Acclimation Period Research Articles

Automated home cage monitoring of an aging colony of mice—Implications for welfare monitoring and experimentation

IntroductionOur understanding of laboratory animal behavior and the implications of husbandry activities on their wellbeing remains incomplete. This is especially relevant with an aging colony as their activity patterns may change as they mature. Home Cage Monitoring (HCM) provides valuable insights into mouse activity within the animal's own environment and can shed light on acclimatization periods and responses to husbandry activities such as cage changing. The aim of this study was to monitor and explore changes in the activity and rest disturbance (RDI) patterns of an aging colony of male and female C57/BL6 mice.MethodsThe mice were housed in the Digitally Ventilated Cage® system, for up to 18 months of age. Data was then downloaded to investigate how the activity patterns and RDI of the mice changed over time. Habituation, aging and cage change assessments were conducted using linear mixed models, while cage separation and stereotypic behavior investigations were conducted by visual inspection of the data.ResultsAs expected during the study, mice were less active during the light phase compared to the dark phase. However, on arrival mice displayed heightened activity and RDI during the light phase and reduced activity and RDI during the dark phase, taking several days to adjust to baseline “acclimatized” patterns. With age, overall activity significantly decreased from 5 months until 14 months of age, after which it increased back toward baseline levels. We also observed activity spikes during our monitoring of this colony. Prolonged housing can lead to alarming stereotypic behaviors in animals. Cages of mice flagged for potential stereotypy displayed sustained activity spikes in the light and dark phases. Spikes in activity during the dark phase were much more pronounced than in the light phase. Cage changing led to an increase in the light phase activity and RDI compared to the previous day, with no observed difference in the dark phase post-cage change. This effect remained consistent as the animals aged.DiscussionThis study explores changes in the activity patterns of an aging colony of male and female C57/BL6 mice housed in the Digitally Ventilated Cage® system. We identified distinct aging phases concerning activity and RDI differences and a potential new welfare application for the DVC®, specifically for early detection of stereotypy. In conclusion, the adoption of HCM systems should be considered for long-term animal housing from both a welfare and behavioral perspective.

Microbial community acclimation during anaerobic digestion of high-oil food waste

Anaerobic digestion is one of the most promising options for the disposal of biodegradable food waste. However, the relatively high content of oil in food waste inhibits the conversion efficiency of anaerobic digestion because of the accumulation of long-chain fatty acids (LCFAs). In this study, activated anaerobic sludge was acclimated to accommodate high-oil conditions. The methane yield of high-oil food waste digested by the acclimated sludge increased by 24.9% compared to that digested by the raw sludge. To determine the internal changes in the acclimated sludge, the shifts in the microbial communities during the acclimation period were investigated via high-throughput sequencing (HTS) based on the 16 S rRNA gene. The results indicated that Bacteroidetes, Firmicutes, Chloroflexi and Proteobacteria were the dominant bacteria at the phylum level. The acclimation time allows some functional bacterial taxa to proliferate, such as Clostridium and Longilinea, which are able to degrade LCFAs and turn them into small organic molecules that also have nutrient value for other bacteria. Among the archaeal communities, the hydrogenotrophic methanogen Methanobacterium nearly supplanted the acetotrophic methanogen Methanosaeta. The time profiles of volatile fatty acids (VFAs) and pH during this period provided additional evidence for the success of the acclimation. This study demonstrated the effectiveness of acclimation and the dynamic of microbial communities, which further contributed to the management and resource utilization of high-oil food waste.

Optimized partial freezing protocol enables 10-day storage of rat livers

Preserving organs at subzero temperatures with halted metabolic activity holds the potential to prolong preservation and expand the donor organ pool for transplant. Our group recently introduced partial freezing, a novel approach in high-subzero storage at -15 °C, enabling 5-day storage of rodent livers through precise control over ice nucleation and unfrozen fraction. However, increased vascular resistance and tissue edema suggested a need for improvements to extend viable preservation. Here, we describe an optimized partial freezing protocol with key optimizations, including an increased concentration of polyethylene glycol (PEG) to enhance membrane stability while minimizing shear stress during cryoprotectant unloading with an acclimation period and a maintained osmotic balance through an increase in bovine serum albumin (BSA). These approaches ensured the viability during preservation and recovery processes, promoting liver function and ensuring optimal preservation. This was evidenced by increased oxygen consumption, decreased vascular resistance, and edema. Ultimately, we show that using the optimized protocol, livers can be stored for 10 days with comparable vascular resistance and lactate levels to 5 days, outperforming the viability of time-matched static cold stored (SCS) livers as the current gold standard. This study represents a significant advancement in expanding organ availability through prolonged preservation, thereby revolutionizing transplant medicine.

