Izvorni znanstveni članak
A model to determine growth rate of heavy hybrid turkeys
Gordana Kralik
Rudolf Scitovski
Zoran Škrtić
Sažetak
The objective of this study was to investigate the application of generalized logistic function to the heavy hybrid turkey growth modeling. The growth of 20 turkey toms and 20 turkey hens of Nicholas 700 provenience was monitored over 19 weeks. During the whole fattening period, differences in live weights between males and females were statistically highly significant (P<0.001). At the end of the experiment, turkey toms weighed on average 15.17 kg, compared to 10.88 kg of average turkey hens live weight. Males weighed approximately 4.3 kg or 39.53% more than females. Average weekly gain of turkey toms was 795 g, and of turkey hens 577 g. Average growth rate of turkey toms was 12.45% and of turkey hens 12.11%. Evaluation of inflection point and each growth phase for both turkey sexes was carried out by using generalized logistic function:
Coefficients of asymmetry were γ=0.2 (males) and γ=0.3 (females). Biological maximum was 18.57 kg for males, and 12.63 kg for females. According to calculated parameters, inflection point in turkey hens occurred at the beginning of the 10th week of fattening, when they reached 5.27 kg; in turkey toms it occurred in the middle of the 10th week, at the weight of 7.46 kg. On the basis of the results obtained by using the model of generalized logistic function for turkey growth rate description, it was concluded that turkey hens ended their intensive growth phase about a week earlier than turkey toms, with the inflection point also starting earlier than in turkey toms.
Ključne riječi
turkeys; growth; generalized logistic function
Hrčak ID:
2182
URI
Datum izdavanja:
5.9.2005.
Posjeta: 1.356 *