Calculation of adjustment factors for standardizing lactations to mature age and 305-day estimation of heritability and repeatability of standardized milk yield of Simmental cattle reared on Kazova State Farm
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Tarih
2006
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info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, Kazova Tarım İşletmesinde yetiştirilen Simental ırkı ineklerin süt veriminin 305 gün ve ergin çağa göre düzeltme katsayıları ile tekrarlama ve kalıtım dereceleri tahmin edilmiştir. İşletmede, 1992-2002 yılları arasında yetiştirilen sığırlara ait 1549 laktasyon kaydı kullanılmıştır. Süt verimini 305 güne göre düzeltme katsayıları 7 yaş grubu (2, 3, 4, 5, 6-8, 9, ve 10 yaş ve üzeri) dikkate alınarak hesaplanmıştır. Polinom metodu ile hesaplanan ergin çağa göre düzeltme katsayıları 24. ay ile 143. ay ve daha yukarısı arasındadır. Süt veriminin tekrarlama derecesi sınıf içi korelasyon metodu ile 0,44 0,028 olarak tahmin edilmiştir. Kalıtım derecesi baba bir üvey kardeşler metodu ile tahmin edilmiştir. Kalıtım derecesi bütün laktasyonlar için 0,24 0,08 olarak; birinci laktasyon için 0,30 0,154 olarak tahmin edilmiştir.
Adjustment factors of lactation milk yield to mature age and 305-day were calculated and heritability and repeatability of milk yield were estimated for Simmental cows reared oh Kazova State Farm. A total of 1549 lactation records of Simmental cows reared on Kazova State Farm between 1992 and 2002 were used. The factors for standardizing incomplete lactations to 305-day were estimated by taking 7 calving age groups into consideration (2, 3, 4, 5, 6-8, 9 and 10 years of age and older). The factors for standardizing to mature equivalent estimated by polynomial regression are between the 24th and 143rd month and older. The repeatability of milk yield was estimated as 0.44 ± 0.028 using intra- class correlation. Heritability of milk yield was estimated using paternal half-sib correlation. Heritability of milk yield for all lactations was estimated as 0.24 ± 0.08. Heritability for first lactation was estimated as 0.30 ± 0.154.
Adjustment factors of lactation milk yield to mature age and 305-day were calculated and heritability and repeatability of milk yield were estimated for Simmental cows reared oh Kazova State Farm. A total of 1549 lactation records of Simmental cows reared on Kazova State Farm between 1992 and 2002 were used. The factors for standardizing incomplete lactations to 305-day were estimated by taking 7 calving age groups into consideration (2, 3, 4, 5, 6-8, 9 and 10 years of age and older). The factors for standardizing to mature equivalent estimated by polynomial regression are between the 24th and 143rd month and older. The repeatability of milk yield was estimated as 0.44 ± 0.028 using intra- class correlation. Heritability of milk yield was estimated using paternal half-sib correlation. Heritability of milk yield for all lactations was estimated as 0.24 ± 0.08. Heritability for first lactation was estimated as 0.30 ± 0.154.
Açıklama
Anahtar Kelimeler
Ziraat Mühendisliği, simmental, milk yield, adjustment factors, repeatability, heritability.
Kaynak
Turkish Journal of Veterinary and Animal Sciences
WoS Q Değeri
Scopus Q Değeri
Cilt
30
Sayı
3
