Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 444
Filtrar
1.
Acta sci., Anim. sci ; 45: e58130, 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1413152

Resumo

The objective of this study was to estimate genetic parameters for body weight at 60 (P60), 90 (P90), and 120 (P120) days of age in escargotsof the subspecies Cornu aspersum maximum, evaluating the influence of fixed and covariable effects on these traits. The data used were collected from escargotskept in a total confinement system. The significant fixed effects and covariates for these traits were tested in a general linear model by the F-test, considering a level of significance of 5%. Both the fixed effects of box and birth year and the quadratic effect of age of weighing as a covariate were significant (p < 0.05) for P60, P90, and P120. The Restricted Maximum Likelihood (REML) methodology was used to estimate (co)variance components and genetic parameters. High heritability for P60, P90, and P120 (0.38, 0.55 and 0.78, respectively) and high genetic correlations (0.58 to 0.77) among the traits were observed. The genetic parameterscan be used as a basis for studies and practical applications to increase zootechnical indexes in this population.(AU)


Assuntos
Animais , Gastrópodes/fisiologia , Fenômenos Genéticos/fisiologia , Peso Corporal/genética , Funções Verossimilhança
2.
Semina ciênc. agrar ; 44(1): 97-112, jan.-fev. 2023. tab
Artigo em Inglês | VETINDEX | ID: biblio-1418811

Resumo

The aim was to estimate the genetic correlations between residual feed intake (RFI) and dry matter intake (DMI) with carcass finish (CF), rib eye area (REA), and marbling (MAR) of Nellore cattle. Data from 7,808 animals were considered. In addition, data from 2,261 females included in the complete database were also considered. Estimates of variance and covariance components, as well as heritabilities and genetic correlations were obtained by means of two-character analysis under animal model. Heritability estimates were found to be moderate for the RFI (0.22) and DMI (0.29) traits. It was observed that genetic correlation was close to zero for all traits, except between RFI and REA (-0.11). However, considering the female population, there was an increase in the estimated genetic correlation between RFI and DMI, although still a favorable genetic association of low magnitude (-0.30). There was also an increase in the genetic association of REA with RFI (-0.21). It can be concluded that the direct selection for RFI and DMI will not influence the CF, MAR, or REA of Nellore cattle. However, this selection may generate some favorable responses in MAR and REA in Nellore females.


Objetivou-se estimar as correlações genéticas entre consumo alimentar residual (CAR) e ingestão de matéria seca com acabamento de carcaça (ACAB), área de olho de lombo (AOL) e marmoreio (MAR) para bovinos da raça Nelore. Foram consideradas informações de 7.808 animais. Além disso foram consideradas informações de 2.261 animais fêmeas que compunham o banco de dados completo. As estimativas dos componentes de variâncias e covariâncias, bem como das herdabilidades e correlações genéticas foram obtidas por meio de análises bicaracterísticas sob modelo animal. Verificou-se que as estimativas de herdabilidade foram moderadas para as características de CAR (0,22) e IMS (0,29). Observou-se que as estimativas de correlação genética foram próximos a zero para todas as Características, exceto entre CAR e AOL (-0,11). No entanto, considerando a população de fêmeas, houve um aumento na estimativa de correlação genética com CAR e IMS, apesar de ainda ser uma associação genética favorável de baixa magnitude (-0,30). Também houve um aumento na associação genética da AOL com o CAR (-0,21). Conclui-se, assim, que a seleção direta para o CAR e IMS não influenciará no ACAB, MAR e AOL de bovinos da raça Nelore. No entanto, essa seleção poderá gerar alguma resposta favorável em MAR e AOL em fêmeas Nelore.


Assuntos
Animais , Bovinos , Bovinos/genética , Ingestão de Alimentos
3.
Ciênc. rural (Online) ; 53(12): e20210246, 2023. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1434385

Resumo

This study evaluated the levels of heavy metals in the soil and castor bean plant after fertilization with sewage sludge (SS) subjected to different stabilization processes. The study was conducted in a Haplic Cambisol with the following treatments: control (CO), fertilization with solarized sewage sludge (SSS), composted sewage sludge (CSS), vermi composted sewage sludge (VSS), limed sewage sludge (LSS), and mineral fertilizer (MF). The experimental design included a subdivided plot scheme with fertilization being the primary factor and soil layers or leaf parts being the secondary factor. The data obtained were analyzed using analysis of variance and the Scott-Knott test with 5% significance. Fertilization with SSS, CSS, and LSS led to the highest increase in Zn in the soil, mainly in the surface layer. In the leaf tissues, Zn and Cu levels were higher with the CO and SSS treatments, whereas the Ni level was higher with SSS, CSS, VSS, and MF treatments. In general, Zn and Cu levels were higher in the leaf limb than in the petiole, whereas Ni, Pb, and Cr levels were higher in the petiole than in the leaf limb. In any case, no symptoms of toxicity in the plants and no risk of soil contamination were observed with any of the fertilization treatments.


