Cattle Temperament Research Articles

Characterization of the Temperament and Reactivity of Nelore Cattle (Bos indicus) Associated with Behavior Scores during Corral Management in the Humid Tropics.

The evaluation of the reactivity and distress of cattle during corral management, by means of subjective scores, aims at the standardization of behavioral indicators, through non-invasive methods, in addition to enabling the development of more appropriate management practices, thus promoting the comfort and well-being of these animals. Therefore, in this study, we aimed to characterize the temperament and distress of cattle managed in a corral using behavioral indicators during the rainiest period. For this, the experiment was conducted on a property located in the municipality of Mojuí dos Campos, during the rainiest quarter (February-April). Thus, 30 male cattle, not castrated, approximately 29 months of age, clinically healthy, and weighing 310 + 20 kg, were divided into three rearing systems: silvopastoral (SP), traditional (SS), and integrated (SI) systems. There were 10 animals per system. Physiological parameters were collected to evaluate rectal temperature (RT) and respiratory rate (RR), as well as body surface temperature (BST), through thermal windows (head and flank infrared temperature and rump infrared temperature). To evaluate temperament and reactivity, scores indicative of corral behavior were used, namely escape speed (ES), tension score (SS_1), tension score (SS_2), reactivity scale (RS), movement score (MS), and temperament scale (TS). The results showed that there was a thermal amplitude of 5.9 °C on average and 8.6 °C at maximum when comparing the structure of the corral and the trees. In addition, the comparisons between the production systems for the behavioral variables did not differ at the 5% significance level, except for ES, where the traditional system differed from the integrated system and the silvopastoral system, showing intermediate average values for both. In addition, there was a positive correlation between the variables RT and RR (r = 0.72; p < 0.01), RR and SS_2 (r = 0.38; p = 0.04), flank infrared temperature and MS (r = 0.47; p = 0.01), rump infrared temperature and RS (r = 0.37; p = 0.04), SS_1 and RS (r = 0.41; p = 0.02), SS_1 and SS_2 (r = 0.39; p = 0.03), RS and SS_2 (r = 0.58; p = 0.00), RS and MS (r = 0.50; p = 0.01), RS and TS (r = 0.61; p = 0.00), SS_2 and MS (r = 0.51; p = 0.00), SS_2 and TS (r = 0.47; p = 0.01), and MS and TS (r = 0.44; p = 0.02), and a negative correlation between ES and TS (r = -0.42; p = 0.02). The rainy season had a major influence on the evaluation of temperature and distress levels during handling in the corral, as evidenced by the association between physiological and behavioral parameters.

Consistent individual differences in behavior among beef cattle in handling contexts and social-feed preference testing

Consistent individual differences (CIDs) in animal behavior, also known as personality or temperament, are measured in a variety of assays and are presumed to represent relatively stable traits of individual animals. Because these behaviors are presumed to represent stable traits, repetition of assays over short and long-term time frames and contexts is crucial; such repetitions are not commonly achieved in literature regarding the topic of CIDs, especially not in a singular study. In beef cattle, CIDs are often related to feeding and social preferences, which is relevant for extensively managed herds of ruminants. This study investigated the consistency of behavior among 50 breeding Angus x Hereford cows across repetitions within one year and over one year during three distinct contexts: handling and isolation in a chute corral system, choice in a social-feed tradeoff test, and response in a novel bucket approach test. We found that cows were consistent across short-term (assessed with repeatabilities [R]) and long-term (assessed with correlations across multivariate models [r]) timeframes in durations of behaviors exhibited in the management context (e.g. while handled [R = 0.60, r = 0.39], while traversing a cement chute [R = 0.69, r = 0.67] and an open squeeze stall [R = 0.76, r = 0.85]). Repeatable behaviors from the handling and isolation in chute system context were input into PCA with varimax rotation. Behaviors loaded onto three principal components that explained 66 % of the variance in the data and distinguished cows along axes of activity, fearfulness and excitability. Cows that were deemed less active (p = 0.010) and less excitable (p = 0.039) chose to approach the supplement bucket over gaining proximity to conspecifics in a social-feed tradeoff test. Even though the cows were not restrained in a squeeze stall, consistent individual differences in behavior across short (within year) and long-term (between years) timeframes were found. This suggests that future research can use unrestrained methods to evaluate cattle temperament, which could improve animal welfare and safety of handlers during experiments. Passive and less excitable beef cattle were more feed-centric, indicating that CIDs in behavior assays could potentially be used to predict feeding behavior because of an underlying stable trait in cows that ties response to handling and management with feed choice in a social-feed tradeoff task.

