Associations between response to handling and growth and meat quality in frequently handled Bos taurus beef cattle

Calming Hungarian Grey Cattle in Headlocks Using Processed Nasal Vocalization of a Mother Cow

Sound analysis is an important field of research for improving precision livestock farming systems. If the information carried by livestock sounds is interpreted correctly, it could be used to improve management and welfare assessment in this field. Therefore, we hypothesized that the nasal vocalization of a mother cow could have a calming effect on conspecifics. The nasal vocalization in our study was recorded from a mother cow (not part of the test herd) while it was licking its day-old calf. The raw sound was analyzed, cleaned from noises, and the most representative vocalization was lengthened to two minutes. Thirty cows having calves were randomly selected from eighty Hungarian grey cattle cows. Two test days were selected, one week apart; the weather circumstances in both days were similar. The herd was collected in a paddock, and the test site (a restraining crate with a headlock) was 21 m away from them. The cows from the herd were gently moved to the restraining crate, and, after the installation of the headlock, Polar® heart rate monitors were fixed on the animals. The recording of the RR intervals was carried out for two minutes. On day one of the test, the processed nasal sound was played to every second cow during the heart rate monitoring. When the sound ended, the heart rate monitor was removed. On test day two, the sound and no sound treatments were switched among the participating cows. At the end of the measurement, the headlock was opened, letting the animals out voluntarily, and a flight test was performed along a 5 m distance. The time needed to pass the 5 m length was measured with a stopwatch and divided by the distance. The RR intervals were analyzed with the Kubios HRV Standard (ver. 3.5.0) software. The following data were recorded for the entire measurement: average and maximum heart rate; SD1 and SD2; pNN50; VLF, LF, and HF. The quasi-periodic signal detected in the sound analyses can hardly be heard, even when it is enhanced to the maximum. This can be considered a vibration probably caused by the basis of articulation, such as a vibration of the tongue, for example. The SD2/SD1 ratio (0.97 vs. 1.07 for the animals having no sound and sound played, respectively, p = 0.0110) and the flight speed (0.92 vs. 1.08 s/m for the animals having no sound and sound played, respectively, p = 0.0409) indicate that the sound treatment had a calming effect on the restrained cows. The day of the test did not influence any of the measured parameters; therefore, no effect of the routine was observed. The yes-no sequence of the sound treatment significantly reduced the pNN50 and flight speed values, suggesting a somewhat more positive association with the headlock and the effectiveness of the processed nasal sound. In conclusion, we have demonstrated that, by means of sound analyses, not only information about individuals and the herd can be gathered but that, with proper processing, the sound obtained can be used to improve animal welfare.

Probability and number of bruises in bovine carcasses according to animal type, handling and transport

The aim of this study was to evaluate pre-slaughter risk factors on the probability of bruising and the number of bruises in different regions of the bovine carcass. The study evaluated the data from 4061 batches of slaughtered cattle, totalling 199,026 carcasses, from Hereford and Aberdeen Angus animals in crosses with continental European breeds and Zebu cattle. The factors that caused injury were sex, handling conditions (score), vehicle type, vehicle load density (kg/m2), travel time (minutes), travel distance (kilometres), physiological maturity (dentition), animal reactivity (score), and carcass fat (score). The type of vehicle had the greatest influence on the probability of carcass bruising and affected all carcass cuts. More bruising occurred in vehicles with a greater load capacity. A higher chance of bruising was seen in groups of older animals, those with an excitable temperament and, especially, in groups of females. Higher load densities during transport resulted in a greater chance of bruising occurring in all cuts except the hindquarters. Distance and travel time are unstable in the models, but also detrimental, increasing the probability of bruising and the number of bruises in the various cuts. The results of this study suggest that good practices in the welfare, handling and transport of the animals, as well as training the personnel responsible for their handling, should be adopted to minimise the risk of injury at different locations on the carcass.

Hematological Normality, Serum Biochemistry, and Acute Phase Proteins in Healthy Beef Calves in the Brazilian Savannah

The Brazilian savannah region, characterized by high average temperatures, well-defined rainy and dry seasons, soil with low productive potential, and high pressure for parasitic diseases, is home to the highest percentage of the beef herd, which is the world's largest commercial beef producer. Therefore, breeds that present rusticity combined with productivity are the focus of research in cattle breeding in the region. Considering their geographic particularities and their effects on the animals' blood parameters, the objective was to study the behavior of hematological variables, serum biochemistry, and acute phase proteins in beef calves at weaning age. Jugular blood samples were collected in a single day from 30 weaning calves (about eight months old and 200 kg of body weight) from the following breeds: Nellore, Senepol, Nellore × Aberdeen Angus cross, Nellore × Senepol cross, and Nellore × Aberdeen Angus × Senepol cross. Hematological data were obtained using an automatic cell counter, serum biochemical measurements were obtained using commercial kits, and the electrophoretogram was obtained using the SDS-page technique. In general, the results were consistent with data already published in similar situations regarding health status, age, and level of metabolic activity. However, differences observed between groups can be explained by differences observed in other concurrent variables like temperament. The pure zebu breed was more reactive than pure taurine. While crossbreds showed intermediate values, and parasitic infestation, the pure taurine breed with higher parasite infestation, while the zebu breed had lower values, which produced effects in some laboratory tests, and generated differences between breeds. In conclusion, the reference intervals available for healthy animals can be routinely used without interference from the geographic region for animals produced without nutritional failures as long as changes are recorded in pathological, infectious, metabolic, or nutritional deficiency situations. However, it is suggested that a study covering a larger number of herds may demonstrate a greater geographic effect on the studied variables.

Behavioural Traits in Bos taurus Cattle, Their Heritability, Potential Genetic Markers, and Associations with Production Traits

People who work with cattle are at severe risk of serious injury due to the size and strength of the cattle. This risk can be minimised by breeding less dangerous cattle, which have a more favourable reaction to humans. This study provides a systematic review of literature pertaining to cattle genetics relating to behaviour. The review protocol was developed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) framework, with Population, Exposure and Outcome components identified as Bovine, Genetics and Behaviour respectively. Forty-nine studies were identified in the sifting and assigned non-exclusively to groups of heritability (22), genomic associations (13) and production traits related to behaviour (24). Behavioural traits were clustered into the following groups: "temperament, disposition and/ or docility", "aggression", "chute score", "flight speed", "milking temperament", "non-restrained methods" and "restrained methods". Fourteen papers reported high accuracy (Standard Error ≤ 0.05) estimates of heritability, the majority (n = 12) of these studies measured over 1000 animals. The heritability estimates were found to vary between studies. Gene associations with behavioural traits were found on all chromosomes except for chromosome 13, with associated SNPs reported on all chromosomes except 5, 13, 17, 18 and 23. Generally, it was found that correlations between behaviour and production traits were low or negligible. These studies suggest that additive improvement of behavioural traits in cattle is possible and would not negatively impact performance. However, the variation between studies demonstrates that the genetic relationships are population specific. Thus, to assess the heritability, genetic associations with production and genomic areas of interest for behavioural traits, a large-scale study of the population of interest would be required.

Influence of Excitability Rate on Physiological Responses to Stress in Goats

This study was conducted to determine if excitability score (ES) in goats can influence their physiological responses when subjected to stress. Thirty-six intact male Spanish goats (8-mo-old) were individually weighed and scored for excitability: 1 for calm (13 goats), 2 for moderately excitable (11 goats), and 3 for highly excitable (12 goats). To impose stress, goats were assigned to one of three treatments (TRT) for 90 min: (i) isolation in an open pen with metal grill panels, (ii) isolation in a pen with side panels covered using tarp sheets, and (iii) no isolation (control). Blood samples were collected at 0, 30, 60, and 90 min of isolation and physiological data were analyzed using MIXED procedures in SAS. The data from the two isolation treatments were pooled and compared with that of the control group. Plasma cortisol and non-esterified fatty acid concentrations were the lowest in goats with ES 1 (p < 0.05). Neutrophil−lymphocyte ratios were also the lowest in goats with a calm temperament (p < 0.01). Application of full quadratic model using response surface methodology (PROC RSREG) in SAS revealed that the influence of ES on physiological stress responses over time was not the same between the TRT groups. The results indicate that physiological stress responses are greater in goats with an excitable temperament compared to goats with a calm temperament.

