Effect of different crossbreeds of Lacaune and East Friesian breeds on milk yield and basic milk parameters

The aim of the study was to evaluate the effect of different crossbreeds (CB) of Lacaune (LC) and East Friesian (EF) breeds (LC 50 EF 50, LC 75 EF 25 and LC 87.5 EF 12.5) on daily milk yield (DMY) and basic milk composition (contents of total solids (TS), fat (F), protein (P), casein (C) and lactose (L) for the whole lactation. The evaluation of the interactions between CB and parity (PA) and between CB and litter size (LS) on above mentioned indicators was also an integral part of this study. The study was carried out on the organic farm in Valašská Bystřice. The factor of CB had a significant effect only on DMY and contents of P and C for the whole lactation whilst the higher proportion of LC breed in genotype, the higher DMY and the lower P and C contents. The CB x PA had a significant effect on all indicators except for the lactose content when in all CB the DMY increased with the increase of the lactation number. On the other hand, in all CB the contents of TS, F, P and C were relatively very variable depending on the parity. Lastly, as for the interaction between CB and LS, the ewes with twins produced significantly more milk compared to ewes with singles and these ewes had also significantly higher contents of P and C and not significantly higher contents of TS and F.