Insights into physiological roles of flavonoids in plant coldacclimation.

Flavonoids represent a diverse group of plant specialised metabolites which are also discussed in the context of dietary health and inflammatory response. Numerous studies have revealed that flavonoids play a central role in plant acclimation to abiotic factors like low temperature or high light, but their structural and functional diversity frequently prevents a detailed mechanistic understanding. Further complexity in analysing flavonoid metabolism arises from the different subcellular compartments which are involved in biosynthesis and storage. In the present study, non-aqueous fractionation of Arabidopsis leaf tissue was combined with metabolomics and proteomics analysis to reveal the effects of flavonoid deficiencies on subcellular metabolism during cold acclimation. During the first 3 days of a 2-week cold acclimation period, flavonoid deficiency was observed to affect pyruvate, citrate and glutamate metabolism which indicated a role in stabilising C/N metabolism and photosynthesis. Also, tetrahydrofolate metabolism was found to be affected, which had significant effects on the proteome of the photorespiratory pathway. In the late stage of cold acclimation, flavonoid deficiency was found to affect protein stability, folding and proteasomal degradation, which resulted in a significant decrease in total protein amounts in both mutants. In summary, these findings suggest that flavonoid metabolism plays different roles in the early and late stages of plant cold acclimation and significantly contributes to establishing a new protein homeostasis in a changing environment.

Directionality in BiCROS hearing aids: an investigation of objective and subjective outcomes

Objectives To assess the effect of forward and omnidirectional microphone configurations in BiCROS versus monaural hearing aids on objective and subjective outcomes in different noise conditions. Design After fitting and a 4-week acclimatisation period, speech recognition and sound quality were measured using forward directional, omnidirectional, and unaided settings. Two noise configurations were used, surrounding noise and noise presented from the aided (better) ear. Subjective outcomes were assessed using the SSQ-b and BBSS questionnaires and participant interviews. Study sample Eighteen adult participants (mean: 74.6 y; range: 61–94 y; ten males, eight females) with mild to moderately severe SNHL in their better ear (PTA0.5–4khz > 20 dB HL) and limited usable hearing in their poorer ear (average PTA0.5–4khz > 100 dB HL). Results Significant improvement in speech recognition and sound quality for BiCROS and monaural directional settings over omnidirectional and unaided, in both noise configurations. There were no significant differences observed between monoaural and BiCROS directional settings. Conclusion Speech in noise recognition and sound quality scores demonstrated a significant directional benefit for both BiCROS and monaural directional fitting settings over omnidirectional and unaided conditions. Unique BiCROS-specific experiences were identified in a patient-oriented approach. These can inform the development of BiCROS-tailored tools.

Dietary thiamine supplementation modulates ruminal microbiota and partly restores lactation performance in lactating Hu ewes under heat-stress conditions

