Vaginal Temperature Research Articles

Relationship between higher estrus-associated temperatures and the bovine preovulatory follicular fluid metabolome

IntroductionA higher estrus-associated temperature (HEAT) is a hallmark feature in sexually active females; however, its functional importance is unclear. Our objective was to examine the relationship between HEAT and the preovulatory follicular fluid metabolome. It was hypothesized that HEAT is functionally important as it affects fertility-related components in the preovulatory follicle.MethodsEstrus was synchronized in non-lactating Jersey cows. A Thermochron iButton temperature data logger was affixed to blank controlled internal drug release (CIDR) devices and intravaginally inserted after CIDR device removal. The follicular fluid was aspirated 14.9 h + 3.3 h after an animal first stood to be mounted. Regression models were performed using metabolite abundance and HEAT variables. Best-fit models were determined using backward manual selection (p < 0.05).ResultsA total of 86 metabolites were identified in cow follicular fluid samples. The vaginal temperature at first mount and when it was expressed as a change from baseline was positively related to the abundance of four metabolites (i.e., taurine, sn-glycerol 3-phosphate, glycine, and cysteine) and negatively related to one metabolite (i.e., serine). The vaginal temperature at the first standing mount was related to the differential abundance of two metabolites (i.e., jasmonate and N-carbamoyl-L-aspartate). Three metabolites were related to the maximum vaginal temperature (i.e., N-carbamoyl-L-aspartate, uracil, and glycodeoxycholate). When expressed as a change from baseline, the maximum vaginal temperature was related to the differential abundances of uracil, uric acid, and 6-phospho-D-gluconate. The time taken to reach maximum vaginal temperature was related to N-carbamoyl-L-aspartate, glycodeoxycholate, jasmonate, and tricarballylic acid. Pertaining to the combination of HEAT and its duration, the area under the curve associated with the time between the first increase in vaginal temperature and the maximum vaginal temperature was related to 6-phospho-D-gluconate, sulfolactate, guanidoacetic acid, and aspartate. The area under the curve associated with the time between the initial vaginal temperature increase and up to 10 h after a cow first stood to be mounted or when a cow’s temperature returned to baseline was related to the differential abundances of uracil, sn-glycerol 3-phosphate, methionine sulfoxide, and taurodeoxycholate.DiscussionOur findings support the notion that HEAT is related to changes in the preovulatory follicular fluid metabolites involved in energy metabolism, thermoregulation, and oxidative stress management.

PSVI-12 Comparison of a Visual Health Scoring System with Vaginal Temperatures of Newly Received Feedlot Heifers

Abstract Newly received feedlot cattle frequently succumb to bovine respiratory disease (BRD), which can be visually diagnosed and medically treated by employing a 4-point scoring system based on depression, appetite, respiration, and temperature (DART). Using this system, cattle are treated with antimicrobial medications for BRD if they have a rectal temperature (RT) ≥ 40°C and a DART score of 2 (scale = 1 to 4), or if they have a DART score of 3 or 4 regardless of the 40°C RT threshold. However, cattle often exhibit several visible clinical symptoms of BRD but do not have an RT above the 40°C threshold to warrant medical treatment. The objective of this study was to evaluate if DART scoring could be used to identify cattle with elevated vaginal temperatures (VT) throughout a 28-day receiving period. Upon feedlot arrival, 198 crossbred heifers (primarily Angus influence; initial BW = 219 ± 63 kg) were initially processed, weighed, and allocated to one of 10 soil-surfaced pens (12 x 35 m; 20 heifers per pen). A blank Controlled Intravaginal Drug Release (CIDR) device attached with an indwelling temperature probe (iButton DS1925L) was inserted vaginally into each heifer to collect and store VT every 10 minutes for 28 days. All heifers were evaluated daily (0700 h) for signs of morbidity by three individuals (blinded from each other) implementing the DART scoring system. Individual DART evaluations were then pooled prior to determination of heifers needing further evaluation for medical treatment. Results confirmed that DART score increases as VT increases (P < 0.001). Similarly, mean time DART ≥ 2 (TDART≥2) increased as mean time VT ≥ 40°C (TVT≥40) increased (P < 0.001). Accuracy of DART ≥ 2 to VT ≥ 40°C analogous by day is denoted as (MATCH). Simple regression analysis of MATCH and TVT≥40 for determining accuracy of visually diagnosing clinical BRD, was MATCH = 0.89 – 0.71 × TVT≥40 (r2 = 0.70; P < 0.001). The accuracy to visually diagnose BRD decreases as the number of days spent with a VT ≥ 40°C increases. Average daily gain decreased (P < 0.001) as TDART≥2 and TVT≥40 increased. The BRD symptoms indicating high VT and DART score (P ≤ 0.01) were nasal discharge, anorexia, abnormal respiration, and teeth grinding. Additionally, weakness, cough, lowered head, and ocular discharge indicate greater DART score (P ≤ 0.01). Basophils and hemoglobin decreased with elevated VT and DART score (P ≤ 0.02). Monocytes increased with increased DART score (P ≤ 0.04). In conclusion, data from this evaluation employing VT sensors and the DART scoring method provided an overview of how effective clinical BRD can be visually diagnosed, therefore contributing to the improvement and development of more effective strategies for identifying respiratory diseases in feedlot cattle.

