicam and flunixin meglumine are compounds used in many species for pain management because they are easy to administer, long lasting, and cost-effective. Assessing an animal's biomechanical parameters using such tools as the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system provides an objective, sensitive, and precise means to detect animals in lame states. The objectives of this study were to determine the efficacy of meloxicam and flunixin meglumine for pain mitigation in lame sows using the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system. Lameness was induced in 24 mature mixed-parity sows using a chemical synovitis model and compared 3 treatments: meloxicam (1.0 mg/kg per os), flunixin meglumine (2.2 mg/kg intramuscular) and sterile saline (intramuscular). Weight distribution (kg) for each foot was collected twice per second for a total of 5 min for each time point using the embedded microcomputer-based force plate system. Stride time, stride length, maximum pressure, activated sensors, and stance time were collected using 3 quality walks (readings) for each time point using the GAITFour pressure mat gait analysis walkway system. Sows administered flunixin meglumine or meloxicam tolerated more weight on their lame leg compared with saline sows (P < 0.005). Sows administered flunixin meglumine or meloxicam had smaller differences in stance time, maximum pressure, and activated sensors between the sound and lame legs compared with saline-treated sows between 37 and 60 h after lameness induction (P < 0.03). In conclusion, flunixin meglumine and meloxicam administration mitigated pain sensitivity in sows after lameness induction when pain sensitivity was evaluated with the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system. Analgesic drugs may be a key tool to manage negative pain affective states associated with lameness.

Abstract P193: Upregulation of Brain Renin-angiotensin System and Inflammation Mediates Leptin Sensitization of Angiotensin Ii-induced Hypertension

Leptin, an adipocyte-derived hormone, contributes to the increase in blood pressure (BP) associated with obesity. Obesity has also been shown to promote the renin-angiotensin system (RAS) activity and inflammation in the hypothalamus that increase BP and sympathetic activity. Our previous studies using an Induction-Delay-Expression experimental design demonstrated that a central leptin pretreatment resulted in an enhanced hypertensive response to subsequent treatment with angiotensin (ANG) II. The present study tested whether this central leptin sensitization of ANG II-induced hypertension is mediated by an increase in RAS acitivity and inflammation in the brain. Male rats prepared for telemetry BP recording and were pretreated during Induction with central leptin (20 ng/kg/min, ICV) alone or with either ANG II type 1 receptor (AT1R) antagonist irbesartan (125 μg/d) or the TNF-α synthesis inhibitor pentoxifylline (10 μg/h) for one week. After one week Delay, rats were treated during Expression with subcutaneous ANG II (120 ng/kg/min) for 2 weeks. The animals pretreated with central leptin responded with enhanced hypertension to ANG II ([[Unable to Display Character: &#8710;]]39.3±3.8 mmHg vs. [[Unable to Display Character: &#8710;]]21.2±5.2 mmHg). Central infusion of pentoxifylline or irbesartan during Induction blocked the sensitization produced by central leptin. RT-PCR analysis of tissue from the lamina terminalis indicated that leptin up-regulated mRNA expression of several components of the RAS and proinflammatory cytokines including AT1R, angiotensin converting enzyme, TNF-α and interleukin 1β. The results indicate that leptin-induced sensitization of ANG II-elicited hypertension is mediated by upregulation of central RAS and proinflammatory cytokines.

Consumption of a high n-3 polyunsaturated fatty acid diet during gradual mild physiological stress in rats

n-3 Polyunsaturated fatty acids (n-3PUFAs) may be beneficial for anxiety and depression under stressful conditions. Studies however, typically utilise physical or sudden physiological stress, while gradual physiological stress is also relevant to human conditions. Using deoxycorticosterone acetate (DOCA) administration to induce gradual physiological stress, this study investigated the impact of n-3PUFAs under gradual physiological stress in rats. Animals (aged 2 months) (N=8-12/group) received daily injections of DOCA or vehicle and were concurrently fed a high n-3PUFA or control diet for eight weeks. Behavioural measures were taken throughout. Behavioural tests and physiological measures were conducted after six and eight weeks respectively. DOCA administration decreased plasma renin, plasma proteins and relative adrenal weight, and increased water intake, relative kidney weight, and anxiety in the open field. These findings demonstrate disruptions to the renin-angiotensin-aldosterone system, a result of mild physiological stress, that also impact on anxiety behaviours. No effects of n-3PUFAs were found.