O objetivo deste trabalho foi avaliar os teores de metais pesados no solo e na planta de mamoneira em resposta à adubação com lodo de esgoto (LE) submetido a diferentes processos de estabilização. O experimento foi desenvolvido em Cambissolo Háplico com os tratamentos: testemunha, adubação com LE solarizado, LE compostado, LE vermicompostado, LE caleado e adubação mineral. O delineamento experimental foi em esquema de parcelas subdivididas, sendo as adubações o fator primário e as camadas do solo ou as partes da folha o fator secundário. Os dados obtidos foram submetidos à análise de variância e teste de Scott-Knott a 5% de probabilidade. No solo, as adubações com LE solarizado, compostado e caleado promoveram os maiores incrementos dos teores de Zn, principalmente na camada superficial. No tecido foliar, os teores de Zn e Cu foram mais elevados na testemunha e no LE solarizado, enquanto o Ni foi mais elevado nos LE solarizado, compostado, vermicompostado e na adubação mineral. De modo geral, os maiores teores de Zn e Cu ocorreram no limbo foliar em comparação ao pecíolo, enquanto os teores de Ni, Pb e Cr foram mais elevados no pecíolo do que no limbo foliar. Contudo, não foram constatados sintomas de toxidez nas plantas e nenhum risco de contaminação do solo com os diferentes tipos de adubações realizadas.


Assuntos
Ricinus , Esgotos , Análise do Solo , Gerenciamento de Resíduos , Metais Pesados
4.
Rev. bras. zootec ; 51: e20210188, 2022. tab
Artigo em Inglês | VETINDEX | ID: biblio-1442767

Resumo

We aimed to estimate genetic parameters for growth, reproductive, and carcass traits in Tabapuã cattle. Phenotypic data were collected between 1990 and 2019 in 1,218 farms, and the pedigree file had 340,868 animals. The traits evaluated were body weight at 120 (W120), 210 (W210), 365 (W365), and 550 (W550) days of age; age at first calving (AFC), scrotal circumference at 365 days of age (SC365), ribeye area (REA), backfat thickness (BF), and rump fat thickness (RF). The (co)variance components were estimated using the restricted maximum likelihood method, considering single and two-traits animal models. For all traits, the models considered fixed, direct additive genetic, and residual random effects. In addition, for W120 and W210, the maternal additive genetic and maternal permanent environmental effects were also included. Heritabilities for W120, W210, W365, W550, SC365, REA, BF, and RF were of moderate magnitude (0.15, 0.16, 0.23, 0.19, 0.22, 0.36, 0.31, and 0.27, respectively). Low heritability was observed for AFC (0.07). The genetic correlations between growth traits were higher than 0.90, while AFC and SC365 presented negative moderate correlation (−0.66). The REA showed low genetic correlations with BF (0.07) and RF (0.07), whereas BF and RF were highly correlated (0.77). Considering the heritability estimates, selection for AFC would result in limited genetic gain, while for the other traits, it would be satisfactory. Based on the high genetic correlations between growth traits, selection of Tabapuã animals can be performed at younger ages. Additionally, animals can be indirectly selected for AFC through SC365, and only one fat thickness trait may be used in the selection process considering the high genetic correlation and similar heritability values for BF and RF.(AU)


Assuntos
Animais , Variação Genética , Bovinos/genética , Brasil , Correlação de Dados
5.
Iheringia, Sér. zool ; 112: e2022014, 2022. mapas, tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1380350

Resumo

Habitat fragmentation is one of the sources of the global threat to wildlife populations. During the last four decades, urban development in Brazil's southern coastline has seen considerable growth, fragmenting the habitat of the sand lizard Liolaemus occipitalis Boulenger, 1885, thus threatening it with extinction. In order to assess the influence of urban development on this species, we used tagging and recapture data to study two populations in Brazil's southern coastline, one in a conserved area rarely subjected to disturbance and the other in an area undergoing different kinds of anthropogenic disturbance. We explored the consequences of this change in the natural landscape by comparing estimates of survival and abundance with Robust Design Model, and the body condition of individuals in both populations with analysis of covariance and variance. Survival of individuals were lower in the disturbed population than in the conserved population. The abundance of this lizard species was similar between populations. The body condition of females was higher in the disturbed area than in the conserved area, while males were similar among populations, but longer (SVL). This study shows how anthropic impacts can affect a population of lizards and the importance of maintaining protected areas and their interconnection to preserve Liolaemus occipitalis.(AU)


A fragmentação do habitat é uma das fontes de ameaça global às populações de vida selvagem. Durante as últimas quatro décadas, o desenvolvimento urbano do litoral sul do Brasil teve um crescimento considerável, fragmentando o habitat da lagartixa-da-praia lagarto-da-areia Liolaemus occipitalis Boulenger, 1885, ameaçando-o de extinção. Para avaliar a influência do desenvolvimento urbano sobre esta espécie, usamos dados de marcação e recaptura para estudar duas populações, uma em uma área conservada raramente sujeita a perturbações, e a outra em uma área submetida a diferentes tipos de perturbações antrópicas. Exploramos as consequências dessa mudança na paisagem natural comparando estimativas de sobrevivência e abundância com Modelo Robusto de Pollock, e condição corporal dos indivíduos com análises de covariância e variância, em ambas as populações situadas no litoral sul do Brasil. A abundância da espécie foi semelhante nas duas áreas, mas a sobrevivência dos indivíduos foi menor na população perturbada do que na conservada. A condição corporal das fêmeas foi maior na área perturbada, enquanto que o CRC dos machos foi maior na área conservada. Este estudo mostra como impactos antrópicos podem afetar uma população de lagartos e a importância da manutenção de áreas protegidas e sua interconexão para a preservação de Liolaemus occipitalis.(AU)


Assuntos
Animais , Masculino , Feminino , Efeitos Antropogênicos , Lagartos/fisiologia , Animais Selvagens/fisiologia , Composição Corporal/fisiologia , Alteração Ambiental , Áreas Protegidas
6.
Bol. ind. anim. (Impr.) ; 79: e1511, 2022. tab
Artigo em Inglês | VETINDEX | ID: biblio-1410395

