ÇEVRESEL FAKTÖRLERiN SİYAH-ALACA SIĞIRDA SÜTÜN PROTEİN KOMPOZİYONUNA ETKİLERİ

Çalışmada Siyah-Alaca sığırlarda sütün protein içeriği ve komposizyonuna mevsim, laktasyon sayısı, laktasyon dönemi ve somatik hücre sayısının (SHS) etkileri araştırılmıştır. Laktasyon boyunca toplanan süt örneklerinde protein fraksiyonları Poliakrilamid-Jel-Elektroforezi’nde ayrılmış ve densitometre yardımıyla her bir protein fraksiyonunun içeriği belirlenmiştir. Sütün protein içeriğine mevsim, laktasyon dönemi ve SHS’nın etkileri önemli bulunmuştur. αS1-kazein (-Cn) içeriğine mevsim, laktasyon dönemi, laktasyon sayısı, SHS; β-Cn içeriğine mevsim, laktasyon sayısı, SHS; κ-Cn içeriğine laktasyon sayısı, laktasyon dönemi, mevsim; α-Laktalbumin (-La) içeriğine mevsim, laktasyon dönemi, SHS; β-Laktoglobulin (-Lg) içeriğine laktasyon dönemi, laktasyon sayısı, mevsim ve SHS önemli etkiye sahiptir. Sütün protein, αS1-Cn ve β-Lg içeriği EylülAralık döneminde maksimum seviyededir. Laktasyon sayısının artmasıyla birlikte αS1-Cn içeriği azalmakta, β-Cn içeriği artmaktadır. Beşinci ve daha sonraki laktasyonlarda κ-Cn ve β-Lg içeriği minimum seviyededir. Laktasyonun ikinci ayında minimum olan protein ve β-Lg içeriği laktasyon sonuna kadar sürekli artmaktadır. αS1-Cn içeriğinde laktasyon süresince azalma belirlenmiştir. SHS’nın artmasıyla α-La, β-Lg ve κ-Cn içeriğinin arttığı; αS1-Cn ve β-Cn içeriğinin azaldığı tespit edilmiştir.

Anahtar Kelimeler:

Çevresel faktörler, αS1-Kazein, β-Kazein, κ-Kazein, α-Laktalbumin, β-Laktoglobulin

Environmental Effects on Milk Protein Compositon in Holstein Friesian Cattle

Effects of season, parity number, stage of lactation and somatic cell count (SCC) on protein content as well as protein composition were investigated in Holstein Friesian cattle. Milk protein fractions were quantified after polyacrylamide gel electrophoresis, using computer-assisted densitometer. Milk protein content was effected by season, stage of lactation and SCC. Season, stage of lactation, parity number and SCC affected αS1-casein (-Cn) content. β-Cn content was effected by season, parity number and SCC. Parity number, stage of lactation and season had significant effect on κ-Cn content. α-Lactalbumin (-La) content was effected by season, stage of lactation and SCC, while stage of lactation, parity number, season as well as SCC affected β-Lactoglobulin (-Lg) content. Protein, αS1-Cn and β-Lg content was higher between September-December. Increased parity number was associated with decreased αS1-Cn and increased β-Cn content. Last parity subclass had minimum κ-Cn and β-Lg content. Protein and β-Lg content was minimum in second lactation monat and then increased as lactation progressed, while αS1-Cn content was decreased. Increased SCC were associated with increased α-La, β-Lg, κ-Cn as well as decreased αS1-Cn and β-Cn content.

Keywords:

Environmental factors, αS1-Casein, β-Casein, κ-Casein, α-Lactalbumin, β-Lactoglobulin,

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Geliş Tarihi:13.03.2008
Kabul Tarihi:08.05.2008