Growth of lambs of crossbreeds of romanov,suffolk and charollais breeds - Effect of sex,litter size and season [Růst jehňat kříženců plemen romanovská,suffolk a charollais vliv pohlaví,četnosti vrhu a sezony]

The aim of the study was the evaluation of the growth of the lambs crossbreeds of Romanov breed (RO),Suffolk (SF) and Charollais (CH) reared on the organic sheep farm in Kuklík. Following genotypes and effects were evaluated: CH × RO: n = 10,RO: n = 37,RO × (SF × RO): n = 12,SF × (SF × RO): n = 11 and SF × RO: n = 64,sex (males: n = 79,females: n = 5 5),litter size (singles: n = 16,twins: n = 55,triples and multipath (n = 63) and season of rearing of lambs (winter: n = 84,summer: n = 50). The crossbreeds had a significant effect on all live weights (LWs) and daily gains (DGs) under study. The highest DGs in all periods were found in SF × (SF × RO),whilst the DG from birth till 100 days of age (DG 0-100) was in this group 0.213 kg. The lowest DGs in all periods were found in SF × RO,whilst DG 0-100 was in this group 0.181kg. The sex had not a significant effect on all DGs and LWs. However in all periods were found higher DGs in males. The litter size had a significant effect on all DGs and LWs. The highest DG 0-100 was found in singles,whilst the triples had higher DG 0-100 than twins (0.184 vs 0.176 kg) The season had not a significant effect on live birth weight. On the other hand this factor had a significant effect on all growth parameters. In all periods were found higher DGs in lambs reared in summer,whereas the DG 0-100 in this group of lambs was 0.223 kg.