16 research outputs found

    Can in vitro embryo production be estimated from semen variables in Senepol breed by using artificial intelligence?

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    Thoroughly analyzing the sperm and exploring the information obtained using artificial intelligence (AI) could be the key to improving fertility estimation. Artificial neural networks have already been applied to calculate zootechnical indices in animals and predict fertility in humans. This method of estimating the results of reproductive biotechnologies, such as in vitro embryo production (IVEP) in cattle, could be valuable for livestock production. This study was developed to model IVEP estimates in Senepol animals based on various sperm attributes, through retrospective data from 290 IVEP routines performed using 38 commercial doses of semen from Senepol bulls. All sperm samples that had undergone the same procedure during sperm selection for in vitro fertilization were evaluated using a computer-assisted sperm analysis (CASA) system to define sperm subpopulations. Sperm morphology was also analyzed in a wet preparation, and the integrity of the plasma and acrosomal membranes, mitochondrial potential, oxidative status, and chromatin resistance were evaluated using flow cytometry. A previous study identified three sperm subpopulations in such samples and the information used in tandem with other sperm quality variables to perform an AI analysis. AI analysis generated models that estimated IVEP based on the season, donor, percentage of viable oocytes, and 18 other sperm predictor variables. The accuracy of the results obtained for the three best AI models for predicting the IVEP was 90.7, 75.3, and 79.6%, respectively. Therefore, applying this AI technique would enable the estimation of high or low embryo production for individual bulls based on the sperm analysis information

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Classificação do tamanho de animais da raça Nelore com base na tabela da Federação Americana de Melhoramento de Gado de Corte (BIF)

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    Medidas de altura na garupa de animais Nelore, machos e fêmeas ao sobreano (n=3,948) e vacas em monta (n=6,174), pertencentes à Estação Experimental de Zootecnia de Sertãozinho, foram usadas para estudar a viabilidade do uso das equações e tabelas publicadas no Beef Improvement Federation (2006) para obtenção do escore de frame. Foi observada alta freqüência de frame entre 6 e 7 nos animais jovens e entre 7 e 9 nas vacas, caracterizando-os como de grande porte, mas não extremo. Entretanto, a maioria das vacas teve o escore de frame alterado conforme a idade. As vacas da raça Nelore apresentaram peso corporal, por escore de frame, menor que os pesos citados na literatura para as raças européias. As estimativas de repetibilidade (0,76) e herdabilidade (0,58) do escore de frame das fêmeas foram altas, entretanto menores que as estimadas para a altura (0,67 e 0,84, respectivamente)

    Effects of fatty acid suplementation in Holstein cows at pre and post partum period, on estrous cycle return and in vitro production of embryos

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    The supplementation of dairy cattle with sources of polyunsaturated fatty acids (PUFA) can be use to increase the energy level of the diet in addition to having positive effects on reproductive functions of important tissues including the hypothalamus, pituitary, ovaries and uterus. The aims of this study were to evaluate the reproductive conditions of the postpartum, number of follicles, corpus luteum (CL) presence, concentration of progesterone (P4), aspirated oocytes, amount of viable oocytes and in vitro production of embryos (IVPE) of the Holstein multiparous donors supplemented with rich diet in protected PUFA (especially linoleic acid - n- 6) and non-protected (especially linolenic acid - n-3) during pre and post partum. The diets had been given for pre-partum during 30 d and post partum 60 d. The donors were divided into three groups: Control (n=6), Megalac-E® (n=5; supplemented with protected fat source 100 g/donor/ day in pre-partum and 300 g/donor/day in postpartum) and linseed (n=5; supplemented with fat source unprotected containing 1 kg/donor/day pre-partum and 1.5 kg/donor/day in postpartum). The animals were submitted to ovum pick-up (OPU) on days 30, 45 and 60 d postpartum. The recovered oocytes were selected and the viable ones were submitted to IVPE procedures. The data were analyzed by the method of least squares variance using the GLM protocol. The differences between averages were compared by Tukey test with 5% significance. There was no detectable effect of treatment, aspirations of postpartum days and interactions on variables: CL presence, concentration of P4, amount of viable oocytes, viable oocytes rate, IVPE and embryos production rate. However, was observed in the group supplemented with linseed more follicles and total oocytes than Megalac-E® and Control group. Supplementation with PUFA didn't increase the number of viable oocytes and IVPE.</p

    Sex ratio of in vitro produced embryos 60 days after fixed-time embryo transfer according to the developmental stage of the implanted embryo

