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Öz

This study conducted to evaluate semen quality and plasma testosterone (T), tetra-iodothyronine (T), and tri­iodothyronine (T) concentrations for different strains of Awassi sheep of different ages in Jordan. Physical traits, semen characteristics and blood samples were assessed in 12 local Awassi rams (6 matures and 6 yearlings) and the 7 crosses of improved Awassi rams (4 matures and 3 yearlings) from the beginning of April until the end of September at the Khanasry Station in Jordan. Local Awassi rams had greater (P<0.01) ejaculate appearance (EA) scale (2.66 ± 0.14 and 2.00 ± 0.19), mass motility (MM) (75.8 ± 1.2% and 70.2 ± 1.6%) and higher (P<0.001) live sperm percent; higher (P<0.05) sperm concentration and (SCN) progressive motility (PM) than crosses of improved Awassi. Local Awassi rams had lower (P<0.001) primary (PAb) and secondary (SAb) abnormal sperm than crosses of improved Awassi. Mature rams had a greater (P<0.05) ejaculate volume (EV), EA scale, SCN and live sperm percent than yearlings. Yearling rams had greater (P<0.001) plasma T (2.05 nmol/L) than mature (1.75 nmol/L) rams. Weekly variations were significantly (P<0.01) different from both strains for some of semen characteristics and blood parameters with fluctuations in different trends. This study indicates that cross breeding of local Awassi with improved Awassi did not improve semen quality and quantity of Awassi sheep in Jordan

Anahtar Kelimeler

• Ram, semen, age, testosterone, thyroid, season

ÜRDÜN'DE YERE L V E ÇAPRAZ ISLAH ÇALIŞMALARI YAPILAN İVESİ IRKLARINDA PLAZMA TESTOSTERON, TİROİD DÜZEYLERİ VE SEMEN ÖZELLİKLERİNİN KARŞILAŞTIRILMASI

Öz

Bu çalışmada, Ürdün'de farklı yaşlardan İvesi koyunlarına ait farklı kökenlerin semen kalitesi ve plazma testosteron (T), tetra-iodothyronine (T4) ve tri-iodothyronine (T3 ) düzeyleri değerlendirilmiştir. Nisan başından itibaren Eylül sonuna kadar Ürdün'de Khanasry İstasyonu'nda bulunan 12 yerel İvesi koç (6'sı yetişkin ve 6'sı toklu) ve 7 çapraz ıslah çalışması yapılmış İvesi koçuna (4'ü yetişkin ve 3'ü toklu) ait fiziksel incelemeleri, sperm özellikleri ve kan örnekleri değerlendirildi. Yerel İvesi koçlarında, çapraz ıslah çalışmaları yapılan İvesi koçlarına oranla daha geniş (P < 0,01) ejakulat varlığı (EV) skalası (2,66 ± 0,14 ve 2,00 ± 0,19), kitle motilitesi (KM) (%75,8 ± 1,2 ve %70,2 ± 1,6) ve daha yüksek (P < 0,001) canlı sperm yüzdesi; daha yüksek (P < 0,05) sperm konsantrasyonu (SK) ve progresif motilite (PM) saptanmıştır. Yerel İvesi koçlarında çapraz ıslah çalışmaları yapılan İvesi koçlarına oranla düşük (P < 0,001) primer (PAb) ve sekunder (SAb) anormal sperm oluşumu belirlenmiştir. Yetişkin koçlarda toklu koçlardan daha geniş (P < 0,05) ejekulat hacmi (EH), EV skalası, SK ve canlı sperm yüzdesi saptanmıştır. Toklu koçlarda yetişkin koçlardan (1,75 nmol/L) daha yüksek (P < 0,001) plazma T3 seviyesi (2,05 nmol/L) belirlenmiştir. Haftalık varyasyonlara bakıldığında her iki ırkta sperm özellikleri ve kan parametrelerinde anlamlı (P < 0,01) farklılıklar saptanmıştır. Bu çalışma ile Ürdün'de yerel İvesi ırkı ile ıslah çalışmaları yapılan İvesi ırkının birlikte yetiştirilmesinin semen kalitesini ve miktarını etkilemediği belirlenmiştir.

Anahtar Kelimeler

• Koç, semen, yaş, testosteron, tiroid, mevsim

Kaynakça

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