Characterization of the lactation curve of f1 Holstein-Zebu cows
Por:
Castillo Gallegos, Epigmenio
Publicada:
1 ene 2018
Resumen:
The objective was to find a function to describe the lactation curve of
grazing Holstein - Zebu cows (n=23) in tropical Mexico. Twelve were
based on the general nonlinear function A*?(1)(x)*?(2)(x): A, a
positive scalar; ?(1), a positive monotonically increasing function with
asymptote ?(1) = 1; ?(2), is a monotonically decreasing function with
asymptote ?(2)=0 and initial value of 1; and x is lactation time (days).
For ?(1), the Mitscherlitsch, Michaelis-Menten, generalized saturation
kinetics, logistic, Gompertz and hyperbolic tangent equations were used,
whilst for ?(2), they were the exponential and inverse linear. A gamma
function, the more used, and the addition of two logistic equations, the
more biologically explicit, were also included. The smaller value of the
Akaike information criterion corrected (AIC(c)) indicated the latter was
the one with the best fit, so its use to study factors affecting the
lactation curve is suggested.
Filiaciones:
Castillo Gallegos, Epigmenio:
Univ Nacl Autonoma Mexico, Ctr Ensenanza Invest & Extens Ganaderia Trop, Fac Med Vet & Zootecnia, Apartado Postal 136, Martinez De La Torre 93600, Veracruz, Mexico
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