Ruminal pH and N-NH3 behavior: a Bayesian approach

Abstract

In this work, we present the Bayesian approach as an alternative to frequentist analysis regarding correlated data of pH and N-NH 3 in the Holstein cow rumen. It was observed that for pH and N-NH3 data, a posteriori estimates of coefficients of the regression models were significant, which was not observed for least-squares estimates. Thus, the Bayesian approach allowed inferences that were directly linked to the sampling of parameters of interest and statistical comparisons of non-linear functions of the estimated parameters. Key words: Gibbs sampling, statistical inference, least squares estimators ResumoNeste trabalho objetivou-se estudar a abordagem Bayesiana como alternativa à análise frequentista, para tratar dados correlacionados de pH e N-NH 3 coletados no rúmen de vacas Holandesas. Observou-se que tanto para os dados de pH quanto N-NH 3 , as estimativas a posteriori dos coeficientes dos modelos de regressão foram significativas, o que não foi observado nas estimativas de mínimos quadrados. Desta forma, a abordagem Bayesiana permitiu inferências ligadas diretamente ao conceito de amostragem dos parâmetros de interesse, assim como comparações estatísticas sobre funções não-lineares dos parâmetros estimados. Palavras-chave: Amostrador de Gibbs, dados correlacionados, inferência estatística, estimadores mínimos quadrados

Effect of slow release urea in sheep feed on intake, nutrient digestibility, and ruminal parameters

“…For the pH and concentration of ammonia in the rumen fluid, statistical analysis that considered the subdivision of the parcel was undertaken, which included the time of evaluation after feeding the animals. This method of frequentist analysis, was considered with the regression for each level of inclusion of SRU beyond the average of experiments rations (SOUZA et al, 2016).…”

Distiller’s dried grain with solubles (Zea mays L) in the diet of sheep reared in the tropical region of Brazil: ingestive behavior and physiological parameters

“…When significance was verified for DDGS inclusion levels in the experimental rations, regression analysis was performed, considering the linear and quadratic effect at p < 0.05. For the ingestive behavior data and physiological parameters, were considered the subdivisions of the plots, considering daytime and night time evaluation in the ingestive behavior, and morning and afternoon in the physiological parameters of ovine fed with DDGS, for the periods evaluated were compared by the test tukey at 0.05 probability (SOUZA et al, 2016). …”