Cattle acclimate more substantially to repeated handling when confined individually in a pen than when assessed as a group

Chute (CS) and exit (ES) scores are common subjective methods used to evaluate temperament in cattle production systems. A pen test, which allows behavior to be observed in a non-restrained setting, may also be an effective method to evaluate temperament by allowing more variation among animals to be expressed. The merit of pen scores in assisting producers in evaluating temperament is equivocal. The objectives of this study were to validate the usefulness of a pen score in delineating temperamental cattle and to determine whether these behavioral scores change under repeated and routine management. Over 3 consecutive years, a factorial design of two measurement protocols (frequent [F], infrequent [IN]) and three recording periods was used. The F measurements were collected over 3 consecutive days and IN measurements only on day 1 within a recording period. Each year, 20 mostly Angus commercial Bos taurus heifers were randomly assigned to each protocol. Behavior was measured using a CS, ES, and exit velocity. Body temperature and heart rate also were recorded. A fecal and blood sample were collected and analyzed for levels of various metabolites including glucose concentration and serum cortisol. Following routine handling, each heifers’ response to 30 s of exposure to a human stressor was recorded both individually and in groups of four. An individual (IPS) and group (GPS) pen scores were assigned from 1 (docile) to 6 (aggressive). For all heifers, protocol, event, and their interaction, were compared on the first day of an event. For F heifers, event and day within event were instead used. Body weight was included as a covariate, with sire and year fitted as random effects. Reliability of IPS and GPS were determined using a kappa (K) coefficient. Both IPS and GPS were reliably assigned (K = 0.64 and 0.44 for IPS and GPS, respectively) and positively correlated with body temperature, heart rate, glucose, and serum cortisol (r = 0.28 to 0.37). Furthermore, F heifers acclimated to repeated handling in an individual pen setting (P < 0.05) while acclimation to handling within groups was not evident (P > 0.14). IPS provides a reliable evaluation of temperament in a non-restrained setting that is indicative of an animal’s response to stress and may be useful when attempting to make phenotypic selection decisions. However, temperamental heifers became calmer with repeated gentle handling.

Chute and exit scores are common subjective methods used to evaluate temperament in cattle production systems. A pen test, which allows behavior to be observed in a non-restrained setting, may also be an effective method to evaluate temperament by allowing more variation among animals to be expressed. However, the merit of pen scores in assisting producers in evaluating temperament has yet to be discerned. Therefore, the objectives of this study were to validate the usefulness of pen scores in delineating temperamental cattle and to determine whether these behavioral scores change under repeated and routine management. Pen scores collected on heifers either individually or as a group could be assigned reliably and were indicative of an animal’s response to stress during normal handling practices. Temperamental heifers, when handled more frequently, acclimated to repeated handling in an individual pen setting but not in a group. Therefore, regardless of method, when cattle are excitable during their first handling experience, more than one observation of temperament may be beneficial before assessing temperament.

Development and Utilization of an Isolation Box Test to Characterize Personality Traits of Dairy Calves

The use of an isolation box test (IBT) to characterize personality traits has been used in non-bovine species with success. We aimed to develop an IBT for dairy calves and determine if the behavioral responses to an IBT were associated with personality traits found from traditional tests (novel person, novel object, and a startle tests) and average daily gain (ADG; Kg/d) through weaning. Calf movement while in the IBT was measured via accelerometers attached to 5 locations on the exterior of the box. A total movement index (TMI) was calculated based on accelerometer readings during the IBT. We performed a principal component analysis on the traditional tests and identified 3 influential factors that we labeled as “fearful,” “bold,” and “active.” Calves were weighed biweekly to track liveweight ADG. Factor scores and ADG were regressed against TMI. A significant negative association was found between the TMI and the factor “active,” indicating the validity of IBT as a tool for assessing some personality traits of dairy calves. Furthermore, TMI had a positive association with ADG through the entire experimental period and thus has potential to help predict performance through weaning. IBT has potential to be used as a personality test in research scenarios. Further development is needed to produce an IBT that would be appropriate to measure animals' responses reliably in production settings. An automated test that can accommodate a wide range of ages and developing a computer learning model to interpret output from the IBT would be a possible option to do so.

Effects of Temperament on the Reproduction of Beef Cattle

Simple Summary

In 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.

Abstract

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.

Effect of Finishing Diet and Lairage Time on Steers Welfare in Uruguay

Simple Summary

The transport and general handling of slaughter animals are associated with a series of events that cause stressful and unfavorable conditions that can compromise animal welfare. All these stressful events start at the farm and end with the death of the animal. In this experiment, we evaluated the effect of two finishing strategies and two contrasting lairage times through the combination of several indicators regarding productivity, physiology, behavior and postmortem variables. Individual temperaments and their impact on welfare and carcass quality were also considered. Animal welfare was not compromised in any diet during the finishing period. Individual temperament had a positive impact on the productivity and on all physiological indicators at different preslaughter stages. For that reason, we consider that it should be given paramount importance when talking about animal welfare. According to our results, with pasture-based animals, without fasting on the farm and after a short time of transportation (3.5 h), a longer preslaughter resting time (15 vs. 3 h) is desirable from the animal welfare perspective. Furthermore, our results suggest that this longer resting period, would also be more convenient from the carcass quality perspective.

Abstract

The objective of this experiment was to evaluate the effect of two different pasture-based finishing strategies and lairage time on steers welfare in Uruguayan conditions. Sixty Hereford (H) and Braford (B) steers were assigned to two different diets for finishing purposes: (D1) native pasture plus corn grain (1% of live weight) (H n = 15, B n = 15) and (D2) high-quality pasture (H n = 15, B n = 15). The average daily gain was registered every 14 days, and temperaments were individually assessed one week before slaughter by three individual tests: crush score, flight time and exit speed, building a multicriterial temperament index (TIndex). Animals were slaughtered the same day in two groups (50% from D1 and 50% from D2 in each group) after traveling for 3.5 h and staying 15 (long lairage) and 3 h (short lairage) in the lairage pens, respectively. The behaviors were observed during lairage, and physiological indicators were used to assess stress at the farm after transport, after lairage and at slaughter. Bruises incidence and final pH were registered at the abattoir as a means of assessing the overall animal welfare. Calmer animals had higher average daily gains with no differences either between diets or between breeds. Calmer animals also had a lower stress response during all preslaughter stages, regardless of the time in lairage. Transport did not imply psychological stress (cortisol) for any slaughter group, but physical stress was evident after transport in both groups through NEFA and CPK increases. Bruise incidences did not differ between lairage groups. The short lairage group did not have enough time to cope with the environment before slaughter, with the consequent deleterious effects on the carcass pH. Animals from the long lairage group had a higher metabolic response shown through NEFA values, but they had enough time to rest and recover overnight, reaching final pH values lower than 5.8, considered the upper limit of the normal range. According to this experiment, with pasture-based animals without fasting on the farm and after 3.5 h of transportation, a resting period of 15 h in lairage should be better than a 3-h one.

Researching Human-Cattle Interaction on Rangelands: Challenges and Potential Solutions

Simple Summary

Research investigating the influence of human-animal interactions on beef cattle production and welfare often occurs during stress-inducing contexts, such as restraint and transport. Given that beef cattle which graze on expansive rangelands do not frequently interact with humans, assessment of animal response to humans may be inaccurate if they are only recorded during such stressful context. Future research aimed at identifying the causes and impacts of individual human–cattle relationships may consider conducting experiments while the cattle are in a low stress context, such as while ruminating, resting, or, grazing. By adapting methods used to research wildlife response to humans, researchers may be able to better understand how animal personality and previous experience can influence cattle production and welfare.

Abstract

Human-animal interaction (HAI) research spans across many scientific fields and animal taxa. For livestock species, HAI research tends to focus on animals that are managed in close proximity with humans such as poultry, dairy cattle, and swine. Given the nature of rangeland cattle production, HAI research with beef cattle often occurs in and around the processing environment. This high arousal context may skew behavioral and physiological responses by the animals due to the potentially negative interaction. The aim of this review is to describe cattle production on rangelands, examine the considerations and limitations of current HAI research used to evaluate interaction quality or traits of rangeland cattle, identify contexts in which rangeland cattle interact with humans, and provide recommendations for improving future HAI research with rangeland cattle. Current research delineating individual differences in response to humans by beef cattle occur during routine husbandry and management on rangelands (pragmatic) and in a research context (experimental). Human-cattle interactions can be distinguished based on the quality and goal of the interaction into four broad categories: human presence, human approach, human contact, and restraint. Limitations of HAI research with rangeland cattle are identified and reconciled by recommendations for HAI research that can take place outside of the processing environment (i.e., while cattle are ruminating, resting or grazing on rangelands).