Resumo

A study was carried out to evaluate the inclusion of increasing levels of a residue from the rendering plant after obtaining meat and bone meal for growing pigs on performance, carcass characteristics, incidence of diarrhea and economic viability of the diets. Forty-eight pigs were allotted in a completely randomized design with four treatments (0, 2, 4 and 6% of residue inclusion), six replicates and two animals per experimental unit (barrows and females) with 30 ± 0.662 kg of initial weight in a 24-day trial period. Statistical assumptions of normality and homogeneity were verified using Shapiro-Wilk and Barllet tests, respectively, at 5% probability. The assumptions were met and the data were subjected to analysis of variance at 5% significance. The performance variables, carcass characteristics and diarrhea incidence did not show significant differences (P<0.05) between the levels of inclusion of residue in the diet. The residue can be used up to 6% in the feed without affecting performance, carcass characteristics and diarrhea incidence in growing pigs, however, the inclusion of 4% of the residue presents greater economic viability.


Foi conduzido um trabalho para avaliar a inclusão de níveis crescentes de um resíduo, proveniente da graxaria, após a obtenção de farinha de carne e ossos de abatedouro de bovinos, para suínos em fase de crescimento sobre o desempenho, características de carcaça, incidência de diarreia e viabilidade econômica das dietas. Foram utilizados 48 suínos, distribuídos em delineamento inteiramente ao acaso com 4 tratamentos (0, 2, 4 e 6% de inclusão do resíduo), seis repetições e dois animais por unidade experimental (machos castrados e fêmeas) com 30 ± 0,662 kg de peso inicial em período experimental de 24 dias. Foram verificadas as pressuposições estatísticas de normalidade por meio do teste de Shapiro-Wilk e homogeneidade pelo teste de Barllet a 5% de probabilidade. As pressuposições foram atendidas e os dados foram submetidos a análise de variância e teste F a 5% de significância. As variáveis de desempenho, características de carcaça e incidência de diarreia não apresentaram diferenças significativas (P<0,05) entre os níveis inclusão do resíduo na ração. O resíduo pode ser utilizado em até 6% na ração sem afetar o desempenho, as características de carcaça e causar diarreia em suínos em fase de crescimento, no entanto, a inclusão de 4% do resíduo apresenta maior viabilidade econômica.


Assuntos
Animais , Suínos/crescimento & desenvolvimento , Resíduos de Alimentos , Ração Animal/economia , Aumento de Peso , Matadouros/economia
7.
Sci. agric ; 782021.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1497902

Resumo

ABSTRACT: This study was designed to simulate productive and economic losses due to the withdrawal of antibiotic growth promoters (AGP) from pig diets. Articles that compared diets with AGP (AGP+) or without AGP (AGP) for pigs were collected from electronic databases and the performance results were entered in a database. A meta-analysis was performed following the sequence: graphical analysis, correlation, and variance-covariance. The performance results observed in the meta-analysis, feed cost, and AGP costs were used to build equations to estimate the economic effect of withdrawing AGP. The database comprised 81 scientific articles containing 103 experiments totalizing 42,923 pigs. Avilamycin (24.7 %) was the most frequent AGP in the database, followed by Colistin (15.4 %), Tiamulin (11.7 %), Tylosin (8.0 %), Lincomycin (9.4 %), and Bacitracin (5.4 %). Weight gain (p 0.05) increased in AGP+ diets during post-weaning (6.5 %). However, there was no effect of AGP on weight gain of growing-finishing pigs. There was better (p 0.05) feed conversion in pigs fed AGP+ diets in all rearing phases. Weight gain and feed conversion improved (p 0.05) with the addition of Avilamycin, Bacitracin, and Tylosin. AGP withdrawal in the post-weaning phase increased feed costs by US$ 0.86 per animal and in growing-finishing phase the increase was US$ 3.11. Thus, pigs fed AGP+ diets have a better performance than pigs fed AGP- diets and the withdrawal of AGP increases feed costs.

8.
Rev. bras. zootec ; 50: e20200077, 2021. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1443233

Resumo

The aim of this study was to evaluate genomic information inclusion in genetic parameter estimation of standardized body weight at birth and at 240, 365, and 450 days of age, and visual scores for body structure, precocity, and body muscularity, measured as yearlings in Nelore cattle. We compared genetic parameters, (co)variance components (estimated from Bayesian inference and Gibbs sampling), breeding value accuracies, genetic trends, and principal component analysis (PCA) obtained through traditional GBLUP and ssGBLUP methods. For all traits analyzed, part of the phenotypic variation was explained by the additive genetic effect, thus indicating the capacity of traits to respond to the selection process. Estimates of genetic correlation, in both methodologies, between body weights and visual scores were, in general, high and positive, showing that the selection for visual scores can lead to heavier animals. Genetic trends showed genetic progress, both when estimated breeding values and genomic estimated breeding values were used. The PCA, genetic trends, and accuracy estimates on breeding values showed that inclusion of single nucleotide polymorphism information contributed towards slightly better estimates of the genetic variability of evaluated traits. Genomic information did not bring greater gains in genetic estimates, due to redundancy of kinship information from the pedigree, which already had complete animal kinship data.


