The comparison of growth performance of beef breed Aberdeen Angus twins

Aberdeen Angus (originated in Scotland) is the second most common beef breed in the Czech Republic due to its resistance to adverse climatic events, modesty, earliness, ease of calving, low birth weight of calves and good maternal instincts of cows. The main economic indicator of suckler cows rearing is the number of born and weaned calves. Production of twins is possible way to improve these indicators. The aim of this thesis was to compare the growth potential of twins of Aberdeen Angus beef breed with individuals who were born as singletons. The work is focused on comparing the weight at birth, in 120 and 210 days of age. Most twins in the population of Aberdeen Angus breed reared in the Czech Republic in 2009-2013 was born in 2012 - 9.44 % (270 pcs.), the least in 2013 - 6.67 % (184 pcs.). The incidence of twins by birth order increased from 1 to 3 birth order (78, resp. 130, resp. 131 pcs.) as further increasing order resulted into decline of twin's incidence. The difference in weight between twins and singletons at birth was 5.81 kg, in 120 days 28.32 kg and 37.32 kg 210 days (P 0.001). Differences within twins by sex were for bulls and heifers statistically significant (P 0.001). The relationship between weight at birth and calving ease was also investigated - in the case of twins relationship was not statistically significant (P> 0.05). The lowest mortality rate of twins was in 2013 - 8.70 % (16 pcs.), the highest mortality rate was in 2012 36.67 % (99 pcs.). Most twins were born in 2011 (179 pcs.), whereas least twins were born in 2010 (160 pcs.)