Curvas de crescimento de ovinos Bergamácia criados no Distrito Federal
By C. McManus, Cibele Evangelista, L. A. C. Fernandes, R. Miranda, F. E. Moreno-Bernal, Nataliana Ribeiro dos Santos. 2003
63 citations recorded by the source corpus.
Fifteen years of data from a flock of Bergamasca sheep weighed every two weeks was analyzed using non-linear methods to determine parameters of three growth curves (Brody , Richards and Logistic). The curve parameters were analyzed using Statistical Analysis System (SAS) procedures GLM and CORR to determine factors which influenced them and correlations between the parameters and weights at determined ages. Fixed effects in the model included lambing number, sex of lamb, type of birth and month and age of lambing. The management system is semi-extensive, with the sheep at pasture during the day and imprisoned at night to protect them against predators. Means of the parameters were: Richards; A = 50.024, B = 0.647, k = 0.003, M = 17.771 and R2= 0.838; Brody; A= 52.763, B=0.885, k=0.003, R2= 0.842; Logistic; A =47.894, B=-3.895, k=0.007 and R²= 0.840. The environment influenced the growth of sheep in the region of Brasilia. The Logistic curve estimated adult weights lower than the other curves but the actual weights were better correlated with those estimated by this curve. There was no difference between the curves in terms of R2, and the error mean square was higher for the Richards curve. The negative correlation between A and k indicates that early maturing animals were less likely to reach high mature weights, compared with late maturing ones. The recommended curve for adjusting growth curves in Bergamasca sheep is the Logistic curve.
Subfields: Environmental Chemistry, Genetics, Soil Science
View Paper: https://www.semanticscholar.org/paper/c0029873d192762a10531643fccf19ba4e78cdbb
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
- V. Sarıyel
- M. Gokmen
- B. Dağ
- I. Keskin
- M. Behzadi
Citations in the corpus
- Estimation of growth curve parameters in Konya Merino sheep (Short communication) (2009, result): “However, the R2 value (0.84) for the Logistic model estimated by McManus et al. (2003) in Bergamasca sheep was lower than in the current study.”