Genetic Backgound of Cattle Temperament

Genetic Backgound of Cattle Temperament

13 Effects of an acclimation protocol during the handling events of the 7 d CO-synch + CIDR protocol on temperament and reproductive performance of Bos taurus commercial beef heifers

Abstract It has been previously reported that cattle temperament significantly impacts fertility to estrous synchronization (ES) protocols. In addition, enrolling heifers to acclimation protocols following weaning resulted in improved reproductive parameters with an increased proportion of acclimated heifers reaching puberty earlier when compared with non-acclimated cohorts. The objective of the present experiment was to assess the effects of an acclimation protocol during the handling events of an ES on changes in temperament and fertility to the ES protocol in Bos taurus commercial beef heifers. A total of 361 Angus-influenced commercial heifers from 5 different locations were enrolled in the experiment. Before enrolling heifers in the 7-d CO-Synch + CIDR protocol (d -10), individual heifers were evaluated for reproductive tract score (RTS), and chute score (CS) and stratified to receive acclimation (TRT) or to serve as control (CTRL). On d -10, heifers from TRT and CTRL groups received ear tags of different colors and individuals from CTRL and TRT were kept together in their pastures. Before each handling event of the ES (d 0,7,10), TRT heifers were sorted from CTRL and submitted to acclimation, which consisted of running heifers through the handling facilities without catching individuals in the restraining chute. Treatment heifers were then comingled with CTRL heifers, and all heifers were brought to the handling facilities for the ES event. Individual CS and exit velocities (EV) were recorded for all animals at all days (-10,0,7,10). Chute scores were recorded in a 1 to 5 scale, where 1 = calm, no movement; 2 = restless movements; 3 = frequent movement, vocalization; 4 = constant moving, vocalization, shaking of the chute; 5 = violent, continuous struggling. Individual estrus detection patch scores were assessed at the day of fixed-time artificial insemination (FTAI) based on percentage of activation, where 0 = lost; 1 = less than 25% activated, 2 = less than 50% activated, 3 = less than 75% activated, 4 = more than 75% activated. Pregnancy status was determined by rectal ultrasonography approximately 40 d after FTAI. Estrus detection patch scores did not differ between CTRL and TRT heifers (P = 0.1906). In addition, pregnancy rates to FTAI did not differ between TRT and CTRL heifers (56.81% and 52.74%; P = 0.3563). Reproductive tract scores (P = 0.777), EV (P = 0.9607) and CS (P = 0.990) did not differ between CTRL and TRT on d -10. However, CS, but not EV was decreased on d 7 (P = 0.001) and 10 (P = 0.0002) for TRT heifers when compared with CTRL. We conclude that enrolling heifers to an acclimation protocol during the handling events of the ES protocol was effective at decreasing excitability of heifers by the day of FTAI, as evidenced by decreased CS observed for TRT heifers on d 7, and 10 but did not support an increase in fertility to the ES protocol.

PSXIV-25 Investigating the Relationship Between Maternal Protectiveness and Temperament in Beef Cattle

