Effects of the association between whole cottonseed and calcium salts of fatty acids on nutrient intake, feedlot performance, and carcass characteristics of Bos indicus animals offered a high-concentrate diet

This experiment evaluated the effects of feeding whole cottonseed (WC) and/or calcium salts of fatty acids (CSFA) on dry matter intake (DMI), performance, and carcass characteristics of Bos indicus animals receiving a high-concentrate diet during the finishing phase. On day 0, 96 Nellore bulls were blocked according to initial shrunk body weight (BW; 302 ± 26.7 kg) into group pens (four animals/pen) and, within blocks, pens were randomly assigned to receive: 1) 15% of WC and 2% of CSFA (dry matter [DM] basis) of palm, cottonseed, and soybean oil (15WC; n = 6); 2) 10% of WC and 3% of CSFA (DM basis) of palm, cottonseed, and soybean oil (10WC; n = 6); 3) 5% of WC and 4% of CSFA (DM basis) of palm, cottonseed, and soybean oil (5WC; n = 6); and 4) 0% of WC and 5% of CSFA (DM basis) of palm, cottonseed, and soybean oil (0WC; n = 6). Diets were formulated to be isocaloric, isonitrogenous, and isolipidic. Experimental period lasted 108 d; DMI was evaluated daily, whereas blood samples and carcass measurements were obtained on days 0, 55, and 108 of the study. Upon slaughter on day 109, steaks were collected for determination of the chemical and fatty acid (FA) profile of the meat. No treatment effects (P ≥ 0.35) were observed on DMI, performance, average daily gain (ADG), carcass ultrasound measurements, and chemical variables of the steak. Nonetheless, including WC into the diets decreased C12:0, C16:0, C16:1 trans-9, C17:0, C18:0, C18:1 cis-9, C18:2 cis-9, cis-12, C18:3 cis-9, cis-12, cis-15, saturated, and unsaturated FA intake (P < 0.01). Moreover, adding WC increased DMI fluctuation and feed efficiency (FE; P = 0.03) but decreased marbling (P ≤ 0.03). A treatment × day interaction was observed (P < 0.01) for serum leptin concentration, as 10WC animals had greater leptin concentration on day 103 vs. other treatments (P < 0.01). Regarding steak FA profile, WC addition into the diet increased C18:2 cis-7, trans-9 and C18:3 cis-9, cis-12, cis-15 (P < 0.001), whereas saturated FA was quadratically affected (P = 0.02) and unsaturated FA was reduced for 15WC (P < 0.04). In summary, increasing levels of CSFA into isolipidic finishing diets containing WC did not negatively impact feedlot performance but reduced FE and increased marbling scores of B. indicus bulls, demonstrating its feasibility as a technology to improve carcass traits of low-marbling animals.

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).

Understanding the Determination of Meat Quality Using Biochemical Characteristics of the Muscle: Stress at Slaughter and Other Missing Keys

Despite increasingly detailed knowledge of the biochemical processes involved in the determination of meat quality traits, robust models, using biochemical characteristics of the muscle to predict future meat quality, lack. The neglecting of various aspects of the model paradigm may explain this. First, preslaughter stress has a major impact on meat quality and varies according to slaughter context and individuals. Yet, it is rarely taken into account in meat quality models. Second, phenotypic similarity does not imply similarity in the underlying biological causes, and several models may be needed to explain a given phenotype. Finally, the implications of the complexity of biological systems are discussed: a homeostatic equilibrium can be reached in countless ways, involving thousands of interacting processes and molecules at different levels of the organism, changing over time and differing between animals. Consequently, even a robust model may explain a significant part, but not all of the variability between individuals.