112 Definition and Genetic Parameters Estimation for Climatic Resilience Indicators Derived from Longitudinal Vaginal Temperature Records in Lactating Sows Under Heat Stress Conditions

Abstract Climatic resilience (CR) can be defined as the ability of an animal to maintain euthermia under thermally stressful conditions. However, CR based on longitudinal physiological variables has not been included in current swine genetic selection schemes. This is the first study deriving novel CR indicators using automatically recorded vaginal temperatures (TV) and estimating genetic parameters for them. Therefore, the study objectives were to: 1) derive novel indicators of CR based on automatically recorded vaginal temperature (TV); and 2) estimate (co)variance components and genetic parameters for these indicators. TV of 1,381 lactating sows (parities 2 to 7; Landrace × Large White) were measured automatically every 10 minutes from June 5th, 2021 to July 30th, 2021 using a vaginally implanted thermochron data recorder. A total of 1,639 F1 (Landrace x Large White) sows within the studied population were genotyped using the PorcineSNP50K Bead Chip. A total of 18 HS indicators derived from Tv, their definitions, heritability estimates, and mean genomic estimated breeding value (GEBV) accuracies are shown in Table 1. Multi-trait animal models were fitted for estimating the (co)variance components, considering the effects of week of data collection, parity, and location (barn and room within barn) as fixed. Heritability estimates for these resilience traits ranged from 0.0004 ± 7.16E-6 (SlopeDe) to 0.291 ± 0.047 (HSAB). Most traits derived directly from vaginal temperature (e.g., Duration: 0.201 ± 0.033, MaxTv: 0.203 ± 0.032) are moderately heritable with substantial additive genetic variance. Besides, LnVar(Med) that is derived from the deviation between the real and predicted value had moderate heritability (0.196 ± 0.041) and high mean GEBV accuracy (0.616 ± 0.042). The indicators defined based on the slope of Tv and time had low heritability estimates, which are close to zero, and low mean GEBV accuracy (0.106 ± 0.050 – 0.337 ± 0.065). Among all the CR indicators, Duration, MaxTv, Nor_medvar, Nor_avevar, HSAA, and HSAB outperformed the other indicators with moderate heritability estimates and high average GEBV accuracies. Genetic correlations were estimated among the six indicators with moderate heritability and high mean GEBV accuracy. Moderate to high positive genetic correlations (0.508 ± 0.034 to 0.992 ± 0.025) were estimated among Duration, MaxTv, Nor_medvar, HSAB, and HSAA. LnVar(Med) showed low negative genetic correlations (-0.218 ± 0.028 to -0.039 ± 0.018) with the traits Duration, MaxTv, HSAA, and HSAB, except with Nor_medvar, which was positive (0.156 ± 0.022). Thus, Duration, LnVar(Med), MaxTv, Nor_medvar, HSAB, and HSAA might be promising CR indicator and contribute toward improving lactating sows’ resilience to thermal stress through genetic selection. New studies about the relationship between these new indicators and other economic important traits in pigs are required before including them in selection indexes.

311 Evaluation of Post-Transit Growth Performance and Carcass Characteristics of Feedlot Heifers Sourced and Finished in Different Regions of the U.S

Abstract The objective was to evaluate growth performance and carcass traits following transit of feedlot heifers sourced and finished in different geographical regions in the U.S. Yearling heifers [n = 190; initial body weight (BW) 483 and 425 kg for SD and TX sourced, respectively] were used in a 2×2 factorial arrangement of origin state (SD vs TX) and finishing state (SD vs TX). Heifers were allotted on d -1 into four treatments: sourced from SD and finished in SD (SD-SD), sourced from SD and finished in TX (SD-TX), sourced from TX and finished in SD (TX-SD), and sourced from TX and finished in TX (TX-TX). Heifers were weighed on d -1, 3, 15, 28, 56, 78 (TX-TX and SD-TX) and 90 (SD-SD and TX-SD). On d 0, SD-TX and TX-SD heifers were shipped to the finishing location and weighed the following morning (d 1) to determine transportation shrink. To monitor transportation effects, vaginal temperature probes were inserted into all SD-TX and TX-SD heifers and a portion of SD-SD and TX-TX heifers on d -1 and removed on d 3. Clinical attitude scores (CAS) were recorded on d -1, 0, 1, 2 and 3 for indications of bovine respiratory disease symptoms. The GLIMMIX procedure of SAS was used to analyze growth performance and carcass measures with fixed effects of origin and finishing state. The MIXED procedure was used for CAS and temperature data with the same fixed effects and time as a repeated measure. Transported heifers had reduced temperatures (P < 0.05) during transit and post-transit compared with non-transported heifers. Temperatures of transported heifers increased (P < 0.05) during loading and unloading. On d 0, 1 and 3 there was a shift in the distribution of heifers that had a CAS score greater than 0 for TX-TX, SD-TX and TX-SD. Cattle endured high ambient temperatures (temperature humidity index value > 75) 54% and 18% of the feeding period for TX and SD finished heifers, respectively. All cumulative growth performance measures and carcass trait interactions were statistically significant (P < 0.05) besides initial BW, percent shrink of transported heifers, average daily gain, dressing percent, ribeye area and liver abscess severity, which were similar (P > 0.30). There was a shift in the distribution (P < 0.05) towards a greater proportion of Yield Grade 1 and Select carcasses for heifers fed in TX compared with those fed in SD, likely due to fewer days on feed. Overall, heifers transported to higher ambient temperatures had reduced dry matter intake, quality grades (QG) and limited growth recovery (45 kg lighter) compared with non-transported heifers. Heifers transported to lower ambient temperatures recovered growth and had improved QG at the same level of rib fat compared with non-transported heifers.