Assuntos
Animais , Bovinos , Peso Corporal/genética , Pesos e Medidas Corporais/veterinária , Expressão Gênica , Genômica
9.
Arq. bras. med. vet. zootec. (Online) ; 73(6): 1391-1402, Nov.-Dec. 2021. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355689

Resumo

This study was carried out for two purposes: comparing performances of Regression Tree and Automatic Linear Modeling and determining optimum sample size for these methods under different experimental conditions. A comprehensive Monte Carlo Simulation Study was designed for these purposes. Results of simulation study showed that percentage of explained variation estimates of both Regression Tree and Automatic Linear Modeling was influenced by sample size, number of variables, and structure of variance-covariance matrix. Automatic Linear Modeling had higher performance than Regression Tree under all experimental conditions. It was concluded that the Regression Tree required much larger samples to make stable estimates when comparing to Automatic Linear Modeling.(AU)


Este estudo foi realizado com dois objetivos: comparar os desempenhos da Árvore de Regressão e da Modelagem Linear Automática e determinar o tamanho ideal da amostra para estes métodos sob diferentes condições experimentais. Um abrangente Estudo de Simulação de Monte Carlo foi projetado para estes propósitos. Os resultados do estudo de simulação mostraram que a porcentagem de estimativas de variação explicada tanto da Árvore de Regressão como da Modelagem Linear Automática foi influenciada pelo tamanho da amostra, número de variáveis e estrutura da matriz de variância-covariância. A Modelagem Linear Automática teve um desempenho superior ao da Árvore de Regressão em todas as condições experimentais. Concluiu-se que a Árvore de Regressão exigia amostras muito maiores para fazer estimativas estáveis quando comparada à Modelagem Linear Automática.(AU)


Assuntos
Modelos Lineares , Método de Monte Carlo , Análise de Regressão , Análise de Dados , /métodos
10.
Rev. bras. zootec ; 50: e20200121, 2021. tab
Artigo em Inglês | VETINDEX | ID: biblio-1443177

Resumo

Estimation of genetic variability and genetic correlations between production traits (milk yield, fat yield, fat content, protein yield, and protein content) and selected type traits (angularity, fore udder height, rear udder height, front teat placement, teat length, and udder depth) was done using data sets of 10,860 first-calving Holstein-Friesian cows raised in the territory of the Republic of Serbia. Genetic variance and covariance were obtained using the Restricted Maximum Likelihood (REML) method, VCE v6 software, and the multi-trait mixed model. To enable more precise estimates of values for genetic variances and covariance, a relationship matrix was formed for the individual model (animal model), encompassing 21363 animals. The highest heritability values were obtained for milk yield (0.182), fat yield (0.134), and protein yield (0.170). The lowest heritability estimates were for teat length, front teat placement, rear udder height, and udder depth, all being under 0.110. Genetic correlations between production traits and linear type traits were between −0.131 (fat content and front teat length) and 0.307 (protein yield and fore udder attachment). The largest number of traits shows a positive genetic correlation with the traits of milk yield, which thus indicates possibility of genetic improvements of milk yield in cattle without jeopardizing the type traits or vice versa.


Assuntos
Animais , Feminino , Bovinos , Padrões de Referência , Hereditariedade , Leite/classificação , Eficiência , Filogenia , Sérvia
11.
Arq. bras. med. vet. zootec. (Online) ; 73(1): 18-24, Jan.-Feb. 2021. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1153046

Resumo

The objective of this study was to estimate the components of variance and genetic parameters of test-day milk yield in first lactation Girolando cows, using a random regression model. A total of 126,892 test-day milk yield (TDMY) records of 15,351 first-parity Holstein, Gyr, and Girolando breed cows were used, obtained from the Associação Brasileira dos Criadores de Girolando. To estimate the components of (co) variance, the additive genetic functions and permanent environmental covariance were estimated by random regression in three functions: Wilmink, Legendre Polynomials (third order) and Linear spline Polynomials (three knots). The Legendre polynomial function showed better fit quality. The genetic and permanent environment variances for TDMY ranged from 2.67 to 5.14 and from 9.31 to 12.04, respectively. Heritability estimates gradually increased from the beginning (0.13) to mid-lactation (0.19). The genetic correlations between the days of the control ranged from 0.37 to 1.00. The correlations of permanent environment followed the same trend as genetic correlations. The use of Legendre polynomials via random regression model can be considered as a good tool for estimating genetic parameters for test-day milk yield records.(AU)


O objetivo deste estudo foi estimar os componentes de variância e os parâmetros genéticos da produção de leite no dia do teste (TDMY) em vacas Girolando de primeira lactação, usando modelo de regressão aleatória. Foram utilizados 126.892 registros de produção de leite no dia controle de 15.351 vacas primíparas das raças Holandesa, Gir e Girolando, obtidas na Associação Brasileira dos Criadores de Girolando. Para estimar os componentes de (co) variância, as funções genéticas aditivas e de covariância ambiental permanente foram estimadas por regressão aleatória em três funções: Wilmink, polinômios de Legendre (terceira ordem) e polinômios splines lineares (três nós). A função polinomial de Legendre apresentou melhor qualidade de ajuste. As variâncias genéticas e de ambiente permanente para produção de leite no dia do controle variaram de 2,67 a 5,14 e de 9,31 a 12,04, respectivamente. As estimativas de herdabilidade aumentaram gradativamente do início (0,13) para o meio da lactação (0,19). As correlações genéticas entre os dias do controle variaram de 0,37 a 1,00. As correlações de ambiente permanente seguiram a mesma tendência das correlações genéticas. A utilização dos polinômios de Legendre via modelos de regressão aleatória pode ser considerada como uma boa ferramenta para estimação de parâmetros genéticos da produção de leite no dia do teste.(AU)


