Yazarlar

• Aksakal, V.(2)
• Bayram, B.(2)
• Akbulut, O.(1)
• Aksakal, Vecihi(1)
• Bayram, Bahri(1)
• Topal, M.(1)
• Yanar, M.(1)
• Yaǧanoǧlu, M.(1)

• MakaleYalnız künye2012Scopus SJRQ3/r/gumushane/12034
  Estimation of variance components and heritability of birth weight through different methods in Swedish Red and White cattle

  Aksakal, V.; Bayram, B.; Yanar, M.; Akbulut, O.

  Data on 368 birth records of Swedish Red and White cattle herd raised organically at Dogan Organic Dairy Cattle Farm for a period of 2006 and 2009 (4 years) were used to estimate the effects of different environmental factors on birth weight. Additionally, a comparison of four methods for variance component estimation to compute heritability of birth weight was performed using ML (Maximum likelihood), MINQUE (Minimum variance quadratic unbiased estimation), REML (Restricted maximum likelihood) and Henderson's Method III. Average abortion rate, stillbirth rate, twin and single birth rates of Swedish Red and White cattle were as 4.5%, 4.3%, 3.2% and 87.7% respectively. The least squares mean for birth weight was 37.4±0.70 kg. While effects of calving year (P<0.01), calving season (P<0.05) and sex of calve (P<0.01) were significant, and the effect of age of dam was not significant (P>0.05). Sire and error variance components and standard error of the heritability obtained by using ML method were lower than those obtained by the other three methods. Heritability estimates for birth weight obtained by ML, REML, MINQUE and Henderson Method III were 0.57±0.22, 0.62±0.24, 0.65±0.25 and 0.59±0.24, respectively. It is concluded that the ML procedure was superior for estimating variance components and heritability of birth weight of Swedish Red and White cattle and non-genetic factors influencing the birth weight should also be considered in selection and an adjustment for the significant environmental factors should be made.

  AtıfScopus2·WoS1

  İncele
• MakaleYalnız künye2010Scopus SJRQ4/r/gumushane/15696
  An analysis of the factors affecting birth weight and actual milk yield in swedish red cattle using regression tree analysis

  Topal, M.; Aksakal, V.; Bayram, B.; Yaǧanoǧlu, M.

  Performance records (birth weight and actual milk yield) on 206 Swedish Red cattle maintained at private organic diary cattle enterprise in Kelkit district of Gümüşhane province, in Turkey, were analyzed through regression tree method to determine the effects of some factors affecting birth weight and actual milk yield. The birth weight of calves averaged as 41.034±4.218 kg. Out of total calves born, twin born calves were 2.9%. Single born calves were heavier (41.185±3.840 kg) than twin born (36.000±10.545 kg). The results revealed that the most significant variable affecting birth weight was birth type, followed by birth season, sex and body condition score (BCS2) of the dam during birth. Lactation period and peak milk yield were important variables affecting the actual milk yield in the dairy herd under investigation.

  AtıfScopus39·WoS37

  İncele
• MakaleYalnız künye2009Scopus SJRQ4/r/gumushane/15045
  Estimates of genetic and phenotypic parameters for the birth weight of calves of Holstein Friesian cattle reared organically

  Aksakal, Vecihi; Bayram, Bahri

  The aim of this study, was to estimate genetic and phenotypic parameters for birth weight and to determine the survival rate of calves of Holstein Friesian cattle reared organically. Aborting rate, still born rate and the calving difficulty rate were 4.6, 3.9 and 9.1 %, respectively. The average birth weight was 42.76±0.229 kg in present study. This value was quite higher than the birth weight in Holstein Friesian calves that breed conventionally in Turkey's conditions. The effect of calving season (p<0.01) and farming system (p<0.05) on birth weight were significant. Male calves had 2.69 kg higher birth weight than females and this difference was found significant (p<0.01). The mean birth weight of single calves was 6.26 kg (17%) higher than that of twin calves. The effect of the years on birth weight was not significant, because caring, feeding and the other breeding methods were made according to the conditions of the regulations. As the birth parity was increased, the birth weight decreased (p<0.05). Heritability and repeatability estimates belong to birth weight were found as 0.232±0.110 and0.206±0.073, respectively.

  AtıfScopus21·WoS20

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