Abstract Observations were made on 73 dams on two ranches in Colorado and one in Wyoming during the spring 2022 calving season to investigate the relationship between temperament and calf protection. The objective was to compare temperament scores to the distances of protective behavior performed by the dam as the observer moved closer to the pair. The protective actions of the cow were: Approach (alerted by raising her head to presence of the observer), Protective (moved between observer and calf), Vocalization (called to calf), and Closest (closest distance the observer reached before the pair moved away). Temperament scores included chute score, exit score, exit velocity, and blood lactate. One hundred percent of the dams alerted to the presence of the observer, twenty-five percent (n = 18) moved between the observer and the calf, and sixty-three percent (n = 46) vocalized to their calf. Thirty-five (47.9%) dams allowed the observer to touch the calf, categorized as Touch, while the other thirty-eight (52.1%) walked away from the observer before contact with the calf, categorized as No Touch. In a linear model using Touch/No Touch as the predictor and the continuous variables of Approach, Protect, Vocalize, Closest, exit velocity, and blood lactate; only closest (P &amp;lt; 0.001) and exit velocity (P = 0.011) had significant differences (P &amp;lt; 0.05) between the means. Dams that allowed the observer to touch the calf, on average, exited the chute with greater velocity (P = 0.01). Blood lactate and exit velocity were predictors in a mixed model with Ranch as a random factor with Touch/No Touch as the outcome; no significant difference was found (P &amp;gt; 0.05). The Kruskal-Wallis test was performed individually on Approach, Protection, Vocalization, and Closest with predictor values of Ranch, date of birth (DOB), and hair whorl. A significant difference (P = 0.04) appeared between the medians of Closest when grouped by hair whorl; dams with abnormal hair whorls moved away from the observer at a greater distance. When divided by Ranch, there were differences (P &amp;lt; 0.001) in the average chute score. This study suggests that dams with a faster exit velocity are approachable in the field. Exit velocity is not a good indicator of how close an observer can get to a calf in the field. Attraction to novelty could have a larger role than previously thought in temperament. No impactful relationships were observed between the temperament of a dam and her maternal protectiveness. Ranchers can continue selecting for docile temperament without fear of decreasing maternal protection.

Efeito do tipo animal, manejo e condições de transporte no temperamento pré-abate de bovinos de corte

ABSTRACT This study aimed to investigate the effects of animal type, on-farm handling, and transport conditions on temperament of beef cattle pre-slaughter. The study evaluated 4,061 cattle batches, averaging 49 animals, with a total of 199,026 cattle. Temperament was evaluated through a behavioral assessment carried out based on the temperament shown by cattle when approached by humans. One of three different temperament scores were assigned to each batch: calm, anxious, or excitable. Excitable temperament was reported in animals subjected to long transport time and distance and high loading density. The degree of carcass fatness was higher in calm animals, followed by anxious animals, with the excited temperament animals having the lowest carcass fatness degree. Older animals showed more excitable temperament, while younger animals showed calmer temperament. The excitable temperament was more evident in horned animals in relation to polled animals. Animal temperament was more reactive in batches with older cattle, low carcass fatness degree, and with more than 20% horned animals. Good handling and loading facilities and procedures at the farm contributed to adequate cattle temperament expression prior to slaughter.

Estimation of temperament of dairy cows by response to a novel object

The presented study aims to develop on farm test temperament in dairy cattle based on individual differences in behavior during approaching the novel object. The novel object was a red cycling light. Behavior traits (duration of walking and standing at stops) were recorded from the video records as well as numeric modifier (distance of stop). Individual differences in the behavior were evaluated by differences in duration of approaching the novel object. Due to differences in walking speed in the cows the corrected duration of approaching (CDA) was calculated from real duration of approaching the novel object, number of stops and 1st stop distance. A group of 53 tested cows was split into 4 distinctive clusters. Members of cluster 1 had calm type of temperament, cluster had 28 members, median CDA was 28 s (min 11 s, max 53 s). Members of cluster 2 had curious type of temperament, cluster had 14 members, median CDA was 87 s (min 58 s, max 121 s). Members of cluster 3 had vigilant type of temperament, cluster had 9 members, median CDA was 155 s (min 132 s, max 250 s). Members of cluster 4 had fearful type of temperament, and cluster had only 2 members, median CDA was 460 s (min 439 s, max 482 s). Results showed the possibility of on farm temperament type measure by simple test. Testing discovered inappropriate type of temperament in 2 of tested dairy cows with higher risks of problem with habituation to novel objects or during manipulation.

Characterization of intronic SNP located in candidate genes influencing cattle temperament

Characterization of intronic SNP located in candidate genes influencing cattle temperament

Contemporary Knowledge on the Assessment of Temperament in Cattle and Its Impact on Production and Reproduction Including Some Immunological, Genetic and Metabolic Parameters.