Assuntos
Animais , Feminino , Bovinos , Lactação/fisiologia , Padrões de Herança , Leite , Gestão da Qualidade Total , Padrões de Referência , Correlação de Dados
12.
Sci. agric ; 78(supl. 1): e20200266, 2021. graf, tab
Artigo em Inglês | VETINDEX | ID: biblio-1497997

Resumo

This study was designed to simulate productive and economic losses due to the withdrawal of antibiotic growth promoters (AGP) from pig diets. Articles that compared diets with AGP (AGP+) or without AGP (AGP–) for pigs were collected from electronic databases and the performance results were entered in a database. A meta-analysis was performed following the sequence: graphical analysis, correlation, and variance-covariance. The performance results observed in the meta-analysis, feed cost, and AGP costs were used to build equations to estimate the economic effect of withdrawing AGP. The database comprised 81 scientific articles containing 103 experiments totalizing 42,923 pigs. Avilamycin (24.7 %) was the most frequent AGP in the database, followed by Colistin (15.4 %), Tiamulin (11.7 %), Tylosin (8.0 %), Lincomycin (9.4 %), and Bacitracin (5.4 %). Weight gain (p < 0.05) increased in AGP+ diets during post-weaning (6.5 %). However, there was no effect of AGP on weight gain of growing-finishing pigs. There was better (p < 0.05) feed conversion in pigs fed AGP+ diets in all rearing phases. Weight gain and feed conversion improved (p < 0.05) with the addition of Avilamycin, Bacitracin, and Tylosin. AGP withdrawal in the post-weaning phase increased feed costs by US$ 0.86 per animal and in growing-finishing phase the increase was US$ 3.11. Thus, pigs fed AGP+ diets have a better performance than pigs fed AGP- diets and the withdrawal of AGP increases feed costs.


Assuntos
Animais , Aditivos Alimentares/análise , Antibacterianos , Suínos/crescimento & desenvolvimento
13.
Sci. agric. ; 78(supl. 1): e20200266, 2021. graf, tab
Artigo em Inglês | VETINDEX | ID: vti-765599

Resumo

This study was designed to simulate productive and economic losses due to the withdrawal of antibiotic growth promoters (AGP) from pig diets. Articles that compared diets with AGP (AGP+) or without AGP (AGP–) for pigs were collected from electronic databases and the performance results were entered in a database. A meta-analysis was performed following the sequence: graphical analysis, correlation, and variance-covariance. The performance results observed in the meta-analysis, feed cost, and AGP costs were used to build equations to estimate the economic effect of withdrawing AGP. The database comprised 81 scientific articles containing 103 experiments totalizing 42,923 pigs. Avilamycin (24.7 %) was the most frequent AGP in the database, followed by Colistin (15.4 %), Tiamulin (11.7 %), Tylosin (8.0 %), Lincomycin (9.4 %), and Bacitracin (5.4 %). Weight gain (p < 0.05) increased in AGP+ diets during post-weaning (6.5 %). However, there was no effect of AGP on weight gain of growing-finishing pigs. There was better (p < 0.05) feed conversion in pigs fed AGP+ diets in all rearing phases. Weight gain and feed conversion improved (p < 0.05) with the addition of Avilamycin, Bacitracin, and Tylosin. AGP withdrawal in the post-weaning phase increased feed costs by US$ 0.86 per animal and in growing-finishing phase the increase was US$ 3.11. Thus, pigs fed AGP+ diets have a better performance than pigs fed AGP- diets and the withdrawal of AGP increases feed costs.(AU)


Assuntos
Animais , Suínos/crescimento & desenvolvimento , Antibacterianos , Aditivos Alimentares/análise
14.
Acta sci. vet. (Impr.) ; 49: Pub. 1836, 2021. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1363704

Resumo

Videolaparoscopic procedures have gained prominence due to their low invasiveness, causing less surgical trauma and better post-surgical recovery. However, the increase in intra-abdominal pressure due to the institution of pneumoperitoneum can alter the patient's homeostasis. Therefore, volume-controlled ventilation, associated with positive end-expiratory pressure (PEEP), improves arterial oxygenation and prevents pulmonary collapse, but it can lead to important hemodynamic changes. The aim of this study was to evaluate, comparatively, the effects of positive end expiratorypressure (PEEP) on hemodynamic variables of pigs submitted to volume-controlled ventilation, during pneumoperitoneum and maintained in head-down tilt and determine which PEEP value promotes greater stability on hemodynamic variables. Twenty-four pigs were used, between 55 and 65-day-old, weighing between 15 and 25 kg, randomly divided into 3 distinct groups differentiated by positive end-expiratory pressure: PEEP 0 (volume-controlled ventilation and PEEP of 0 cmH2O), PEEP 5 (volume-controlled ventilation and PEEP of 5 cmH2O) and PEEP 10 (volume-controlled ventilation and PEEP of 10 cmH2O). Volume-controlled ventilation was adjusted to 8 mL/kg of tidal volume and a respiratory rate of 25 movements per min. Anesthesia was maintained with continuous infusion of propofol (0.2 mg/kg/min) and midazolam (1 mg/kg/h). Pneumoperitoneum was performed with carbon dioxide (CO2), keeping the intraabdominal pressure at 15 mmHg and the animals were positioned on a 30° head-down tilt. The evaluations of hemodynamic variables started 30 min after induction of anesthesia (M0), followed by measurements at 15-min intervals (from M15 to M90), completing a total of 7 evaluations. The variables of interest were collected over 90 min and submitted to analysis of variance followed by Tukey's post-hoc test, with P < 0.05. The PEEP 10 group had higher values of CVP and mCPP, while the PEEP 5 group, mPAP and PVR were higher. The PEEP 0 group, on the other hand, had higher means of CI. Regarding the moments, there were differences in HR, SAP, DAP, MAP, CO, IC and TPR. According to the literature, important hemodynamic effects due to pneumoperitoneum are reported, which can be caused by the pressure used in abdominal insufflation, CO2 accumulation, duration of the surgical procedure, hydration status and patient positioning. Mechanical ventilation associated with PEEP can also cause an increase in intrathoracic pressure and, therefore, reduce cardiac output. Cardiovascular changes are proportional to the PEEP used. Central venous pressure (PVC) measure the patient's preload, and intrathoracic pressure can interfere with this parameter. The peak pressure values in the PEEP 10 group were higher than the other groups, demonstrating that the increase in intrathoracic pressure results in higher PVC values. Regarding PAPm and PCPm, these variables can be influenced according to the PEEP values and the patient's position. In relation to CI, the increase in PEEP may reflect on intrathoracic pressure, resulting in greater compression of the heart, with a consequent reduction in cardiac output and cardiac index. Therefore, it is concluded that the PEEP effects of 0 cmH2O and 5 cmH2O on hemodynamics are discrete, under the proposed conditions.(AU)