Temperament influences mitochondrial capacity in skeletal muscle from 8 through 18 mo of age in Brahman heifers

Temperamental cattle tend to yield carcasses of poorer quality, and Brahman cattle are reportedly more temperamental than non-indicus cattle breeds. A potential link between temperament and product quality may be mitochondrial activity. We hypothesized that mitochondrial measures would be greater in temperamental compared with calm heifers and that the relationships between temperament and mitochondria would persist as heifers age. Serum cortisol and skeletal muscle (longissimus thoracis [LT] and trapezius [TRAP]) mitochondrial profiles and antioxidant activities were quantified from the same calm (n = 6) and temperamental (n = 6) Brahman heifers at 8, 12, and 18 mo of age. Data were analyzed using a mixed model ANOVA in SAS (9.4) with repeated measures. Serum cortisol was greater in temperamental compared with calm heifers throughout the study (P = 0.02). Mitochondrial volume density (citrate synthase [CS] activity) increased over time (P < 0.0001) but was similar between temperament and muscle groups. Mitochondrial function (cytochrome c oxidase activity) was greatest in the temperamental LT at 8 mo of age (P ≤ 0.0006), greatest in the temperamental TRAP at 18 mo of age (P ≤ 0.003), and did not differ by temperament at 12 mo of age. Integrative (relative to tissue wet weight) mitochondrial oxidative phosphorylation capacity with complex I substrates (PCI), PCI plus complex II substrate (PCI+II), noncoupled electron transfer system capacity (ECI+II), and E with functional complex II only (ECII) were greater in the TRAP than LT for calm heifers at all ages (P ≤ 0.002), but were similar between muscle groups in temperamental heifers. Overall, calm heifers tended to have greater intrinsic (relative to CS activity) PCI and flux control of PCI+II (P ≤ 0.1) than temperamental heifers, indicating greater utilization of complex I paired with greater coupling efficiency in calm heifers. Within the LT, integrative PCI+II was greater (P = 0.05) and ECI+II tended to be greater (P = 0.06) in temperamental compared with calm heifers. From 8- to 18-mo old, glutathione peroxidase (GPx) activity decreased (P < 0.0001) and superoxide dismutase activity increased (P = 0.02), and both were similar between muscle groups. The activity of GPx was greater in temperamental compared with calm heifers at 8 (P = 0.004) but not at 12 or 18 mo of age. These results detail divergent skeletal muscle mitochondrial characteristics of live Brahman heifers according to temperament, which should be further investigated as a potential link between temperament and product quality.

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.

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.

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.

Evaluating the Relationship of Animal Temperament to Carcass Characteristics and Meat Quality

The purpose of this study was to compare meat quality and sensory characteristics of steaks from longissimus dorsi of steers with different temperaments. Calves (n = 49; 314kg) were processed and scored for temperament according to Beef Improvement Federation Guidelines and divided into three groups: Docile (D), Restless (R) and Nervous-Flighty (NF). Steers were housed with access to pasture then transferred to a research feedlot until harvest and processed with carcass data recorded. Striploins were wet-aged for 14 d before, frozen and were then cut into 2.54 cm steaks, and individually vacuum packed. Instrumental color was measured on thawed and tray overwrapped steaks on d 0, 1, 2, 3, 5, and 7 of simulated retail display. The CIE L*, a*, and b* color values were collected and oxymyoglobin, hue angle and saturation index values were calculated. A 7-member trained sensory panel evaluated steak samples for myofibrillar tenderness, connective tissue amount, overall tenderness, juiciness, and beef flavor intensity. The NF group had reduced (P < 0.05) hot carcass weight compared to the other groups. The D and R groups were lighter (L*; P < 0.05), and R group yellower (b*; P < 0.05) and greater (P < 0.05) in hue angle than the other groups. No difference (P > 0.05) between groups for redness (a*), saturation index, and oxymyoglobin ratio were observed. Display time affected color with d 0 being redder (a*; P < 0.05), yellower (b*; P < 0.05), greater (P < 0.05) saturation index, and greater (P < 0.05) oxymyoglobin ratio than d 7. Steaks from D and R groups were more tender (P < 0.05) in myofibrillar tenderness, had less (P < 0.05) perceived connective tissue, were overall more tender (P < 0.05), and more (P < 0.05) juicy than steaks from the NF group. There was no difference (P > 0.05) in off-flavor between the temperament groups. Temperament had minimal effect on carcass characteristics except hot carcass weight. Sensory panelists detected differences between temperament groups.