PSXIV-17 Examining Mammary Gland Transcriptomic Profiles Using Rna-Seq in Slick and Wild-Type Haired Holstein Cattle Under Tropical Conditions

Abstract In lactating dairy cows, heat stress reduces feed intake, alters the metabolism of the animal, and compromises milk production. Holstein cattle carrying the prolactin receptor gene mutation (SLICK) have been shown to have superior performance under tropical conditions by exhibiting increased milk yield compared with wild-type haired Holstein cattle (WT). Recent research indicated that SLICK cattle have greater mammary gland blood flow and lower vaginal temperatures, while maintaining prolonged voluntary exposure to direct solar radiation than their WT counterparts. Nevertheless, differences in molecular mechanisms between genotypes at the mammary gland level have been unexplored. The objective of the current study was to investigate possible differences in the mammary gland transcriptome from SLICK (n = 7) and WT (n = 6) Puerto Rican Holstein cattle. At 160 ± 3 days in milk (DIM), ultrasound guided mammary biopsies were collected from the left rear quarter of each animal and samples were snap frozen. Unstranded RNA-seq libraries were created from the frozen mammary tissue and sequenced using Illumina Novaseq 2x150bp. Quantification of expression was done by salmon [v1.9.0] using the Bos taurus (ARS UCD1.3) transcriptome database. Testing for significant differential expression (DE) was done using a pipeline consisting of the R packages tximport [v1.26.1] and edgeR [v3.40.2]. The fry method from edgeR was used to do gene set enrichment analysis (GSEA) for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms. A single gene (GeneID:513329, major allergen Equ c 1 isoform X2) showed significant (B.H. adjusted P-value ≤ 0.05) differential expression. Aligning the protein sequence for this gene using the BLASTp against the non-redundant (NR) database revealed high similarity to two pheromones, salivary lipocalin 2 and salivary lipocalin-like. Both the KEGG pathway and GO term GSEA showed no statistically significant enrichment at B.H. adjusted P-value ≤ 0.05; however, using a less stringent criteria with a normal P-value ≤ 0.05, multiple relevant pathways were identified. For example, the KEGG pathway analysis revealed that the arachidonic acid metabolism pathway (bta00590) was enriched, and the tight junction function pathway (bta4530) was depleted in the SLICK Holstein samples. Among the GO analysis, genes were found to be downregulated in response to cold (GO:0009409), hair follicle development (GO:0001942), and vasoconstriction (GO:0042310), whereas positive regulation of oxytocin production (GO:0140668), and defense response to Gram-positive bacterium (GO:0050830) were upregulated. In conclusion, differences in gene expression were limited, but after enrichment interesting pathways were revealed and deserve further exploration to aid in elucidating different molecular mechanisms between SLICK and WT cattle.

PSXII-3 Including Non-Additive Genetic Effects in Genomic Prediction and Estimation of Variance Components for Performance and Heat Stress Traits in Pigs

Abstract Non-additive genetic effects may have important roles in the phenotypic expression of performance and adaptation traits in livestock. Therefore, we aimed to evaluate the inclusion of non-additive genetic effects in genomic prediction models and variance component estimation of performance traits in a purebred pig population and heat tolerance indicators in a crossbred pig population. The first dataset consisted of 3,534 individuals with genotypes for 52,843 SNPs and five pre-adjusted phenotypes from a public database of a purebred pig line. Twelve models fitting or not dominance and/or epistasis effects (additive-by-additive, additive-by-dominance, and dominance-by-dominance) and inbreeding were used to estimate variance components. Prediction ability was assessed based on 10-fold cross-validation and the bias, dispersion, and accuracy estimates were computed based on the LR method. We also evaluated the impact of including non-additive genetic effects on the ranking of the animals’ breeding value and in the proportion of commonly selected individuals. The second dataset consisted of records from 1,645 lactating sows (Large White x Landrace cross) genotyped for 50,703 SNPs and traits related to heat stress response: skin temperature (ear, shoulder, rump, and tail), vaginal temperature measured every 10 minutes, and the average of the six records per hour corresponding to 08:00, 12:00, 16:00, and 20:00 hours during four days; respiration rate, panting score (PS; score scale from 0 to 3), and hair density (HD, score scale from 0 to 2). Four models including or not, inbreeding and the effect of dominance and additive-by-additive epistasis were used to estimate variance components. There was no effect on residual variance estimates due to the inclusion of non-additive genetic effects in the models for most traits. However, non-additive genetic effects reduced additive variance estimates, especially when additive-by-additive epistasis was fitted. Including non-additive genetic effects in the model did not improve the prediction accuracy of breeding values for purebreds, but there was a substantial change in the ranking of the animals and in the proportion of commonly selected individuals. For the crossbred traits, small non-additive genetic variance with large standard error estimates were obtained. Nevertheless, PS and HD presented notable additive-by-additive epistatic variance. PS presented h2aa estimates of 0.15 and additive-by-additive epistasis corresponding to 86.76% of the total genetic variance, while HD presented additive-by-additive epistatic heritability (h2aa) estimates from 0.46 to 0.49 and the proportion of total genetic variance explained by additive-by-additive epistasis ranged from 66.91% to 71.87%. In conclusion, including non-additive genetic effects did not improve the accuracy of prediction of breeding values for purebreds, but it changed the ranking of animals and selection decisions. Although PS and HD had large additive-by-additive epistasis effects, most of the traits related to heat stress in the crossbred population did not present relevant non-additive genetic effects.

