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Item Delipidação química na produção in vitro e criopreservação de embriões bovinos(Universidade Federal de Goiás, 2018-09-13) Diesel, Tiago Omar; Porto, Regiani Nascimento Gagno; http://lattes.cnpq.br/6367040339353532; Arnhold, Emmanuel; http://lattes.cnpq.br/7156945506134934; Gambarini, Maria Lúcia; http://lattes.cnpq.br/4440003524956701; Meirinhos, Maria Lúcia Gambarini; Biancardi, Manoel Francisco; Oliveira Filho, Benedito Dias de; Matos, Moema Pacheco Chediak; Mascioli, Arthur dos SantosChemical delipidation has been used as an alternative to improve the cryotolerance of in vitro produced embryos (IVP). The aim of this study was evaluate the effect of L-carnitine (LC) on the development and survival of vitrified IVP bovine embryos by the Cryotop method in the first assay, and in the second trial the effect of LC and Forskolin on Cryotop cryopreserved embryos Experiment 1), or by modified slow freezing (Experiment 2), so mitochondrial activity, intracytoplasmic lipid (LI) content, cellular apoptosis (NCA) and hatching after heating were evaluated. In the first essay LC was used at the concentration of 0,6 mg/mL in maturation culture medium (IVM), embryo culture (IVC) and / or post-thawing (REC), in four treatments: without LC (Control), LC added to CIV (LCiv), LC to CIV + LC to REC (LCivR), and LC to MIV / CIV + LC to REC (LMivCR). The addition of LC increased the production of blastocysts in D7 by 28.6% (LCiv) and the amount of embryos grade I by 36.9% (LCivR), the re-expansion rate in 22,7% and hatching in 20.1% (LCiv), and mitochondrial activity was 1.9 times higher (P <0.001) (LCivR) than Control. The LI quantity was 29% lower in LCiv and LCivR and 50.2% in LMivCR compared Control (P <0.001). In the second experiment the embryos were cultured without addition of delipidators (Control), in the presence of 10μM of Forskolin added to the IVC in D5 (FORSK) or L-carnitine (0.6 mg / mL) added to the IVC and in post-thawing (LC). LC supplementation increased the production of blastocysts in D7 by 22.0% and grade I embryos by 30.1% (P <0.05), in relation to Control and FORSK. In Experiment 1, the re-expansion rate in LC increased (P <0.05) 28.9% in relation to FORSK. In Experiment 2, two Control treatments were used for slow freezing (Classic and Modified). Hatching after 48 hours was greater (P <0.05) in LC compared to FORSK and Classical and Modified Controls (77.5%, 41.9%, 40.5%, 40.8% respectively). In the LC treatment, there was a decrease (P <0.05) of 64.7% in the degenerate embryo rate in relation to the Classical Control. Treatment with delipidators reduced LI content (P <0.001) by 2.2 fold in FORSK and four times in the LC compared to Control. The addition of 0.6 mg / mL of L-carnitine to the culture medium and the post-thawing increased the rate of in vitro production of bovine embryos acting positively on mitochondrial potential, reducing the amount of intracellular lipids and cellular apoptosis and increasing cryotolerance of embryos submitted to the modified slow freezing protocol.Item Características de estro pós-parto associadas às chances de prenhez de vacas holandesas em lactação(Universidade Federal de Goiás, 2020-03-03) Frota, Wilson Vagner Vilas Boas; Alves, Benner Geraldo; http://lattes.cnpq.br/2502439704413583; Gambarini, Maria Lúcia; http://lattes.cnpq.br/4440003524956701; Gambarini, Maria Lúcia; Lopes, Dyomar Toledo; Carmo, Adriana Santana doThe detection of estrus remains a major problem in dairy cattle, despite the enormous progress in the knowledge of the reproductive physiology of the cow and in the development of auxiliary methods. The success of any estrus detection program will depend, at least in part, on the cows' ability to exhibit estrus, which is affected by a multitude of physiological and management factors that favor or suppress estrus behavior. Parity, number of days postpartum, body condition score, milk production, calving problems, postpartum disease is recognized for influencing estrus expression. In addition, heat stress, building and the size of the herd can also affect estrus behavior. The aim of this study was to evaluate the risk factors associated with estrus behavior, identified by an automated estrus detection system. Data from three experiments carried out between August 2015 and July 2018, in the state of Florida, United States of America, were collected and processed. The number of animals that participated in the experiments A, B and C was 565, 671 and 678, totaling 1914 lactation cows and 3029 estrus events. The animals enrolled in the experiments were monitored by an automated estrus detection device (SCR Inc., Netanya, Israel). Estrus was determined according to changes in activity and rumination patterns within the two-hour interval compared to the average activity and rumination for the same period in the previous five and seven days, respectively. Data were analyzed using ANOVA, logistic regression and Cox proportional regression using the SAS statistical software. The duration and intensity of estrus showed a negative correlation with the proportion of time cows were subjected to heat stress. The return to ovarian cyclicity before the end of the voluntary waiting period increased the chances of pregnancy at the first service and the pregnancy for artificial insemination up to 150 DIM. Uterine disease, subclinical ketosis and BCS were associated with delayed return to cyclicity, potentially negatively impacting reproductive performance.Item Alternativas para melhorar o desenvolvimento e a criotolerância de embriões bovinos produzidos in vitro(Universidade Federal de Goiás, 2016-02-23) Marques, Thaisa Campos; Oliveira Filho, Benedito Dias de; http://lattes.cnpq.br/6171669841505540; Martins, Carlos Frederico; http://lattes.cnpq.br/1432343540761591; Gambarini, Maria Lúcia; http://lattes.cnpq.br/4440003524956701; Gambarini, Maria Lúcia; Leão, Karen Martins; Biancardi, Manoel Francisco; Costa, Marcos Fernando Oliveira e; Porto, Regiani Nascimento GagnoMelatonin treatment and blastocoel collapse had been suggested to be potent options to enhance embryo development and viability after cryopreservation of bovine embryos. The present study tested these alternatives with the aim to improve cryotolerance of bovine embryos produced in vitro. First, the effects of melatonin (MEL) were evaluated at three concentrations in Maturation Media (IVM) and/or Culture Media (IVC) (0, 10-7, 10-9, 10-11 M). The results showed that MEL10-9 in IVM could improve slightly the cleavage rate. However, when applied during IVC, MEL10-9 resulted in improved blastocysts rates and reduced numbers of apoptotic cells (NAC), a higher expression of antioxidative genes without changing the expression metabolism-related, placentation and anti-apoptotic genes. After, the MEL treatment giving the best result in first experiment (MEL 10-9 M in IVC) was combined with blastocoel collapse (BC) immediatly before vitrification. The survival and embryo quality were investigated. This experiment confirmed that independent of BC, MEL supplementation in IVC enhanced re-expansion and hatching rates of vitrified embryos. However, embryos cultured without MEL required more time during re-culture for all expansion. Embryos produced with MEL had similar NAC irrespective of vitrification and BC. BC did not affect embryo quality, in terms of the expression of genes involved in metabolism, oxidative stress, cell repair, placentation and implantation. Therefore, this research concluded that: (i) at 10-9 M concentration, MEL used during IVC improved embryo quality and development, and it minimized the oxidative stress and apoptosis in cells; (ii) embryos cultured with melatonin, vitrified and re-cultured can be transfered in less time; (iii) the blastocoel collapse benefited hatching when embryos were cultured with MEL in IVC; (iv) embryos cultured in IVC with MEL showed better quality and viability, and independently of BC. This information has a potential value for researchs on embryo cryotolerance.