Effects of temperament on physiological, productive, and reproductive responses in Bos indicus beef cows1

Abstract

This experiment evaluated the effects of temperament on physiological, productive, and reproductive responses in beef cows. A total of 953 lactating, multiparous, non-pregnant Nelore cows (age = 99 ± 2 mo; days post-partum = 51.4 ± 0.3 d; BCS = 5.34 ± 0.04; BW = 430 ± 2 kg) were allocated into 8 groups of approximately 120 cows each. Groups were assigned to an estrus synchronization + timed-AI protocol at the beginning of the breeding season. Concurrently with AI, blood samples were collected, hair samples were clipped from the tail switch, and cow temperament was evaluated via chute score and exit velocity. Individual exit score was calculated within each group by dividing exit velocity into quintiles and assigning cows with a score from 1 to 5 (1 = slowest; 5 = fastest cow). Temperament scores were calculated by averaging cow chute score and exit score, and used to define cow temperament ( ≤ 3 = adequate, = 726; ADQ; > 3 = excitable, = 227; EXC). Cows not pregnant to AI were assigned to a second timed-AI protocol ( = 184 ADQ and 72 EXC) or exposed ( = 269 ADQ and 90 EXC) to bulls for 60 d. Pregnancy status was verified 30 d after each AI and 45 d after the breeding season via transrectal ultrasound. Cow age, BW, BCS, and d post-partum at the beginning of the breeding season were similar ( ≥ 0.27) between ADQ and EXC cows. At first timed-AI, EXC had greater ( < 0.01) serum cortisol but similar ( ≥ 0.87) serum haptoglobin and hair cortisol concentrations compared with ADQ cows (49.1 vs. 39.1 ng/mL of serum cortisol, SEM = 1.0). Pregnancy rate to first timed-AI tended ( = 0.09) to be less in EXC vs. ADQ cows (41.0 vs. 47.3%; SEM = 3.6), whereas no treatment differences were detected ( ≥ 0.23) for subsequent pregnancy outcomes. Calving rate was less ( = 0.04) in EXC vs. ADQ cows (68.3 vs. 74.8%; SEM = 2.2), which can be attributed to the greater ( = 0.05) pregnancy loss detected in EXC cows (9.9 vs. 5.9%; SEM = 1.4). Weaning rate tended ( = 0.09) to be less, whereas calf weaning BW and age were less ( ≤ 0.05) in EXC vs. ADQ cows (63.9 vs. 69.4%, SEM = 2.4; 209 vs. 212 d, SEM = 1; 204 vs. 210 kg, SEM = 2). Hence, kg of calf weaned/cow exposed to breeding was reduced ( = 0.04) in EXC vs. ADQ cows (130 vs. 146 kg, SEM = 5). In summary, cows with excitable temperament had reduced reproductive performance and overall productivity compared to cohorts with adequate temperament when exposed to timed-AI + natural breeding.

Use of a food neophobia test to characterize personality traits of dairy calves

“…Overall, the identification of personality traits of dairy cattle is an important field of research with animal welfare, productivity and economic benefits. Personality traits in beef and dairy cattle have been associated with a number of performance measures including feeding behaviour 2,3,48 , weight gain 49,50 , fertility 51,52 , and milk production 8,53 (also see reviews by Neave et al 10 and Haskell et al 54 ). However, common tests of responses to novelty or challenge in dairy cattle (open field, novel object or novel human tests) are often impractical to conduct on farms; the food neophobia test has potential to be an ecologically relevant test that can be easily implemented on-farm.…”

Reproductive programs for beef cattle: incorporating management and reproductive techniques for better fertility

“…The present study evaluated the effects of BCS at calving and postpartum BCS change on reproductive performance of suckled Nelore cows submitted to TAI ( Carvalho et al, 2017; UNESP, Department of Animal Production, Botucatu, SP, Brazil; unpublished data). A total of 1,909 cows were allocated based on age and days postpartum into 17 groups.…”

“…Based on these outcomes, we concluded that temperament has a significant impact on reproductive performance of B. indicus cows exposed to TAI protocols, whereas strategies to ameliorate temperament or the cowherd (such as selecting cattle for adequate temperament or encouraging interaction between young cattle and humans) are necessary to optimize reproductive and overall efficiency of Brazilian cow-calf operations. A follow-up experiment was conducted to further comprehend the impacts of temperament on productive and reproductive outcomes in B. indicus cowherds, including reproductive and overall productivity in females following a typical TAI + bull breeding season, calving season, and at offspring weaning (Cooke et al, 2017). In this experiment, temperament was evaluated in 953 multiparous Nelore cows at the time of TAI as in Cooke et al (2011).…”

Impacts of stocking density on development and puberty attainment of replacement beef heifers

“…Cortisol concentration in hair from the tail switch has been recently validated as biomarker of chronic stress in cattle (Burnett et al, 2014;Moya et al, 2015). Cortisol is gradually accumulated in the emerging tail hair and its concentration represents long-term adrenocortical activity rather than concurrent circulating cortisol concentrations (Moya et al, 2013;Burnett et al, 2014;Cooke et al, 2017). Hence, measuring cortisol in hair from the tail switch eliminates the confounding effects that gathering and handling cattle exert on plasma cortisol concentrations (Moya et al, 2013, Moya et al, 2015.…”