139 Genomic-Based Genetic Parameters of Behavioral Ethogram Traits in Lactating Sows Under Heat Stress Conditions and Their Relationship with Direct Indicators of Heat Tolerance

Abstract Increased global temperatures pose challenges to livestock agriculture. Domestic swine are particularly sensitive to hotter environments due to their inability to sweat, litter bearing nature, difficulty in expressing natural cooling behaviors, and intense genetic selection for production traits. Since animal welfare is central to livestock production as a matter vital to efficiency as much as ethics, developing novel traits that may be genetically related to heat tolerance may assist in improving and sustaining animal welfare. The objective of this study was to develop novel traits of behavior using an ethogram designed for efficiency in production settings, estimate the variance components, and correlate these traits with indicators of heat tolerance and maternal ability. This study considered 1,312 individual Landrace-Large White cross production sows between 6 and 19 days of lactation. Animals were housed in farrowing crates in a commercial setting in southern North Carolina in June and July of 2021, an environment susceptible to potential heat stress. These sows were subjected to a standardized procedure involving a person removing hair from both hips using an electric clipper while an observer was positioned in front of the sow to record behaviors. Scores were later applied to the variations in behavior both for changes in positions and types of vocalizations displayed by the animals during handling. Genotypes were obtained from hair follicles and captured by a 50K porcine SNP panel. Variance components for novel behavior traits were obtained using the BLUPF90+ programs and genomic relationship matrix to estimate genetic correlations of behavior with several indicators of heat tolerance and maternal ability. Heritabilities for behavior traits ranged from 0.131 for vocalization score to 0.072 for shaving time, while heritabilities for heat tolerance and maternal ability ranged from 0.15 to 0.03 for vaginal temperature and respiration efficiency, respectively. The maternal ability traits were based on the single current litter and had the lowest heritabilities ranging from 0.101 to 0.04 for number born alive and number of mummies, respectively. High and positive genetic correlations indicate a potential for coupled selection for both fewer mummified piglets and a greater number of liveborn using the behavior trait of vocalization score. These correlations between favorable maternal traits and behavior traits suggest the potential that one or more complex biological pathways exist that share relevancy between these traits. However, genetic correlations between the behavior traits and heat tolerance indicators were low to negligible, most with a magnitude falling below 0.10, revealing the need for other traits to be used as selection parameters for heat tolerance. Further studies may be able to capture additional environmental effects to improve models of behavior and create indirect measures more obtainable than direct measures of heat tolerance.

62 The Impact of Hair Coat Color on Body Temperature in Beef Cattle

Abstract Ambient temperature has a fundamental role in animal health and performance. Selecting for coat color may improve animal productivity and welfare through management and breeding decisions. The thermoneutral zone of cattle, 0°C - 25°C, is characterized as the range in ambient temperature that does not require cattle to expend energy to maintain core body temperature. When the ambient temperature is above or below these values, cattle must expend energy to keep their body temperature in homeostasis resulting in a reduction in efficiency. A proper herd management plan to mitigate heat stress can increase efficiency and decrease mortality in serious cases. Registered Hereford and commercial black cows (n = 39; average 4 yr of age) were placed in a 23-ha pasture, to determine if coat color affects internal body temperature. Cattle were on a typical fescue dominated pasture located in Mountain Grove, MO, with areas of shade and one pond centralized in the pasture. Cattle were divided into treatments based on hair coat color: black (n =13) or red (n = 26). Using temperature data loggers, vaginal temperatures were recorded in 5-min intervals during a 14-d period in Mid-July 2022, and combined into 6-hour timing intervals, A = 0400-1000 h, B = 1001-1600 h, C = 1601-2200 h, and D = 2201-0359 h. Environmental temperature data loggers were suspended in two locations of partial sun to record ambient temperature. In addition, the Mountain Grove weather station operated by the University of Missouri Extension provided a daily data archive that recorded wind speed, total precipitation, maximum and minimum air temperature. Throughout the study, the mean environmental temperature was 34.4°C and ranged from 19.5°C to 40.2°C. Temperature data were evaluated using the Glimmix procedure of SAS and pairwise comparisons between timepoints were determined utilizing the GLM procedure of SAS. Differences were considered significant at P = 0.05. Black-haired cattle were warmer at all intervals (P ≤ 0.04) with temperature differences between the treatments of 0.07, 0.10, 0.03, and 0.09°C for timepoints A, B, C and D, respectively (Table 1). Based on our results black-hided cattle get warmer earlier in the day and take longer to dissipate heat than those with red hair coats.

Effect of shading on the physiological and reproductive parameters in Nelore cows.

This study aimed to evaluate the physiological and reproductive parameters of Nelore cows under various microclimatic conditions. The experiment was performed in Central Brazil, which has a tropical climate with dry winters and rainy summers. The experimental groups were divided into an area with shading (5.8 trees/ha; n = 42) and an area with little shading (0.4 trees/ha; n = 42). The physiological (heart rate, respiratory rate, rectal temperature, surface body temperature, and vaginal temperature) and reproductive (estrus detection, conception rate, and rate of pregnancy loss) parameters were then assessed. The rectal temperature (p = 0.002); surface body temperature on the flanks, forehead, and shoulder (p < 0.001); and vaginal temperature (p < 0.001) of cows in the group with shading were significantly lower than those of cows in the group without shading. Estrus was higher (p = 0.08) in the shaded group; however, no effect was observed on conception and pregnancy loss rates. In conclusion, shading (5.8 trees/ha) provided better thermal comfort for Nelore animals in the tropical climatic region. However, this did not affect their performance after fixed-time artificial insemination.

