Sütçü Sığırlarda Laktasyon Persistensini Etkileyen Faktörler

Öz

Laktasyon persistensi sütçü sığırlarda pik verime ulaşıldıktan sonra süt veriminin sürdürülebilme düzeyidir. Süt verimi, laktasyon eğrisi ve eğriye ilişkin temel parametreler [laktasyonun başlangıç süt verimi (a), yükselen eğrinin katsayısı (b), pik süt verimi (Ymax), pik verime ulaşma süresi (Tmax), pik verim sonrası iniş eğrisi katsayısı (c)] seleksiyonda ölçüt olarak kullanılabilmektedir. Denetim günü süt verimi kayıtları ile laktasyon eğrisinin şekli ve laktasyon persistensi tahmin edilerek erken dönemde isabetli bir seleksiyon yapılabilir. Persistensi yüksek olan inekler, daha az konsantre yemle aynı miktarda süt verdikleri, metabolik ve enfeksiyöz hastalıklara karşı daha dirençli oldukları için daha ekonomiktirler. Süt veriminde olduğu gibi laktasyon persistensi de genetik ve çevresel faktörlerden etkilenmektedir. Additif genetik varyansın ve sağım sıklığının artırılması (özellikle robotik sağım ile erken laktasyonda), servis periyodunun uzatılması ve genetik potansiyeli yüksek sığırların (tek nükleotid polimorfizmi) damızlıkta kullanılması ile laktasyon persistensinin artırılabileceği söylenebilir. Persistensin yükseltilmesi ile daha sağlıklı ve ekonomik bir yetiştiricilik yapılabilir. Bu derlemede, sütçü sığırların laktasyon persistensini etkileyen genetik ve çevresel faktörler hakkında kapsamlı bilgi vermek amaçlanmıştır.

Anahtar Kelimeler

• Laktasyon persistensi
• laktasyon eğrisi
• robotik sağım
• sütçü sığır

Factors Affecting Lactation Persistency in Dairy Cows

Öz

Lactation persistency is the level of sustainability of milk yield after reaching peak milk yield in dairy cows. Milk yield, lactation curve and basic parameters related to lactation curve [initial milk yield (a), increasing slope coefficient (b), peak milk yield (Ymax), time to reach peak yield (Tmax) and decreasing slope coefficient (c)] can be used as criteria for selection. The prediction of the shape of the lactation curve and lactation persistency, with test day milk yield records, provides the possibility of accurate selection in the early periods. Cows with high persistency are more economical because of produce the same amount of milk with less concentrated feed, are more resistant to metabolic and infectious diseases. As in milk yield, lactation persistency is affected by many genetic and environmental factors. It can be said that lactation persistency can be increased by increasing additive genetic variance and milking frequency (especially with robotic milking in early lactation), prolonging the service period and using cattle with high genetic potential (single nucleotide polymorphism) in breeding. By raising the persistency, a healthier and economic animal breeding can be made. In this review, it is aimed to give comprehensive information about genetic and environmental factors affecting lactation persistency in dairy cows.

Anahtar Kelimeler

• Lactation persistency
• lactation curve
• robotic milking
• dairy cow

Kaynakça

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