This study aimed to investigate the impact of dietary thiamine supplementation on milk production, rumen microbiota profile and inflammatory response of Hu ewes under heat-stress conditions. Twenty-seven multiparous pregnant and lactating Hu ewes of 71.6 ± 1.4 kg body weight, 11 ± 0.5 months gestation age, 31 ± 1 days in milk, 1.68 ± 0.15 L/d milk yield, and 2.14 ± 0.12 kg of daily dry matter intake (DMI), were used in the study. Following an acclimation period of 7 days, ewes were divided into 3 blocks of 9 each (one Hu ewe per pen), in a complete randomized design and assigned to one of three environmental temperature conditions for 15 days: thermoneutrality without supplementation (CON), heat-stressed without supplementation (HS) or heat-stressed with dietary thiamine supplementation (200 mg/kg of DMI; HST). The results indicated that the HS group experienced notable declines in milk protein, fat, and lactose content from day 10–15 (P < 0.05) compared to the CON group. In contrast, thiamine supplementation significantly elevated milk protein content from day 13–15 and raised milk fat and lactose content on days 14 and 15 (P < 0.05) compared to the HS group, thereby enhancing milk quality to a certain extent. Additionally, thiamine supplementation (HST group) significantly increased the circulating thiamine and Immunoglobulin A (IgA) concentrations accompanied by a significant decline in LPS-binding protein, interleukin-1 (IL-1), and serum amyloid A protein (SAA) levels compared to the HS group (P < 0.05). Rumen microbial composition analysis revealed that thiamine supplementation increased the abundance of Pyramidobacter, Butyrivibrio, Bacteroides, and Saccharofermentans. In conclusion, heat exposure during lactation in Hu ewes lowered milk production and quality, affecting rumen microbes. Dietary thiamine supplementation could improve rumen fermentation, mitigate heat stress-induced inflammation, and restore milk production in Hu ewes under heat stress conditions.

8663 Sex differences in delayed fear incubation in mice

Abstract Disclosure: M. Littlepage-Saunders: None. M. Rusnak: None. M. Tsuda: None. T. Wu: None. Post-traumatic stress disorder (PTSD) has a lifetime prevalence of 1 in 13 people. It is not fully understood why some are more vulnerable to developing PTSD whereas others are more resilient. Among those who develop PTSD, about a quarter have delayed-onset PTSD where onset of symptoms occur at 6 months or later after experiencing a traumatic event. While there is recognition of this type of PTSD, the underlying mechanism is poorly understood. The development of PTSD is more prevalent in women than men. However, previous preclinical and clinical studies have focused mainly on males. Thus, there lacks an understanding of this sex difference. To enhance our understanding of the causal mechanisms, we designed a study with mice to compare the effect of sex on delayed fear incubation. We expected the female mice to show increased fear responses that would suggest more chronic delayed fear incubation than the male mice. To test this, we evaluated distance travelled, freezing, and latency until the first freezing episode in adult male and female C57Bl/6J mice (7-8 weeks of age; n=8/group) using a delayed fear incubation behavioral assay. Animals were placed in a fear conditioning chamber for a 198 s acclimation period and then administered a single 2 s scrambled footshock of 1.5 mA via the metal grid floor. After an additional 60 s, animals were returned to their home cage. At specific time after shock application, animals underwent a fear recall test where the animals were placed back in the shock chamber for a total of 180 s without any additional footshocks and then returned to their home cage. The study was based on a 2X2 factorial design comprising of sex (male vs female) and recall time (1 day and 14 days post shock). The data showed an increasing freezing trend (p=0.08) at d 14 compared to their recall d 1 counterparts. There was no effect of time or sex on distance travelled or latency until the first freezing episode. Interestingly, female mice showed less freezing when compared to the male mice. Ongoing experiments will look more into circuitry-level changes by comparing neuronal activation through cFos expression in different brain regions that are a part of the limbic system and/or have been associated with fear: the amygdala, hippocampus, prefrontal cortex, and paraventricular nucleus. Presentation: 6/2/2024

The effect of several growth regulators and biostimulant on biochemical and physiological changes in acclimation of micropropagated Echinacea purpurea Moench. ‘Raspberry Truffle’

Micropropagation is currently one of the primary methods for plant propagation, known for its efficiency in producing disease-free and vigorous plants. However, the final stage of this—acclimatization, is critical due to the transfer from a controlled in vitro environment to an external one. To reduce mortality and alleviate acclimation stress, plant growth regulators (PGRs) or biostimulants can be employed. This study investigated the effects of exogenously sprayed PGRs: 0.001 mg L−1 abscisic acid (ABA), 0.001 mL L−1 brassinolide (BL), 0.001 mL L−1 24-epibrassinolide (24-epiBL), and 0.3 mL L−1 biostimulant Goteo on the physiological and biochemical responses of Echinacea purpurea ‘Raspberry Truffle’ plantlets during the acclimation process. The effects of treatments at various acclimation stages on chlorophyll (chl) and carotenoids content, hydrogen peroxide (H2O2), catalase (CAT), malondialdehyde (MDA), free amino acids, soluble proteins, total soluble sugar and reduced soluble sugars were tested in this research. The results confirmed changes in biochemical parameters, including an increase in chlorophyll and carotenoids in the acclimatization period where the highest level obtained by BL spraying. A decline in stomatal conductance was also observed, where ABA influenced the most on drop. It was also recorded the decrease in H2O2 and MDA concentration. CAT activity increased, especially with biostimulant treatment. We recorded an increase in total soluble proteins along acclimatization. Goteo affected the most on morphology parameters, ABA, BL and 24-epiBL increased acclimatization efficiency. Our studies indicate that potentially the most effective substances in the acclimatization of E. purpurea ‘Raspberry Truffle’ are brassinosteroids and ABA.

