Genetic evaluation of aspects of temperament in Nellore–Angus calves1,2

Abstract

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.

Effects of Multivalent BRD Vaccine Treatment and Temperament on Performance and Feeding Behavior Responses to a BVDV1b Challenge in Beef Steers

“…Additionally, temperament affected DMI and feeding behavior patterns, with calm steers having increased DMI and feeding durations, and slower eating rates during the BV events compared with excitable steers. Previous analyses in these cattle have demonstrated a substantial genetic influence for temperament at weaning [26], and for DMI and ADG following this BVDV challenge [20]. We observed that the same impacts of VT may not occur across all animal temperament categories The increased stress responsiveness of excitable steers in this study appeared to have mitigated the beneficial effects of the MLV vaccine.…”

“…Previous analyses of these data have documented significant sire effects on DMI and ADG [20]. However, in the current study, sire was excluded from the statistical models in order to fully evaluate the effects of temperament on the response variables, as sire differences in animal temperament have been demonstrated to exist in this population [26].…”

Feed Intake and Weight Changes in Bos indicus-Bos taurus Crossbred Steers Following Bovine Viral Diarrhea Virus Type 1b Challenge Under Production Conditions

“…The distribution of rectal temperatures did not correspond to clinical observations. It is speculated that in these cattle, rectal temperatures may have been more indicative of their temperament [ 22 ] and/or stress responsiveness rather than outright illness, particularly because several animals exhibited elevated temperature on d 0 with no visual signs of illness, showed no measurable titers to BVDV or IBR (data not shown), and differences in rectal temperature between year seemed to correspond with observed cattle behaviors associated with routine handling.…”

“…Steers were stratified by sire and genomics cow family of the structured McGregor Genomics population [ 22 ] and assigned to one of three BRD vaccine strategies utilizing killed (KV), modified-live (MLV), or no (NON) vaccine at approximately 12 months’ age. Cattle were managed as a single contemporary group within each year.…”

Characterization of carcass bruises in cattle in Northern Portugal, a preliminary study

“…The high occurrence of bruises observed in female cattle, according to what has been reported in the literature (Strappini et al 2010;Mendonça et al 2018;Bethancourt-Garcia et al 2019), can be associated with the high proportion of sample females. However, some hormonal interference in the behaviour has been suggested (Riley et al 2014). Regarding the age of cattle, the lower occurrence of bruises in the youngest cattle could be associated with the type of management of the area under study, in which steers are usually raised isolated.…”