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The aim of the present study was to investigate the effect of N-acetylcysteine (NAC) on freezability of Tushin ram semen. Ejaculates from four Tushin rams were collected with artificial vagina and then pooled. Pooled semen was divided into four aliquots to be diluted with skim milk-based-egg yolk-glycerol (SEG) extender supplemented with various concentrations of NAC (0, 0.25, 0.5 and 0.75 mM). The semen was loaded into 0.25 mL straws, equilibrated (at 4°C for 2 h), frozen in liquid nitrogen (LN) vapour (at -120°C for 15 min) and stored in LN (-196°C). After thawing (at 37°C for 1 min), sperm motility, dead-live ratio, morphology, abnormal acrosome and membrane integrity (HOST) were evaluated. Results showed that 0.75 mM NAC has detrimental effects on motility, compared to the other three NAC doses evaluated (P<0.05). Membrane integrity was higher in 0.25 and 0.5 mM NACs. There was significant differences in semen viability among NAC doses (P<0.05). In conclusion, higher doses of NAC, especially used with SEG extender, may have some detrimental effects on freezability of ram semen. Moreover, although modest doses of NAC slightly improved freezability of Tushin ram semen. Keywords: Tushin ram, Semen, Cryopreservation, N-acetylcysteine, Post-thaw semen quality N-Asetilsistein (NAC)'in Dondurulmuş-Çözdürülmüş Tuj Koçu Spermasının Kalitesi Üzerine Etkisi ÖzetÇalışmanın amacı, Tuj koç spermasının dondurulabilirliği üzerine N-asetil sistein (NAC)'in etkisini araştırmaktı. Dört tuj koçundan suni vajen ile alınan sperma birleştirildi. Karışım sperma dört eşit hacme bölündü ve 0 mM, 0.25 mM, 0.5 mM ve 0.75 mM NAC içeren yağsız süt yumurta sarısı ve gliserollü sulandırıcı ile sulandırıldı. Sperma 0.25 mL'lik payetlere çekildi, ekilibre edidi (4°C'de 2 saat), sıvı azot buharında donduruldu (-120°C'de 15 dak.) ve sıvı azot (-196°C) içinde saklandı. Çözüm (37°C'de 1 dak.) sonrası, sperm motilitesi, ölü-canlı oranı, morfolojisi, anormal akrozom ve membrane bütünlüğü (HOST) değerlendirildi. Sonuçlar, 0.75 Mm NAC'ın, diğer NAC dozları ile karşılaştırıldığında, motilite üzerine olumsuz etkilere sahip olduğunu gösterdi (P<0.05). Membran bütünlüğü 0.25 ve 0.5 mM NAC derişimlerinde en yüksekti (P<0.05). Ayrıca, NAC dozları arasında, sperma canlılığı açısından önemli farklar da belirlendi (P<0.05). NAC'ın yüksek dozlarının, düşük dozları dondurulabilirliği bir miktar iyileştirse de, özellikle sütlü sulandırıcılarla kullanıldığında, koç spermasının dondurulabilirliği üzerine bazı olumsuz etkileri olabileceği sonucuna varıldı.

Efficacies of hCG and GnRH with respect to follicular diameter in Cosynch protocol were investigated. Lactating cows (n=119) received injections of GnRH and PGF 2 7 d apart. Norgestomet ear implant was inserted at GnRH administration and removed prior to PGF 2 injections. Presence of the corpus luteum (CL) at GnRH and PGF 2 injections, and diameter of preovulatory follicle [small (SPF) <8 mm or large (LPF) ≥8 mm] at PGF 2 were determined with transrectal ultrasonography (USG). The animals were randomly treated with GnRH (0.01 mg; GPG, n=62) or hCG (1,500 IU; GPH, n=57) at timed artificial insemination (TAI) 56 h after injection of PGF 2α . Pregnancies were diagnosed with USG 32-35 d after TAI. Pregnancies per TAI (P/TAI) were significantly (P<0.05) lower in GPH cows (28.1%; 16/57) compared to those in GPG animals (46.8%; 29/62). P/TAI with respect to follicular size did not differ between GPG and GPH cows, although P/TAI was numerically higher in LPF (30.0%; 15/50) than in SPF (14.3%; 1/7) in GPH cows. P/TAI in cows without CL at PGF 2 was 2.5 (1.0-6.7) times higher (P<0.01) in GPG (20.0%; 3/15) compared to GPH (10.5%; 2/19). In conclusion, use of hCG in milieu of the second GnRH in Cosynch+progesterone insert protocol did not have any advantage in lactating cows.

