Analysis of live weight growth in rusty-red fox and standard silver fox

The aim of this work was to analyse the live weight growth in gold foxes and to set its intervals during the ontogenesis, compare the growth of animals after years, sex and growth prediction for the performance recording. The experiments were performed with youngs of gold foxes (AABb) during the years 1998-1999. The average weight of males rose from 758-977 g at the age of 30 days to 6638 - 6883 g at the age of 180 days. The weight of females rose from 749-816 g to 5545 - 5690 g. From the viewpoint of relative variability were the males at the age of 180 days 9.08-times heavier than at the age of 30 days, their weight rose 6.79-times in 1999. The females showed 7.62 - multiple of live weight in 1998 and 6.80-multiple in 1999 compared with the first weighing. From the viewpoint of growth evaluation after the Minotïs coefficient of the average relative growth rate (R) we can state that this coefficient had the value 1.566 in 1998 and 1.488 in 1999. As far as the relative rate modified to the average of the initial and final live weight is in question we can say that the live weight gain was 156.6% in the first year (irrespective of sex), and 148.8% in the second year. The coefficient of growth intensity after Fisher (k) had the value 0.0140 in 1998, and k = 0.0128 in the following year. The results of two-way variance analysis of live weight confirm unambiguously that we cannot speak of live weight growth additivity with age as the interactions were statistically highly significant in both years. From the results of the linear-regression analysis of five weight growth follows that approximately at the age of 101 days in 1998 and at the age of 109 days in 1999 was the expected theoretical live weight of males 3825 g and females 3415 g in the first year, and 4291 g and 3746 g, respectively, in the second year. The linear-regression analyses showed that they grew linearly only in males in 1998. The linearity of growth was not so explicit in other subgroups as well as in evaluation without regard to sex. From the viewpoint of linear growth showed the males the daily gain 40.7 g, females 33.1 g, estimated from the regression coefficient in 1998, and 32.9 g males and 28.0 g females in 1999. The gold foxes had statistically highly significantly higher live weight at the age of 30, 60 and 90 days irrespective of sex in 1999. In older animals (120, 150 and 180 days) were found no differences between the years. Differences caused by sexual dimorphism were found only at the age of 60, 150 and 180 days. The authors calculated the intervals of reliability of live weight growth in males and females on the basis of gained results. They can be used as basis for the control of optimum growth in animals not only from the viewpoint of breeders but also for the prediction