Vaginal temperature and collar activity variations in relation to fecal progestagens of captive moose

BackgroundTiming of reproductive events can be crucial for a species’ population growth and stability. Accurate detection of reproductive phenology presents a challenge to scientists studying wild species, including moose (Alces alces). Currently, there are several established methods for monitoring reproductive activity and events in domestic ruminants, including the use of biologging devices. The main objective of this study was to determine whether female moose display a distinct thermal and activity pattern associated with luteal activity during the estrous cycle, which could be used to determine the onset of their breeding season. We deployed biologging devices and collected fecal samples from 12 captive female moose on the Kenai Peninsula, Alaska, USA to explore variation in vaginal temperature and collar activity and the relationship between these variables and fecal progestagen concentrations. Fecal samples were collected from mid-August to mid-October and analyzed using radioimmunoassay to determine the concentration of fecal progestagens to classify luteal activity.ResultsCaptive female moose displayed an identifiable thermal pattern during the onset of luteal activity from mid-September to mid-October, associated with the initial estrous cycle of their breeding season. In contrast, we did not observe a distinct pattern in activity during this period. Recurring patterns in both vaginal temperature and activity were identified between mid-October and mid-November, however, which were likely associated with subsequent estrous cycles but not included in our fecal sampling period.ConclusionsThis study supports that female moose display an identifiable pattern in vaginal temperature which is associated with luteal activity of the initial estrous cycle of the breeding season. An identifiable pattern was observed for both vaginal temperature and activity registrations at the presumed timing of subsequent estrous cycle of the breeding season.

Voluntary solar radiation exposure and vaginal temperature in slick-haired purebred Senepol and Senepol x Red Angus crossbred heifers

Senepol is a slick-haired Bos taurus breed highly adapted to tropical countries, and their meat is usually low in intramuscular fat. Crossbreeding with breeds more suited to higher marbling scores (e.g., Angus; a wild type-haired breed) may help improve this meat quality trait. However, the question of adaptability to tropical weather in the resulting crossbreeds remains. This study compared the voluntary exposition to direct solar radiation or shade and the vaginal temperatures of slick-haired 50% Senepol - 50% Red Angus (n=5; 50:50), 75% Senepol - 25% Red Angus (n=5; 75:25), and 100% Senepol (n=5; 100:0) heifers in February 2023. Data were analyzed by the GLIMMIX procedure (SAS). The 50:50 heifers recorded lower solar radiation exposure than their 75:25 and 100:0 counterparts at 1100 (P≤0.001), 1115 (P≤0.0003), 1130 (P&lt;0.0001), 1145 (P≤0.004), and 1200 h (P≤0.004). Respective average values of 20,601.40±3,615.03; 32,627.40±4,437.84; and 32,260.40±4,424.65 lx were observed during this period. No differences in vaginal temperature were observed between heifer groups (P=0.8135), with daily averages of 37.27±0.54, 37.23±0.53, and 37.23±0.54 °C for the 50:50, 75:25, and 100:0 heifers, respectively. Heifers with 50% Red Angus blood needed to spend more time under shade during the hottest hours of the day to maintain a body temperature similar to those heifers with greater Senepol influence.

Genetic parameters for automatically-measured vaginal temperature, respiration efficiency, and other thermotolerance indicators measured on lactating sows under heat stress conditions

BackgroundGenetic selection based on direct indicators of heat stress could capture additional mechanisms that are involved in heat stress response and enable more accurate selection for more heat-tolerant individuals. Therefore, the main objectives of this study were to estimate genetic parameters for various heat stress indicators in a commercial population of Landrace × Large White lactating sows measured under heat stress conditions. The main indicators evaluated were: skin surface temperatures (SST), automatically-recorded vaginal temperature (TV), respiration rate (RR), panting score (PS), body condition score (BCS), hair density (HD), body size (BS), ear size, and respiration efficiency (Reff).ResultsTraits based on TV presented moderate heritability estimates, ranging from 0.15 ± 0.02 to 0.29 ± 0.05. Low heritability estimates were found for SST traits (from 0.04 ± 0.01 to 0.06 ± 0.01), RR (0.06 ± 0.01), PS (0.05 0.01), and Reff (0.03 ± 0.01). Moderate to high heritability values were estimated for BCS (0.29 ± 0.04 for caliper measurements and 0.25 ± 0.04 for visual assessments), HD (0.25 ± 0.05), BS (0.33 ± 0.05), ear area (EA; 0.40 ± 0.09), and ear length (EL; 0.32 ± 0.07). High genetic correlations were estimated among SST traits (> 0.78) and among TV traits (> 0.75). Similarly, high genetic correlations were also estimated for RR with PS (0.87 ± 0.02), with BCS measures (0.92 ± 0.04), and with ear measures (0.95 ± 0.03). Low to moderate positive genetic correlations were estimated between SST and TV (from 0.25 ± 0.04 to 0.76 ± 0.07). Low genetic correlations were estimated between TV and BCS (from − 0.01 ± 0.08 to 0.06 ± 0.07). Respiration efficiency was estimated to be positively and moderately correlated with RR (0.36 ± 0.04), PS (0.56 ± 0.03), and BCS (0.56 ± 0.05 for caliper measurements and 0.50 ± 0.05 for the visual assessments). All other trait combinations were lowly genetically correlated.ConclusionsA comprehensive landscape of heritabilities and genetic correlations for various thermotolerance indicators in lactating sows were estimated. All traits evaluated are under genetic control and heritable, with different magnitudes, indicating that genetic progress is possible for all of them. The genetic correlation estimates provide evidence for the complex relationships between these traits and confirm the importance of a sub-index of thermotolerance traits to improve heat tolerance in pigs.