The aim of this study was to determine the influence of different doses of L-Ergothioneine (LE), cystein and N-acetylcystein (NAC) on post-thawing semen parameters in rams. Ejaculates collected from four Tushin Rams were evaluated and pooled at 35°C. Semen samples were diluted with skim-milk based extender containing LE (5, 10 mM), Cystein (5, 10 mM), NAC (5, 10 mM) or not containing any antioxidant (control) and loaded to 0.25 ml French straws. Straws were cooled to 5°C for 2 h, frozen in liquid nitrogen vapour (aprox. -120°C) for 15 min and then being stored in liquid nitrogen until thawing process. Straws were thawed in water bath (37°C for 1 min). The percentages of motility, viability, abnormal acrosome, total abnormalities, membrane integrity (hypoosmatic swelling test, HOST) were statistically assessed. Also total antioxidant capacity (TAC) and total oxidatif stres (TOS) were evaluated in samples from replications. It was seen that LE was superior to N-acetylcystein and cystein in motility, viability, defected acrosome, total morphological abnormalities, HOST and TAC, (P<0.05) except cystein in motility. Neverthless, there was not any statistically difference between LE and control groups (P>0.05). It was conlcluded that there was not any beneficial or detrimental effects of LE on post thawing semen parameters in rams while it was determined that cystein and NAC may have been some detrimental effects on post thawing semen parameters in rams. These results warrants future scientific studies on LE, NAC and cystein in ram semen cryopreservation. Keywords: Ram semen, Cryopreservation, L-Ergothioneine, Cystein, N-acetylcystein, Tushin Koç Spermasının Dondurulması Üzerine L-Ergothionin, N-asetil sistein ve Sisteinin Etkileri ÖzetBu çalışmanın amacı, koçlarda L-Ergothionin (LE), sistein ve N-asetil sisteinin (NAC) farklı dozlarının çözüm sonu sperma parametreleri üzerine etkisini belirlemekti. Dört Tuj ırkı koçtan alınan ejakülatlar değerlendirildi ve 35°C'de karışım yapıldı. Sperma örnekleri, LE (5, 10 mM), Sistein (5, 10 mM), NAC (5, 10 mM) içeren veya antioksidan içermeyen (kontrol), yağsız süt temelli sulandırıcıyla sulandırılarak, 0.25 ml'lik payetlere dolduruldu. Payetler 5°C'ye 2 saat süreyle soğutuldu, sıvı azot buharında (yaklaşık -120°C) 15 dak. süre ile donduruldu ve çözme işlemine kadar sıvı azot içinde saklandı. Payetler su banyosunda (37°C'de 1 dak.) çözüldü. Motilite, canlılık, anormal akrozom, toplam anormalite ve membran bütünlüğü (hipoozmotik şişme testi, HOST) yüzdeleri istatistiksel olarak değerlendirildi. Ayrıca, toplam antioksidan kapasite (TAK) ve toplam oksidatif stres (TOS), replikasyonlardan elde edilen örneklerde değerlendirildi. LE'nin motilite (sistein hariç), canlılık, akrozom hasarı, total morfolojik anormalite, HOST ve TAK oranları bakımından, NAC ve sisteine üstünlük sağladığı görüldü (P<0.05). Yine de, LE ve kontrol grubu arasında istatistiksel bir fark yoktu (P>0.05). Sistein ve NAC'ın koçlarda çözüm sonu spermatolojik parametreler üzerine bazı olumsuz etkileri belirlen...