Microbial community acclimation via polarity reversal supports extensive dechlorination and anaerobic mineralization of 2,4,6-trichlorophenol in biocathode

In the anaerobic biocathode, reductive dechlorination of 2,4,6-trichlorophenol (2,4,6-TCP) mainly proceeded to produce 4-monochlorophenol (4-MCP) and phenol, and anaerobic mineralization was challenging. In this study, biocathodes microbial communities were first acclimated via potentials repeatedly adjusted between −0.278 V and +0.200 V (T-200), −0.278 V and +0.400 V (T-400), and −0.278 V and +0.600 V (T-600). Subsequently, all biocathode potentials were stabilized at −0.278 V for the degradation of 2,4,6-TCP. The results revealed that the T-600 achieved the highest degradation rate of 2,4,6-TCP (0.43 d−1), outperforming T-200 (0.051 d −1), T-400 (0.020 d −1), and open-circuit bioreactor (OC, 0.038 d−1) groups. In T-600, pare-dechlorination was facilitated, allowing for the conversion of 2,4,6-TCP to 2-monochlorophenol (2-MCP). Additionally, the detection of 4-hydroxybenzoic acid, an anaerobic mineralization intermediate of 2,4,6-TCP, indicated that anaerobic mineralization was also occurring. Polarity reversal occurred only in T-600 during the acclimation period, resulting in alterations to the electrical properties of the biocathode and microbial community. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) results indicated that there were more electroactive sites in biocathode of T-600, and the bidirectional extracellular electron transfer (EET) might be related to cytochrome. Mycobacterium (24.33 % in slurry and 19.92 % in biofilm), Thiobacillus (2.47 % in slurry and 17.85 % in biofilm), and Arenimonas (4.23 % in slurries and 4.32 % in cathode biofilm) were identified as the dominant electroactive bacteria in T-600, with Mycobacterium also playing an important role in the degradation of chlorophenols. These findings suggested that polarity reversal may represent a viable strategy for constructing microbial communities capable of achieving simultaneous dechlorination and mineralization of 2,4,6-TCP.

Evolution of microbial community structure during biohydrogen production process of palm oil anaerobic sludge

Anaerobic microbial communities and their functions can provide information about waste management practices, as well as reveal novel degradation metabolisms that can be utilized in wastewater treatment. This study was aimed towards sustainable palm oil industry with assessing the microbial evolution during the dark fermentative processing of palm oil anaerobic sludge and palm oil mill effluent (POME) in batch-mode over two-months with a distinct incubation time of 24 h. The process was designed using response surface methodology (RSM) by acclimatization of inoculum using POME with a chemical oxygen demand (COD) of 36 g-COD/l. The effect of mesophilic and thermophilic conditions and pH on COD removal, hydrogen content, and hydrogen yield (HY) were investigated. A potential sample was selected for microbial analysis after the first and second months of operation based on the maximum outputs achieved throughout the experiment. The bacterial community at pH 5.6 and temperature 55 ˚C with maximum hydrogen content of 64.13 %, and HY of 0.93 ml H2/g-COD was dominated by three phyla: Firmicutes, Actinobacteria, and Bacteroidota. The results obtained from high throughput pyrosequencing showed that how acclimatization period affects the microbial community structure towards Firmicutes phylum, which includes the majority of hydrogen-producing microorganisms.

