scholarly journals 119 Effects of temperament on growth, plasma cortisol concentrations, and puberty attainment in Bos indicus beef heifers.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 371-372
Author(s):  
R Cooke ◽  
P Moriel ◽  
B Cappellozza ◽  
J Moraes Vasconcelos
2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 309-310
Author(s):  
Felipe Alves Correa Carvalho da Silva ◽  
Gabriela da Silva ◽  
Bruna Vieira ◽  
Adomar Neto ◽  
Cecilia Constantino Rocha ◽  
...  

Abstract In cattle, uterine luminal fluid (ULF) is the main source of molecules that support embryo development and survival during the peri-implantation period. Overarching hypothesis was that peri-estrus changes in ULF volume through accumulation and resorption mechanisms influence ULF composition during the estrous cycle and early pregnancy. Objectives were (1) to characterize individual temporal and spatial changes in ULF volume, endometrial and luteal vascularity, endometrial and luteal size, and progesterone (P4) concentrations during the peri-estrus period in beef heifers and, (2) associate such changes with the metabolite composition in the ULF, four days after estrus. Fourteen Bos indicus heifers that presented a PGF2α responsive CL received 500 µg PGF2α analog i.m. and were examined daily by rectal B-mode and pulse-wave color-Doppler ultrasonography until the fifth day after estrus (estrus = d 0). Plasma P4 was measured daily. On d 4, the uterine body was sampled using a cytology brush for targeted metabolomic analysis by mass spectrometry. Multivariate analyses clustered heifers according to ovarian, uterine, and hormonal variables in clusters A (n = 5) and B (n = 8 heifers). Individual metabolite concentrations were compared between clusters A and B by univariate analysis using t-test after FDR correction. Concentrations of Pro, Ala, Leu, Gly, Val, Lys, Ile, Phe, Asp, Orn, Tyr, Arg, Trp, Suc, Cit, ADMA, the sum of essential Amino Acids (AA), sum of non-essential AA, sum of aromatic AA, and total AA were greater in cluster A (FDR ≤ 0.05). ULF volume dynamics and associated uterine, ovarian, and hormonal variables during the peri-estrus period presented a concerted variation among heifers, which was associated with the ULF composition four days after estrus. Potential implications for embryo receptivity and reproductive outcomes are the focus of the current investigation.


2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 615-615
Author(s):  
G. M. Silva ◽  
P. Moriel ◽  
J. M. B. Vendramini ◽  
J. D. Arthington

2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.


2013 ◽  
Vol 91 (1) ◽  
pp. 382-394 ◽  
Author(s):  
J. C. Petherick ◽  
K. McCosker ◽  
D. G. Mayer ◽  
P. Letchford ◽  
M. McGowan
Keyword(s):  

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 17-17
Author(s):  
Juliana Ranches ◽  
Marcelo Vedovatto ◽  
Elizabeth Palmer ◽  
Miguel Miranda ◽  
John Arthington ◽  
...  

Abstract This study evaluated the performance of Bos indicus-influenced beef heifers submitted to a puberty induction protocol and offered two supplementation amounts and delivery frequencies. Sixty-four Brangus crossbred heifers were stratified by BW and age (244 ± 4 kg; 311 ± 18 d) and assigned into 1 of 16 bahiagrass pastures on d 0. Treatments were randomly assigned to pastures in a 2 × 2 factorial design (4 pastures/treatment) and consisted of soyhulls-based supplementation at 1.25% or 1.75% of BW (DM basis) offered daily or 3 times weekly for 168 d. The puberty induction protocol consisted of CIDR insert on d 56 and removal on d 70, 5-mL PGF2a injection on d 86, 2-mL GnRH injection and timed-AI on d 89. Heifers were exposed to Angus bulls from d 89 to 167 (1 bull/pasture). Pregnancy diagnosis was assessed on d 212. Frequency × rate effects were not detected (P ≥ 0.19) for any variable. Reducing the supplementation frequency from daily to 3X weekly tended (P = 0.07) to decrease overall ADG and puberty attainment on d 56 (53 vs. 41 ± 6%), but not puberty attainment on d 89 (P = 0.45; 84 vs. 78 ± 6%) and pregnancy percentage on d 212 (P = 0.97; 69 vs. 69 ± 7%). Increasing the supplement amount from 1.25% to 1.75% of BW increased (P = 0.04) overall ADG, tended (P = 0.09) to hasten puberty attainment on d 56 (40 vs. 54 ± 6%) and d 89 (74 vs. 88 ± 6%), and enhanced (P = 0.03) pregnancy percentage on d 212 (53 vs. 80 ± 7%). Therefore, the inclusion of a puberty induction protocol, but not increasing the supplement amount, enabled a reduced frequency of supplementation (3 vs. 7 times weekly) without detrimental impacts on percentage of pregnant yearling beef heifers.


2017 ◽  
Vol 95 (suppl_4) ◽  
pp. 249-249
Author(s):  
N. Oosthuizen ◽  
P. L. P. Fontes ◽  
C. D. Sanford ◽  
F. M. Ciriaco ◽  
D. D. Henry ◽  
...  