Abstract 441: Sex Differences in Microglia Activation During Subpressor Dose of Angiotensin (Ang) II Sensitization of Subsequent Pressor Dose of Ang II

In previous studies using the Induction-Delay-Expression (I-D-E) experimental design we have shown that there are sex differences in the effects of one-week Ang II pre-treatment to sensitize the brain to produce an enhanced hypertensive response to subsequent Ang II. In other studies, we have shown that females are protected from hypertension and brain infiltration of T lymphocytes during Ang II infusion. The purpose of the present study was to test whether there is a sex difference in brain microglia activation on the sensitizing effects of Ang II. The present studies followed an I-D-E experimental design. Three male and three female Sprague-Dawley rats were assigned to each of the following experimental groups: 1) Control ( I saline + D) ; 2) I-Ang II+D ( I with subpressor dose of Ang II, 10 ng/kg/min); 3) I-saline+D+E-Ang II (I with saline plus E with a pressor dose of Ang II, 120 ng/kg/min); 4) I-Ang II+D+E-Ang II (I with subpressor dose of Ang II plus E with pressor dose of Ang II). At the end of the experiment, animals were anesthetized and perfused with formalin. Thirty-micron frozen slices of the area postrema (AP), nucleus tractus solitarius (NTS), and subfornical organ (SFO) were processed for IHC staining with IBa-1 microglia antibody (WAKO, 1:200). The number of IBa-1+ activated microglia (MG) in each region were counted in an approx 3 consecutive brain slices from 3 separate animals. The subpressor dose of Ang II resulted in a significant increase in NTS activated microglia in males (MG 19.2 vs. 5.1) but not in females (MG 1.5 vs 2.3) when compared to control. In females, the pressor dose of Ang II did not increase the activated microglia in the NTS. The numbers of activated microglia in the AP was similar in males and females in the I-Ang II+D+E-Ang II group, but in the I-Sal+D+E-Ang II, males had greater number of MG in the AP as compared to females (21.5 vs 11.8, P=0.05). The number of MG in the SFO were low across all groups compared to the number of MG in other regions examined (males I-Ang II+D+E-Ang II group averaged 3.9 MG vs females averaged 2.3 MG). These results suggest that sex differences observed in the brain sensitization to Ang II may involve differential induction of microglia activation in selective brain regions important for Ang II generation of hypertension.

Evaluation of mechanical and thermal nociception as objective tools to measure painful and nonpainful lameness phases in multiparous sows

The objective of this study was to quantify pain sensitivity differences using mechanical nociception threshold (MNT) and thermal nociception threshold (TNT) tests when sows were in painful and nonpainful transient lameness phases. A total of 24 mixed parity crossbred sows (220.15 ± 21.23 kg) were utilized for the MNT test, and a total of 12 sows (211.41 ± 20.21 kg) were utilized for the TNT test. On induction day (D0), all sows were anesthetized and injected with Amphotericin B (10mg/mL) in the distal interphalangeal joint space in both claws of one randomly selected hind limb to induce transient lameness. Three days were compared: (1) D-1 (sound phase, defined as 1 d before induction), (2) D+1 (most lame phase, defined as 1 d after induction), and (3) D+6 (resolution phase, defined as 6 d after induction). After completion of the first round, sows were given a 7-d rest period and then the procedures were repeated with lameness induced in the contralateral hind limb. During the MNT test, pressure was applied perpendicularly to 3 landmarks in a randomized sequence for each sow: 1) middle of cannon on the hind limb (cannon), 2) 1 cm above the coronary band on the medial hind claw (medial claw), and 3) 1 cm above the coronary band on the lateral hind claw (lateral claw). During the TNT test, a radiant heat stimulus was directed 1 cm above the coronary band. The data were analyzed using the MIXED procedure in SAS with sow as the experimental unit. Differences were analyzed between sound and lame limbs on each day. For the MNT test, pressure tolerated by the lame limb decreased for every landmark (P < 0.05) when comparing D-1 and D+1. The sound limb tolerated more pressure on D+1 and D+6 than on baseline D-1 (P < 0.05). Thermal stimulation tolerated by the sound limb did not change over the 3 d (P > 0.05). However, the sows tolerated less heat stimulation on their lame limb on D+1 compared to D-1 levels (P < 0.05). Both MNT and TNT tests indicated greater pain sensitivity thresholds when sows were acutely lame.