Cucurbita Pepo L. Seed Oil Modulates Dyslipidemia and Neuronal Dysfunction in Tramadol-Induced Toxicity in Wistar Albino Rats.

Objective: The modulating effects of Cucurbita pepo seed oil (CPSO) on dyslipidemia and neuronal dysfunction in tramadol toxicity were studied. Methods: Fifty-six albino rats were divided into seven groups of eight rats each after a 2-week acclimatization period. All animals had unrestricted access to water and feed, and treatments were administered orally once daily for 42 days. Glutamate dehydrogenase and glutaminase activities were assessed using brain homogenate, while lipid profiles were analyzed in serum samples. Results: Tramadol toxicity was evidenced by significant (P < 0.05) increases in brain glutamate dehydrogenase along with significant (P < 0.05) decreases in the activities of glutaminase in the group administered only tramadol. Also, serum levels of total cholesterol, LDL-C and triglycerides also increased significantly (P < 0.05) following administration of tramadol with decreased level of HDL-C (P < 0.05). However, treatment with CPSO significantly restored the activities and levels of the altered biochemical parameters in a dose-dependent manner. The results of the biochemical investigation using the lipid profile and the enzymes of glutamate metabolism were corroborated by the results obtained from the histopathological examination of the brain. Conclusion: The results of this study therefore suggest that tramadol-induced dyslipidemia and neuronal dysfunction be managed and prevented by the administration of Cucurbita pepo seed oil.

Reinforcement of an endangered goose population: the effect of age and interspecific fostering on survival of released birds

The release of captive‐bred or translocated individuals is a strategy used worldwide to support threatened animal populations. By capture–recapture analysis, we examined the survival of released individuals when reinforcing a critically endangered Lesser White‐fronted Goose population. Our analysis includes data from 646 birds, released 1984–2017, including two different age classes, divided in two distinct periods when different techniques were used. Fledglings were released with foster parents of Barnacle Geese in the first period and by a soft release without support of foster parenting in the second period. Yearlings were released by soft release in both periods. We find that use of foster parents enhances survival rates, but these differences were detectable only in the first year of life. Fledglings supported by foster parents showed significantly higher survival compared to yearlings released by soft release, but this difference was not clear when soft release was applied to both groups. Resighting data suggest that most losses occurred during the acclimation period following the release. Foster parenting may enhance survival rates due to social learning enabling the transfer of crucial behaviors (e.g. feeding, anti‐predator, and migration) to released individuals. However, these conservation benefits need to be balanced against costs and potential inherent risks related to foster parenting, including the imprinting of undesired behaviors in released individuals, such as hybridization. Based on our results, we advise conservationists to carefully consider foster parenting as one method to improve survival probability, especially if capacity to produce individuals to be released is a limiting factor.

Effects of temperature on fish aggression and the combined impact of temperature and turbidity on thermal tolerance

Deforestation can increase light penetration and runoff entering adjacent freshwaters leading to increased average water temperature, stronger diel temperature fluctuations, and increased water turbidity. Changes in temperature extremes (particularly upper peaks) are important for fishes as their body temperature and rate of oxygen consumption varies with environmental temperature. Here, we compare effects of diel-fluctuating versus stable water temperature regimes on the behaviour and upper thermal tolerance (measured as Critical Thermal Maximum, CTmax) of the Bluntnose Minnow, Pimephales notatus. Fish were acclimated to either a static 18°C, static 24°C or a diel-fluctuating treatment of low to high (18-24°C) for a total of 10 weeks. Activity level and aggression were measured for 6 consecutive weeks during the acclimation period. Activity level remained high across treatments and over time. However, fish from the diel-fluctuating treatment exhibited a significant increase in aggression over the day as temperatures increased from 18°C to 24°C. Following acclimation, upper thermal limits of fish from each treatment were measured under two conditions: clear water (<2 NTU) and turbid water (25 NTU). This was to evaluate effects of acute turbidity exposure that might arise with heavy rain on deforested streams. CTmax was lowest in fish acclimated to static 18°C and highest in fish acclimated to static 24°C; fish acclimated to diel 18-24°C showed an intermediate CTmax. Exposure to acute turbidity during CTmax trials significantly lowered CTmax across all treatments, highlighting the importance of multiple-stressor studies in evaluating upper thermal tolerance of fishes.

