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Dergiler / Turkish Journal of Veterinary and Animal Sciences / 2012 / Cilt: 36 - Sayı: 6

Comparison of different lactation curve models in Sahiwal cows

Vilas DONGRE
Ravindar Singh GANDHI
Avtar SINGH
Sayfa
723–726
Yayın Tarihi
2012-06-01
DOI
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⚡ TL;DR(1 Cümlede Hızlı Çıkarım)

However, the gamma-type function gave a low peak yield, and therefore it is recommended that this function can give the best fit for low-yielding cows.

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Amaç & Hipotez:The present investigation was carried out on 12,859 fortnightly test-day milk yield records of first lactation pertaining to 643 Sahiwal cows spread over a period of 49 years (1961-2009), maintained at the National Dairy Research Institute, Karnal, India.
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Temel Bulgular & Veri:The comparison of 3 lactation curve models, i.e. the quadratic model, gamma-type function, and mixed log function, was done using fortnightly test-day milk yield records.
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Sonuç & Katkı:However, the gamma-type function gave a low peak yield, and therefore it is recommended that this function can give the best fit for low-yielding cows.
🔬Tür:Modelleme & Sayısal Simülasyon
📍Kapsam:2009 Verileri
⚙️Değişkenler:Key words: Fortnightly test-day milk yields · gamma-type function · quadratic model

Özet

The present investigation was carried out on 12,859 fortnightly test-day milk yield records of first lactation pertaining to 643 Sahiwal cows spread over a period of 49 years (1961-2009), maintained at the National Dairy Research Institute, Karnal, India. The comparison of 3 lactation curve models, i.e. the quadratic model, gamma-type function, and mixed log function, was done using fortnightly test-day milk yield records. The mixed log function was the best fit, with the highest (88.75%) coefficient of determination (R2 value) and the lowest (0.08 kg) root mean square error (RMSE) value, whereas the lowest (56.93%) R2 value was observed in the quadratic model with maximum (0.15 kg) RMSE value. The closeness of fit of the mixed log function and gamma-type function with the observed lactation curve was almost of the same order. However, the gamma-type function gave a low peak yield, and therefore it is recommended that this function can give the best fit for low-yielding cows.

Abstract

The present investigation was carried out on 12,859 fortnightly test-day milk yield records of first lactation pertaining to 643 Sahiwal cows spread over a period of 49 years (1961-2009), maintained at the National Dairy Research Institute, Karnal, India. The comparison of 3 lactation curve models, i.e. the quadratic model, gamma-type function, and mixed log function, was done using fortnightly test-day milk yield records. The mixed log function was the best fit, with the highest (88.75%) coefficient of determination (R2 value) and the lowest (0.08 kg) root mean square error (RMSE) value, whereas the lowest (56.93%) R2 value was observed in the quadratic model with maximum (0.15 kg) RMSE value. The closeness of fit of the mixed log function and gamma-type function with the observed lactation curve was almost of the same order. However, the gamma-type function gave a low peak yield, and therefore it is recommended that this function can give the best fit for low-yielding cows.

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Bu Makaleye Atıf Yap

DONGRE, V., GANDHI, R. S., SINGH, A. (2012). Comparison of different lactation curve models in Sahiwal cows. Turkish Journal of Veterinary and Animal Sciences, Cilt: 36 - Sayı: 6, 723–726. https://ajindex.com/articles/121678

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Kaynakça (8)

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