Effect of different air speeds at cow resting height in freestalls on heat stress responses and resting behavior in lactating cows in Wisconsin

Heat abatement (e.g., soakers, fans) effectively reduces the negative physiological and production effects of heat stress, but no previous studies have documented effective interventions for the reduced lying times observed in response to hot weather. Although likely adaptive for heat dissipation, the reduction in motivated lying behavior may be an animal welfare concern. We evaluated the effect of air speed from fans with variable frequency drives on the heat stress responses of cows in a naturally ventilated freestall barn. Eight groups of lactating Holsteins (16 cows/group) were exposed to 3 treatments in a replicated crossover design: control (fans off, 0.4 ± 0.2 m/s, measured 0.5 m above the stall surface to represent cow resting height) vs. 60% (1.7 ± 0.5 m/s; ≥ 1 m/s in all stalls) and 100% (2.4 ± 0.8 m/s) fan power. Each treatment was applied for 3 d of acclimation and 4 d of data collection. The effects of treatment on daily maximum vaginal temperature (VT) and lying time (LT; both measured with data loggers), respiration rate (RR; recorded from video), unshaved scapular skin temperature (ST), milk yield (MY), and dry matter intake (DMI) were analyzed using linear mixed models. All models included the fixed effect of treatment and a repeated term for treatment day within group of cows, with group as the subject. The models for LT, VT, and RR also included a fixed effect for same-day Temperature Humidity Index (THI; recorded in the pens with data loggers) and the THI × treatment interaction. The models for DMI and MY, using data from the latter 3 d of each treatment period, also included a fixed effect for the previous day's THI and the -1 d THI × treatment interaction. Lying time differed among treatments (100% vs. 60% fan power vs. control: 14.2 vs. 13.9 vs. 13.2 h/d, respectively, SEM = 0.15 h/d), but both fan treatments prevented the reduction in LT observed in the control treatment as THI increased. Relative to the control, both fan treatments effectively reduced ST, RR, and VT and increasing DMI and MY. In the control, average values were elevated for both RR (68.7 ± 1.5 breaths/min, mean ± SEM, greater than a common benchmark of 60 breaths/min) and VT (39.3 ± 0.05°C) but remained in the normal range in both fan treatments (54.2 vs. 50.7 breaths/min in the 60% vs. 100% fan power treatments; 39.0°C in both fan treatments). Both fan treatments resulted in greater overall MY (42.6 vs. 43.0 ± 0.4 kg/d in the 60% vs. 100% fan power treatments) relative to the control (41.0 kg/d) and similarly avoided the reduction in MY when -1 d THI increased. Compared with natural ventilation alone, fans delivering air speeds of at least 1 m/s at cow resting height were effective not only for reducing thermoregulatory responses, but also for maintaining lying time, DMI, and milk yield in heat stress conditions. This is the first study to demonstrate an intervention to improve animal welfare by maintaining lying times during periods of heat stress.

Plant polyphenol extract supplementation affects performance, welfare, and the Nrf2-oxidative stress response in adipose tissue of heat-stressed dairy cows

We examined the effects of a supplement of plant polyphenols extracts of green tea, capsicum, and fenugreek, and electrolytes ([Na+, K+]; AXT, Axion ThermoPlus, CCPA, France] during summer heat load on production, welfare, and oxidative stress proteins in adipose tissue (AT) of dairy cows. A total of 42 multiparous mid-lactation cows were divided into 3 groups during summer, and were fed for 2 wk either a standard milking cow diet (CTL, n = 14) or diets supplemented with 100 g/d of AXT (100AXT, n = 14), or 150 g/d of AXT (150AXT, n = 14), while being cooled 5 times a day. Then, half of the cows from each dietary treatment were cooled (CL) or not cooled (NCL) for 2 wk, after which the cooled and uncooled groups were switched for additional 2 wk. Cows were milked 3 times a day, and milk composition was analyzed at the end of each 2-wk period. Vaginal temperature (VT) was measured for 3 consecutive days in each period. Biopsies of subcutaneous AT were taken from 10 NCL cows (5 each of CTL and 150AXT) at the end of the period and examined by liquid chromatography-tandem mass spectrometry proteomics analysis. Data were analyzed with PROC MIXED of SAS (version 9.2, SAS Institute Inc.). The model included the effects of dietary treatment, cooling regimen, period, and their interactions. Protein and mRNA abundances and proteomic data (P ≤ 0.05 and fold change [FC] ± 1.5) were analyzed by t-test. Milk yields and 4% fat-corrected milk (FCM) were higher in 100AXT than in CTL; milk components were not different. Dry matter intake (DMI) was higher in 100AXT than in CTL. The effect of cooling and the interactions of period × cooling were significant for DMI, 4% FCM, energy-corrected milk, and milk/DMI. The proportion of time that VT was >39°C was lower in 100AXT and in 150AXT than in CTL. Daily rumination time was greater in 150AXT than in CTL, and lying time was greater in 100AXT and 150AXT than in CTL. Proteomics of AT demonstrated that 150AXT had increased abundances of peroxidasin (FC = 1.6), microsomal glutathione S-transferase 2 (FC = 2.5), and heme oxygenase 1 (FC = 3.6) compared with CTL. Top enriched canonical pathways included acute phase response signaling, Nrf2-mediated oxidative stress response, and lipopolysaccharide (LPS)/IL-1-mediated inhibition of RXR function. Immunoblots of AT showed a higher abundance of the transient receptor potential vanilloid 1 and of LPS binding protein in AT of 150AXT compared with CTL. Supplementation of AXT increased DMI, milk, and 4% FCM, lowered VT, improved welfare indices, and enriched the AT with Nrf2-oxidative stress response and acute phase response proteins in heat-stressed dairy cows.