Alterations of meat quality, lipid composition and flavor in breast meat of laying hens with fatty liver hemorrhagic syndrome

Fatty liver hemorrhagic syndrome (FLHS) has a high incidence rate in laying hens, and lots of FLHS-affected meat products enter the market every year. At the same time, the meat of laying hens is an important component of the human diet. However, the impact of FLHS on meat of laying hens is unknown, which could have a negative impact on consumers. To explore the effects of FLHS on chicken breast meat, a total of 36 twenty-five-wk-old Jingfen laying hens were used in the experiment. The hens were randomly divided into Control group and Model group, with 6 replicates per group and 3 hens per replicate. All chickens were raised in double-story step cages with individual pens. After a 3-wk acclimation period, the formal experiment began at 28 wk of age and lasted for 8 wk. Blood, liver, and breast meat samples were collected for the study of FLHS effects on breast meat. The impact of FLHS on meat quality was assessed by measuring indicators such as water-holding capacity and tenderness of the breast meat. Absolute quantitative lipidomics was employed to reveal the impact of FLHS on the lipid composition of chicken breast meat, and then validated by using RT-qPCR. Moreover, the volatilomics was utilized to detect changes in volatile organic compounds (VOCs) in chicken breast meat and to elucidate the resulting flavor changes. This research results showed that the meat quality of chicken breast meat decreased under FLHS, mainly manifested as reduced water holding capacity and decreased tenderness. The lipid content in the breast meat of FLHS-affected hens was significantly increased (P < 0.05). Among the affected lipids, 38 triglycerides exhibited notable elevation, possibly linked to heightened gene expression, such as lysophosphatidylcholine acyltransferase 3. The breast meat of laying hens with FLHS demonstrated an increased presence of VOCs, with 20 differential VOCs identified. Notably, 14 VOCs, particularly in 2-Undecenal, trans-Geranylacetone and ethyl nonanoate, exhibited substantial increases. These 3 VOCs had been identified as playing an important role in the formation of flavor in the breast meat of FLHS-affected laying hens. Correlation analysis suggested that the increase in these 3 VOCs might be related to the increase in lipid molecules such as phosphatidylethanolamine (38;3e) and acyl carnitine (10:3). In summary, FLHS reduced the breast meat quality of laying hens, altered its lipid profiles, and enhanced its flavor. These findings underscore the profound impact of FLHS on lipid and VOC profiles in chicken breast meat, offering valuable insights for chicken meat quality affected by FLHS.

PSLBI-27 Rumen microbiome dynamics in feedlot steers receiving free-choice garlic-infused mineral supplements

Abstract Garlic (Allium sativum) in its dehydrated or distillate (garlic oil) form has been used as a feed additive owing to its insecticidal, antimicrobial, and organoleptic properties. Commercial mineral mixtures have been formulated to contain a low proportion of dehydrated garlic powder as a strategy to deter pest flies and increase mineral intake in cattle. As an antimicrobial, garlic powder has the potential to alter the rumen microbiome, with possible implications for feed digestibility and the growth performance of beef cattle. This study evaluated the effect of short-term feeding of a garlic-mineral mixture in feedlot steers receiving high-grain diets. Four groups of twenty steers [total = 80, ~14 mo old, body weight (BW) = 599 ± 32 kg] were randomly assigned to either a 5% garlic-mineral (5DGP) or plain mineral supplement (MS). The individual feed and mineral intakes of the steers were measured with an automatic feeding system. Feed and mineral supplements were tracked in different bunks for each group. Baseline rumen fluid samples were collected from all steers at the end of an acclimatization period before administering the trial supplements. Rumen samples were later collected from 10 steers in each group with the greatest mineral supplement intake over the trial period. Total DNA and RNA were extracted from all rumen samples and subjected to metagenomic and metatranscriptomic sequencing, respectively. None of the bacterial species with an overall relative abundance of greater than 0.1% were differentially abundant between the two supplement treatments, nor did the rumen microbial community structures differ between the two groups (PERMANOVA: R2 = 0.02, P = 0.43). Regardless of the dietary supplement, the rumen microbiome of the steers was dominated by uncultured Prevotella spp. (in addition to Prevotella lacticifex) as well as the uncharacterized UBA2810 sp900317945 and UBA2810 sp002351705. Overall, these results show that a 5DGP can be effectively administered to cattle without significantly disrupting the rumen microbiome.

