Publications by authors named "Joao H J Bittar"

Supervised machine-learning (SML) algorithms are potentially powerful tools that may be used for screening cows for infectious diseases such as bovine leukemia virus (BLV) infection. Here, we compared six different SML algorithms to identify the most important risk factors for predicting BLV seropositivity in dairy cattle in Florida. We used a dataset of 1279 dairy blood sample records from the Bronson Animal Disease Diagnostic Laboratory that were submitted for BLV antibody testing from 2012 to 2022.

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Global warming is a major challenge to the sustainable and humane production of food because of the increased risk of livestock to heat stress. Here, the example of the prolactin receptor () gene is used to demonstrate how gene editing can increase the resistance of cattle to heat stress by the introduction of mutations conferring thermotolerance. Several cattle populations in South and Central America possess natural mutations in that result in affected animals having short hair and being thermotolerant.

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The University of Florida's Cervidae Health Research Initiative (CHeRI) conducted a post-mortem examination of a two-year-old white-tailed doe deceased at a northern Florida white-tailed deer farm. The carcass of the deer had notable emaciation and bloating. Upon opening of the carcass, there was pneumonia and the rumen was tympanic and enlarged.

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This study evaluated the effects of maternal supplementation of a Bacillus-based direct-fed microbial (DFM) on the physiology and growth performance of Bos indicus-influenced cow-calf pairs. On day 0 (~139 d before expected calving date), 72 fall-calving, Brangus crossbred beef heifers (20 to 22 mo of age) pregnant with first offspring were stratified by their initial body weight (BW; 431 ± 31 kg) and body condition score (BCS; 6.0 ± 0.

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This study evaluated the growth and immune response of beef calves born from Bos indicus-influenced beef heifers provided pre- and postpartum heat abatement on pasture. On 83 ± 4 d prepartum (day 0), 64 Brangus crossbred beef heifers (~¼ B. indicus) were stratified by body weight (BW; 454 ± 37 kg) and body condition score (BCS; 6.

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This study evaluated the growth and immune function of beef calves born to cows supplemented with bakery waste containing two concentrations of crude fat. On day 0 (~90 d before calving), 108 multiparous Brangus crossbred cows were stratified by body weight (BW; 551 ± 65 kg) and body condition score (BCS, 5.5 ± 0.

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Background: Little is known about the effects of trace mineral supplementation on the stress response in beef calves.

Objectives: To investigate the effect of injectable trace mineral supplementation (ITM) on the stress response in beef calves exposed to different types of stress.

Animals: Thirty weaned Angus and Angus crossbred calves.

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Introduction: Monitoring circulating progesterone concentration ([P4]) is an important component of basic and applied reproduction research and clinical settings. IMMULITE 2000 XPi (Siemens Healthineers, Cary, NC) is a newly upgraded fully automated immunoassay system marketed for human use to measure concentrations of different measurands including P4.

Objectives: Our objective was therefore to characterize the analytical performance of the IMMULITE 2000 XPi P4 immunoassay (IPI) across the reportable range in serum and plasma of cattle.

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Monitoring circulating progesterone (P4) concentration is an important component of basic and applied reproduction research and clinical settings. IMMULITE® 2000 XPi (Siemens) is a newly upgraded fully automated immunoassay system marketed for human use to measure concentrations of different analytes including P4. Our objective was therefore to characterize the analytical performance of the IMMULITE® 2000 XPi P4 immunoassay across the reportable range in ovine serum.

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This study aimed to assess the ovulatory response of deslorelin acetate during the fall and the response to PGF2α 8 d post-ovulation. One hundred estrous cycles from 22 mares kept in 40° latitude were evaluated. Mares were checked by transrectal ultrasonography until a preovulatory follicle was detected and ovulation induced with deslorelin acetate.

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This study was performed to elucidate whether the route of booster vaccination affects the immune response against respiratory vaccine viruses in pre-weaning beef calves that receive primary intranasal (IN) vaccination during the first month of life. The objective was to compare the serum neutralizing antibody (SNA) titers to BHV1, BRSV, and BPI3V, cytokine mRNA expression and mucosal BHV1- and BRSV-specific IgA in nasal secretions following administration of IN or subcutaneous (SC) modified-live virus (MLV) booster vaccines 60 days after primary IN vaccination in young beef calves. Twenty-one beef calves were administered 2 mL of an IN MLV vaccine containing BHV1, BRSV, and BPI3V (Inforce3®) between one and five weeks of age.

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Strategies to improve the onset of protective immunity induced by vaccination against respiratory pathogens may have a significant impact on health of newly received beef calves. The objective was to determine if the use of injectable trace minerals (ITM; Se, Zn, Cu, and Mn) concurrent with a modified-live virus (MLV) vaccine enhances the immune response and onset of protection in beef calves challenged with BVDV2 five days after vaccination. Forty-five calves were randomly assigned to one of three groups (15/group): VAC + ITM, received MLV-vaccine and ITM (Multimin®90) subcutaneously (SC); VAC + SAL, received the same vaccine and saline SC; or UNVAC, unvaccinated.

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The use of 4-day CoSynch + Controlled internal drug release (CIDR) + timed artificial insemination (TAI) in dairy heifers has resulted in adequate pregnancy rates compared with the 5-day CoSynch + CIDR + TAI protocol. The objective of this study was to compare follicular growth, timing of ovulation and serum progesterone (P ), estradiol (E ) and luteinizing hormone (LH) concentrations in dairy heifers treated with modified 4- or 5-day CoSynch + CIDR protocols (CIDR for 4 or 5 days, PGF α at CIDR removal and GnRH + TAI 72 h later). Twelve cycling Holstein heifers were randomly assigned to either the 4- or 5-day Co-Synch+CIDR (n = 6/treatment) to receive an intravaginal insert CIDR containing 1.

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