- Volume 17 Issue 9
A line of Japanese quail selected for increased body weight for 15 generations (C) and an unselected control line (K) were used to examine the impact of selection for body weight on the growth curve of Japanese quail. In addition, the effect of sex on the growth curve in each line was also studied, namely females of C (CF), males of C (CM), females of K (KF) and males of K (KM). The monophasic and diphasic growth models were studied for adequacy in describing growth curves of quail in both sexes of the C and K lines. The monophasic function provided almost the same growth rate for both sexes in both lines. However, the growth rates calculated by means of the diphasic function differed between sexes for both lines, except for those calculated for C during the second growth phase. While there were 2-3 days difference between sexes in age at maximum gain in both lines with a monophasic model, the difference between sexes in the age at maximum gain in both lines became greater according to the diphasic model. There were 5 and 7 days difference between sexes in the age at maximum gain in line C for the first and second growth phases, respectively. A difference between sexes of 18 and 11 days in the age at maximum gain for the first and second phases, respectively, was estimated for line K when the diphasic function was fitted. The use of diphasic functions provides more detailed information on growth patterns. The results showed that the use of the diphasic function was better because it provided greater insights into understanding the biology of growth.
- Brody, S. 1921. The rate of growth of the domestic fowl. J. Gen. Physiol. 36:765-770.
- Koops, W. J. 1986. Multiphasic growth curve analysis. Growth 50:169-177.
- Kwakkel, R. P., B. J. Ducro and W. J. Koops. 1993. Multiphasic analysis of growth of the body and its chemical components in White Leghorn pullets. Poult. Sci. 72:1421-1432.
- Peil, J. and H. Helwin. 1981. A phenomenologic-mathematical model of growth dynamics. Biom. J. 23:41-54.
- Werker, A. R. and K. W. Jaggard. 1977. Modeling asymmetrical growth curves that rise and then fall: Applications to foliage dynamics of sugar beet (Beta vulgaris L.) Ann. Bot. 79:657-675.
- Koops, W. J. and M. Grossman. 1991. Applications of a multiphasic growth function to body composition in pigs. J. Anim. Sci. 69:3265-3273.
- Grossman, M. and W. J. Koops. 1988. Multiphasic analysis of growth curves in chickens. Poult. Sci. 67:33-42.
- Koops, W. J., M. Grossman and E. Michalska. 1987. Multiphasic growth curve analysis in mice. Growth 51:372-382.
- Eisen, E. J. 1976. Results of growth curve analysis in mice and rats. J. Anim. Sci. 42:1008-1023. https://doi.org/10.2527/jas1976.4241008x
- Hyankova, H., H. Knizetova, L. Dedkova and J. Hort. 2001. Divergent selection for shape of growth curve in Japanese quail. 1. Responses in growth parameters and food conversion. Br. Poult. Sci. 42:583-589.
- Aggrey, S. E. 2003. Dynamics of relative growth rate in Japanese quail lines divergently selected for growth and their control. Growth, development & Aging 67:47-54.