Calm Hu ram lambs assigned by temperament classification are healthier and have better meat quality than nervous Hu ram lambs

The objective of this study was to evaluate the effects of temperament classification (assessed using an arena test) on health and productivity of Hu ram lambs. In experiment one, eight ram lambs classified as calm and eight classified as nervous (selected from 100 ram lambs) were fed individually for 60-days to compare food intake, food digestibility, weight gain, and biochemical indices of health. In experiment two, nine ram lambs classified as calm and nine classified as nervous (selected from 150 ram lambs) were fed in a group and slaughter traits, meat quality, and muscle histology were compared. Calm lambs had higher dry matter digestibility, lower serum TNF-α, higher total antioxidant capacity, higher total superoxide dismutase activity, higher dressing percentage, higher cross-sectional area of loin, higher myofibre density, lower ultimate pH of the meat, and higher meat redness, than nervous lambs. Selection for calm temperament could be beneficial to health, slaughter, and carcass traits in Hu ram lambs.

Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha)

Simple Summary

The paca (Cuniculus paca), a Neotropical caviomorph rodent, provides the most sought-after game meat in all its range, and it therefore faces high hunting pressure and consequent poor welfare. The species is categorised as having a conservation status of “least concern” and appears resilient to over-hunting by humans, which may be related to individuals’ behavioural characteristics. To investigate this, we submitted captive pacas to temperament (personality) tests designed to assess individual responses to short challenges and to evaluate individuals’ emotional states. Our results showed that paca with a “restless” temperament performed more abnormal behaviour and less exploratory behaviour in a test of defensive behaviour, which elevations in faecal glucocorticoid metabolites indicated to be stressful. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to different levels of risk. Our results suggest that individual differences and consistency of behavioural responses displayed by paca toward challenges may reflect a generally flexible and successful defensive behavioural response that underpins the paca’s survival, despite the threat of overhunting throughout its range.

Abstract

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals’ affective states. Results indicated across-time and context stability in closely correlated “agitated”, “fearful” and “tense” responses; this temperament dimension was labelled “restless”. Individual “restless” scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals’ conservation status and vulnerabilities.

The Effect of Stress on Reproduction and Reproductive Technologies in Beef Cattle-A Review

Researchers have contributed by increasing our understanding of the factors affecting reproduction in beef, mainly physical health and nutrition aspects, which have been main concerns during decades. Animal welfare is of outmost relevance in all animal production systems and it is strongly associated to stress. Stress responses involve endocrine, paracrine and neural systems and the consequences of this stress on the reproductive efficiency of specifically, beef cattle and bulls, need to be highlighted. We, therefore, describe the fundamentals of stress and its quantification, focusing in beef herds, reviewing the highly valuable pieces of research, already implemented in this field. We examine major factors (stressors) contributing to stress in beef cattle and their effects on the animals, their reproductive performance and the success of reproductive biotechnologies. We include terms such as acclimatization, acclimation or temperament, very relevant in beef systems. We examine specifically the management stress due to handling, social environment and hierarchy or weaning effects; nutritional stress; and thermal stress (not only heat stress) and also review the influence of these stressors on reproductive performance and effectiveness of reproductive biotechnologies in beef herds. A final message on the attention that should be devoted to these factors is highlighted.

Association between temperament related traits and single nucleotide polymorphisms in the serotonin and oxytocin systems in Merino sheep

Animal temperament is defined as the consistent behavioral and physiological differences that are seen between individuals in response to the same stressor. Neurotransmitter systems, like serotonin and oxytocin in the central nervous system, underlie variation in behavioral traits in humans and other animals. Variations like single nucleotide polymorphisms (SNPs) in the genes for tryptophan 5-hydroxylase (TPH2), the serotonin transporter (SLC6A4), the serotonin receptor (HTR2A), and the oxytocin receptor (OXTR) are associated with behavioral phenotype in humans. Thus, the objective of this study was to identify SNPs in those genes and to test if those variations are associated with the temperament in Merino sheep. Using ewes from the University of Western Australia temperament flock, which has been selected on emotional reactivity for more than 20 generations, eight SNPs (rs107856757, rs107856818, rs107856856 and rs107857156 in TPH2, rs20917091 in SLC6A4, rs17196799 and rs17193181 in HTR2A, and rs17664565 in OXTR) were found to be distributed differently between calm and nervous sheep. These eight SNPs were then genotyped in 260 sheep from a flock that has never been selected on emotional reactivity, followed by the estimation of the behavioral traits of those 260 sheep using an arena test and an isolation box test. We found that several SNPs in TPH2 (rs107856757, rs107856818, rs107856856 and rs107857156) were in strong linkage disequilibrium, and all were associated with behavioral phenotype in the nonselected sheep. Similarly, rs17196799 in HTR2A was also associated with the behavioral phenotype.

Deciphering Cattle Temperament Measures Derived From a Four-Platform Standing Scale Using Genetic Factor Analytic Modeling

The animal's reaction to human handling (i.e., temperament) is critical for work safety, productivity, and welfare. Subjective phenotyping methods have been traditionally used in beef cattle production. Even so, subjective scales rely on the evaluator's knowledge and interpretation of temperament, which may require substantial experience. Selection based on such subjective scores may not precisely change temperament preferences in cattle. The objectives of this study were to investigate the underlying genetic interrelationships among temperament measurements using genetic factor analytic modeling and validate a movement-based objective method (four-platform standing scale, FPSS) as a measure of temperament. Relationships among subjective methods of docility score (DS), temperament score (TS), 12 qualitative behavior assessment (QBA) attributes and objective FPSS including the standard deviation of total weight on FPSS over time (SSD) and coefficient of variation of SSD (CVSSD) were investigated using 1,528 calves at weaning age. An exploratory factor analysis (EFA) identified two latent variables account for TS and 12 QBA attributes, termed difficult and easy from their characteristics. Inclusion of DS in EFA was not a good fit because it was evaluated under restraint and other measures were not. A Bayesian confirmatory factor analysis inferred the difficult and easy scores discovered in EFA. This was followed by fitting a pedigree-based Bayesian multi-trait model to characterize the genetic interrelationships among difficult, easy, DS, SSD, and CVSSD. Estimates of heritability ranged from 0.18 to 0.4 with the posterior standard deviation averaging 0.06. The factors of difficult and easy exhibited a large negative genetic correlation of -0.92. Moderate genetic correlation was found between DS and difficult (0.36), easy (-0.31), SSD (0.42), and CVSSD (0.34) as well as FPSS with difficult (CVSSD: 0.35; SSD: 0.42) and easy (CVSSD: -0.35; SSD: -0.4). Correlation coefficients indicate selection could be performed with either and have similar outcomes. We contend that genetic factor analytic modeling provided a new approach to unravel the complexity of animal behaviors and FPSS-like measures could increase the efficiency of genetic selection by providing automatic, objective, and consistent phenotyping measures that could be an alternative of DS, which has been widely used in beef production.

Relationships between temperament, meat quality, and carcass traits in Nellore cattle1

The aim of this study was to evaluate the relationship between temperament in Nellore bulls with carcass and meat quality traits. In total, 1,400 bulls were studied, and temperament was assessed using two measurements: movement score (MOV) and flight speed test (FS). Both MOV and FS were measured at two time points, with background (MOVb and FSb) temperament measured at yearling age, ~550 d after birth, and the preslaughter (MOVps and FSps) temperament measured at the end of the feedlot period. The change of temperament resulting in an increase or decrease in reactivity was also used to measure meat quality. The traits used to define carcass and meat quality included carcass bruises (BRU), hot carcass weight (HCW, kg), ribeye area (REA, cm2), backfat thickness (BFT, cm), marbling score (MS), meat pH after thawing (pH), presence or absence of dark cutters, color parameters of luminosity (L*), redness (a*) and yellowness (b*), cooking loss (CL, %), and Warner-Bratzler shear force (WBSF, kg). A principal component (PC) analysis was initially applied to the carcass and meat quality traits, followed by logistic regression models and linear mixed models to evaluate the effects of temperament on carcass and meat quality. The risks of carcass bruises and dark cutters did not differ as a function of any temperament trait (P > 0.05). In turn, animals classified as high MOVb (reactive) had lower PC3 values (P = 0.05), CL (P = 0.02), and tended to have lower MS (P = 0.08). In addition, animals classified as high FSb (faster and reactive cattle) produced carcasses with smaller REA (P < 0.01), higher meat pH (P < 0.01), lower color gradients (L*, P = 0.04; b*, P < 0.01), and lower PC1 and PC4 scores (P < 0.01) when compared with the low FSb class. For preslaughter temperament, high MOVps was related to lower color a* (P = 0.04), whereas high FSps was related to lower HCW, MS, and PC2 (P < 0.01) than the calmer ones (low FSps). The reduction in MOV was related to more tender meat, and the reduction in FS to heavier carcass and brighter meat. We conclude that excitable temperament in Nellore cattle may have negative effects in some of the carcass and meat quality attributes assessed, mainly those related to muscle deposition on carcass and color gradients. Measurement of temperament before the cattle entered the feedlot was a better predictor of carcass and meat quality traits, compared with temperament assessment at the end of the feeding period.

