Mathematical Models of Growth Data of Male and Female Wrolstad White Turkeys

A growth model for Wrolstad White turkeys was developed based on the growth data obtained weekly from a flock of 911 Wrolstad White turkeys. The Gompertz growth model was fitted to the data of mean weights as well as the data of the enveloping weight limits that formed the 95% enveloping curves of the mean weights. The Gompertz equation which provided an excellent fit was in the form: W=A·exp(−B·exp(−C·t)) where: W = weight at time t, kg. t = turkey age, days The parameters A, B and C were interpreted as: A = asymptotic weight approached; that is, the weight at time t = ∞, kg. A · exp(−B) = weight at time t = 0, kg. C = the rate of exponential decay of the specific growth rate, days−1 Values of the parameters A, B and C in the Gompertz equation were presented for the best fitting Gompertz equation to the means of: the weights of the entire flock, the weights of all the males, and the weights of all the females. The Gompertz equation was also fitted to the two enveloping curves for each curve of the mean weights.