Shade of solar panels relieves heat load of sheep

Use of solar panels as shading resource combines better animal welfare, generation of renewable energy and animal production in the same area. This concept is termed Animal Agrivoltaics. In this study we integrated behavioural and physiological data in order to determine benefits provided by shade of solar panels on heat stress indicators of sheep. Nine adult Corriedale ewes (Body mass: 70 ± 12 kg; fleece length: 70 ± 5 mm) had miniature temperature loggers attached on them for every-minute samplings of wool-surface, skin and vaginal temperature, from 08:00 to 17:00 h, along 20 consecutive days. Ewes also had shade-use behaviour directly and continuously monitored. Ewes were kept in a paddock shaded with a roof structure that consists of ten photovoltaic panels (shade availability: 2.14 m2 animal−1). Over the study period, ewes were exposed to levels of solar radiation as much as 900 W m−2. From 08:00 to 17:00 h, regardless of the duration of sun exposure or in the shade of solar panels, the vaginal temperature of ewes remained within a narrow range (38.5 ºC - 39.2 ºC). At levels of solar irradiance above 500 W m−2, ewes increased wool-surface temperature by 10 ºC and skin temperature by 2 ºC with increasing heat load and time exposed to sun. Under such circumstances, they were more likely to move to shade of solar panels. Between 10:00 and 14:00 h, shade of solar panels provided to ewes 30 % less radiant heat load than if they were exposed to sun. As a result, as the time in shade increased, the wool-surface temperature of ewes was reduced by 7 ºC - 8 ºC, and skin temperature by 1.0 ºC - 1.5 ºC. In conclusion, this study provides strong evidence that shade of solar panels efficiently reduces heat load in sheep.

Vaginal temperature modeling in Holstein cows and cluster analysis by the cophenetic correlation coefficient

The objective was to establish a model for the prediction and characterization of vaginal temperature in Holstein cows, based on environmental predictors and thermal comfort indices, through cluster analysis, validation by the cophenetic correlation coefficient, and multiple regression analysis. The micrometeorological characterization of the site was carried out by recording the air temperature (Tair), the relative humidity (RH), the black globe temperature (BGT), the black globe temperature and humidity (BGHI), and dew point temperature (TDP). The recording of vaginal temperature (Tv) was performed in eight dairy cows using temperature sensors, equipped with data loggers, coupled with intravaginal devices. The data were analyzed using descriptive statistics and cluster analysis (CA) by using the hierarchical agglomerative method based on the value of the cophenetic correlation coefficient (CCC >0.70), in which representative physiological models were established, characterizing the Tv through multiple regression. In the afternoon the coefficient of variation (CV) was low for all variables, indicating homogeneity of the meteorological variables and efficiency of the ventilation system. The temperature and humidity index (THI) was mild only on the morning. There was a variation of 0.28 °C of Tv between shifts, sufficient to characterize the condition of comfort and stress of the animal, with values above 39 °C indicating animal stress. Tv showed strong correlation with BGT, Tair, TDP and RH, assuming that physiological variables, such as Tv, tend to have greater relationship with abiotic variables. Empirical models were established for estimating Tv based on the analyses performed in this study. Model 1 is recommended for TDP ranges of 14.00–21.00 °C and RH of 30–100%, while model 2 can be used for Tair situations up to 35 °C. The regression models for estimating Tv are promising for characterizing the thermal comfort of dairy cows housed in compost barn systems.

Development of Thermoresponsive Hydrogels with Mucoadhesion Properties Loaded with Metronidazole Gel-Flakes for Improved Bacterial Vaginosis Treatment.

Bacterial vaginosis is an infectious disease that has significantly affected women's health. Metronidazole has been widely used as a drug for treating bacterial vaginosis. Nevertheless, the currently available therapies have been found to be inefficient and inconvenient. Here, we developed the combination approach of gel flake and thermoresponsive hydrogel systems. The gel flakes were prepared using gellan gum and chitosan, showing that the incorporation of metronidazole was able to provide a sustained release pattern for 24 h with an entrapment efficiency of >90%. Moreover, the gel flakes were incorporated into Pluronics-based thermoresponsive hydrogel using the combination of Pluronic F127 and F68. The hydrogels were found to exhibit the desired thermoresponsive properties, showing sol-gel transition at vaginal temperature. Following the addition of sodium alginate as a mucoadhesive agent, the hydrogel was retained in the vaginal tissue for more than 8 h, with more than 5 mg of metronidazole retained in the ex vivo evaluation. Finally, using the bacterial vaginosis infection model in rats, this approach could decrease the viability of Escherichia coli and Staphylococcus aureus with reduction percentages of more than 95% after 3 days of treatment, with the healing ability similar to normal vaginal tissue. In conclusion, this study offers an effective approach for the treatment of bacterial vaginosis.

Sow Temperature Probe Design

With temperatures increasing steadily throughout the last century, the swine production industry is beginning to confront an increasingly urgent dilemma. Ambient barn temperatures are now regularly exceeding ideal conditions for optimal milk production, as well as maximum litter size. Temperatures that exceed these conditions can lead to heat stress among sows, which can ultimately lead to death. With sows usually being housed in larger group settings, keeping track of an individual sow’s temperature has never been harder. The focus of this project is efficiently tracking the internal vaginal temperature of a sow. A prototype probe was developed and consists of a 3010 Wi-Fi module, a 2200 mAh battery, and two thermocouples. It was created to track the internal temperatures of individual sows over a span of 21+ days. The probe assembly is made of six components: the base, the front cover, the front seal, the back cover, the O-ring plate, and the top cover. In total, three different iterations of the probes were designed and prototyped using 3D printing to ensure correct fits with the required electrical components. Due to the high risk of heat stress in sows over the summer months, developing a probe that tracks internal temperatures constantly will ultimately give hog farmers a chance to catch the warning signs of heat stress in nursing sows, which could ultimately save animals and earn millions of dollars for the hog industry.