Assuntos
Animais , Pneumoperitônio , Respiração Artificial , Volume de Ventilação Pulmonar , Laparoscopia/veterinária , Decúbito Inclinado com Rebaixamento da Cabeça/efeitos adversos , Suínos
15.
Braz. J. Biol. ; 80(1): 142-146, fev. 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-28543

Resumo

The objective of this study was to investigate genetic variances and covariances among features of the male Japanese quail advertisement call. Duration of the first, second and third syllable, the length of interval 1 (between the first and the second syllable), interval 2 (between the second and the third syllable) and damping (extension of the third syllable) were measured as temporal properties of the call. Spectral properties were peak frequencies of each syllable and the damping component. In this study, 1730 calls were recorded from 488 male Japanese quail. The restricted maximum likelihood procedure for repeated measurements was applied to estimate (co)variance components and genetic parameters for the examined traits. Heritability estimates of call parameters of the male Japanese quail ranged from low to high values (0.04-0.65) and they were generally higher for temporal properties than for spectral properties. Among the temporal properties of the call, the highest genetic correlation was between the first and the second syllable (0.96±0.251) while the lowest genetic correlation was between the first and the third syllable (0.03±0.231). Significant genetic correlations were generally high and positive among peak frequencies of the syllables. Despite the lack of apparent pattern, interval lengths tended to have positive correlation with spectral properties of the call, but the correlation of syllable lengths with spectral properties of the call was negative.(AU)


O objetivo deste estudo foi investigar as variâncias e covariâncias genéticas entre as características do canto de anúncio de codornas japonesas. A duração da primeira, segunda e terceira sílaba, o comprimento do intervalo 1 (entre a primeira e a segunda sílaba), o intervalo 2 (entre a segunda e a terceira sílaba) e o amortecimento (extensão da terceira sílaba) foram medidos como propriedades temporais da chamada. As propriedades espectrais foram as frequências de pico de cada sílaba e o componente de amortecimento. Neste estudo, 1730 chamadas foram registradas de 488 codornas japonesas masculinas. O procedimento de máxima verossimilhança restrita para medidas repetidas foi aplicado para estimar componentes de (co) variância e parâmetros genéticos para as características examinadas. As estimativas de herdabilidade dos parâmetros de chamada das codornas japonesas masculinas variaram entre valores baixos e altos (0,04-0,65) e foram geralmente mais elevadas para as propriedades temporais do que para as propriedades espectrais. Dentre as propriedades temporais da chamada, a maior correlação genética foi entre a primeira e a segunda sílaba (0,96 ± 0,251), enquanto a menor correlação genética foi entre a primeira e a terceira sílaba (0,03 ± 0,231). Correlações genéticas significativas foram geralmente altas e positivas entre as frequências de pico das sílabas. Apesar da falta de padrão aparente, os comprimentos de intervalo tenderam a ter uma correlação positiva com as propriedades espectrais da chamada, mas a correlação dos comprimentos das sílabas com as propriedades espectrais da chamada foi negativa.(AU)


Assuntos
Animais , Masculino , Publicidade , Coturnix , Fenótipo
16.
Ciênc. anim. bras. (Impr.) ; 21: e, 23 mar. 2020. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1473747

Resumo

Classical methods of analysis of nonlinear models are widely used in studies of ruminal degradation kinetics. As this type of study involves repeated measurements in the same experimental unit, the use of mixed nonlinear models (MNLM) is proposed, in order to solve problems of heterogeneity of variances of the responses, correlation among repeated measurements and consequent lack of sphericity in the covariance matrix. The aims of this work are to present an evaluation of the applicability of MNLM in the estimation of parameters to describe the in situ ruminal degradation kinetics of the dry matter of Tifton 85 hay and to compare the results with those obtained from the usual analysis in two-phases. The steers used in the trial were fed diets composed of three different combinations of roughage and concentrate and two hays with different nutritional qualities. The proposed approach was proven as effective as the traditional one for estimating model parameters. However, it adequately models the correlation among the longitudinal data, which can affect the estimates obtained, the standard error associated with them and potentially change the results of the inferences. It is quite attractive when the research seeks to understand the behavior of the process of food degradation throughout the incubation times.