Randomised Control Trial Comparing Cypermethrin-Based Preparations in the Prevention of Infectious Bovine Keratoconjunctivitis in Cattle

Simple Summary

Infectious bovine keratoconjunctivitis (IBK) caused by the bacteria Moraxella bovis is commonly seen in the summer months spread by face flies causing a painful eye disease. This trial investigated the difference in number of cases of IBK between two groups of animals that were treated with two different fly control products, one a pour-on and one an impregnated ear tag. The growth rate per day was also investigated between animals with cases and those without and between the treatment groups. The trial enrolled 197 animals. Cases of IBK and growth rate were recorded over the grazing season (April–November 2018). Fifty-four cases of IBK were recorded. There was no difference in number of cases between the two treatment groups and there was no difference in growth rate between animals that had a case and animals that had not. Animals that had white faces, which in this trial were Hereford cattle and also the animals under 12 months old were found to be more likely to get a case. Overall, there was no significant difference between the two fly control preparations in preventing IBK, younger animals and white-faced breeds are significantly more likely to suffer from IBK.

Abstract

Infectious bovine keratoconjunctivitis (IBK) caused by Moraxella bovis is commonly seen in the summer months spread by face flies. This trial investigated the difference in incidence of IBK cases from natural exposure between two groups of animals, one treated with Cypermethrin pour-on preparation (PON, n = 98) and one with Cypermethrin impregnated ear tags (TAG, n = 99). Daily Live Weight Gain (DLWG) difference was investigated between animals with cases and those without and between treatment groups. A randomised positive control study, enrolled 197 animals split into two treatment groups. Cases of IBK and DLWG were recorded over the grazing season (April–November 2018). Fifty-four cases of IBK were recorded. There was no association between the two treatment groups (p = 0.362) and case status. Breed and under 12 months old were significant factors for having a case; (OR 2.3, p = 0.014 and OR 3.5, p < 0.001 respectively). There was no difference in DLWG between animals that had a case and animals that had not (p = 0.739) or between the two treatment groups (p = 0.215). Based on our results, there is no significant difference between PON or TAG preparations in the prevention of IBK. Younger animals and white-faced breeds are significantly more likely to suffer with IBK.

The Influence of Temperament on Body Temperature Response to Handling in Angus Cattle

Simple Summary

Understanding animal responses to stressful stimuli is a fundamental aspect to evaluating animal welfare. Stress-induced hyperthermia (SIH) is a term used to describe a short-term increase in body temperature that occurs in response to stressful stimuli. Recently there has been increasing interest in SIH as a physiological measure of psychological stress in livestock species. Previously, studies have suggested that cattle with more excitable temperaments exhibit an increased stress response. This study evaluated the influence of temperament on SIH, during a standardized handling procedure in Bos taurus cattle. In this study, body temperature increased, regardless of sex or temperament traits, characterizing SIH. Nevertheless, both flight speed (FS) and crush score (CS) were associated with an elevated rectal temperature (T_REC) 30 min prior to the handling procedure, and this continued from the start of handling (T0) to 10 min post-handling (T10). The results from this study suggest that temperament may be related to variation in SIH in cattle during handling. Understanding the variation in behavioral and physiological response to stressful events may enable the development of new measures for genetic selection in cattle.

Abstract

Previous studies have indicated that cattle with more excitable temperaments exhibit an increased stress response. The objective of this study was to investigate the relationship between temperament traits, handling, and stress-induced hyperthermia (SIH) in beef cattle. Rectal temperatures (T_REC, °C) of 60 purebred Angus cattle (30 heifers, 30 steers; 235.2 ± 5.11 kg) were recorded at 20 s intervals from 30 min prior to handling until two hours post handling. All cattle were exposed to a standardized handling procedure consisting of (i) being restrained in a weighing box for 30 s; (ii) being held within the crush for 30 s; and then (iii) being restrained in a head bail for 60 s. Cattle temperaments were evaluated via three traits: (1) agitometer score (AG); (2) crush score (CS); and (3) flight speed (FS) during the handling procedure. Agitometer scores and FS measures were used to describe an AG category (AG_CAT) and an FS category (FS_CAT) that were used to classify animals into three temperament categories: 1, calm; 2, intermediate; and 3, temperamental. Pearson’s correlation coefficients were used to evaluate the associations between (i) AG, CS, FS, and T_REC 30 min prior to entry into the weighing box (T-30) and then at 1 min intervals between time of entry into the weighing box (T0) until 10 min post-weighing (T10); and (ii) the relationship between AG, CS, and FS. The relationship between T_REC and temperament traits over the 2.5 h were modeled by using a first-order autoregressive repeated measures model. Flight speed had strong to moderate associations with T_REC at T-30 (r ≥ 0.37; p ≤ 0.006) and between T0 and T10 (r ≥ 0.36; p ≤ 0.01). There were moderate associations amongst T_REC between T0 and T10 and CS (r ≥ 0.31; p ≤ 0.01). A weak relationship existed with CS (r = 0.16; p = 0.16). There were no associations between AG and T_REC at T-30 (r ≥ −0.15; p = 0.84) or between T0 and T10 (r ≤ 0.04; p ≥ 0.4). Rectal temperature, irrespective of sex and temperament traits, was influenced by time (p < 0.0001), and maximum T_REC (39.3 ± 0.04 °C) occurred between 4 and 5.7 min after entry into the weighing box. In addition, CS (p = 0.007) influenced T_REC in these cattle. There were also time × temperament trait × sex interactions with the CS (p = 0.0003) and FS_CAT (p = 0.043) categories; however, time × temperament trait interactions were not statistically significant. Results from this study suggest that cattle with excitable temperaments, as evaluated by FS and CS, have a greater increase in T_REC. In addition, these results suggest that a relationship exists between basal T_REC and FS and CS. Together, these results highlight that temperament, as assessed by FS and CS, influences both basal T_REC and the peak temperature recorded following handling but does not influence the magnitude of change in T_REC post handling.

Welfare of beef cattle in Australian feedlots: a review of the risks and measures

The rising global demand for animal protein is leading to intensification of livestock production systems. At the same time, societal concerns about sustainability and animal welfare in intensive systems is increasing. This review examines the risks to welfare for beef cattle within commercial feedlots in Australia. Several aspects of the feedlot environment have the potential to compromise the physical and psychological welfare of cattle if not properly monitored and managed. These include, but are not limited to, animal factors such as the influence of genetics, temperament and prior health, as well as management factors such as diet, pen design, resource provision, pregnancy management, and stock-person attitudes and skills. While current industry and producer initiatives exist to address some of these issues, continuous improvements in welfare requires accurate, reliable and repeatable measures to allow quantification of current and future welfare states. Existing measures of welfare are explored as well as proxy indicators that may signal the presence of improved or reduced welfare. Finally, potential future measures of welfare that are currently under development are discussed and recommendations for future research are made.