PSII-12 The effect of the diffusion of geranium and clary sage essential oils on relaxation responses in horses

Abstract Aromatherapy has been used in holistic medicine to improve relaxation in humans; however, there are limited studies on its use in horses. This study investigated the potential of aromatherapy on relaxation responses in horses using two common essential oils geranium (Pelargonium asperum) and clary sage (Salvia sclarea). We hypothesized that aromatherapy using essential oils would improve relaxation responses in horses. Geranium aromatherapy (GA) and clary-sage aromatherapy (CA) were tested against a control (CO; deionized water only) in a replicated 3 x 3 Latin square with three treatments, three horses (584 ± 9 kg of body weight and 11 ± 1 yr old), and three experimental periods. The experiment was replicated using the same horses, and the two experimental replicates were considered the square blocking factor. Aromatherapy session involved a 5-min acclimation period followed by 15 min of aromatherapy using a diffusor. Heart rate and respiration rate at min 0, 7 and 15, and average counts for body position and facial expressions from min 0 to 7 and from 7 to 15 (early and late session, respectively) were used as measure of relaxation. Aromatherapy improved eye expression over time (P = 0.01), with GA and CA horses showing significantly increased durations of relaxed eyes from early to late session (2.8 min vs. 5.3 min for GA and 3.7 min vs. 4.8 min for CA), while horses on CO showed reduced duration from early to late session (2.7 min vs. 1.2 min), indicating increased level of alertness and tension. Aromatherapy tended (P = 0.07) to improve ear expression. Horses receiving CA tended to show longer durations of relaxed ears compared with CO (4.33 min vs. 1.25 min), while GA (3.25 min) did not differ from CA and CO. Aromatherapy did not affect (P &amp;gt; 0.05) measures of body posture and heart and respiratory rates. Although not all relaxation responses were improved by aromatherapy, the results indicate that aromatherapy has potential for improving relaxation in horses as indicated by facial expressions.

374 Efficacy of phytase and/or chromium tripicolinate supplementation on nutrient digestibility and blood metabolites in grower pigs

Abstract Phytase supplementation is widely used in diet formulations to enhance nutrient use efficiency in pigs, while supplemental chromium tripicolinate has been shown to help optimize glucose metabolism by enhancing insulin sensitivity. Therefore, the objectives of this metabolism study were to examine potential synergies of these additives to evaluate if nutrient digestibility and/or blood metabolites could be improved in grower pigs. Grower pigs [n = 6; body weight (BW) = 21.8 ± 0.19 kg; Genesus genetics] were randomly allotted by initial BW to four treatments in a 2 x 2 factorial arrangement of treatments. Treatment (Trt) 1 consisted of a control diet without phytase while Trt 2 had decreased levels of calcium and phosphorus with added phytase (1,500 FYT/kg; HiPhorius; dsm-firmenich, Plainsboro, NJ). Treatment 3 was the control diet without phytase with added chromium from chromium tripicolinate (200 ppb; Chromax, Kent Nutrition Group, Inc., Muscatine, IA) while Trt 4 consisted of the diets with decreased levels of calcium and phosphorus with added HiPhorius (1,500 FYT/kg) and chromium tripicolinate (200 ppb). With six metabolism crates available and four treatment groups, it took a 4-wk duration to allow for each pig to be evaluated on each of the four treatments. The pigs were allowed a 4-d acclimation period followed by a 3-d collection period with the experimental diets fed at 4% BW divided into two meals each day. Water was added at 2.5 times the amount of feed fed each day. A second group of grower pigs (n = 6; BW = 19.6 ± 0.12 kg; Genesus) were utilized following the same procedures as above and pooled with the first group for data analysis. On the last day of the collection period, blood samples were collected before the meal (fasting) and then 2 h after the meal (post-meal). Added phytase resulted in a reduction (P &amp;lt; 0.05) in fasting blood urea nitrogen. Nitrogen digestibility and nitrogen retention were both improved (P &amp;lt; 0.01) with pigs fed supplemental phytase. Furthermore, dry matter digestibility was also improved (P &amp;lt; 0.001) in pigs fed added phytase. Supplemental chromium was without effect on any of the nitrogen and/or dry matter digestibility measurements. These data suggest that supplemental phytase has positive effects by significantly improving nitrogen and dry matter digestibility with no further improvements observed from supplemental chromium.