Temperament is associated with the well-being, health, production and reproduction of cattle. In order to increase the population of individuals with the desired temperament, its evaluation should be standardized and be made one of the obligatory elements of breeding and veterinary examination. A number of different tests are used for temperament assessment. In this article, the importance of temperament correlation with some metabolic, genetic, immunological, production and reproductive parameters have been shown, pointing at its influence on the economy and cattle handling. The most common methods for assessing the temperament of cattle are presented, including long-time scales of temperament assessment. At the same time, the relationship of the temperament of cattle with production efficiency, immunity and reproductive indicators has been shown, indicating that its correct assessment is an important aspect of the proper development of the herd and the associated economic growth.

Integrative genomics analysis highlights functionally relevant genes for equine behaviour.

Behavioural plasticity enables horses entering an exercise training programme to adapt with reduced stress. We characterised SNPs associated with behaviour in yearling Thoroughbred horses using genomics analyses for two phenotypes: (1) handler-assessed coping with early training events [coping] (n=96); and (2) variation in salivary cortisol concentration at the first backing event [cortisol] (n=34). Using RNA-seq derived gene expression data for amygdala and hippocampus tissues from n=2 Thoroughbred stallions, we refined the SNPs to those with functional relevance to behaviour by cross-referencing to the 500 most highly expressed genes in each tissue. The SNPs of high significance (q < 0.01) were in proximity to genes (coping - GABARAP, NDM, OAZ1, RPS15A, SPARCL1, VAMP2; cortisol - CEBPA, COA3, DUSP1, HNRNPH1, RACK1) with biological functions in social behaviour, autism spectrum disorder, suicide, stress-induced anxiety and depression, Alzheimer's disease, neurodevelopmental disorders, neuroinflammatory disease, fear-induced behaviours and alcohol and cocaine addiction. The strongest association (q=0.0002) was with NDN, a gene previously associated with temperament in cattle. This approach highlights functionally relevant genes in the behavioural adaptation of Thoroughbred horses that will contribute to the development of genetic markers to improve racehorse welfare.

Genetic parameters for behavioral and growth traits of Nellore cattle.

The growing concern of consumers with the welfare of production animals searches welfare in a production system extremely important; thus, the study of animal temperament is necessary to select less excitable temperament animals resulting in healthy development and fewer accidents. The objective of this study was to estimate genetic parameters for traits related to animal temperament and growth traits of Nellore cattle. In addition to exploring the genetic pattern of these traits through cluster and principal component analysis (PCA), to reveal possible groups of individuals that express less excitable temperament and greater growth. A total of 2,332 measurements from 1,245 male and female Nellore cattle born between 2008 and 2016 were utilized in the study. The (co)variance components were estimated by Bayesian inference using a two-trait animal model. The heritability for temperament score (TS), flight speed (FS), body condition score (BCS), live weight (LW), and hip height (HH) were 0.08, 0.12, 0.06, 0.13, and 0.48, respectively. The genetic correlation between the temperament indicator traits was strong and positive (0.78 ± 0.24). The TS and FS showed a favorable or null genetic correlation with LW, BCS, and HH. The third cluster included animals with low EBV for TS and FS and with high EBV for BCS, LW, and HH. In the PCA, the PC1 was what best evidenced the aim of this study; thus, our findings suggest that we could explore select animals based on cluster 3 and PC1 in breeding programs to select Nellore cattle with less excitable temperament and greater growth.

DNA methylation patterns and gene expression from amygdala tissue of mature Brahman cows exposed to prenatal stress.

Prenatal stress can alter postnatal performance and temperament of cattle. These phenotypic effects may result from changes in gene expression caused by stress-induced epigenetic alterations. Specifically, shifts in gene expression caused by DNA methylation within the brain’s amygdala can result in altered behavior because it regulates fear, stress response and aggression in mammals Thus, the objective of this experiment was to identify DNA methylation and gene expression differences in the amygdala tissue of 5-year-old prenatally stressed (PNS) Brahman cows compared to control cows. Pregnant Brahman cows (n = 48) were transported for 2-h periods at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 days of gestation. A non-transported group (n = 48) were controls (Control). Amygdala tissue was harvested from 6 PNS and 8 Control cows at 5 years of age. Overall methylation of gene body regions, promoter regions, and cytosine-phosphate-guanine (CpG) islands were compared between the two groups. In total, 202 genes, 134 promoter regions, and 133 CpG islands exhibited differential methylation (FDR ≤ 0.15). Following comparison of gene expression in the amygdala between the PNS and Control cows, 2 differentially expressed genes were identified (FDR ≤ 0.15). The minimal differences observed could be the result of natural changes of DNA methylation and gene expression as an animal ages, or because this degree of transportation stress was not severe enough to cause lasting effects on the offspring. A younger age may be a more appropriate time to assess methylation and gene expression differences produced by prenatal stress.