Determining the influence of dietary roughage concentration and source on ruminal parameters related to sulfur toxicity

Cattle feedlot diets often include ethanol coproducts that provide excess dietary sulfate, which is reduced to sulfide by ruminal bacteria and can be converted to hydrogen sulfide, which has been correlated to S toxicity. The objective of this study was to determine the impact of feeding varying concentrations of NDF from chopped cornstalks (CS) or chopped bromegrass hay (BH) on ruminal pH, ruminal H2S concentration, and DMI of steers fed a high-S finishing diet. Five ruminally fistulated steers (595 ± 87 kg BW) were used in a 6 × 6 Latin square with 14-d periods and fed diets containing 0.45% S from a mixture of dried distillers grains and condensed corn distillers solubles. The study was a 2 × 3 factorial arrangement of treatments with 2 roughage sources--CS or BH--and 3 concentrations of added roughage NDF (rNDF)--4, 7, or 10%. Steers had individual ad libitum access to feed and adapted to each diet for the first 7 d of each period. Effective NDF linearly increased (P < 0.01) as rNDF increased and did not differ between sources (P = 0.44). There was no effect of concentration or source of rNDF on DMI (P ≥ 0.69). Steer behavior was observed on d 13 of each period for 3 h postfeeding. Source of rNDF did not affect time at bunk, DMI during observation, or rate of DMI (P ≥ 0.42). Time at bunk linearly increased as rNDF increased (P = 0.01), while rate of DMI linearly decreased (P = 0.02). Area under the curve for ruminal pH of 5.4, 5.6, and 5.8, calculated using data from d 8 to 14 via an indwelling ruminal bolus, were linearly decreased (P ≤ 0.03) as rNDF increased. Manual ruminal pH taken 6 h postfeeding on d 14 of each period did not differ by source (P = 0.12) but linearly increased (P < 0.01) as rNDF increased. Ruminal H2S concentrations measured 6 h postfeeding on d 14 of each period did not differ by source (P = 0.47) but linearly decreased (P < 0.01) as rNDF increased (0.62, 0.35, 0.31 g/m(3) for 4, 7, and 10% rNDF, respectively). A segmented linear model was found to best fit the ruminal pH and H2S relationship data, suggesting that at or below a pH of 5.6 ± 0.08 with 95% confidence intervals of 5.4 and 5.8, pH is a strong predictor of H2S (P ≤ 0.05), while above this pH range H2S concentrations are not well correlated with ruminal pH (P > 0.50). In conclusion, adding at least 7% NDF from CS or BH to high-S feedlot cattle diets will increase ruminal pH and decrease H2S concentrations, thus decreasing potential for S toxicity.

Angiotensinergic and cholinergic receptors of the subfornical organ mediate sodium intake induced by GABAergic activation of the lateral parabrachial nucleus