Métodos clássicos de análise de modelos não lineares são amplamente utilizados em estudos da cinética de degradação ruminal. Como esse tipo de estudo envolve medidas repetidas na mesma unidade experimental, propõe-se o uso de modelos não lineares mistos (MNLM), buscando resolver os problemas de heterogeneidade de variâncias das respostas, de correlação entre as medidas repetida se a consequente falta de esfericidade da matriz de covariâncias. Os objetivos deste trabalho envolvem apresentar uma avaliação da aplicabilidade dos MNLM na estimação de parâmetros para descrever a cinética de degradação ruminal in situ da matéria seca de fenos de capim-Tifton 85 e comparar os seus resultados com os obtidos da análise usual realizada em duas fases. Os novilhos utilizados no ensaio foram alimentados com rações compostas por três diferentes combinações de volumoso e concentrado e dois fenos com diferentes qualidades nutricionais. A abordagem proposta mostrou-se tão efetiva quanto à tradicional para a estimação dos parâmetros do modelo. Contudo, ela modela de forma adequada a correlação entre os dados longitudinais, o que pode afetar as estimativas obtidas, o erro padrão associado a elas e, potencialmente, alterar os resultados das inferências. É bastante atraente quando a pesquisa busca entender o comportamento do processo da degradação dos alimentos ao longo dos tempos de incubação.


Assuntos
Dinâmica não Linear , Rúmen/fisiologia , Rúmen/química , Análise de Variância , Bovinos/metabolismo , Cinética , Estudos Longitudinais
17.
Ci. Anim. bras. ; 21: e-57596, June 16, 2020. ilus, tab, graf
Artigo em Inglês | VETINDEX | ID: vti-32025

Resumo

Classical methods of analysis of nonlinear models are widely used in studies of ruminal degradation kinetics. As this type of study involves repeated measurements in the same experimental unit, the use of mixed nonlinear models (MNLM) is proposed, in order to solve problems of heterogeneity of variances of the responses, correlation among repeated measurements and consequent lack of sphericity in the covariance matrix. The aims of this work are to present an evaluation of the applicability of MNLM in the estimation of parameters to describe the in situ ruminal degradation kinetics of the dry matter of Tifton 85 hay and to compare the results with those obtained from the usual analysis in two-phases. The steers used in the trial were fed diets composed of three different combinations of roughage and concentrate and two hays with different nutritional qualities. The proposed approach was proven as effective as the traditional one for estimating model parameters. However, it adequately models the correlation among the longitudinal data, which can affect the estimates obtained, the standard error associated with them and potentially change the results of the inferences. It is quite attractive when the research seeks to understand the behavior of the process of food degradation throughout the incubation times.(AU)


Métodos clássicos de análise de modelos não lineares são amplamente utilizados em estudos da cinética de degradação ruminal. Como esse tipo de estudo envolve medidas repetidas na mesma unidade experimental, propõe-se o uso de modelos não lineares mistos (MNLM), buscando resolver os problemas de heterogeneidade de variâncias das respostas, de correlação entre as medidas repetida se a consequente falta de esfericidade da matriz de covariâncias. Os objetivos deste trabalho envolvem apresentar uma avaliação da aplicabilidade dos MNLM na estimação de parâmetros para descrever a cinética de degradação ruminal in situ da matéria seca de fenos de capim-Tifton 85 e comparar os seus resultados com os obtidos da análise usual realizada em duas fases. Os novilhos utilizados no ensaio foram alimentados com rações compostas por três diferentes combinações de volumoso e concentrado e dois fenos com diferentes qualidades nutricionais. A abordagem proposta mostrou-se tão efetiva quanto à tradicional para a estimação dos parâmetros do modelo. Contudo, ela modela de forma adequada a correlação entre os dados longitudinais, o que pode afetar as estimativas obtidas, o erro padrão associado a elas e, potencialmente, alterar os resultados das inferências. É bastante atraente quando a pesquisa busca entender o comportamento do processo da degradação dos alimentos ao longo dos tempos de incubação.(AU)


Assuntos
Dinâmica não Linear , Rúmen/fisiologia , Rúmen/química , Cinética , Estudos Longitudinais , Análise de Variância , Bovinos/metabolismo
18.
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1959-1964, Sept.-Oct. 2020. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1131525

Resumo

This study aimed to estimate genetic parameters for simulated data of body weight (BW), abdominal width (AW), abdominal length (AL), and oviposition. Simulation was performed based on real data collected at apiaries in the region of Campo das Vertentes, Minas Gerais, Brazil. Genetic evaluations were performed using single- and two-trait models and (co)variance components were estimated by the restricted maximum likelihood method. The heritability for BW, AW, AL and oviposition were 0.54, 0.47, 0.31 and 0.66, respectively. Positive genetic correlations of high magnitude were obtained between BW and AW (0.80), BW and oviposition (0.69), AW and oviposition (0.82), and AL and oviposition (0.96). The genetic correlations between BW and AL (0.11) and between AW and AL (0.26) were considered moderate and low. In contrast, the phenotypic correlations were positive and high between BW and AW (0.97), BW and AL (0.96), and AW and AL (0.98). Phenotypic correlations of low magnitude and close to zero were obtained for oviposition with AL (0.02), AW (-0.02), and BW (-0.03). New studies involving these characteristics should be conducted on populations with biological data in order to evaluate the impact of selection on traits of economic interest.(AU)