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.

Cattle temperament influences metabolism: metabolic response to glucose tolerance and insulin sensitivity tests in beef steers

Cattle temperament, defined as the reactivity of cattle to humans or novel environments, can greatly influence several physiological systems in the body, including immunity, stress, and most recently discovered, metabolism. Greater circulating concentrations of nonesterified fatty acids (NEFAs) found in temperamental cattle suggest that temperamental cattle are metabolically different than calm cattle. Further, elevated NEFA concentrations have been reported to influence insulin sensitivity. Therefore, the objective of this study was to determine whether cattle temperament would influence the metabolic response to a glucose tolerance test (GTT) and insulin sensitivity test (IST). Angus-cross steers (16 calm and 15 temperamental; 216 ± 6 kg BW) were selected based on temperament score measured at weaning. On day 1, steers were moved into indoor stanchions to allow measurement of individual ad libitum feed intake. On day 6, steers were fitted with indwelling rectal temperature probes and jugular catheters. At 9 AM on day 7, steers received the GTT (0.5-mL/kg BW of a 50% dextrose solution), and at 2 PM on day 7, steers received the IST (2.5 IU bovine insulin/kg BW). Blood samples were collected and serum isolated at -60, -45, -30, -15, 0, 10, 20, 30, 45, 60, 90, 120, and 150 min relative to each challenge. Serum was stored at -80°C until analyzed for cortisol, glucose, NEFA, and blood urea nitrogen concentrations. All variables changed over time (P < 0.01). For the duration of the study, temperamental steers maintained greater (P < 0.01) serum NEFA and less (P ≤ 0.01) serum blood urea nitrogen and insulin sensitivity (calculated using Revised Quantitative Insulin Sensitivity Check Index) compared with calm steers. During the GTT, temperamental steers had greater (P < 0.01) serum glucose, yet decreased (P = 0.03) serum insulin and (P < 0.01) serum insulin: serum glucose compared to calm cattle. During the IST, temperamental steers had greater (P < 0.01) serum insulin and a greater (P < 0.01) serum insulin: serum glucose as compared with calm steers. These data demonstrate that differences exist in the manner in which temperamental steers respond to glucose and insulin, potentially a result of elevated serum NEFA concentrations, which may result in changes in utilization and redistribution of energy in temperamental vs calm cattle.

Male traits and herd reproductive capability in tropical beef cattle. 1. Experimental design and animal measures

Research into the genetics of whole herd profitability has been a focus of the Beef Cooperative Research Centre for Beef Genetic Technologies over the past decade and it has been identified that measures of male reproduction may offer a potential indirect means of selecting for improved female reproduction. This paper describes the experimental design and provides a descriptive analysis of an array of male traits in Brahman and Tropical Composite genotypes managed under the medium to high stress, semi-extensive to extensive production systems of northern Australia. A total of 1639 Brahman and 2424 Tropical Composite bulls with known pedigrees, bred and raised in northern Australia, were evaluated for a comprehensive range of productive and reproductive traits. These included blood hormonal traits (luteinising hormone, inhibin and insulin-like growth factor-I); growth and carcass traits (liveweight, body condition score, ultrasound scanned 12–13th rib fat, rump P8 fat, eye muscle area and hip height); adaptation traits (flight time and rectal temperature); and a bull breeding soundness evaluation (leg and hoof conformation, sheath score, length of everted prepuce, penile anatomy, scrotal circumference, semen mass activity, sperm motility and sperm morphology). Large phenotypic variation was evident for most traits, with complete overlap between genotypes, indicating that there is likely to be a significant opportunity to improve bull fertility traits through management and bull selection.

Development of psychophysiological motoric reactivity is influenced by peripubertal pharmacological inhibition of gonadotropin releasing hormone action--results of an ovine model

This study reports the effects of peripubertal GnRH receptor inactivation on development of psychophysiological motoric reactivity (PMR; sometimes also called emotional reactivity), plasma cortisol concentrations and the relationship between plasma cortisol and PMR in male and female sheep. The study formed part of a larger trial and utilised 46 same sex twins. One twin remained untreated (control) while the other received a subcutaneous GnRH agonist (GnRHa Goserelin-Acetate) implant every 4th week, beginning at 8 and 28 weeks of age, in males and females, respectively (different, due to sex specific age of puberty). PMR, a measure of an animals' response to social isolation, was measured over a two minute period at 8, 28 and 48 weeks of age, using a three axis accelerometer. During the test period vocalisation rate was recorded. Cortisol was assayed in blood samples collected on a single day when animals were 40 weeks of age. PMR and vocalisation rate were significantly higher in females than males at all ages tested. At 28 weeks of age (20 weeks treatment) PMR was increased in treated males to the level seen in control females, by 48 weeks of age treated males' PMR was significantly less than controls. In females, 20 weeks of GnRHa treatment (28-48 weeks of age) was not associated with differences in PMR. Cortisol concentrations were significantly higher in females than males but were not affected by treatment. Plasma cortisol concentrations were positively correlated with PMR; this relationship being driven by the treated animals in both sexes. The results demonstrate that PMR is sexually dimorphic and cortisol dependent in sheep from at least 8 weeks of age. Importantly, they also demonstrate that long-term treatment of males with a GnRH agonist results in changes in age-dependent development of PMR.

A comparison of commonly used and novel electronic techniques for evaluating cattle temperament

Schwartzkopf-Genswein, K. S., Shah, M. A., Church, J. S., Haley, D. B., Janzen, K., Truong, G., Atkins, R. P. and Crowe, T. J. 2012. A comparison of commonly used and novel electronic techniques for evaluating cattle temperament. Can. J. Anim. Sci. 92: 21–31. The temperament of steers (n=28) was assessed using five quantitative techniques including: flight time, flight distance, electronic (strain-gauge and accelerometer) tests, and three visual scores (VS) made during entry, restraint and exit from a squeeze chute. The objective of this study was to determine the most important predictive parameters based on those measurements and evaluate the relationship between the techniques. Flight time and distance were correlated with exit VS (r=−0.51, and 0.41, P<0.05; n=56), but were not related to restraint VS. Data from strain-gauge and accelerometer sensors were used to generate parameters such as peak response and area under the curve that were correlated with all three VS. Regression models using VS as the dependent variable and a combination of 2 to 5 parameters from the strain-gauge and accelerometer tests as independent variables predicted temperament with values of 29 to 65 or 41 to 57%, respectively. When all techniques, excluding VS, were used as independent variables, model accuracy increased to 72, 81 and 77% for restraint, exit and the sum of all VS, respectively. These findings suggest the objective measures of temperament assessed in this study could be used to identify highly reactive animals.