188 Prediction of individual grazing beef cattle dry matter intake

Abstract Estimation of individual dry matter intake (DMI) of pastured beef cattle is critical to grassland management, genetic improvement of efficiency, and increasing the sustainability of animal agriculture. Currently, the only way to measure individual DMI of grazing cattle is through expensive, labor intensive, and spatially demanding research protocol. Very few options for assessment of individual DMI of grazing animals exist for cattle producers. We have developed a machine learning approach to predicting individual DMI of pastured beef cattle that requires only body weight (BW), water intake, and open-source climate variables. Training data were collected in Wardensville, WV at the West Virginia University Research, Outreach, and Education Center. Crossbred steers (n = 32) were phenotyped for Residual Feed Intake (RFI) in the barn. Animals were split into four groups of two low RFI and two high RFI. After a grazing acclimation period, animal groups were rotationally grazed concurrently through 0.05 ha plots for 7 d. Daily BW and water intake data were collected throughout the experiment using an RFID-equipped front-end scale and metered waterers. Beginning on d 2, animals were provided a bolus of Cr2O3 (10 g) at 0700 and 1900 h. Beginning on d 5, fecal samples were collected from each animal at 0700 and 1900 h. Samples were analyzed for Cr2O3 content and used in conjunction with forage digestibility from paired clipped samples to generate individual intakes. These data were used as ground truth data to assess model performance. We used our Repeated Measures Random Forest (RMRF) model to predict individual DMI of animals using daily BW, water intake, and climate variables. Intakes estimated by RMRF were compared with intakes estimated by NASEM equations. Our model outperformed NASEM predictions by 70%, indicating that our method achieves better results than the current most efficient approach. Though iterative model improvements will be made (collection of more training data, collection of more diverse training data, and use of first-differenced, moving average, and seasonally adjusted variables), our work demonstrates a novel, efficient method for researchers and producers to more accurately estimate DMI of individual pastured beef cattle.

Oxidative Stress Bio-markers in Labeo rohita Fingerlings Exposed to Silica Oxide Nanoparticles

Background: The present study was conducted to study the Oxidative stress bio-markers in Labeo rohita fingerlings exposed to Silica oxide nanoparticles. Methods: A total number of 180 fishes were randomly divided into 4 groups with 15 fishes each viz. E0 (control), E1 (SiO2NPs @ 2 mg/L), E2 (SiO2NPs @ 4 mg/L) and E3 (SiO2NPs @ 6 mg/L) and each group was set in triplicates. After acclimatization period of 14 days fishes were exposed to SiO2NPs in groups E0, E1, E2 and E3 and oxidative stress was estimated every 15 days up to experimental period of 90 days. Result: Findings showed a significant decline in Catalase activity and Superoxide dismutase and an increase in Lipid peroxidation at the end of the experimental period in the fingerlings exposed to Silica oxide nanoparticles.

Environmental conditions elicit a slow but enduring response of histone post-translational modifications in Mozambique tilapia.

This study sheds new light on the timescale through which histone post-translational modifications (PTMs) respond to environmental stimuli, demonstrating that the histone PTM response does not necessarily precede the proteomic response or acclimation. After a variety of salinity treatments were administered to Mozambique tilapia (Oreochromis mossambicus) throughout their lifetimes, we quantified 343 histone PTMs in the gills of each fish. We show here that histone PTMs differ dramatically between fish exposed to distinct environmental conditions for 18 months, and that the majority of these histone PTM alterations persist for at least 4 weeks, irrespective of further salinity changes. However, histone PTMs respond minimally to 4-week-long periods of salinity acclimation during adulthood. The results of this study altogether signify that patterns of histone PTMs in individuals reflect their prolonged exposure to environmental conditions.