PT  - JOURNAL ARTICLE
AU  - Novotná, Lenka
AU  - Kuchtík, Jan
AU  - Dobeš, Igor
AU  - Šustová, Květoslava
AU  - Zajícová, Pavlína
TI  - Effect of somatic cell count on ewe's milk composition, its properties and the quality of rennet curd
DP  - 2014 Nov 27
TA  - Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis
PG  - 59--64
VI  - 55
IP  - 2
AID - 10.11118/actaun200755020059
IS  - 12118516
AB  - The evaluation of the effect of somatic cells count on ewe's milk composition, its properties and on the quality of rennet curd was carried using milk samples obtained from a total 10 ewes F<sub>112</sub> crossbreeds of Lacaune (L), East Friesian (EF) and Improved Wallachian (IW), reared on a ecological sheep farm in Valašská Bystřice. All ewes were on the 1<sup>st</sup> lactation, in good nutritive condition and clinically healthy. The sampling was carried on 47<sup>th</sup>, 81<sup>st</sup>, 123<sup>rd</sup>, 152<sup>nd</sup> and 189<sup>th</sup> day of lactation. The analysis involved a total of 50 milk samples, which were categorized into 5 different SCC groups: 1<sup>st</sup> group (≤ 10 000 SC/ml), 2<sup>nd</sup> group (11 000-50 000 SC/ml), 3<sup>rd</sup> group (51 000-100 000 SC/ml), 4<sup>th</sup> group (101 000-200 000 SC/ml), 5<sup>th</sup> group (≥ 201 000 SC/ml). Milk composition and milk properties were determined by standard methods. For the evaluation of the quality of rennet curd (class quality) was used following scale: 1<sup>st</sup> class - very good and hard curd, 2<sup>nd</sup> class - good curd, 3<sup>rd</sup> class - bad curd, 4<sup>th</sup> class - very bad curd, 5<sup>th</sup> class - no or invisible flocculation of casein. Recorded data were statistically analyzed using the classical least squares method (SAS; PROC GLM variant ss4). The SCC had a significant effect on all components of milk under study. The lowest contents of total solids (TS), fat (F), solids non-fat (SNF), protein (P) and casein (CN) were found in the group with the highest SCC (5<sup>th</sup> group). On the other hand, the highest contents of all above-mentioned milk components were found in the group with the lowest SCC. The significantly lowest content of lactose (4.42 %) was found in the group with the lowest SCC. The SCC had also significant effect on pH and titrable acidity. However on the other hand SCC had not a significant effect on rennetability and rennet curd quality (RCQ). The highest value of pH was found in the 5<sup>th</sup> group (the highest SCC). Titrable acidity has decreased from 10.10 °SH to 8.66 °SH depending on growth of SCC. The longest rennetability (257 s) was found in the group with the highest SCC. The best RCQ (class: 1.90) was found in the group where SCC per1 ml of milk ranged from 51 000 to 100 000. On the other hand the worst RCQ (class: 2.28) was found in the group with the lowest SCC.