Genetic Modeling and Genomic Analyses of Yearling Temperament in American Angus Cattle and Its Relationship With Productive Efficiency and Resilience Traits.

Cattle temperament has been considered by farmers as a key breeding goal due to its relevance for cattlemen’s safety, animal welfare, resilience, and longevity and its association with many economically important traits (e.g., production and meat quality). The definition of proper statistical models, accurate variance component estimates, and knowledge on the genetic background of the indicator trait evaluated are of great importance for accurately predicting the genetic merit of breeding animals. Therefore, 266,029 American Angus cattle with yearling temperament records (1–6 score) were used to evaluate statistical models and estimate variance components; investigate the association of sex and farm management with temperament; assess the weighted correlation of estimated breeding values for temperament and productive, reproductive efficiency and resilience traits; and perform a weighted single-step genome-wide association analysis using 69,559 animals genotyped for 54,609 single-nucleotide polymorphisms. Sex and extrinsic factors were significantly associated with temperament, including conception type, age of dam, birth season, and additional animal–human interactions. Similar results were observed among models including only the direct additive genetic effect and when adding other maternal effects. Estimated heritability of temperament was equal to 0.39 on the liability scale. Favorable genetic correlations were observed between temperament and other relevant traits, including growth, feed efficiency, meat quality, and reproductive traits. The highest approximated genetic correlations were observed between temperament and growth traits (weaning weight, 0.28; yearling weight, 0.28). Altogether, we identified 11 genomic regions, located across nine chromosomes including BTAX, explaining 3.33% of the total additive genetic variance. The candidate genes identified were enriched in pathways related to vision, which could be associated with reception of stimulus and/or cognitive abilities. This study encompasses large and diverse phenotypic, genomic, and pedigree datasets of US Angus cattle. Yearling temperament is a highly heritable and polygenic trait that can be improved through genetic selection. Direct selection for temperament is not expected to result in unfavorable responses on other relevant traits due to the favorable or low genetic correlations observed. In summary, this study contributes to a better understanding of the impact of maternal effects, extrinsic factors, and various genomic regions associated with yearling temperament in North American Angus cattle.

101. Effect of bull beef diet on hair cortisol concentration, and associations with behavioural temperament in cattle

101. Effect of bull beef diet on hair cortisol concentration, and associations with behavioural temperament in cattle

Human-Animal Interactions with Bos taurus Cattle and Their Impacts on On-Farm Safety: A Systematic Review.

Simple SummaryCattle are large animals that can cause serious injuries to humans. Humans may encounter cattle through working on farms, living on a farm, or traversing fields with cattle. A systematic review was carried out to assess the factors which may lead to a dangerous interaction with cattle. A literature search was carried out to find papers that included the criteria ‘Bovine’, ‘Handling’, ‘Behaviour’ and ‘Safety’, or terms therein. The search returned 17 papers, and after collation, six themes were identified: actions of humans; human demographics, attitude, and experience; facilities and the environment; the animal involved; under-reporting and poor records; and mitigation of dangerous interactions. Exploration of these themes shows that more accurate recording of interactions before an injury is required. Furthermore, targeted, tailored education for anyone who may come into contact with cattle could reduce cattle-induced injuries.Cattle production necessitates potentially dangerous human–animal interactions. Cattle are physically strong, large animals that can inflict injuries on humans accidentally or through aggressive behaviour. This study provides a systematic review of literature relating to farm management practices (including humans involved, facilities, and the individual animal) associated with cattle temperament and human’s on-farm safety. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) was used to frame the review. Population, Exposure, and Outcomes (PEO) components of the research question are defined as “Bovine” (population), “Handling” (exposure), and outcomes of “Behaviour”, and “Safety”. The review included 17 papers and identified six main themes: actions of humans; human demographics, attitude, and experience; facilities and the environment; the animal involved; under-reporting and poor records; and mitigation of dangerous interactions. Cattle-related incidents were found to be underreported, with contradictory advice to prevent injury. The introduction of standardised reporting and recording of incidents to clearly identify the behaviours and facilities which increase injuries could inform policy to reduce injuries. Global differences in management systems and animal types mean that it would be impractical to impose global methods of best practice to reduce the chance of injury. Thus, any recommendations should be regionally specific, easily accessible, and practicable.