Bilateral injections of the GABA(A) agonist muscimol into the lateral parabrachial nucleus (LPBN) induce 0.3 M NaCl and water intake in satiated and normovolemic rats, a response reduced by intracerebroventricular (icv) administration of losartan or atropine (angiotensinergic type 1 (AT₁) and cholinergic muscarinic receptor antagonists, respectively). In the present study, we investigated the effects of the injections of losartan or atropine into the subfornical organ (SFO) on 0.3M NaCl and water intake induced by injections of muscimol into the LPBN. In addition, using intracellular calcium measurement, we also tested the sensitivity of SFO-cultured cells to angiotensin II (ANG II) and carbachol (cholinergic agonist). In male Holtzman rats with cannulas implanted bilaterally into the LPBN and into the SFO, injections of losartan (1 μg/0.1 μl) or atropine (2 nmol/0.1 μl) into the SFO almost abolished 0.3M NaCl and water intake induced by muscimol (0.5 nmol/0.2 μl) injected into the LPBN. In about 30% of the cultured cells of the SFO, carbachol and ANG II increased intracellular calcium concentration ([Ca²⁺](i)). Three distinct cell populations were found in the SFO, i.e., cells activated by either ANG II (25%) or carbachol (2.6%) or by both stimuli (2.3%). The results suggest that the activation of angiotensinergic and cholinergic mechanisms in the SFO is important for NaCl and water intake induced by the deactivation of LPBN inhibitory mechanisms with muscimol injections. They also show that there are cells in the SFO activated by both angiotensinergic and cholinergic stimuli, perhaps those involved in the responses to muscimol into the LPBN.

Development and refinement of a technique for short-term intravascular auricular vein catheter placement in mature sows

Intravenous drug administration in adult swine is difficult to perform due to inaccessible superficial veins and thick subcutaneous fat layers. However, successful intravenous drug administration is critical for many biomedical applications including pharmacokinetic studies as extravascular drug administration can influence the drug’s absorption and elimination rate. The purpose of this study was to develop and refine an effective technique for indwelling auricular vein catheter placement in the conscious mature sow. We developed a protocol using a topical anesthetic cream and minimal physical restraint to place indwelling catheters in the auricular vein of six multiparous sows. This method was quick (3 min 20 s ± 8 s [mean ± SE per catheter]), effective (11/12 catheters successfully placed) and reliable, allowing a large drug volume (20–22 mL) to be administrated successfully during the trial without relying on prolonged restraint or general anesthesia of the sow.

Abstract 515: Central Angiotensin (ang) (1-7) Inhibits the Sensitizing Effects of a Low Dose Ang Ii in Hypertension Produced by a Subsequent Slow Pressor Dose of Ang Ii in Male and Female Rats

Previous studies using an Induction-Delay-Expression (I-D-E) experimental design demonstrated that pre-treatment with ANG II for 1 week produces a sensitized hypertensive response to subsequent ANG II administration in males but not in females. In this sensitization process, several brain renin-angiotensin-aldosterone system components including angiotensin converting enzyme 2 (ACE2) expressions were enhanced. It has been shown that ANG (1-7), formed from ANG II by ACE2, plays an anti-hypertensive role in the central nervous system. The present study tested whether central ANG (1-7) protects against the sensitizing effects of a low dose of ANG II.

Male and female rats were implanted for telemetered blood pressure (BP) recording. During I low doses of ANG II alone or with concurrent icv administration of ANG (1-7) or its antagonist A-779 were given for 1 week. After a 1 week rest ( D ), a slow pressor dose of ANG II was given for 2 weeks ( E ).

In males, the low dose of ANG II during I resulted in an enhanced pressor response to the subsequent slow pressor dose of ANG II given during E in comparison to those rats receiving vehicle during I (Δ42.8±7.2 vs Δ21.2±5.3 mmHg). Central administration of ANG (1-7) during I blocked the low dose ANG II-induced sensitization (Δ16.4±4.0 mmHg). In contrast, the low dose of ANG II did not sensitize the hypertensive response in females to the subsequent slow pressor dose of ANG II (Δ13.0±5.4 vs Δ9.9±3.4 mmHg). Central blockade of ANG (1-7) by icv infusion of A-779 during I resulted in sensitization by the low dose of ANG II (Δ26.7±2.0 mmHg) in females. The results indicate that ANG (1-7) plays a protective role during the sensitization process, especially in females, and its administration can attenuate the development of ANG II-induced hypertension in both male and female.

Validation of a lameness model in sows using physiological and mechanical measurements

The objective of this study was to develop a validated, transient, chemically induced lameness model in sows using subjective and objective lameness detection tools. Experiment 1 determined an effective joint injection technique based on volume and placement of dye using feet collected from 9 finisher pigs and 10 multiparity cull sow carcasses. Experiment 2 confirmed the injection technique in live animals and produced a transient clinical lameness in 4 anesthetized sows injected with amphotericin B (15 mg/mL) in the distal interphalangeal joints of the claw. Clinical lameness was assessed by a categorical lameness scoring system, and a postmortem visual confirmation of joint injection technique was obtained. In Exp. 3, 6 sows were injected with 0, 10, or 15 mg/mL amphotericin B in either the left or right hind foot and were monitored until clinical resolution. Treated sows demonstrated elevated clinical lameness scores. These changes resolved by 7 d after lameness induction. Control sows injected with sterile saline developed a clinical lameness score of 0.5, which resolved 72 h post injection. In Exp. 4, 36 sows were injected with 10 mg/mL amphotericin B in 1 of 4 injection sites (left front claws, right front claws, left rear claws, and right rear claws). All injected sows exhibited a decrease in maximum pressure, stance time, and number of sensors activated on the GaitFour (P < 0.05) sensor system. A static force plate also demonstrated a decrease in weight (kg) being placed on the injected foot when all feet were injected (P ≤ 0.05). Injection of amphotericin B induced a predictable acute lameness that resolved spontaneously and is an effective method to model lameness in sows.

Abstract 658: Pressor And Sympathetic Response To 2% Saline Augmented By Prior Treatment With Intracerebroventricular (icv) Angiotensin II (ANGII)

Previous studies from our laboratory demonstrate that the sensitizing effects of sub-pressor ANGII or aldosterone treatments on ANGII-induced hypertension are mediated through the CNS. The present study tested if pressor response sensitization extends to another hypertensive challenge, 2% saline given as the sole drinking fluid. The study followed an Induction-Delay-Expression ( I-D-E ) experimental design. We instrumented rats with telemetry devices to continuously record blood pressure (BP) and heart rate throughout the experiments. After one week recovery and one week baseline ( B ) recording, rats underwent a second surgery to implant icv cannulas to continuously deliver ANGII (1 ng/kg/min; prior ANGII) or vehicle (control) for one week ( I ). After I and after a 1 week D , drinking water was switched to 2% saline ( E ). The degree of autonomic tone was assessed via ganglionic blockade (hexamethonium, 30 mg/kg, ip) during B , after I , and during E . During B, group BPs were not different (103±2 mmHg control vs. 107±4mmHg, prior-ANGII). Although drinking only 2% saline increased BPs in both groups (122±3 mmHg, control vs. 141±9 mmHg, prior-ANGII), the absolute increase was greater in rats treated with ANGII during I (19±3, control vs. 34±6, prior-ANGII, p<0.05). At B, control and prior-ANGII treated rats showed no difference in the depressor response to hexamethonium (-17±3%, control vs. -13±1%, prior-ANGII) or after I (-13±5%, control vs. -20±9%, prior-ANGII). However, during E while drinking2% saline, prior-ANGII treated rats displayed a significantly larger fall in BP to hexamethonium than controls (-20±5%, control vs. -36±7%, prior-ANGII, p<0.05), suggesting that during E a higher degree of sympathetic tone maintained BP in the prior-ANGII treated rats. These data show that icv treatment with ANGII sensitizes the hypertensive response induced by 2% saline intake and that this enhanced pressor effect is accompanied by elevated sympathetic tone. These results provide new insights into the etiology of salt-sensitive hypertension by implicating a role for ANGII-induced neuroplasticity in CNS systems controlling sympathetic tone.

Abstract 411: Cytokine Receptors in the Subfornical Organ Mediate Sympathetic and Hemodynamic Responses to Peripherally Administered TNF-α and IL-1β in Rat

Introduction: Pro-inflammatory cytokines (PIC) play an important role in regulating autonomic and cardiovascular function in hypertension (HTN) and heart failure (HF). Peripherally administered PIC such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) act within the brain to increase blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA). These molecules are too big to cross blood brain barrier (BBB), and so the mechanisms by which they activate sympathetic drive to elicit hemodynamic responses remain quite a mystery. Our preliminary data indicate a dense distribution of TNF-α and IL-1β receptors in the subfornical organ (SFO), a forebrain which lacks a BBB and can be accessed readily by circulating PIC. The SFO projects to the hypothalamic paraventricular nucleus, which has been implicated as an important source of cardiovascular and autonomic dysfunction in HTN and HF.

Hypothesis: SFO neurons sense circulating PIC and mediate their effects on sympathetic drive and hemodynamic responses.

Methods: One week after an SFO lesion or a sham lesion (SHAM), urethane anesthetized male SD rats underwent an intracarotid artery (ICA) injection of TNF-α (200 ng) or IL-1β (200 ng). BP (mmHg), HR (beats/min) and RSNA (% change) responses were recorded.

Results: In SHAM rats (n=5), ICA TNF-α dramatically increased (* p<0.05 vs. baseline) the BP (23 ± 1.5*), HR (61 ± 5*) and RSNA (88.5 ± 4.3 %*) responses, which peaked ∼30 min after injection. These early excitatory responses to ICA TNF-α were absent in SFO-lesioned rats (n=5), though a moderate excitatory response occurred hours later. Similarly, ICA IL-1β elicited increases in BP (21.8 ± 2.1*), HR (62 ± 6*) and RSNA (116.5 ± 5.2*) in the SHAM rats (n=5). In the SFO-lesioned rats (n=5), the BP (8.6 ± 1.3 †), HR (24 ± 2 †) and RSNA (26.8 ± 1.6 †) responses to ICA IL-1β were significantly († <0.05 vs. SHAM) attenuated.

Conclusion: These data suggest that the SFO plays an important role as a central nervous system sensor of the peripheral inflammatory state, mediating the effects of circulating PIC on sympathetic drive and cardiovascular function in inflammatory conditions such as HTN and HF. The later occurring excitatory responses to PIC are unexplained but may involve their known vascular effects.

Abstract 417: Central PPAR-γ Activation Attenuates Angiotensin II-Induced Hypertension by Inhibiting Brain Inflammation and Renin-Angiotensin System Activity in Rats

Upregulation of inflammation and renin-angiotensin system (RAS) activity in the brain contributes to hypertension through effects on fluid intake, vasopressin release, and sympathetic nerve activity. Peroxisome proliferator-activated receptor (PPAR)-γ, a nuclear transcription factor, is expressed in key brain areas involved in drinking, vasopressin release and cardiovascular regulation, including the paraventricular nucleus of hypothalamus (PVN). We recently reported that activation of brain PPAR-γ reduced inflammation and RAS activity in the PVN and ameliorated the peripheral manifestations of heart failure. Here we hypothesized that activation of central PPAR-γ might have beneficial effects on angiotensin II (ANG II)-induced hypertension. Spague-Dawley rats received a continuous 2 week subcutaneous infusion of ANG II (120 ng/kg/min), combined with intracerebroventricular infusion of vehicle (VEH) or the PPAR-γ agonist pioglitazone (3 nmoL/h). At 2 weeks, blood pressure (BP) had significantly (*P<0.05) increased (131±3* vs 98±3 mmHg) and the BP response to ganglionic blockade (70±4* vs 43±3 mmHg) was greater in conscious VEH-treated ANG II rats compared with normal (control) rats. Water intake (34±2* vs 25±2 mL) and plasma vasopressin following 4 hours of water restriction (20.79±2.62* vs 10.62±1.27 pg/mL) were increased. PPAR-γ mRNA in the PVN was unchanged in VEH-treated ANG II rats, compared with control rats, but PPAR-γ DNA binding activity (0.05±0.01* vs 0.09±0.01 OD 450nm ) was reduced and mRNA for interleukin-1β (2.76±0.22* vs 1.09±0.21 fold change), tumor necrosis factor-α (1.58±0.09* vs 1.04±0.12 fold change) and ANG II type-1 receptor (1.71±0.15* vs 1.03±0.10 fold change) was augmented. All of these findings were ameliorated (by 24-36%*) in ANG II rats treated with pioglitazone, which increased PPAR-γ mRNA and PPAR-γ DNA binding activity in the PVN (by 73-77%*). The results suggest that activating brain PPAR-γ to reduce central inflammation and RAS activity, thereby suppressing fluid intake, vasopressin release and sympathetic drive, may be a novel approach to the treatment of ANG II-dependent hypertension.