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

Fearful behavioral responses to handling (temperament) are undesirably associated with ADG and meat quality in infrequently handled Bos indicus cattle. It has never been assessed whether these relationships exist in calmer Bos taurus breeds in systems where handling is more frequent. Such systems predominate in some countries where beef production is a major agricultural activity. During fattening, 144 crossbred cattle from Limousin and Aberdeen Angus sires were assessed for temperament using 4 approaches: response to movement along a race (race score; 4 occasions), restraint in a crush (crush score; 4 occasions), flight speed from the crush (flight speed; 4 occasions), and isolation in a pen with a human (isolation score; 1 occasion in yr 1, 2 occasions in yr 2). Measurements of ADG were made between birth and slaughter and between 16 and 18 mo of age during fattening. Fattening occurred indoors on a complete mixed diet fed for ad libitum intake. Meat quality was measured by pH, color, and Volodkevitch shear force and by a sensory panel. The repeatability of temperament traits was 0.17 (race score), 0.35 (crush score), 0.51 (flight speed), and 0.36 (isolation score). The proportion of the total variance of temperament traits attributable to the sire and the social group was low (0.003 to 0.402). However, the sire did affect behavior in all tests apart from the crush score (ranging from P = 0.02 to P < 0.001). Correlations between behavior in the different tests (ranging from r = 0.21 to 0.54, and P = 0.02 to P < 0.001) apart from between-flight speed and isolation score indicate that fearful behavior was consistently shown across assessment methods. A calm response in the crush score test was associated with a greater ADG during fattening (P = 0.05), whereas a calm response during the isolation test was associated with a greater ADG in cold carcass weight (P = 0.02). Animals with a calm isolation score had less tender meat as judged by the sensory panel (P = 0.03), but no other effects were apparent between temperament and meat quality measures, although several tendencies (0.06 ≤ P ≤ 0.10) were found. Temperament did not appear to relate to meat quality in this study of frequently handled Bos taurus genotypes, which is in contrast to other studies using different beef production systems. Genetic correlations between temperament and meat quality under these conditions could, although not measured in this study, still exist in the absence of phenotypic correlations.

Effects of ractopamine supplementation on behavior of British, Continental, and Brahman crossbred steers during routine handling

Equal numbers of British, Continental crossbred, and Brahman crossbred calf-fed steers (n = 420) were used to examine the effects of ractopamine supplementation and biological type on behavior during routine handling. Steers were blocked by BW within type and allocated to pens, resulting in 2 pens (10 cattle per pen) representing each block x type subclass. Pens within each block x type subclass then were randomly assigned to ractopamine supplementation treatments (0 or 200 mg.steer(-1).d(-1)), which were administered during the final 28 d of the finishing period. At the time final BW were obtained (28 d after treatment initiation), a single, trained observer, blinded with respect to treatment designations, recorded subjective scores to characterize behavior of each animal. Scores included entry force score (degree of force required to load the animal into the chute); entry speed score (walk, trot, run); chute behavior score (calm, restless shifting, moderate struggling); and exit speed score (walk, trot, run). Ractopamine supplementation had no effect on entry force score, chute behavior score, or exit speed score; however, cattle supplemented with ractopamine entered the chute more rapidly than did control cattle. Biological cattle type was a significant source of variation in entry force score and exit speed score. Continental crossbreds required greater (P < 0.05) force to enter the squeeze chute than did Brahman crossbred or British steers. In addition, Continental crossbred and Brahman crossbred steers left the processing chute with the greatest speed, whereas British steers exited the processing chute most slowly. Biological cattle type did not affect scores for entry speed or behavior during restraint in the chute. No adverse effects of ractopamine supplementation on cattle behavior were observed in this study.

Technical note: Exit velocity as a measure of cattle temperament is repeatable and associated with serum concentration of cortisol in Brahman bulls1

The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, to gauge temperament over the long-term and 2) to evaluate the relationship of the temperament appraisals with serum concentrations of cortisol (CS). Measures of temperament were gathered over 3 repeated observations (60-d interval) of yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n = 66). Temperament assessments included exit velocity (EV), which was the rate at which the bulls exited the squeeze chute and traversed a fixed distance (1.83 m); pen scores (PEN; 1 = quiet to 5 = excited), ascertained from animal behavior while penned in small groups (n = 5); and chute scores (CHUTE; 1 = quiet to 5 = excited), determined from behavioral responses to restraint on the weigh scale. Temperament measures obtained during the initial data collection (d 0) were all positively correlated (r > or = 0.35, P < 0.005) with one another. Additionally, PEN (r = 0.29, P < 0.05) and EV (r = 0.26, P < 0.05) were positively correlated with CS, whereas CHUTE was not (r = 0.09, P = 0.46). All serial EV measures were positively correlated (r > 0.31, P < 0.02). All PEN were positively correlated (r > 0.31, P < 0.01), whereas serial measures of CHUTE were not (P > 0.3). Exit velocity was positively correlated with CS within d 0 (r = 0.26, P = 0.04) and 120 (r = 0.44, P < 0.01). The EV data obtained at d 0 were transformed into a discrete variable, EV ranking (EV RANK; 1 to 3 scale), in which 1 equated to <1 SD below the mean and 3 equated to >1 SD above the mean. Mean EV (P < 0.01) decreased from d 0 (2.82 +/- 0.07 m/sec) to 120 (2.11 +/- 0.10 m/sec). Time also influenced (P < 0.01) CS; mean CS decreased between d 0 (14.6 +/- 0.7 ng/mL) and 120 (11.1 +/- 0.8 ng/mL). Measures of EV can be a valuable tool for the assessment of cattle temperament and a possible predictor of temperament and stress responsiveness to future animal handling events.

