COMPARISON OF DIFFERENT METHODS FOR WOOL YIELD EVALUATION

Dimtar Panayotov, Stefan Boykovski

Abstract: The research was performed on 308 female sheep at the age of 18 months from the Caucasian merino breed. Individual wool yields were determined using three methods. differing mainly by the sampling technique used: Method 1. The commonly accepted technique for determination of wool yield of elite flocks in Bulgaria (on 50 g wool clipped from the side); Method 2. Method of Kogan-Bergman and Novikova (on 200 g wool sample collected from the fleece using a rectangular 20×20 cm frame grid); Method 3. On 50 g bulk wool samples clipped from six body areas (neck. shoulder. side. back. belly and thigh). After collection of individual samples (a total of 924). wool yields were determined uniformly using the following protocol: determination of the air-dry weight of grease wool sample; washing in a washing machine with alkaline soapy solution containing 0.3% soap and 0.3% sodium hydroxide; drying of samples in a dryer and determination of the air-dry weight of clean wool; determination of wool yield. Wool yields determined by the three sampling methods varied within a very narrow range – from 53.43 to 54.58%. The lowest yield was obtained in bulk samples from six areas of the fleece and the highest – by the method of Kogan-Bergman and Novikova. The lowest and statistically insignificant repeatability coefficient was between the first and the third method – 0.571. and the highest – between the second and the third (0.705**). The difference between average yields between the method traditionally used in the selection practice and that of Kogan-Bergman and Novikova was insignificant. with repeatability coefficient of 0.633*.

Keywords: clean wool; sheep; wool; wool yield

Date published: 2023-03-07