Altered ADAR 2 equilibrium and 5HT(2C) R editing in the prefrontal cortex of ADAR 2 transgenic mice

Modulation of serotonin signaling by RNA editing of the serotonin 2C receptor (5HT(2C) R) may be relevant to affective disorder as serotonin functions regulate mood and behavior. Previously, we observed enhanced endogenous behavioral despair in ADAR2 transgenic mice. As the transcript of the 5HT(2C) R is a substrate of ADAR2, we hypothesized that perturbed ADAR2 equilibrium in the prefrontal cortex of ADAR2 transgenic mice alters the normal distribution of edited amino acid isoforms of the 5HT(2C) R and modifies the receptor function in downstream basal extracellular signal-regulated kinase (ERK) signaling. We examined groups of naive control and ADAR2 transgenic mice and found significantly increased ADAR2 expression, increased RNA editing at A, C, D and E sites and significantly altered normal distribution of edited amino acid isoforms of the 5HT(2C) R with increased proportions of valine asparagine valine, valine serine valine, valine asparagine isoleucine, isoleucine asparagine valine and decreased isoleucine asparagine isoleucine amino acid isoforms of the 5HT(2C) R in ADAR2 transgenic mice. Localized serotonin levels (5-HT) were unchanged and perturbed ADAR2 equilibrium coincides with dysregulated edited amino acid isoforms of the 5HT(2C) R and reduced basal ERK signaling. These results altogether suggest that altered 5HT(2C) R function could be contributing to enhanced depression-like behavior of ADAR2 transgenic mice and further implicate ADAR2 as a contributing factor in cases of affective disorder.

The effect of selection for residual feed intake on general behavioral activity and the occurrence of lesions in Yorkshire gilts

The objectives of this study were to determine the effect of selection for improved residual feed intake on behavior, activity, and lesion scores in gilts in their home pen. A total of 192 gilts were used, 96 from a line that had been selected for decreased residual feed intake over 5 generations (LRFI) and 96 from a randomly bred control line. Gilts were housed in 12 pens (16 gilts/pen; 0.82 m(2)/gilt) containing 8 gilts from each line in a conventional grow-finish unit. Twelve hours of video footage were collected on the day of placement and then every 4 wk for 3 more observational periods. Video was scored using a 10-min instantaneous scan sampling technique for 4 postures (standing, lying, sitting, and locomotion) and 1 behavior (at drinker). Categories of active (standing, locomotion, and at drinker) and inactive (sitting and lying) were also created. Lesion scores were collected 24 h after behavior collection had begun. The body of a gilt was divided into 4 regions, with each region receiving a score of 0 (0 lesions) to 3 (5+ lesions). All statistical analyses used Proc Mixed of SAS. Data were analyzed separately for the day of placement and the subsequent 3 rounds. General activity was summarized on a percentage basis by each posture and behavior and subjected to an arcsine square root transformation to normalize data and stabilize variance. Analysis was performed on each behavior and posture. Lesion scores for each region of the body were analyzed as repeated measures. There were no differences (P > 0.05) between genetic lines for all postures and the behavior at drinker on the day of placement. However, over subsequent rounds it was observed that LRFI gilts spent less (P = 0.03) time standing, more time sitting (P = 0.05), and were less active (P = 0.03) overall. Gilts from the LRFI line had decreased (P < 0.045) lesion scores on the day after placement. However, over subsequent rounds there were no (P > 0.05) differences between the genetic lines. In conclusion, on the day of placement there were no postural, behavior, or general activity differences between genetic lines, but LRFI gilts had decreased lesion scores. Behavioral differences were observed between genetic lines over subsequent rounds, with LRFI gilts becoming less active, but there were no differences in lesion scores.