Do beef cattle react consistently to different handling situations?

Beef cattle responses to handling depend partly on the genetic characteristics of the animals. However, the various methods used in order to assess these responses differ to a great extent. The purpose of this work is to study the relationship between two different situations extensively used to evaluate cattle reactions to handling. Moreover, the genetic variability of cattle responses to these two handling situations was investigated. Behavioural reactions of 245 Limousine heifers, from 10 sires, were evaluated both in a docility test and in a crush test. In the docility test, a human tried to lead and then to maintain the animal in the corner of a pen during 30 consecutive seconds, with a maximum duration of the test of 3.5min. A docility score summarised the animal's behavioural reactions to the test. The crush test procedure consisted of social isolation of the animal in a crush, with the head maintained in a head gate (5min), then exposure to a stationary human (30s), and finally stroking on the forehead (30s). An agitation index for each part of this test was computed from PCA analyses based on agitation behaviours. Sire effect was significant for every part of both tests (P<0.05). Heifers' behavioural responses to the docility test were significantly correlated with their responses to the crush test, when the animals were in isolation (r=0.29; P<0.001), when the human stood motionless in front of the animals (r=0.37; P<0.001), and when the human stroked them (r=0.28; P<0.001). Sires' behavioural reactions to the docility test (computed from their daughters' scores) were correlated with their reactions to the crush test only when the human was present, both when motionless (r=0.88; P<0.001) and when stroking the heifer (r=0.81; P<0.05). No relationship appeared between sires' behavioural reactions to the docility test and their responses to restraint in the crush when the human was absent (P=0.17). Furthermore, the crush test did not reveal the animals which presented aggressive reactions to handling in the docility test. The results exposed in this paper pointed out the existence of a general reactivity of beef cattle to handling, whether the animals are restrained or not, which appears influenced by the sire. Such reactivity is suggested to be mainly a consequence of the animals reactions to humans. The human environment needs to be precisely defined in the handling test procedures before using them as a selection criteria.

The Human-Animal Relationship in Agriculture and Its Consequences for the Animal

Although human factors are recognized as influential factors affecting the welfare and productivity of farm animals, only limited research has been conducted to identify these important human characteristics and to quantify their effects. During the last 13 years we have studied two apparently important human factors: the attitude and the behaviour of stockpersons towards farm animals.

We have proposed that in intensive animal production systems there are some important sequential relationships between the attitude and behaviour of the stockperson towards farm animals and the behaviour, performance and welfare of farm animals. Basically we have suggested that because a stockperson's behaviour towards animals is largely under volitional control it is strongly influenced by the attitudes and beliefs that the stockperson holds about the animals. Furthermore, the stockperson's behaviour towards animals affects the animals’ fear of humans which, in turn, affects the animals’ productivity and welfare. It is the occurrence of a stress response by animals which are highly fearful of humans which places their productivity and welfare at risk We have published data which strongly support these interrelationships between human attitude and behaviour and animal behaviour, productivity and welfare. This paper reviews this and other research on this subject. The results of research in the pig industry and to a lesser extent, the poultry industries indicate the excellent opportunity which exists to improve animal productivity and welfare by training and selecting stockpersons to have desirable attitudinal and behavioural profiles towards farm animals.