carcass.EMI.model {ZeBook}

The Carcass (growth of beef cattle) model with energy as input

Description

Model description. This model is proposed by Hoch et. al (2004) to represent the growth of cattle and the relative body composition of diferent types of animals depending on nuritionnal conditions. It simulates the dynamics of changes in the composition of the body fat and proteins according to nutrient intake. The system is represented by four state variables: the protein and fat in the carcass (resp. ProtC and LIPC) and other tissues (resp. ProtNC and LipNC) grouped under the name of the fifth district (again, gastrointestinal tract, skin .. .). These variables depend on time, the time step used is dt = 1 day. The model is defined by 20 equations, with a total of 18 parameters for the described process.

Usage

carcass.EMI.model(protcmax, protncmax, alphac, alphanc, gammac, gammanc,
  lip0, lipc1, lipnc1, beta, delta, amW, b0c, b1c, b0nc, b1nc, c0, c1,
  energie, PVi, duration)

Arguments

protcmax

: amounts of protein in the carcass of the adult animal (kg)

protncmax

: amounts of protein in the 5th district of the adult animal (kg)

alphac

: maximum protein synthesis rate in the frame (excluding basal metabolism) (j-1)

alphanc

: maximum rate of protein synthesis in the 5th district (except basal metabolism) (j-1)

gammac

: Maximum rate of protein degradation in the frame (excluding basal metabolism) (j-1)

gammanc

: maximum rate of protein degradation in the 5th district (except basal metabolism) (j-1)

lip0

: maximum lipid concentration to the theoretical physiological age (percent)

lipc1

: increase coefficient of the maximum lipid concentration with the physiological age of the carcase (percent)

lipnc1

: increase coefficient of the highest lipid concentration with physiological age area in the 5th (percent)

beta

: lipid synthesis rate (j-1)

delta

: lipid degradation rate (d-1)

amW

:

b0c

: coefficient of the allometric equation linking mass and lipid-protein carcass

b1c

: exponent allometric equation linking mass and defatted protein carcass

b0nc

: coefficient of the allometric equation linking mass and lipid-protein 5th district

b1nc

: exponent allometric equation linking mass and lipid-protein 5th district

c0

: coefficient of the allometric equation between live weight and live weight empty

c1

: exponent allometric equation linking body weight and live weight empty

energie

: Metabolizable energy available

PVi

: initial liveweight

duration

: duration of simulation

Value

matrix with ProtC,LipC,ProtNC,LipNC,PV