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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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Performance comparison of selected populations of two breeds of rabitts
POUSTKA, Milan
The aim of the thesis was performance comparison of selected populations of two breeds of rabbits, the Moravian blue (Mm) and the Dutch rabbit (Ho), large and small breed of rabbit in fact. The monitored aspects were the production characters (growth and carcass yield) and reproduction characters (average numbers of birth, number of all births, live born and still-born births and number of weaning rabbits, ability of pregnancy, milkiness). Population of each of the breeds was monitored in a selected base of 68 litters of Moravian blue and 84 litters of Dutch rabbit. Both monitored breeds are recognized by the Czech Breeders Association as bred breeding and club breeding rabbits. Growth was monitored in regular intervals from birth until the end of fattening, i.e. until 8 months of age at Moravian blue a until 6 months of age at Dutch rabbit. The results were compared with the gain in weight published in pattern book of breeds. To evaluate milkiness, each of litters was weighed at 2 and 21 days of age. To compare the reproduction characters the monitored criteria were number of births, total natality and mortality and the number of raised births. The gained values of both breeds were compared and evaluated depending on increment of living mass and the fattening period. Carcass yield was monitored according to the traditional procedure of selected animals of average live weight and after reaching the slaughter age. The results show significantly higher gain in weight throughout the growth period of Dutch rabbit, than required by the pattern book of breeds. Moravian blue showed lower average increase of weight during the first five months of age from standard. The average number of rabbits in litter was 6,3 births at Moravian blue and 6,48 births at Dutch rabbit. On the other hand breeding succest and overall natality gave better results at Moravian blue. It has also been found that the milkiness of Moravian blue was 3985,4 grams in comparison with 2582,2 grams at Dutch rabbit, which is given by the size of breed. The slaughter analysis showed the carcass yield to be 56,1 % at Moravian blue and 62,4 % at Dutch rabbit, which is a value approaching meat breeds but at a lower meat production. The overall summary of the gained results showed greater production of living matter at Moravian blue rabbit providing greater demands for animal housing and feeding base. Its brood provides greater potential for growth and in some aspects better reproduction character. On the other hand, Dutch rabbit reached paradoxically more births in litter and higher carcass yield of undoubtedly better quality meat. Results of this thesis can be beneficial for choosing breed for novice breeders and for existing breeders it can help in their attempts to improve the strengths and eliminate the weaknesses of their breed.
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