Objetivou-se estimar parâmetros genéticos para dados simulados de peso corporal (PC), largura abdominal (LA), comprimento abdominal (CA) e oviposição (OV). A simulação foi conduzida com base em dados reais, coletados em apiários da região do Campo das Vertentes, Minas Gerais. As estimativas das análises genéticas foram realizadas por modelos uni e bicaracterísticos, sendo os componentes de (co) variância estimados pelo método da máxima verossimilhança restrita. As herdabilidades para PC, LA, CA e OV foram de 0,54, 0,47, 0,31 e 0,66 respectivamente. As correlações genéticas foram positivas e de alta magnitude para PC e LA (0,80), PC e OV (0,69), LA e OV (0,82) e CA e OV (0,96). Para PC e CA (0,11) e LA e CA (0,26), as correlações genéticas foram moderadas e de baixa magnitude. As correlações fenotípicas foram positivas e de alta magnitude para PC e LA (0,97), PC e CA (0,96) e LA e CA (0,98). Para OV e CA (0,02), OV e LA (-0,02) e OV e PC (-0,03), foram encontradas correlações fenotípicas de magnitude baixa e próximas de zero. Novos estudos devem ser realizados em populações com dados biológicos, a fim de se observar o impacto da seleção em características de interesse econômico.(AU)


Assuntos
Animais , Oviposição/genética , Abelhas/genética , Peso Corporal/genética , Pesos e Medidas Corporais/classificação , Hereditariedade , Correlação de Dados
19.
Ci. Rural ; 50(5): e20190578, May 11, 2020. tab
Artigo em Inglês | VETINDEX | ID: vti-29047

Resumo

In this study, we analyzed the role of individuals health-related factors along with socio-demographic and economic characteristics on both the likelihood of tobacco consumption and quantity demanded levels using two competitive econometric methods: double hurdle model versus hyperbolic sine double-hurdle model. Statistical tests confirmed the dependency errors between the prevalence rate of smoking and the consumption level, whilst the inverse-hyperbolic sine double-hurdle model data fits best in describing the normalization of the data and the two data generating processes: the probability and consumption levels of cigarettes. Also, the variance-covariance of the selected model as a function of additional exogenous variables are confirmed, while the error terms between the likelihood to smoke and the consumption levels are positive and statistically significant, indicating that holding control variables fixed, the uncontrolled variables out of the system that increase the prevalence rate of smoking also boost the consumption level, or vice versa. Many individual disease variables are significant in both equations, breaking new grounds in literature for identifying how both the prevalence rate of smoking and amount have shaped.(AU)


Neste estudo, analisamos o papel dos fatores relacionados à saúde dos indivíduos, juntamente com as características sócio-demográficas e econômicas, tanto na probabilidade de consumo de tabaco quanto nos níveis de quantidade demandada, usando dois métodos econométricos competitivos: modelo de obstáculo duplo versus modelo de obstáculo duplo seno hiperbólico. Os testes estatísticos confirmaram os erros de dependência entre a taxa de prevalência de tabagismo e o nível de consumo, enquanto o modelo de seno duplo inverso-hiperbólico se ajusta melhor aos dados para descrever a normalização dos dados e os dois processos geradores de dados: os níveis de probabilidade e consumo de cigarros. Também são confirmadas a covariância de variância do modelo selecionado em função de variáveis exógenas adicionais, enquanto os termos de erro entre a probabilidade de fumar e os níveis de consumo são positivos e estatisticamente significativos, indicando que, mantendo variáveis de controle fixas, as variáveis não controladas são do sistema que aumenta a taxa de prevalência do tabagismo e também cresce o nível de consumo, ou vice-versa. Muitas variáveis individuais da doença são encontradas significativamente em ambas as equações, abrindo novos caminhos na literatura para identificar como a taxa de prevalência de tabagismo e a quantidade se moldaram.(AU)


Assuntos
Humanos , Uso de Tabaco/efeitos adversos , Censos , Saúde Pública , Turquia
20.
Rev. bras. zootec ; 49: e20180177, 2020. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1443797

Resumo

This study was developed using meta-analysis to evaluate the effect of ß-mannanase on both poultry and pig performance. Two databases were constructed using information from previous studies that evaluated the ß-mannanase supplementation in diets for broilers (30 papers; 19,643 birds) and pigs (20 papers; 5,319 animals). The meta-analysis followed three sequential analyses: graphical, correlation, and variance-covariance. The effect of ß-mannanase supplementation on performance considerably varied in both databases. Data analysis considering the study effect showed that ß-mannanase supplementation did not influence feed intake. Diets supplemented with ß-mannanase did not influence weight gain, but improved feed conversion (−1%) of broilers compared with the control group. Feeding pigs diets supplemented with ß-mannanase improved weight gain (+5%) and feed conversion (−6%) compared with pigs fed non-supplemented diets. ß-mannanase supplementation increased the digestibility coefficient of dry matter, crude protein, and energy in both species. The inclusion of ß-mannanase also improved the metabolizable energy content in broiler diets and enhanced the digestibility of energy in pig feeds. Current results indicate that ß-mannanase can be considered as an important tool for nutritionists who search for improved feed conversions and nutrient digestibility coefficients.(AU)


Assuntos
Animais , Suínos/fisiologia , Galinhas/fisiologia , Ingestão de Alimentos/fisiologia , Fenômenos Fisiológicos da Nutrição Animal
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA