Květoslava Šustová

Chemical and physical characteristics of lamb meat related to crossbreeding of Romanov ewes with Suffolk and Charollais sires

The aim was to evaluate the effects of crossbreeding Romanov (RO) ewes with Suffolk (SF) and Charollais (CH) sires on the chemicophysical characteristics and FA profile of the Quadriceps femoris muscle (QFM) in lambs fattened under organic conditions. The experimental animals were male lamb twins of two different crossbreds; CH 50 RO 50 and SF 50 RO 50. Lambs were slaughtered at an average live weight of 31kg. CH 50 RO 50 displayed higher contents of dry matter and intramuscular fat of the QFM. A lower pH value of CH 50 RO 50 was reflected in an increase of WHC. Meat of SF 50 RO 50 lambs had more lightness (L*) and yellowness (b*). The CH 50 RO 50 genotype showed a significantly higher proportion of C18:3n-3cis and n-3 PUFA than the SF 50 RO 50 genotype. The genotype also affected the Δ(9)-desaturase (16) index.

Effects of Lactation Stage and Parity on Milk Yield, Composition and Properties of Organic Sheep Milk

Abstract Novotna, L., Kuchtik, J., Sustova, K., Zapletal, D. and Filipcik, R. 2009. Effects of lactation stage and parity on milk yield, composition and properties of organic sheep milk. J. Appl. Anim. Res., 36: 71–76. Effects of lactation stage (LS) and parity (PA) on daily milk yield (DMY), composition, properties and rennet curd quality (RCQ) of organic sheep milk were evaluated using 10 crossbred ewes reared on an organic sheep farm. Both LS and PA as well as the interaction of LS × PA had a significant effect on DMY and the contents of total solids, fat, protein, casein and lactose. The DMY for the whole lactation increased with the order of lactation. LS, PA and the interaction of LS × PA also had a significant effect on all milk properties as well as the RCQ. In the course of all lactations, titrable acidity (TA) kept increasing. It was found that the higher the values of titrable acidity, the longer the rennet clotting time became and RCQ became worse.