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Growth dynamics in selected rabbit breeds
POUSTKA, Milan
The aim of the thesis was performance comparison of selected populations of three breeds of rabbits, the Moravian Blue (Mm), the Viennese Blue (Vm) and the Dutch rabbit (Ho), that is a large, a medium-sized and a small breed. The monitored aspects were the production characteristics (gain weight and carcass yield) and the reproductive characteristics (the average number of kits born, the number of all kits born, the number of live born and stillborn and successfully weaned kits, the rate of successful pregnancies, the milkness of the doe). The population of each of the breeds was monitored in a selected base of 68 litters of the Mm, 65 litters of the Vm and 84 litters of the Ho. The weight gain of rabbits was monitored in regular intervals from birth until the end of fattening, i. e. until 8 months of age in the Mm and the Vm and until 6 months of age in the Ho. The results were compared with the weight gain required by the breed standard. Based on the observed weight gain, a growth curve has been created using the Richards function in Excel and Statistica 12.0. The monthly weight gain of the monitored breeds was compared. The highest average gain in weight for the Mm was 693 g, for the Ho 480g and for the Vm 539 g. The results show a significantly higher gain in weight throughout the growth period of the Dutch rabbit than is required by the breed standard. The Moravian Blue showed a lower average increase in weight during the first five months of age than is required by the breed standard. High statistical dependence (R = 0,94, p < 0.01) between weight gain and the number of kits per litter was observed during the first month. From the second month dependence get lower. Since the third month of age, this dependence could not be proven. Based on the parameters of the growth curve, the inflection point of growth was established at 59.8 days and weight 1 528 g for the Mm, at 43.2 days and weight 895 g for the Ho and at 67.7 days and weight 1512 g for the Vm. The average number of kits per litter was 6.3 for the Mm, 6.48 for the Ho and 6.23 for the Vm. The milkness was calculated according to the weight of the litter at 2 and 21 days of age. The milkness for the Mm was 3 985 g, for the Ho 2 582 g and 3 176 g for the Ho. A significant statistical dependence (R = 0.97 0.98) between the number of kits in the litter and the milkness was found. The mortality rate was at a low level for all monitored breeds, with the highest (5 per cent) for the Vm , followed by 2.9 per cent forthe Ho and 1.4 per cent forthe Mm. Analysis showed the highest carcass yield for the Dutch rabbit (62.4 per cent), but a lower live weight gain. The carcass yield was 59 per cent for the Vm and only 56.1 per cent for the Mm. Overall, the results of the thesis show a bigger live weight gain in case of the Moravian Blue rabbit provided there are higher demands for housing and feeding. Its progeny shows a greater growth potential and, in some aspects, also better reproductive characteristics. On the other hand, the Dutch rabbit paradoxically reached a higher number of kits per litter and better carcass yield, giving meat of greater quality. The Viennese Blue rabbit had a slightly higher mortality rate than the other breeds but also a relatively large weight gain and carcass yield approaching other medium-sized meat breeds. The results of the thesis can be beneficial for novice breeders in helping them choose the right breed, as well as for existing breeders in helping them improve the strengths and eliminate the weaknesses of these breeds.
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