Performance and carcass characteristics of finishing beef cattle managed in a bedded hoop-barn system

The use of bedded hoop barns in finishing systems for beef cattle has not been widely researched. In this management system, beef cattle are confined to hoop barns throughout finishing, and bedding is used to absorb animal waste, which results in minimal effluent. The objective of this study was to compare the performance and carcass characteristics of finishing beef steers (n = 1,428) managed in a bedded hoop-barn management system vs. an open-feedlot system with shelter. Six feeding trials were conducted over a 3-yr period. Three trials were conducted during summer-fall and 3 trials were conducted during winter-spring. Crossbred steers were allotted to 3 pens in the hoop-barn system and to 3 pens in the open-lot system (approximately 40 steers per pen in both facility systems). Stocking densities for the steers were 4.65 m(2) per steer in the hoop-barn system and 14.7 m(2) per steer in the open-lot system. The steers were begun on trial weighing 410 and 411 kg (SD = 21), were fed for 102.3 and 103.0 d (SD = 3.8), and were weighed off test at 595 and 602 kg (SD = 21) for the hoop-barn and open-lot systems, respectively. Steer performance measures consisted of ADG, DMI, and G:F. Carcass characteristics were HCW, fat thickness, LM area, KPH percentage, marbling score, USDA yield grade, and USDA quality grade. No year, season, or pen (management system) main effects, or season x management system and year x management system interactions were observed for any of the items measured related to cattle performance or carcass characteristics (P > 0.05). Final mud scores (a subjective evaluation of the amount of soil and manure adhering to the hair coat of the animals) were greater for the steers from the open-lot system compared with those from the hoop-barn system (P < 0.02), suggesting steers in the hoop-barn system carried less mud than steers from the open-lot system. Average daily cornstalk bedding use in the hoop-barn system was 2.3 kg/steer during summer-fall and 2.6 kg/steer during winter-spring. The performance of finishing cattle managed in a hoop-barn system was not different from the performance of cattle managed in an open-feedlot system with shelter during summer and winter. Managing beef cattle in hoop barns required more bedding but resulted in decreased mud scores compared with cattle managed in an open-lot system with shelter. Hoop barns are a viable alternative housing management system for finishing beef cattle.

Drinking behavior in nursery pigs: determining the accuracy between an automatic water meter versus human observers

Assimilating accurate behavioral events over a long period can be labor-intensive and relatively expensive. If an automatic device could accurately record the duration and frequency for a given behavioral event, it would be a valuable alternative to the traditional use of human observers for behavioral studies. Therefore, the objective of this study was to determine the accuracy in the time spent at the waterer and the number of visits to the waterer by individually housed nursery pigs between human observers scoring video files using Observer software (OBS) and an automatic water meter Hobo (WM, control) affixed onto the waterline. Eleven PIC USA genotype gilts (22 +/- 2 d of age; 6.5 +/- 1.4 kg of BW) were housed individually in pens with ad libitum access to a corn-based starter ration and one nipple waterer. Behavior was collected on d 0 (day of weaning), 7, and 14 of the trial using 1 color camera positioned over 4 attached pens and a RECO-204 DVR at 1 frame per second. For the OBS method, 2 experienced observers recorded drinking behavior from the video files, which was defined as when the gilt placed her mouth over the nipple waterer. Data were analyzed using nonparametric methods and the general linear model and regression procedures in SAS. The experimental unit was the individual pen housing 1 gilt. The GLM model included the method of observation (WM vs. OBS) and time (24 h) as variables, and the gilt nested within method was used as the error term. Gilts consumed more water (P = 0.04) on d 14 than on d 0. The time of day affected (P < 0.001) the number of visits and the time spent at the waterer regardless of the method. However, the OBS method underestimated (P < 0.001) the number of visits to the waterer (3.48 +/- 0.33 visits/h for OBS vs. 4.94 +/- 0.33 for WM) and overestimated (P < 0.001) the time spent at the waterer (22.6 +/- 1.46 s/h for OBS vs. 13.9 +/- 1.43 for WM) compared with WM. The relationship between the 2 methods for prediction of time spent at the waterer and number of visits made by the gilts was weak (R(2) = 0.56 and 0.69, respectively). Collectively, these data indicate that the use of the traditional OBS method for quantifying drinking behavior in pigs can be misleading. Quantifying drinking behavior and perhaps other behavioral events via the OBS method must be more accurately validated.