Flight speed as an indicator of Zebu cattle growth performance and suitability to the feedlot environment

Context Studies assessing the relationship between cattle reactivity and growth performance, as well as suitability to the feedlot, in Zebu cattle are limited. Based on previous studies using Bos Taurus cattle, it is expected that reactivity measured at weaning could be used as a predictor of feedlot performance, and that cattle with greater flight speed (FS) would have reduced average daily gain (ADG). Aims The aims of this study were to (1) determine if FS (m/s) measured before entry into the feedlot could be used as a predictor of cattle performance, (2) evaluate the consistency of FS over time, and (3) determine when FS should be measured to best predict animal suitability to the feedlot. Methods A total of 54 Nellore and 40 Guzerat calves were assessed by using FS, which was collected at the time of (FS0) and 1 week after weaning (FS1), as well as on Day 28 (FS28), 56 (FS56) and 168 (FS168) after entry into the feedlot, and a FS average was calculated using FS28, FS56 and FS168 (FS28–168). Performance using ADG (kg/calf.day) was calculated for each animal over three periods: ADG1–28, ADG28–168 and ADG1–168. Bunk attendance (min/calf.day) was recorded over a 173-day feeding period. Key results The ADG28–168 was reduced by 0.14 kg/calf.day for each unit increase in FS0 (P &lt; 0.05). Both ADG28–168 and ADG1–168 were reduced by 0.02 kg/calf.day for each unit increase in FS1 (P ≤ 0.01), but neither FS0 nor FS1 was associated with ADG1–28 (P &gt; 0.10). A significant increase was observed between FS1 and FS28 (P &lt; 0.01), followed by a reduction in FS56 (P &lt; 0.01) and FS168 (P &lt; 0.01). Conclusion FS measured at or within 1 week of weaning has the potential to be used as an indicator of feedlot growth performance in Nellore and Guzerat cattle. Implications Although our results do not indicate the efficacy of FS as a predictor of early suitability of cattle to the feedlot, it does have the potential to support its recommendation as an indicator of overall feedlot growth performance in Nellore and Guzerat breeds.

Blood lactate and rectal temperature can predict exit velocity of beef feedlot steers

Interest in beef cattle temperament has increased due to growing consumer awareness of animal welfare and increased concern for handler safety. Temperament measures are based on behavioral responses to a perceived stressor. Subjective chute scoring has been used to give a numeric value to temperament; however, the subjectivity and variability among observers have been questioned. To deal with the perceived subjectivity and variability, other researchers have used exit velocity. Researchers have related faster exit velocities to increased cortisol and plasma lactate. The objectives of this study were to compare temperament between feedlot steers and heifers and to confirm chute side measures of temperament relationship to physiological responses to stress. Body temperature, blood and plasma lactate, serum glucose, salivary and serum cortisol concentrations were measured on Bos taurus commercial crossbred feedlot cattle (n = 197). Fast, medium, and slow classifications were developed from exit velocities. Plasma lactate was significantly different between all exit velocity classes. Exit velocity and physiological measures indicated that heifers were more excitable (faster exit velocities (P = 0.003), higher plasma lactate concentrations (P = 0.03), and cortisol concentrations (P = 0.001)). Simple correlations among these variables indicated body temperature (heifers r = 0.44, P < 0.0001; steers r = 0.45, P < .0001), plasma lactate (heifers r = 0.52, P < 0.0001; steers r = 0.63, P < 0.0001), blood lactate (heifers r = 0.53, P < 0.001; steers r = 0.59, P < 0.001), and glucose (heifers r = 0.54, P < 0.001; steers r = 0.32, P <0.003) were all related to exit velocity. Cortisol measures were not correlated to exit velocity in steers but were in heifers. Linear models constructed and evaluated using the Akaike information criterion indicated that blood lactate in combination with rectal temperature were strong candidates to predict exit velocity. Using the discriminate function analysis, the model correctly categorized fast and slow classifications 69.23% and 61.54%, respectively, indicating that in combination measures of body temperature and blood lactate can potentially increase accuracy of temperament identification or replace exit velocity as a measure of temperament. The plasma lactate and rectal temperature have the potential to become strong objective measures to augment or replace exit velocity.

Extensive human presence and regular gentle handling improve growth, survival and immune competence in ostrich chicks

A total of 416 day-old ostrich chicks were randomly allocated to one of the three different husbandry practices for 3 months after hatch; HP1 (extensive human presence with gentle human voice, visual and gentle physical stimuli), HP2 (similar to HP1 but without physical stimuli) and S (human presence limited to supply of feed and water). Chick weight (kg) was measured at 6 and 12 weeks of age, while mortalities were recorded daily to calculate the survival rate. Finally, chicks' antibody responses to vaccination against Newcastle disease (NCD) was measured using the Hemagglutination-Inhibition (HI) test at 20 weeks of age. While HP1 chicks were heavier and survived better to 6 weeks of age than HP2 and S chicks (p < .05), no difference was observed thereafter (p > .05). Furthermore, HP1 chicks had an improved immune competence, as illustrated by their lower percentage of positive HI titers, compared to HP2 and S chicks (p < .05). Hence, integrating extensive human presence with positive human-chick interactions may assist in alleviating challenges related to chick rearing in the ostrich industry.

Analysis of longissimus muscle quality characteristics and associations with DNA methylation status in cattle

BACKGROUND

As cattle represent one of the most important livestock species for meat production, control of muscle development in regards to quality is an important research focus.

OBJECTIVES

In this study, the phenotypic quality traits and its associations with DNA methylation levels of the longissimus muscle in two cattle breeds were studied.

METHODS

The pH value, water loss rate, fat and protein and fatty acid content were measured in three beef cattle breeds of longissimus mucle; The longissimus mucle was analyzed by MethylRAD-seq and RNA-seq. The differentially methylated and differentially expressed related genes were subjected to BSP.

RESULTS

Methylation status of longissimus mucle was analyzed by MethylRAD-seq. Compared with Simmental, there were 39 differentially methylated and expressed genes in muscle of Yunling cattle, and 123 differentially methylated and expressed genes in Wenshan muscle. A combined analysis of MethylRAD-seq and RNA-seq results revealed differential methylation and expression level of 18 genes between Simmental and Wenshan cattle, and 14 genes between Simmental and Yunling cattle. In addition, 28 genes were differentially methylated between Wenshan and Yunling cattle. Results of promoter methylation analysis of ACAD11, FADS6 and FASN showed that the overall degree of DNA methylation of FADS6 and FASN was negatively correlated with their expression levels. Methylation level of FASN in Simmental was greater than Yunling and Wenshan. The degree of methylation at the FADS6 CpG4 site was significantly higher in Simmental than that in Yunling. The levels of methylation at the CpG7 locus of the Simmental and Yunling breeds were greater than Wenshan cattle. A negative correlation was detected between the methylation levels and the expression of FASN CpG1, CpG2, CpG3, CpG5, CpG7, and CpG10.

CONCLUSION

The functional and molecular regulatory mechanism of the genes related to meat quality can be revealed systematically from aspects of the genetic and epigenetic regulation. These studies will help to further explore the molecular mechanisms and phenotypic differences that regulate growth and quality of different breeds of cattle.

Effects of temperament at feedlot arrival and breed type on growth efficiency, feeding behavior, and carcass value in finishing heifers

Objectives were to evaluate the effects of temperament at feedlot arrival and breed type on productivity, feed efficiency, feeding behavior, and carcass quality traits in finishing beef heifers, and to examine interactions between temperament and breed type. Heifers (Angus, Braford, Brangus, and Simbrah, N = 411, BW = 280 kg) were fed a high-grain diet (ME = 3.0 Mcal/kg DM) in pens equipped with electronic feed bunks. Quality grade (QG), yield grade (YG), and Warner-Bratzler shear (WBS) force values (day 1 and 14 postmortem) were evaluated. Relative exit velocity (REV) at feedlot arrival was used as a covariate in mixed models to assess the effects of temperament and interactions with breed type, with means compared at ±1 SD from the mean initial REV. Calm heifers (mean REV minus 1 SD) had 4% greater (P < 0.001) initial BW, 12% greater (P < 0.001) ADG, 8% greater (P < 0.001) DMI, and 4% greater (P < 0.02) G:F than heifers with excitable temperaments (mean REV plus 1 SD). A temperament × breed interaction was detected (P < 0.01) for residual feed intake (RFI). Braford heifers had a more (P < 0.05) negative REV covariate slope (-1.49 ± 0.65) than the other breeds, such that excitable Braford heifers had lower (P < 0.05) RFI than the other breeds with excitable temperaments. Temperament × breed interactions were observed (P < 0.001) for DMI per BW0.75 and bunk visit (BV) duration. Braford heifers had more (P < 0.05) negative REV covariate slopes for both traits than Angus, Brangus, and Simbrah heifers such that excitable Braford heifers consumed less (P < 0.05) DMI per BW0.75 and had less BV duration compared to excitable Angus and Brangus heifers. Calm heifers had 9% greater (P < 0.01) meal duration, and consumed meals that were 22% longer (P < 0.001) and 17% larger (P < 0.001) compared to excitable heifers. Calm heifers had 12% more (P < 0.001) BV events per meal then excitable heifers. Carcasses from calm heifers were 4% heavier (P < 0.05) and had 7% greater (P = 0.05) backfat (BF) depth and tended to have 4% greater (P = 0.07) USDA YG than carcasses from excitable heifers. Additionally, loin steaks from calm heifers had 8% lower (P < 0.05) WBS force than steaks from excitable heifers. Based on a carcass grid with discounts and premiums for HCW, QG, YG, and tenderness, calm heifers returned $62 more (P < 0.01) revenue per animal than excitable heifers. These results demonstrate that heifers with divergent phenotypes for temperament on feedlot arrival differ in their performance, feed efficiency, and feeding behavior patterns, as well as carcass quality and revenue.

