Characterization of the lactation curve of f1 Holstein-Zebu cows

ABSTRACT: The objective was to find a function to describe the lactation curve of grazing Holstein - Zebu cows (n=23) in tropical México. Twelve were based on the general nonlinear function A* ϕ 1(x)* ϕ 2(x): A, a positive scalar; ϕ 1, a positive monotonically increasing function with asymptote ϕ 1 = 1 ; ϕ 2, is a monotonically decreasing function with asymptote ϕ 2 = 0 and initial value of 1; and x is lactation time (days). For ϕ 1, the Mitscherlitsch, Michaelis-Menten, generalized saturation kinetics, logistic, Gompertz and hyperbolic tangent equations were used, whilst for ϕ 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.

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Bibliographic Details
Main Author: Castillo Gallegos,Epigmenio
Format: Digital revista
Language:English
Published: Universidad Juárez Autónoma de Tabasco, Dirección de Investigación y Posgrado 2018
Online Access:http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S2007-90282018000200335
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