2017 ◽  
Vol 52 (3) ◽  
pp. 526-528
Author(s):  
O Ramirez-Garzon ◽  
N Satake ◽  
RE Lyons ◽  
J Hill ◽  
MK Holland ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 139-139
Author(s):  
Reinaldo F Cooke

Abstract Temperament is defined as the fear-related behavioral responses of cattle when exposed to human handling. Our group evaluates cattle temperament using: 1) chute score: 1 to 5 scale that increases according to excitable behavior during chute restraining, 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 (1 = slowest quintile; 5 = fastest quintile), and 4) temperament score: average of chute and exit scores. Subsequently, cattle are assigned a temperament type; adequate temperament (ADQ; temperament score ≤ 3) or excitable temperament (EXC; temperament score > 3). Our group associated these evaluation criteria with reproductive responses of Bos taurus and B. indicus-influenced females. Cattle classified as EXC had greater (P ≤ 0.04) plasma cortisol vs. ADQ during handling, independent of breed type or parity. Both B. taurus and B. indicus cows classified as EXC had reduced (P ≤ 0.09) annual pregnancy rates vs. ADQ cohorts, resulting in decreased calving rate, weaning rate, and kg of calf weaned/cow exposed to breeding. Bos indicus heifers classified as EXC as yearlings had less (P < 0.01) growth rate and delayed puberty attainment by 15 months of age compared with ADQ heifers. Bos taurus heifers that reached puberty by 12 months of age had less (P ≤ 0.05) temperament score and plasma cortisol concentrations at weaning compared with heifers that did not reach puberty. Acclimating B. indicus-influenced and B. taurus heifers to human handling after weaning improved (P ≤ 0.02) temperament and hastened puberty attainment. Hence, temperament impacts productive and reproductive responses of beef females independent of breed type and parity. Strategies to improve herd temperament are imperative for optimal production efficiency of cow-calf operations based on B. taurus and B. indicus-influenced cattle.


2017 ◽  
Author(s):  
◽  
James William Cameron Locke

The Bos indicus species of beef cattle presents a number of unique reproductive challenges, especially with regard to those that influence reproductive efficiency including timely attainment of puberty, response to certain pharmaceutical drugs used to control estrus and ovulation, and response to physiological stressors. Cattle of this biological type comprise a substantial percentage of the beef cattle population in southern regions of the United States because of their ability to withstand high ambient temperatures and relative humidity. Additionally, Bos indicus cattle are regarded to exhibit increased parasite and disease resistance, resulting in improved production in subtropical climates as compared to Bos taurus cattle in those same regions. Research utilizing composite breeds of Bos taurus and Bos indicus beef heifers has been limited in the United States, and adoption of reproductive technologies such as artificial insemination and estrus synchronization has been sluggish compared to Bos taurus cattle in other regions of the country. To help answer a number of questions about this biological type, an experiment was designed to evaluate reproductive performance of Bos indicus-influenced heifers (n = 1,456). Weights and reproductive tract scores (RTS; Scale 1-5) were obtained for heifers prior to assignment of one of five treatments: Non-synchronized + natural service (NS); melengestrol acetate + natural service (MGA + NS; 0.5 mg x animal-1 x d-1); 14-d controlled internal drug release + natural service (CIDR + NS; 1.38g progesterone); 14-d MGA-PG + fixed-time AI (FTAI); and 14-d CIDR-PG + FTAI. Heifers in the three NS treatments were exposed to fertile bulls for 65 d, beginning 10 d after progestin removal for CIDR + NS and MGA + NS groups. Heifers in FTAI treatments were administered PGF2[alpha] (PG; 25 mg, IM) 16 or 19 d following CIDR or MGA removal. Fixed-time AI was performed 66 and 72h after PG for CIDR-PG and MGA-PG treatments, respectively. Gonadotropin-releasing hormone (GnRH; 100[mu]g, i.m.) was administered at FTAI. Estrus detection aids were applied at PG for heifers in FTAI treatments and evaluated at AI. Heifers in FTAI treatments were exposed to fertile bulls 12 d following FTAI. Blood samples were collected and ovarian ultrasounds performed at PG administration and FTAI to compare serum concentrations of estradiol and progesterone and to evaluate follicular dynamics among a subset of heifers assigned to FTAI treatments. Pregnancy status was determined at the end of a 65-d breeding period. Data were analyzed using PROC FREQ and GLIMMIX procedures of SAS. Mean concentrations of estradiol at AI differed between MGA- versus CIDR-treated heifers (P = 0.04; 8.2 versus 6.6 pg/ml), however estrous response after PG (52% versus 53%) and pregnancy rates after FTAI (40%) did not differ between MGA- and CIDR-PG treatments, respectively. Across all treatments, pregnancy rates were compared on 21, 30 and 60 d of the breeding period based on pubertal status (prepubertal RTS = 1 and 2; peripubertal RTS = 3; pubertal RTS = 4 and 5). Pregnancy rates differed at each time point based on pretreatment pubertal status (P [less than or equal to] 0.02) and weight (P [less than or equal to] 0.05). No differences were apparent with regard to progestin type at any time point, although higher pregnancy rates (P [less than or equal to] 0.004) were observed among NS treatments than FTAI followed by NS exposure at Days 30 and 60. This experiment is the largest comprehensive field trial conducted in the United States and reported in the literature involving Bos indicus-influenced beef heifers utilizing estrus synchronization prior to natural service or FTAI. This study reinforced results from previous studies, however raises a number of questions yet to be answered for heifers of this biological type. These data should be used as a basis for improvements in reproductive management of Bos indicus-influenced beef heifers prior to their first breeding season, and creates a number of possibilities for future research trials that build upon results reported in this thesis. Selection, management, and post-weaning to pre-breeding development of Bos indicus-influenced replacement beef heifers should involve the cooperative efforts of beef producers, veterinarians, and research scientists to further investigate methods to improve reproductive efficiency and genetic merit of these herds.


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