Performance, carcass and meat quality traits of grazing cattle with different exit velocity

To evaluate the effect of grazing cattle temperament on performance, as well as carcass and meat quality traits, exit velocity (EV) was assessed throughout two production cycles (PC1, n = 38 and PC2, n = 52). Individual EV determinations were assessed throughout each PC and then 100-days period averages were calculated for each animal. Animals were ranked based on their EV (EV-RANK) in the first 100-days period as SLOW, FAST and MEDIUM. The EV decreased from weaning to slaughter in FAST and MEDIUM (P &lt; 0.05); but did not change in SLOW (P &gt; 0.10). Initial liveweight was lowest in FAST and highest in MEDIUM (P = 0.03). DM intake (P = 0.08) and average daily gain (P = 0.94) were not affected by EV-RANK, but carcass subcutaneous fat thickness was lowest in FAST and highest in MEDIUM (P = 0.02). Longissimus muscle colour and shear-force were not affected by EV-RANK (P &gt; 0.05), but muscle glycogen content at slaughter was higher in MEDIUM than in SLOW or FAST (P = 0.047). No EV-RANK effects were observed in the present study on meat colour and shear-force. However, its effects on subcutaneous fat thickness and muscle glycogen could result in low meat quality of temperamental cattle under more stressful handling situations.

Thermoregulatory response of Brangus heifers to naturally occurring heat exposure on pasture

Heat stress is a cause of major economic losses to cattle producers, especially in tropical and subtropical environments. The objectives of this study were to assess the phenotypic variability in core body temperature and sweating rate and to evaluate the effect of coat type, temperament, and BW on core body temperature and sweating rate in Brangus heifers. During August and September of 2016, 725 Brangus heifers were evaluated on pasture in four separate groups (n = 200, 189, 197, and 139). Environmental measurements of dry bulb temperature (Tdb) and relative humidity (RH) were measured every 15 min during the entire time of data collection and the temperature-humidity index (THI) was used to quantify heat-stress potential. Coat score, sweating rate, chute score, exit score, and live weight were recorded as the animals passed through the chute. Vaginal temperature was recorded every 5 min for five consecutive days. There was significant variation in vaginal temperature between heifers in the same environmental conditions (σ2u = 0.049), suggesting opportunities for selective improvements. A repeatability of 0.47 and 0.44 was estimated for sweating rate and vaginal temperature, respectively, suggesting that one measurement would be able to adequately describe the sweating capacity or ability to control the body temperature of an individual. Vaginal temperature increased as THI increased, with approximately 1 h lag time in the animal's response. Vaginal temperature (-0.047 °C, P = 0.015) and sweating rate were lower (-5.49 ± 2.12 g/(m2·h), P < 0.01) for heifers that demonstrated a calmer behavior in the chute. Animals with shorter, smoother hair coats had significantly lower vaginal temperatures when compared to animals with longer hair coats (P < 0.01). Also, heavier heifers in this study maintained lower (P < 0.0001) vaginal temperature than the lighter heifers. Our results showed that hair coat, temperament, and weight influenced vaginal temperature regulation.

Effects of temperament on growth, plasma cortisol concentrations and puberty attainment in Nelore beef heifers

Excitable temperament disrupts physiological events required for reproductive development in cattle, but no research has investigated the impacts of temperament on growth and puberty attainment in Bos indicus females. Hence, this experiment evaluated the effects of temperament on growth, plasma cortisol concentrations and puberty attainment in B. indicus heifers. A total of 170 Nelore heifers, weaned 4 months before the beginning of this experiment (days 0 to 91), were managed in two groups of 82 and 88 heifers each (mean ± SE; initial BW=238±2 kg, initial age=369±1 days across groups). Heifer temperament was evaluated via exit velocity on day 0. Individual exit score was calculated within each group by dividing exit velocity into quintiles and assigning heifers with a score from 1 to 5 (1=slowest; 5=fastest heifer). Heifers were classified according to exit score as adequate (ADQ, n=96; exit score⩽3) or excitable temperament (EXC, n=74; exit score&gt;3). Heifer BW, body condition score (BCS) and blood samples were obtained on days 0, 31, 60 and 91. Heifer exit velocity and score were recorded again on days 31, 60 and 91. Ovarian transrectal ultrasonography was performed on days 0 and 10, 31 and 41, 60 and 70, 81 and 91 for puberty evaluation. Heifer was declared pubertal at the first 10-day interval in which a corpus luteum was detected. Exit velocity and exit score obtained on day 0 were correlated (r⩾0.64, P&lt;0.01) with evaluations on days 31, 60 and 91. During the experiment, ADQ had greater (P&lt;0.01) mean BCS and BW gain, and less (P&lt;0.01) mean plasma cortisol concentration compared with EXC heifers. Temperament × time interactions were detected (P&lt;0.01) for exit velocity and exit score, which were always greater (P&lt;0.01) in EXC v. ADQ heifers. A temperament × time interaction was also detected (P=0.03) for puberty attainment, which was delayed in EXC v. ADQ heifers. At the end of the experiment, a greater (P&lt;0.01) proportion of ADQ were pubertal compared with EXC heifers. In summary, B. indicus heifers classified as EXC had reduced growth, increased plasma cortisol concentrations and hindered puberty attainment compared to ADQ heifers. Moreover, exit velocity may serve as temperament selection criteria to optimize development of B. indicus replacement heifers.

Capybara meat: An extraordinary resource for food security in South America

The available information on capybara (Hydrochoerus hydrochaeris) meat, an important resource for the subsistence of many traditional communities in several South American countries, is reviewed. Some features of the species, such as an herbivorous diet, high prolificacy, rapid growth rate, tameness, and social behaviour, which allow its commercial use through harvesting in Venezuela and farming in Brazil, where commercial hunting is not allowed, is discussed. Key characteristics of capybara meat, is low saturated fat and cholesterol content. Discussions about management and handling practices regarding animal welfare and capybara meat quality are also highlighted. After commenting on ethical, political, and economic implications of wildlife use it is concluded that capybara meat has an extraordinary potential to satisfy the growing demand for healthy and high-quality protein of animal origin for the subsistence of many people in the Neotropics.

Temperament and dominance relate to feeding behaviour and activity in beef cattle: implications for performance and methane emissions

In beef cattle, feeding behaviour and activity are associated with feed efficiency and methane (CH4) emissions. This study aimed to understand the underlying traits responsible for the contribution of cattle behaviour to individual differences in feed efficiency, performance and CH4 emissions. A total of 84 steers (530±114 kg BW) of two different breeds (crossbreed Charolais and Luing) were used. The experiment was a 2×2×3 factorial design with breed, basal diets (concentrate v. mixed) and dietary treatments (no additive, calcium nitrate or rapeseed cake) as the main factors. The individual dry matter intake (DMI; kg) was recorded daily and the BW was measured weekly over a 56-day period. Ultrasound fat depth was measured on day 56. Based on the previous data, the indexes average daily gain, food conversion and residual feed intake (RFI) were calculated. The frequency of meals, the duration per visit and the time spent feeding per day were taken as feeding behaviour measures. Daily activity was measured using the number of steps, the number of standing bouts and the time standing per day. Agonistic interactions (including the number of contacts, aggressive interactions, and displacements per day) between steers at the feeders were assessed as indicators of dominance. Temperament was assessed using the crush score test (which measures restlessness when restrained) and the flight speed on release from restraint. Statistical analysis was performed using multivariate regression models. Steers that spent more time eating showed better feed efficiency (P=0.039), which can be due to greater secretion of saliva. Feeding time was longer with the mixed diet (P<0.001), Luings (P=0.009) and dominant steers (P=0.032). Higher activity (more steps) in the pen was associated with poorer RFI, possibly because of higher energy expenditure for muscle activity. Frequent meals contributed to a reduction in CH4 emissions per kg DMI. The meal frequency was higher with a mixed diet (P<0.001) and increased in more temperamental (P=0.003) and dominant (P=0.017) steers. In addition, feed intake was lower (P=0.032) in more temperamental steers. This study reveals that efficiency increases with a longer feeding time and CH4 emissions decrease with more frequent meals. As dominant steers eat more frequently and for longer, a reduction in competition at the feeder would improve both feed efficiency and CH4 emissions. Feed efficiency can also be improved through a reduction in activity. Selection for calmer cattle would reduce activity and increase feed intake, which may improve feed efficiency and promote growth, respectively.