9 Evaluating the Utility of Individual Cattle Brush Use Behavior as a Novel Behavioral Phenotype Regarding Productivity, Temperament, and Feeding Behavior of Bos Indicus Steers and Heifers Housed in Dry Lots

Abstract Little is understood about the relationships among environmental enrichment, temperament, productivity, and feeding behavior in cattle. The objective of this study was to examine the effect of divergent behavioral phenotypes for brush usage on temperament, productivity, and feeding behavior patterns in beef cattle. Four pens of Brahman cattle (n = 2 pens with 15 heifers/pen, and n = 2 pens with 19 steers/pen) were housed in dry lots each equipped with four electronic feedbunks (GrowSafe Systems). Animals were video recorded throughout an 85d commercial gain test. Video recordings were decoded on d 1, 2, 4, 8, 16, 32, and 64 using continuous observations for 15 minutes every 30 minutes from 08:00 to 20:00 to determine the total daily brush usage for focal animals that were selected based on d -19 exit velocities. Exit velocity and body weight were measured on d -19, 0, 1, 25, 50, and 70 and feeding behavior was monitored daily using the GrowSafe 4000E system. Animals were classified within gender into one of three phenotypes (high, medium, and low brush usage) based on ±0.5SD from the brush usage mean. A General Linear Mixed Model (PROC GLIMMIX) with brush use phenotype, sex and the interaction of these as fixed effects and pen as random effect was used for data analysis. For high and medium brush use phenotypes, steers had greater final BW than heifers (P = 0.0005), while heifer and steer final body weight did not differ when brush usage was low. High brush use steers had greater ADG (P = 0.0002) than high and medium brush use heifers, and low brush use steers and heifers. This same pattern was observed for DMI (P = 0.0003). Heifers were more temperamental than steers (P = 0.0008), and high and medium brush use heifers had faster exit velocities than low brush use steers. These results suggest that monitoring animal’s pleasurable behavior (brush use), rather than fear response alone, may be a useful behavioral indicator of cattle productivity.

Genome-wide association study identifies quantitative trait loci affecting cattle temperament.

Cattle temperament is an interesting trait due to its correlation with production efficiency, labor safety, and animal welfare. To date, however, its genetic basis is not clearly understood. Here, we performed a genome-wide association study for a series of temperament traits in cattle, assessed with via open field and novel object tests, using autosomal single nucleotide polymorphisms (SNPs) derived from the whole-genome sequence. We identified 37 and 29 genome-wide significant loci in the open field and novel object tests, respectively. Gene set analysis revealed the most significant pathway was the neuroactive ligand-receptor interaction pathway, which may be essential for emotional control in cattle. Analysis of the expression levels of 18 tissue-specific genes based on transcriptomic data showed enrichment in the brain, with some candidate genes involved in psychiatric and neurodegenerative diseases in humans. Based on principal component analysis, the first principal component explained the largest variance in the open field and novel object test data, and the most significant loci were assigned to SORCS3 and SESTD1, respectively. Our findings should help facilitate cattle breeding for sound temperament by pyramiding favorable alleles to further improve cattle production.