87 Milk Yield, Vaginal Temperature, and Solar Radiation Exposure in Slick and Wild Type-Haired Puerto Rican Holstein Cows

Abstract As heat stress limits dairy cattle performance in the tropics, selection for heat resistant cattle has been proposed as a possible alternative for these countries. Such cattle should be able to regulate their body temperature efficiently so grazing activity is not compromised by environmental conditions. This is particularly important for Puerto Rico’s dairy industry, which depends on grazing as the principal or unique source of dietary fiber. Even though Puerto Rican slick-haired dairy cattle (SLICK) have been associated with superior thermoregulation, empirical data about their capacity to withstand greater solar radiation exposure while maintaining lower body temperature is scarce. The current study aimed to compare the vaginal temperature, solar radiation exposure, and milk yield between SLICK and wild type-haired (WT) cows. Evaluated groups were balanced for lactation number (P = 0.8101) and days in milk (DIM: P = 0.9619). Eight SLICK (2.00 ± 0.33 lactations and 160.33 ± 11.39 DIM) and 8 WT Holstein cows (1.89 ± 0.31 lactations and 159.44 ± 14.34 DIM) were compared. Initially, experimental groups were selected visually, then a genomic test confirmed each the hair coat type of each cow. Vaginal temperature was recorded by means of a HOBO TidbiT v2 Water Temperature datalogger secured to a blank CIDR. Light intensity exposure was recorded using a HOBO Pendant MX Temperature / Light datalogger secured to the top of a neck collar, as an index of solar radiation exposure (previously validated by our group). Data were recorded in each cow every 15 seconds for 48 consecutive hours (August 4-5, 2022) and averaged by hour for statistical analysis using the GLIMMIX Procedure of SAS. The week before the study SLICK cows showed greater milk yields than their WT counterparts (20.76 ± 0.55 vs.8.60 ± 0.56 kg/d; P = 0.0073). No time by hair coat type interaction was observed for vaginal temperatures (P = 0.1396). However, time (P &amp;lt; 0.0001) and hair coat type (P = 0.0042) affected vaginal temperature. The SLICK cows presented lower vaginal temperatures than their WT counterparts, with daily averages of 39.08 ± 0.09 and 39.45 ± 0.10°C, respectively. A time by hair coat type interaction (P = 0.0293) was observed for the light intensity exposure of the cows. The SLICK cows had greater light intensity exposure than their WT counterparts at 1,000 h (15,467.00 ± 1,584.92 vs.10,057.00 ± 787.35 lx; P &amp;lt; 0.0001), 1,100 h (12,028 ± 1,660 vs. 8,571.11 ± 888.13 lx; P = 0.0078), and 1,200 h (13,191.00 ± 2,188.86 vs.10,923.00 ± 1,904.31 lx; P = 0.0801). No other differences in light intensity exposure were observed. Slick-haired cows were able to maintain a lower daily vaginal temperature, even with a greater exposure to direct solar radiation, further suggesting a superior thermoregulatory capacity. Concurrently, a greater milk production was observed in the slick-haired group. Future studies should evaluate grazing activity under direct solar radiation exposure in both hair coat groups.

84 Puerto Rican Slick-Haired Holstein Cattle Exhibit Enhanced Mammary Gland Hemodynamics Compared with Their Wild-Type Haired Counterparts

Abstract A mutation of the prolactin receptor gene (PRLR) results in cattle with short and sleek hair coat and superior thermoregulatory capacity when exposed to heat stress conditions. This mutation, which is present in Puerto Rican Holstein cattle (SLICK) results in decreased vaginal temperatures and increased milk yield (MY) compared with wild-type haired Holstein cattle (WT) under tropical conditions. The superior performance of SLICK Holstein cows has been considered multifactorial in nature and physiological differences between genotypes still need to be elucidated. Thereby, the objective was to compare the mammary gland hemodynamics and udder skin temperature between SLICK (n = 7) and WT (n = 7) Holstein cows during the summer as possible contributors to such physiological differences. Animals were selected for differences in MY (23.77±1.24 vs.19.74±1.24 kg, SLICK vs. WT, respectively; P = 0.041) and stratified by body weight (BW), lactation number, and days in milk (DIM). At 160±3 DIM, left and right pudendoepigastric arteries were assessed transrectally via Doppler ultrasonography and the udder skin temperature was determined using a thermal camera. Data were analyzed by one-way ANOVA using the MIXED procedure of SAS with resistance index (RI), pulsatility index (PI), diameter, total mammary blood flow (MBF), MBF relative to BW, and udder skin temperature as dependent variables and hair coat as the independent variable. The CORR procedure of SAS was used to determine the correlation between MY and MBF. Statistical significance was declared at P ≤ 0.05 and tendencies were established at 0.05 ≤ P ≤ 0.10. The RI was less (P = 0.045) in SLICK Holsteins (0.56 ± 0.02) than WT (0.64 ± 0.02). The PI tended (P = 0.0589) to be less in SLICK Holsteins (0.94±0.07) compared with WT (1.15 ± 0.07). The average diameter of the left and right pudendoepigastric arteries was greater in the SLICK animals compared with WT (1.31 ± 0.07 vs..08±0.07 cm, respectively; P = 0.038). Total MBF was increased in SLICK cattle compared with WT (9.03 ± 1.11 vs. 5.14 ± 1.11 L/min; P = 0.0291). There was a tendency (P = 0.0577) for the MBF relative to BW to be greater in the SLICK Holsteins compared with the WT (16.75 ± 2.14 vs.0.38 ± 2.14 mL/min*kg). No differences were observed in udder skin temperature between SLICK and WT Holsteins (P ≥ 0.05). Lastly, a tendency for a positive correlation between MY and MBF was observed (r = 0.51, P = 0.066). In the current study, SLICK Holsteins had enhanced blood supply to the mammary gland which is indicative of greater amount of oxygen and nutrients available for milk synthesis. Therefore, the gene introgression of the PRLR mutation to a dairy herd may result in animals with superior physiological performance during heat stress conditions preventing economical losses in the dairy industry.