Assessing and mitigating post-operative castration pain in Bos indicus cattle

Cattle on pastoral land are subject to potentially painful husbandry procedures. In northern Australia, these practices generally occur once a year after the muster and the procedures are usually performed on animals older than 6 months of age. It is seldom that any pain mitigating medications are administered at this time and there is increasing concern that this perceived impost on the animal’s welfare will become more significant at both an economic and cultural level. There is a need to investigate the possibility of using simple, cost-effective, readily available medications, administered using relatively quick and easily taught techniques to increase the chance of industry adoption. This research used castration of 6–8-month-old Bos indicus calves as the test model because it is arguably one of the most common and most painful procedures endured by the animals. Forty-eight, 6–8-month-old Brahman bulls were surgically castrated after random assignment to six different treatment groups (n = 8): no castration Control (NC); castration (C); castration with post-operative meloxicam (CMpost-op); castration with lignocaine (CL); castration with lignocaine and post-operative meloxicam (CLMpost-op); castration with pre-operative meloxicam (CMpre-op). Serial measures of weight, blood cortisol concentrations, balk score, crush score, and daily activity (steps taken, number and duration of rest bouts) were taken. Linear mixed modelling was used to compare experimental groups. Bulls that were castrated and did not receive post-operative meloxicam (C and CL) had significantly lower average weights at all time points (Days 0–13, P < 0.001) of 170.9 kg and 168.6 kg, respectively, than those that did (CMpost-op and CLMpost-op) at 174.7 kg and 173.7 kg, respectively. When lignocaine was not administered before castration, Day 1 post-operative cortisol concentrations were significantly lower when post-operative meloxicam was provided than when it was not (CMpost-op: 47.2 nmol/L vs C: 65.5 nmol/L). When post-operative meloxicam was not given, animals that were given lignocaine before castration had significantly lower cortisol concentrations than those that received no lignocaine (CL: 52.7 nmol/L vs C: 65.5 nmol/L). Animals that were given pre-operative meloxicam had, on average, significantly lower Day 1 post-operative cortisol concentrations than animals that received no lignocaine or meloxicam (CMpre-op: 44.8 nmol/L vs C: 65.5 nmol/L). Analysis of Day 1 (the day following castration) data showed that animals that were given pre-operative meloxicam (CMpre-op) were significantly more active than animals in all other treatment groups (P = 0.038). It was concluded that 6–8-month old, Bos indicus bulls benefit from the administration of both lignocaine before surgery and peri-operative meloxicam. The analgesic methods used are readily adoptable by industry with respect to cost, efficiency and degree of technical skill required.

Frequent handling of grazing beef cattle maintained under the rotational stocking method improves temperament over time

Our aims were to assess the effects of handling frequency on temperament evolution in cattle kept under rotational stocking method (RSM), as well as to compare the temperament of animals maintained under rotational versus alternate stocking (ASM) methods. We evaluated 4256 males raised on pasture from four private properties (Farms 1–4), for a total of 9628 observations. The study was divided into two complementary approaches. In the first one, monthly visits were conducted at 35-day intervals to assess the cattle temperament (n = 1979) raised on grazing system using RSM, while, in the second approach, we evaluated the temperament of cattle (n = 3600) kept under two different stocking methods, namely, (1) RSM (n = 2007), characterised by a high frequency of animal handling and a 4-day grazing period, and (2) ASM (n = 1593), characterised by a low frequency of handling and a 20-day grazing period. Composite reactivity score (RS), and flight speed (FS) were considered as temperament indicators. Reductions of RS and FS means were observed during successive assessments under RSM. Significant effects of stocking method on FS (P < 0.05) and RS (P < 0.01) were found, with lower FS and RS means for animals under RSM than for those under ASM. In conclusion, the frequent handling in the rotational stocking method favoured the improvement of cattle temperament over time, with lower levels of reactivity among cattle raised under this stocking method than with animals raised under the alternate stocking method.

Impacts of temperament on Nellore cattle: physiological responses, feedlot performance, and carcass characteristics

Forty-four feedlot-finished Nellore cattle were used to evaluate the impacts of temperament on performance, meat and carcass traits, and serum concentrations of hormones, proteins, enzymes, and immunoglobulins. Individual temperament was assessed at feedlot entry (d 0), 67 d, and 109 d, utilizing chute score (CS; 5-point scale) and exit velocity (EV). Temperament scores were calculated averaging CS and EV scores, and cattle were subsequently classified according to their temperament (an average of ≤3 = adequate temperament [ADQ], or an average of >3 = excitable temperament [EXC]). At the end of the experiment (d 109), all 44 animals were slaughtered, and 16 were randomly selected for final empty body weight (EBW) estimation. Blood samples were collected at 0, 67, and 109 d and analyzed for serum variables (cortisol, insulin, haptoglobin, total protein, lactate, creatinine kinase [CK], lactate dehydrogenase [LDH], and IgA). The incidence of carcass bruises was verified immediately after the hide was removed. Carcass pH was obtained at 0 and 24 h postmortem. Samples of the LM were collected for meat quality analyses. Cattle classified as ADQ had greater final BW ( = 0.03), final EBW ( = 0.02), metabolic weight ( = 0.03), ADG ( = 0.02), feed efficiency ( = 0.03), HCW ( = 0.02), cold carcass weight ( = 0.02), and LM area ( < 0.01) compared to that of the EXC cohorts. Cattle classified as ADQ tended to have a lower percentage of cooler shrink ( = 0.06) compared to that of EXC cattle. No temperament effects were detected for initial BW ( = 0.70), DMI ( = 0.14), cold dressing percentage ( = 0.98), or backfat thickness ( = 0.29). Cattle classified as ADQ had greater marbling ( = 0.02) and meat fat content ( = 0.05) compared with that of EXC cattle. No temperament effects ( > 0.05) were detected for unsaturated fatty acid (UFA), SFA, MUFA, PUFA, and n-6:n-3 ratio. For blood parameters, EXC cattle had greater values of cortisol ( = 0.04) and haptoglobin ( = 0.05) and tended ( = 0.06) to have reduced serum insulin concentration compared with ADQ cattle. Both temperament groups had similar serum concentrations of IgA ( = 0.25) and total protein ( = 0.84). Cattle classified as EXC presented greater amounts ( = 0.05) of carcass bruises. In conclusion, an EXC temperament impaired feedlot performance, carcass characteristics, and meat quality traits in finishing Nellore cattle.

Association of Temperament and Acute Stress Responsiveness with Productivity, Feed Efficiency, and Methane Emissions in Beef Cattle: An Observational Study

The aim of this study was to assess individual differences in temperament and stress response and quantify their impact on feed efficiency, performance, and methane (CH₄) emissions in beef cattle. Eighty-four steers (castrated males) (Charolais or Luing) were used. Temperament was assessed using two standardized tests: restlessness when restrained [crush score (CS)] and flight speed (FS) on release from restraint. Over a 56-day period individual animal dry matter intake (DMI) and weekly body weight was measured. Ultrasound fat depth was measured at the end of 56 days. Average daily gain (ADG), feed conversion ratio (FCR), and residual feed intake (RFI) were calculated. After the 56-day test period, animals were transported in groups of six/week to respiration chamber facilities. Blood samples were taken before and 0, 3, 6, and 9 h after transport. Plasma cortisol, creatine kinase (CK), glucose, and free fatty acids (FFA) were determined to assess physiological stress response. Subsequently, CH₄ emissions were measured over a 3-day period in individual respiration chambers. CS (1.7 ± 0.09) and FS (1.6 ± 0.60 m/s) were repeatable (0.63 and 0.51, respectively) and correlated (r = 0.36, P < 0.001). Plasma cortisol, CK, and FFA concentrations increased after transport (P = 0.038, P = 0.006, and P < 0.001, respectively). Temperament (CS) and CK concentration were correlated (r = 0.29; P = 0.015). The extreme group analysis reveals that excitable animals (FS; P = 0.032) and higher stress response (cortisol, P = 0.007; FFA, P = 0.007; and CK, P = 0.003) were associated with lower DMI. ADG was lower in more temperamental animals (CS, P = 0.097, and FS, P = 0.030). Fat depth was greater in steers showing calmer CS (P = 0.026) and lower plasma CK (P = 0.058). Temperament did not show any relationship with RFI or CH₄ emissions. However, steers with higher cortisol showed improved feed efficiency (lower FCR and RFI) (P < 0.05) and greater CH₄ emissions (P = 0.017). In conclusion, agitated temperament and higher stress responsiveness is detrimental to productivity. A greater stress response is associated with a reduction in feed intake that may both increase the efficiency of consumed feed and the ratio of CH₄ emissions/unit of feed. Therefore, temperament and stress response should be considered when designing strategies to improve efficiency and mitigate CH₄ emissions in beef cattle.

