Maria del Rocio Amezcua

Maria del Rocio Amezcua


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 July 2021 in Animals
Verified
Journal Article
Open access
PDF file
MHMaggie Henry
Maggie Henry
HJHannah Jansen
Hannah Jansen
MAMaria del Rocio Amezcua
Maria del Rocio Amezcua
TOTerri O'Sullivan
Terri O'Sullivan
LNLee Niel
Lee Niel
RFRobert Friendship
Robert Friendship
Tail-biting is globally recognized as a welfare concern for commercial swine production. Substantial research has been undertaken to identify risk factors and intervention methods to decrease and understand this vice. Tail-biting appears to be multifactorial and has proven difficult to predict and control. The primary objective of the scoping review was to identify and chart all available literature on the risk factors and interventions associated with tail-biting in pigs. A secondary objective was to identify gaps in the literature and identify the relevance for a systematic review. An online literature search of four databases, encompassing English, peer-reviewed and grey literature published from 1 January 1970 to 31 May 2019, was conducted. Relevance screening and charting of included articles were performed by two independent reviewers. A total of 465 citations were returned from the search strategy. Full-text screening was conducted on 118 articles, with 18 being excluded in the final stage. Interventions, possible risk factors, as well as successful and unsuccessful outcomes were important components of the scoping review. The risk factors and interventions pertaining to tail-biting were inconsistent, demonstrating the difficulty of inducing tail-biting in an experimental environment and the need for standardizing terms related to the behavior.

1 October 2010
Verified
Journal Article
Closed access
MAMaria del Rocio Amezcua
Maria del Rocio Amezcua
DPDavid L Pearl
David L Pearl
RFRobert M Friendship
Robert M Friendship
WMW Bruce McNab
W Bruce McNab

1 January 2013 in BMC Veterinary Research
Verified
Journal Article
Open access
PDF file
SGShiona K Glass-Kaastra
Shiona K Glass-Kaastra
DPDavid L. Pearl
David L. Pearl
RRRichard John Reid-Smith
Richard John Reid-Smith
BMBeverly McEwen
Beverly McEwen
SMScott A McEwen
Scott A McEwen
RFRobert Friendship
Robert Friendship
The objective of this work was to retrospectively assess records received through the Ontario Swine Veterinary-based Surveillance program July 2007 – July 2009 to describe and assess relationships between reported treatment failure, antimicrobial use, diagnosis and body system affected.

13 July 2022 in Animals
Verified
Journal Article
Open access
PDF file
SHSarah Victoria Hill
Sarah Victoria Hill
MAMaria del Rocio Amezcua
Maria del Rocio Amezcua
EREduardo S. Ribeiro
Eduardo S. Ribeiro
TOTerri O'Sullivan
Terri O'Sullivan
RFRobert Friendship
Robert Friendship
The objective of this systematic review and meta-analysis was to identify the benefits and possible adverse side effects of oxytocin use during farrowing. Randomized controlled trials that were published in English within the last 50 years were eligible for inclusion. Eligible research needed to contain the PICO elements: population (P)—sows at farrowing; intervention (I):—oxytocin given to sows—comparator (C): sows at farrowing not given oxytocin, as well as sows given different dosages and/or different timing of administration; and outcomes (O):—stillbirths, sow mortality, and piglet viability. Four bibliographic databases were used: PubMed, CAB Direct, Web of Science Core Collection, and ProQuest Dissertations, and Theses Global. In addition, we performed a manual search of the table of contents in the American Association of Swine Veterinarians database for relevant conference proceedings and reports. To assess the risk of bias at the study level, a modified version of the Cochrane 2.0 ROB was used. Meta-analyses were performed to examine the average stillbirth rate, farrowing duration, and birth interval between piglets using random-effect standardized mean difference (SMD) models. To explore heterogeneity, a sub-group analysis was performed on the objectives of the study, dose, time, and route of administration. Of the 46 studies eligible for meta-analyses, only 25 had sufficient information. The pooled analyses of the random effect model demonstrated that the average number of stillborn pigs was lower in the comparator group (SMD = 0.23; CI95% = 0.1, 0.36), and both the farrowing duration (SMD = −8.4; CI95% = −1.1, −0.60) and the birth interval between piglets (SMD = −1.41; CI95% = −1.86, −0.97) were shorter in the oxytocin group. The majority of the studies had an overall risk of bias of ‘some concerns’. It was concluded that the use of oxytocin increases the overall number of stillborn piglets, but decreases the farrowing duration and time interval between piglets. However, future studies should focus on the effect of oxytocin on the experience of dystocia among sows.

14 February 2020 in Animals
Verified
Journal Article
Open access
PDF file
LRLima Rodrigues
Lima Rodrigues
MAMaria del Rocio Amezcua
Maria del Rocio Amezcua
GCGlen Cassar
Glen Cassar
TOTerri O'Sullivan
Terri O'Sullivan
RFRobert Friendship
Robert Friendship
In order to efficiently have a consistent supply of service-ready gilts available to incorporate into each batch of breeding sows, it is necessary to manipulate the timing of estrus and possibly the timing of ovulation of gilts. Estrus can be synchronized by the withdrawal of altrenogest after at least 14 days of treatment. It is possible that protocols developed to induce ovulation, and therefore allow fixed-time artificial insemination (FTAI), can improve the predictability of gilt breeding. This study investigated the effect of two FTAI protocols in gilts on reproductive performance and timing of farrowing and piglet weaning weight compared to gilts bred based on signs of estrus after cessation of altrenogest. Puberty was induced in gilts, followed by treatment with altrenogest. Following altrenogest withdrawal, 180 gilts were assigned to one of three treatment groups. Group 1 gilts (LUT, n = 62) were treated with 600 IU equine chorionic gonadotropin 24 h after altrenogest withdrawal and 5 mg porcine luteinizing hormone (pLH) 80 h later, followed by a single FTAI 36 h after pLH. Group 2 gilts (TRI, n= 61) received 2 mL of a gonadotropin-releasing hormone agonist, triptorelin acetate, intravaginally 6 d after altrenogest withdrawal and were bred by a single FTAI 24 h later. Group 3 gilts (CON, n = 57) were observed for estrus and bred twice by AI, 24 h apart. LUT and TRI gilts farrowed closer together (2.4 ± 1.6 and 2.9 ± 1.2 d(days), respectively) compared to CON gilts (4.5 ± 3.3 d). Piglets in LUT were 80 g (p < 0.001) heavier and piglets in TRI were 64 g (p < 0.05) heavier at weaning than CON piglets, when controlling for birth weight. Results indicate that FTAI might be useful as a means of minimizing the time from the first to the last gilt farrowing in a breeding batch of gilts. However, modifications of the protocols may be required to ensure optimum farrowing rates and litter size.

1 January 2011
Verified
Journal Article
Closed access
MAMaria del Rocio Amezcua
Maria del Rocio Amezcua
DPDavid L Pearl
David L Pearl
AMAlejandro Martinez
Alejandro Martinez
RFRobert M Friendship
Robert M Friendship