Beef cattle behavior in integrated crop-livestock systems

ABSTRACT: Temperament often depends on the animals’ reaction to people, social and environmental conditions. However, little is known about the influence of changes in the pasture environment on cattle temperament. Thus, this study was designed to evaluate if an animals’ temperament changes in response to being kept in a silvopastoral system. This study evaluated the effect of the tree components in a pasture environment on the temperament of any grazing cattle in integrated crop-livestock systems. A total of thirty-two Angus steers were allocated to either a livestock (L) or livestock-forest (LF) system and observed from December 2019 to February 2020. Each animal was evaluated for their reactivity score, flight speed, and number of vocalizations. The statistical model established that the animals were random effects and that the treatments and periods were fixed effects using the MIXED procedure, and the means were compared using LSMeans. The flight speed and number of vocalizations were similar in both production systems, while the reactivity score was lower for animals kept in the LF system when compared to those in the L system. This suggested that the LF system interferes positively with the animal’s temperament in relation to the L production system. However, additional research is needed to understand the influence of the production system on animal temperament.

Effects of Temperament on the Reproduction of Beef Cattle.

Simple SummaryIn beef cattle and other livestock species, temperament can be considered as their behavioral responses to human interaction. Temperament evaluation allows classifying cattle according to the level of responsiveness, from calm to excitable. Consistently across studies, beef females classified as more excitable have signs of increased stress response and are less fertile compared to cohorts with calmer temperament. Cattle temperament can be improved via genetic selection and acclimating young animals to human interaction and handling procedures.Temperament is often defined as the behavioral expression of animals in response to human interaction. Cattle temperament can be evaluated using an association of chute score and exit velocity, with cattle then classified as adequate or excitable temperament. To assess the impacts of temperament on various beef systems, these evaluation criteria were associated with productive and reproductive parameters of Bos taurus and B. indicus-influenced cattle. Consistently across studies, excitable cattle had greater plasma cortisol compared to animals with adequate temperament. Studies also reported that excitable beef females have poorer reproductive performance compared to calmer cohorts, including reduced annual pregnancy rates, decreased calving rate, weaning rate, and kg of calf weaned/cow exposed to breeding. Acclimating B. indicus × B. taurus or B. taurus heifers to human handling improved behavioral expression of temperament and hastened puberty attainment. However, similar benefits were not observed when mature cows were acclimated to human handling. Collectively, temperament of beef females measured via behavioral responses upon human handling impacts their reproductive and productive responses independent of breed type, and should be considered for optimal beef cattle production.

PSXIII-20 Using 1H NMR Spectroscopy reveals metabolite markers associated to temperament and carcass quality in feedlot cattle

Abstract The objective of this study was to identify small molecule metabolites in a serum sample taken at entry into the feedlot that can predict performance, and animal health. One-hundred and thirty-one Angus x Simmental steers from a single ranch were sampled at a commercial feedlot in Chappell, NE. Blood samples for metabolite analysis, chute score, exit velocity, and blood lactate concentration for temperament classification were collected in addition to feedlot performance data and carcass quality measurements. The GLM and LSM procedures of SAS (SAS 9.4, 2014) were used to evaluate differences between temperament classifications. Steers were divided into three exit velocity classifications one standard deviation from the mean were classified as fast and exit velocities lower than one standard deviation from the mean were slow. Forty metabolites were quantified using 1H NMR Spectroscopy from serum. Metaboloanalyst was used to analyze serum metabolites and phenotypic values using one way- ANOVA, PCA, PLS-DA, and a permutation test to cross validate. Data were normalized and scaled. No metabolites were predictive of any of the animal health metrics collected. Five metabolites were different in exit velocity class at (P &amp;lt; 0.01; Methanol, Isopropanol, Lactate, Isobutyrate, and Pyruvate). Similarly, seven metabolites were different in chute score classes at (P &amp;lt; 0.01) (Methanol, Isobutyrate, Creatinine, Dimethly Sulfone, Hippurate, Isopropanol, and Succinate). Furthermore, several metabolites in serum at entry in the feedlot were related to carcass quality metrics; Back Fat (Urea and 2-Hydroxyisobutyrate at (P &amp;lt; 0.01), a trend for prediction of quality grade at (P = 0.068), carcass value (P = 0.085). The relationship between serum metabolites identified on entry into the feedlot, feedlot performance traits, and eventual carcass quality warrants further research to elucidate the roles these metabolites play during the feedlot period and in predicting carcass merit.