Genetic parameters for docility, weaning weight, yearling weight, and intramuscular fat percentage in Hereford cattle

Cattle behavior, including measures of docility, is important to beef cattle producers not only from a human safety perspective but also due to potential correlations to economically relevant traits. Field data from the American Hereford Association was used to estimate genetic parameters for chute score (CS; = 25,037), weaning weight (WW; = 24,908), yearling weight (YW; = 23,978), and intramuscular fat percentage (IMF; = 12,566). Single-trait and bivariate animal models were used to estimate heritabilities and genetic correlations. All models included fixed effects of sex and contemporary group, defined as herd-year-season, and direct genetic and residual components were included as random effects. For CS and WW, additional random effects of maternal genetic and maternal permanent environment were also fitted. For CS, WW, YW, and IMF, heritability estimates were 0.27 ± 0.02, 0.35 ± 0.03, 0.36 ± 0.02, and 0.27 ± 0.02, respectively. Genetic correlations between CS and WW, CS and YW, CS and IMF, WW and YW, WW and IMF, and YW and IMF were -0.12 ± 0.06, -0.10 ± 0.05, -0.08 ± 0.06, 0.47 ± 0.05, -0.19 ± 0.09, and -0.41 ± 0.05, respectively. Heritability estimates for all traits suggest that they would respond favorably to selection and that selection for increased WW or YW could decrease marbling. Genetic correlations between CS and WW, YW, and IMF were all favorable but weak, suggesting that selection for improved docility will not have negative consequences on growth or carcass quality. Furthermore, maternal additive and maternal permanent environmental variances for CS were near 0, suggesting that their inclusion in National Cattle Evaluations is not warranted.

Genetic selection for temperament traits in dairy and beef cattle

Animal temperament can be defined as a response to environmental or social stimuli. There are a number of temperament traits in cattle that contribute to their welfare, including their response to handling or milking, response to challenge such as human approach or intervention at calving, and response to conspecifics. In a number of these areas, the genetic basis of the trait has been studied. Heritabilities have been estimated and in some cases quantitative trait loci (QTL) have been identified. The variation is sometimes considerable and moderate heritabilities have been found for the major handling temperament traits, making them amenable to selection. Studies have also investigated the correlations between temperament and other traits, such as productivity and meat quality. Despite this, there are relatively few examples of temperament traits being used in selection programmes. Most often, animals are screened for aggression or excessive fear during handling or milking, with extreme animals being culled, or EBVs for temperament are estimated, but these traits are not commonly included routinely in selection indices, despite there being economic, welfare and human safety drivers for their. There may be a number of constraints and barriers. For some traits and breeds, there may be difficulties in collecting behavioral data on sufficiently large populations of animals to estimate genetic parameters. Most selection indices require estimates of economic values, and it is often difficult to assign an economic value to a temperament trait. The effects of selection primarily for productivity traits on temperament and welfare are discussed. Future opportunities include automated data collection methods and the wider use of genomic information in selection.

Calm temperament improves reproductive performance of beef cows

Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus-cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85-day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus-cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two-point chute exit-gait scoring method was repeatable and identified cattle with an excitable temperament.

Bill E. Kunkle Interdisciplinary Beef Symposium: Temperament and acclimation to human handling influence growth, health, and reproductive responses in Bos taurus and Bos indicus cattle

Temperament in cattle is defined as the fear-related behavioral responses when exposed to human handling. Our group evaluates cattle temperament using 1) chute score on a 1 to 5 scale that increases according to excitable behavior during restraint in a squeeze chute, 2) exit velocity (speed of an animal exiting the squeeze chute), 3) exit score (dividing cattle according to exit velocity into quintiles using a 1 to 5 scale where 1=cattle in the slowest quintile and 5=cattle in the fastest quintile), and 4) temperament score (average of chute and exit scores). Subsequently, cattle are assigned a temperament type of adequate temperament (ADQ; temperament score≤3) or excitable temperament (EXC; temperament score>3). To assess the impacts of temperament on various beef production systems, our group associated these evaluation criteria with productive, reproductive, and health characteristics of Bos taurus and Bos indicus-influenced cattle. As expected, EXC cattle had greater plasma cortisol vs. ADQ cattle during handling, independent of breed type (B. indicus×B. taurus, P<0.01; B. taurus, P<0.01; B. indicus, P=0.04) or age (cows, P<0.01; heifers or steers, P<0.01). In regards to reproduction, EXC females had reduced annual pregnancy rates vs. ADQ cohorts across breed types (B. taurus, P=0.03; B. indicus, P=0.05). Moreover, B. taurus EXC cows also had decreased calving rate (P=0.04), weaning rate (P=0.09), and kilograms of calf weaned/cow exposed to breeding (P=0.08) vs. ADQ cohorts. In regards to feedlot cattle, B. indicus EXC steers had reduced ADG (P=0.02) and G:F (P=0.03) during a 109-d finishing period compared with ADQ cohorts. Bos taurus EXC cattle had reduced weaning BW (P=0.04), greater acute-phase protein response on feedlot entry (P≤0.05), impaired feedlot receiving ADG (P=0.05), and reduced carcass weight (P=0.07) vs. ADQ cohorts. Acclimating B. indicus×B. taurus or B. taurus heifers to human handling improved temperament (P≤0.02), reduced plasma cortisol (P<0.01), and hastened puberty attainment (P≤0.02). However, no benefits were observed when mature cows or feeder cattle were acclimated to human handling. In conclusion, temperament impacts productive, reproductive, and health characteristics of beef cattle independent of breed type. Hence, strategies to improve herd temperament are imperative for optimal production efficiency of beef operations based on B. taurus and B. indicus-influenced cattle.

Genetic evaluation of aspects of temperament in Nellore-Angus calves

The objective of this work was to estimate heritability of each of 5 subjectively measured aspects of temperament of cattle and the genetic correlations of pairs of those traits. From 2003 to 2013, Nellore-Angus F2 and F3 calves (n = 1,816) were evaluated for aspects of temperament at an average 259 d of age, which was approximately 2 mo after weaning. Calves were separated from a group and subjectively scored from 1 (calm, good temperament) to 9 (wild, poor temperament) for aggressiveness (willingness to hit an evaluator), nervousness, flightiness, gregariousness (willingness to separate from the group), and a distinct overall score by 4 evaluators. Data were analyzed using threshold and linear models with additive genetic random effects. Two-trait animal models (nonthreshold) included the additive genetic covariance for pairs of traits and were used to estimate additive genetic correlations. Contemporary groups (n = 104) represented calves penned together for evaluation on given evaluation days. Heifers had greater (worse) means for all traits than steers (P < 0.05). The regression of score on age in days was included in final models for flightiness (P = 0.05; -0.006 ± 0.003) and gregariousness (P = 0.025; -0.007 ± 0.003). Estimates of heritability were large (0.51, 0.4, 0.45, 0.49, and 0.47 for aggressiveness, nervousness, flightiness, gregariousness, and overall temperament, respectively; SE = 0.07 for each). The ability to use this methodology to distinctly separate different aspects of calf temperament appeared to be limited, as estimates of additive genetic correlations were near unity for all pairs of traits; estimates of phenotypic correlation ranged from 0.88 ± 0.01 to 0.99 ± 0.002 for pairs of traits. Distinct subsequent analyses indicated a significant negative relationship of 4 of the various temperament scores with weight at weaning (regression coefficients ranged from -0.008 ± 0.002 for nervousness, flightiness, and gregariousness to -0.003 ± 0.002 for aggressiveness). In subsequent analyses, the regression of temperament trait on sequence of evaluation within a pen was highly significant and solutions ranged from 0.05 ± 0.007 for aggressiveness to 0.08 ± 0.007 for all other traits. The apparent large additive genetic variance for any one of these traits may be useful in identification of genes responsible for differences in cattle temperament.