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    In view of its wide and consolidated sale of bovine embryos and because it has the world’s largest herd, Brazil currently occupies an important position in the worldwide scenario of in vitro production (IVP) of embryos. However, sex ratio deviations have been frequently reported for IVP embryos. The objective of this study was to evaluate the pregnancy rates and fetal sex of IVP bovine embryos 60 days after fixed-time embryo transfer (FTET). Nellore females (Bos taurus indicus, n=2,920) were used as oocyte donors and 30,912 crossbred cows (Bos taurus indicus x Bos taurus taurus) were used as recipients. Of these recipients, 11,341 were submitted to fetal sexing at 60 days of gestation. No difference (P>0.05) in pregnancy rate or embryo loss was observed between stages of embryo development at the time of FTET (early blastocyst, blastocyst, and expanded blastocyst). Regarding the sex of the products obtained, there was a higher percentage of male embryos in the blastocyst and expanded blastocyst stages and a higher percentage of female embryos in the early blastocyst stage. It should be noted that the results obtained for embryos in the blastocyst and expanded blastocyst stages are highly reliable, considering that a significant number of embryos in these stages were transferred. The results obtained for embryos in the early blastocyst stage should be seen with caution in view of the reduced number of embryos in this stage

    Effect of pre- anc postcalving supplementation of primiparous Nellore donor cows with sources of polyunsarurated fatty acids on the number of oocytes obtained in vivo and in vitro embryo production

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    The objective of this study was to evaluate the effects of feeding primiparous Nellore cows supplements rich in protected or unprotected linoleic (n-6) and linolenic (n-3) acids before and after calving on the number of follicles, total number of cumulus-oocyte complexes (COCs) collected by aspiration (OPU) and oocytes suitable for culture (grades I, II and III), and in vitro embryo production (IVEP). The donor cows were randomly divided into three groups: control (n=7), Megalac-E® (n=8; 100 g/donor/day), and flaxseed (n=7; 1.0 kg/donor/day). The diets were offered at least 30 days precalving and 75 days postcalving. The animals were submitted to OPU on postcalving days 30, 45, 60 and 75. Recovered oocytes were selected and those considered suitable for culture were submitted to the IVEP procedures. The data were analyzed using a completely randomized design with repeated measures over time. There was no effect of supplementation on the number of follicles, the number of recovered COCs and those suitable for culture, or IVEP. However, the rate of oocytes suitable for culture recovered by OPU was higher on postcalving days 60 and 75 when compared to days 30 and 45. Additionally, the rate of embryos produced in vitro increased after postcalving day 45. In conclusion, pre- and postcalving supplementation with 100 g/day Megalac-E® or 1.0 kg/day flaxseed does not alter the number of oocytes obtained in vivo or IVEP rates of lactating primiparous Nellore donor cows. However, IVEP improves when the programs are carried out 45 days after calving.</span

    Cytogenetical characterization of bovine breeds Caracu, Junqueira, Pantaneiro and Patua

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    During the adaptive process to Brazilian conditions, the native cattle breeds acquired physiological and phenotypic characteristics wich differs them from European breeds, from which they derive. The objectives of present study were to compare the sex chromosomes morphologies between four Brazilian native cattle breeds as well as the incidence of chromosomal abnormalities. The karyotype of 332 animals from four breeds were analyzed: Caracu (115 females and 159 males), Junqueira (13 females and 3 males), Pantaneiro (8 males) and Patua (21 females and 13 males). The Giemsa coloring were used to read the chromosome. All cattle breeds studied showed the normal chromosome (2n=60) consisting of 58 acrocentric autosomes and two submetacentric X chromosomes in females, and one X and one Y in males. In Caracu breed, selected for dairy or beef, it was developed by animals dimorphism carriers of Y chromosome (acrocentric and submetacentric), and the beef bloodlines showed higher percentage of acrocentric Y chromosome. There was 1% significant difference in Chi-Square test. In two females and two male born from twin birth of Caracu breed it was observed chemerism 60, XX/ 60, XY, and in other female from same breed it was observed 60, XX/ 61 XXY. For other three breeds, no chromosomal abnormality was observed. The Y chromosome morphology of the Pantaneiro and Patua breeds showed dimorphism of Y chromosome (submetacentric an acrocentric). In the Junqueira breed, only submetacentric morphology was observed

    Comparison of Brucella agar, CITA and Farrel media for selective isolation of Brucella abortus from semen of bovine bulls

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    Brucellosis remains as a public health concern worldwide. In domestic animals, the disease is characterized by reproductive disorders in male and female. Besides extensive use of serological tests and recent development of molecular biology techniques, microbiological culture of Brucella species is yet considered a “gold standard” method for diagnosis. Here, semen of 335 bovine bulls was subjected simultaneously to microbiological culture in Brucella agar, Farrell media, and CITA media to evaluate comparatively the best selective media for isolation of Brucella sp. Among all 335 samples, B. abortus B19 strain was isolated from semen of five (1.49%) bulls using the three selective media. However, Farrell media was considered the best selective media for microbiological diagnosis, because of allowed isolation of B. abortus B19 strain from bull semen without bacterial commensal or fungal contamination of plates
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